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Price AT, Schiff JP, Silberstein A, Beckert R, Zhao T, Hugo GD, Samson PP, Laugeman E, Henke LE. Feasibility of simulation free abdominal stereotactic adaptive radiotherapy using an expedited pre-plan workflow. Phys Imaging Radiat Oncol 2024; 31:100611. [PMID: 39253730 PMCID: PMC11382001 DOI: 10.1016/j.phro.2024.100611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 07/02/2024] [Accepted: 07/09/2024] [Indexed: 09/11/2024] Open
Abstract
Background and Purpose Improved hounsfield-unit accuracy of on-board imaging may lead to direct-to-unit treatment approaches We aimed to demonstrate the feasibility of using only a diagnostic (dx) computed tomography (CT)-defined target pre-plan in an in silico study of simulation-free abdominal stereotactic adaptive radiotherapy (ART). Materials and Methods Eight patients with abdominal treatment sites (five pancreatic cancer, three oligometastases) were treated using an integrated adaptive O-Ring gantry system. Each patient's target was delineated on a dxCT. The target only pre-plan served primarily to seed the ART process. During the ART session, all structures were delineated. All simulated cases were treated to 50 Gy in 5 fractions to a planning target optimization structure (PTV_OPT) to allow for dose escalation within the planning target volume. Timing of steps during this workflow was recorded. Plan quality was compared between ART treatment plans and a plan created on a CT simulation scan using the traditional planning workflow. Results The workflow was feasible in all attempts, with organ-at-risk (OAR) constraints met in all fractions despite lack of initial OAR contours. Median absolute difference between the adapted plan and simulation CT plan for the PTV_Opt V95% was 2.0 %. Median absolute difference in the D0.5 cm3 between the adapted plan and simulation CT plan was -0.9 Gy for stomach, 1.2 Gy for duodenum, -5.3 Gy for small bowel, and 0.3 Gy for large bowel. Median end-to-end workflow time was 63 min. Conclusion The workflow was feasible for a dxCT-defined target-only pre-plan approach to stereotactic abdominal ART.
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Affiliation(s)
- Alex T Price
- University Hospitals Seidman Cancer Center, Department of Radiation Oncology, Cleveland, OH, USA
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Joshua P Schiff
- Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, USA
| | - Alice Silberstein
- Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, USA
| | - Robbie Beckert
- Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, USA
| | - Tianyu Zhao
- Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, USA
| | - Geoffrey D Hugo
- Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, USA
| | - Pamela P Samson
- Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, USA
| | - Eric Laugeman
- Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, USA
| | - Lauren E Henke
- University Hospitals Seidman Cancer Center, Department of Radiation Oncology, Cleveland, OH, USA
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
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Misa J, McCarthy S, Clair WS, Pokhrel D. Stereotactic radiotherapy of intracranial tumor beds on a ring-mounted Halcyon LINAC. J Appl Clin Med Phys 2024; 25:e14281. [PMID: 38277473 PMCID: PMC11163492 DOI: 10.1002/acm2.14281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/21/2023] [Accepted: 01/03/2024] [Indexed: 01/28/2024] Open
Abstract
PURPOSE This study sought to evaluate the feasibility and efficacy of the Halcyon Ring Delivery System (RDS) for delivering stereotactic radiotherapy (SRT) treatments for intracranial tumors beds. METHODS Ten previously treated brain SRT patients for 30 Gy in five fractions with non-coplanar HyperArc plans on TrueBeam (6MV-FFF) were replanned on Halcyon (6MV-FFF) using the same number of arcs and Eclipse's AcurosXB dose engine. Plan quality evaluation metrics per SRT protocol included: PTV coverage, GTV dose (minimum and mean), target conformity indices (CI), heterogeneity index (HI), gradient index (GI), maximum dose 2 cm away from the PTV (D2cm), and doses to organs-at-risk (OAR). Additionally, patient-specific quality assurance (QA) results and beam-on-time (BOT) were analyzed. RESULTS The Halcyon RDS provided highly conformal SRT plans for intracranial tumor beds with similar dose to target. When benchmarked against clinically delivered HyperArc plans, target coverage, CI(s) and HI were statistically similar. The Halcyon plans saw no statistical difference in maximum OAR doses to the brainstem, spinal cord, and cochlea. Due to the machine's coplanar geometry, the Halcyon plans showed a decrease in optic pathway dose (0.75 Gy vs. 2.08 Gy, p = 0.029). Overall, Halcyon's coplanar geometry resulted in a larger GI (3.33 vs. 2.72, p = 0.008) and a larger D2cm (39.59% vs. 29.07%, p < 0.001). In this cohort, multiple cases had the PTV and the optic pathway in the same axial plane. In one such instance, the PTV was <2 cm away from the optic pathway but even at this close proximity OAR, Halcyon still adequately spared the optic pathway. Additionally, the Halcyon's geometry provided slightly larger amount of normal brain dose receiving 24.4 Gy (8.99 cc vs. 7.36 cc) and 28.8 Gy (2.9 cc vs. 2.5 cc), although statistically insignificant. The Halcyon plans achieved similar delivery accuracy, quantified by patient-specific QA results evaluated with a 2%/2 mm gamma criteria (99.42% vs. 99.70%). For both plans, independent Monte Carlo second checks calculation agreed within 1%. Average Halcyon BOT was slightly higher by 0.35 min (p = 0.045), however, due to the one-step patient set-up and verification overall estimated treatment times on Halcyon were lower compared to HyperArc treatments (7.61 min vs. 10.26 min, p < 0.001). CONCLUSIONS When benchmarked against clinically delivered HyperArc treatments, the Halcyon brain SRT plans provided similar plan quality and delivery accuracy but achieved faster overall treatment times. We have started treating select brain SRT patients on the Halcyon RDS for patients having tumor beds greater than 1 cm in diameter with the closest OAR distance of greater than 2 cm away from the target. We recommend other clinics to consider commissioning SRT treatments on their Halcyon systems-allowing including remote Halcyon-only clinics to provide exceptionally high-quality therapeutic brain SRT treatments to an otherwise underserved patient cohort.
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Affiliation(s)
- Joshua Misa
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Shane McCarthy
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - William St. Clair
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Damodar Pokhrel
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
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Hajare R, K K S, Kumar A, Kalita R, Kaginelli S, Mahantshetty U. Commissioning and dosimetric verification of volumetric modulated arc therapy for multiple modalities using electronic portal imaging device-based 3D dosimetry system: a novel approach. Radiol Phys Technol 2024; 17:412-424. [PMID: 38492203 DOI: 10.1007/s12194-024-00792-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/18/2024]
Abstract
The purpose of this study was to validate an electronic portal imaging device (EPID) based 3-dimensional (3D) dosimetry system for the commissioning of volumetric modulated arc therapy (VMAT) delivery for flattening filter (FF) and flattening filter free (FFF) modalities based on test suites developed according to American Association of Physicists in Medicine Task Group 119 (AAPM TG 119) and pre-treatment patient specific quality assurance (PSQA).With ionisation chamber, multiple-point measurement in various planes becomes extremely difficult and time-consuming, necessitating repeated exposure of the plan. The average agreement between measured and planned doses for TG plans is recommended to be within 3%, and both the ionisation chamber and PerFRACTION™ measurement were well within this prescribed limit. Both point dose differences with the planned dose and gamma passing rates are comparable with TG reported multi-institution results. From our study, we found that no significant differences were found between FF and FFF beams for measurements using PerFRACTION™ and ion chamber. Overall, PerFRACTION™ produces acceptable results to be used for commissioning and validating VMAT and for performing PSQA. The findings support the feasibility of integrating PerFRACTION™ into routine quality assurance procedures for VMAT delivery. Further multi-institutional studies are recommended to establish global baseline values and enhance the understanding of PerFRACTION™'s capabilities in diverse clinical settings.
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Affiliation(s)
- Raghavendra Hajare
- Department of Radiation Oncology, Homi Bhabha Cancer Hospital & Research Centre, Visakhapatnam, India.
- Division of Medical Physics, JSS Academy of Higher Education and Research, Mysuru, India.
| | - Sreelakshmi K K
- Department of Radiation Oncology, Homi Bhabha Cancer Hospital & Research Centre, Visakhapatnam, India
| | - Anil Kumar
- Department of Radiation Oncology, Homi Bhabha Cancer Hospital & Research Centre, Visakhapatnam, India
| | - Rituraj Kalita
- Department of Radiation Oncology, Tezpur Cancer Centre, Bihuguri, India
| | - Shanmukhappa Kaginelli
- Division of Medical Physics, JSS Academy of Higher Education and Research, Mysuru, India
| | - Umesh Mahantshetty
- Department of Radiation Oncology, Homi Bhabha Cancer Hospital & Research Centre, Visakhapatnam, India
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Ramadhan MM, Wibowo WE, Prajitno P, Pawiro SA. Comparison of deep learning models for building two-dimensional non-transit EPID Dosimetry on Varian Halcyon. Rep Pract Oncol Radiother 2024; 28:737-745. [PMID: 38515817 PMCID: PMC10954275 DOI: 10.5603/rpor.98729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 12/04/2023] [Indexed: 03/23/2024] Open
Abstract
Background This study compared the effectiveness of five deep learning models in constructing non-transit dosimetry with an a-Si electronic portal imaging device (EPID) on Varian Halcyon. Deep learning model is increasingly used to support prediction and decision-making in several fields including oncology and radiotherapy. Materials and methods Forty-seven unique plans of data obtained from breast cancer patients were calculated using Eclipse treatment planning system (TPS) and extracted from DICOM format as the ground truth. Varian Halcyon was then used to irradiate the a-Si 1200 EPID detector without an attenuator. The EPID and TPS images were augmented and divided randomly into two groups of equal sizes to distinguish the validation and training-test data. Five different deep learning models were then created and validated using a gamma index of 3%/3 mm. Results Four models successfully improved the similarity of the EPID images and the TPS-generated planned dose images. Meanwhile, the mismatch of the constituent components and number of parameters could cause the models to produce wrong results. The average gamma pass rates were 90.07 ± 4.96% for A-model, 77.42 ± 7.18% for B-model, 79.60 ± 6.56% for C-model, 80.21 ± 5.88% for D-model, and 80.47 ± 5.98% for E-model. Conclusion The deep learning model is proven to run fast and can increase the similarity of EPID images with TPS images to build non-transit dosimetry. However, more cases are needed to validate this model before being used in clinical activities.
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Affiliation(s)
- Muhammad Mahdi Ramadhan
- Department Physics, Faculty of Mathematics and Natural Sciences Universitas Indonesia, Depok, Indonesia
| | - Wahyu Edy Wibowo
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Prawito Prajitno
- Department Physics, Faculty of Mathematics and Natural Sciences Universitas Indonesia, Depok, Indonesia
| | - Supriyanto Ardjo Pawiro
- Department Physics, Faculty of Mathematics and Natural Sciences Universitas Indonesia, Depok, Indonesia
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Tardi D, Fitriandini A, Fauziah AR, Wibowo WE, Siswantining T, Pawiro SA. Analysis of dose distribution reproducibility based on a fluence map of in vivo transit dose using an electronic portal imaging device. Biomed Phys Eng Express 2023; 10:015013. [PMID: 38052064 DOI: 10.1088/2057-1976/ad124a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
Morphological changes can affect distribution of dose in patients. Determination of the dose distribution changes for each fraction radiotherapy can be done by relativein vivodosimetry (IVD). This study analysed the distribution of doses per fraction based on the fluence map recorded by the electronic portal imaging device (EPID) of the patient's transit dose. This research examined cases involving the cervix, breast, and nasopharynx. Transit dose analysis was performed by calculating the gamma index (GI) with composite and field-by-field methods. The gamma passing rate (GPR) value was assessed for its correlation with the subject's body weight. In the case of the nasopharynx, breast, and cervix, the GPR value decreased as the fraction increased. In the case of the nasopharynx, the correlation between the GPR and fraction radiotherapy showed no difference when using either composite or field-by-field methods. However, in cases involving the cervix and breast, there was a difference in the correlation values between the composite and field-by-field methods, where the subject had a significant correlation (p< 0.05) when it was done using a field-by-field method. In addition, the nasopharynx had the highest number of subjects with significant correlation (p< 0.05) between GPR and body weight, followed by the cervix and breast. In the nasopharynx, breast, and cervix, the reproducibility of the dose distribution decreased. This decreased reproducibility was associated with changes in body weight.
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Affiliation(s)
- Didin Tardi
- Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, West Java, 16424, Indonesia
| | - Aninda Fitriandini
- Department of Radiation Oncology, Faculty of Medicine, Universitas Indonesia, Dr Cipto Mangunkusumo General Hospital, Jakarta, 10430, Indonesia
| | - Annisa Rahma Fauziah
- Department of Radiation Oncology, Faculty of Medicine, Universitas Indonesia, Dr Cipto Mangunkusumo General Hospital, Jakarta, 10430, Indonesia
| | - Wahyu Edy Wibowo
- Department of Radiation Oncology, Faculty of Medicine, Universitas Indonesia, Dr Cipto Mangunkusumo General Hospital, Jakarta, 10430, Indonesia
| | - Titin Siswantining
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, West Java, 16424, Indonesia
| | - Supriyanto Ardjo Pawiro
- Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, West Java, 16424, Indonesia
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Pokhrel D, Misa J, McCarthy S, Yang ES. Two novel stereotactic radiotherapy methods for locally advanced, previously irradiated head and neck cancers patients. Med Dosim 2023; 49:114-120. [PMID: 37867087 DOI: 10.1016/j.meddos.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/08/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023]
Abstract
To determine the feasibility and utility of conebeam CT-guided stereotactic radiotherapy for locally recurrent, previously irradiated head and neck cancer (HNC) patients on the Halcyon, a ring delivery system (RDS). This research aims to quantify plan quality, treatment delivery accuracy, and overall efficacy by comparing against novel clinical TrueBeam HyperArc method. Ten recurrent HNC patients who were treated at our institution on TrueBeam (6MV-FFF) for 30 to 40 Gy in 3 to 5 fractions with noncoplanar HyperArc plans were re-planned on Halcyon (6MV-FFF). These plans were re-planned with the same Acuros-based dose engine. Additionally, we used site-specific full/partial coplanar VMAT arcs. PTV coverage, mean dose to GTV, maximum dose to organs-at-risk (OAR), beam-on time (BOT), and quality assurance (QA) results were investigated and compared. Halcyon provided highly conformal HNC SRT plans with slightly superior mean PTVD99 coverage (96.7% vs 95.5%, p = 0.071), and slightly lower mean GTV dose (37.8 Gy vs 38.2 Gy, p = 0.241) when compared to the HyperArc plans. Differences in plan conformality and maximum dose to OARs were statistically insignificant. Due to Halcyon's coplanar geometry, D2cm was significantly higher (p = 0.001) but Halcyon did result in a reduced normal brain dose by 1 Gy on average and up to 5.2 Gy in some cases. Halcyon provided similar patient-specific QA pass rates with a 2%/2mm gamma criteria (98.2% vs 98.5%) and independent in-house Monte Carlo second check results (97.7% vs 98.2%), suggesting identical treatment delivery accuracy. Halcyon plans resulted in slightly longer beam-on time (3.16 vs 2.30 minutes, p = 0.010), however door-to-door patient time is expected to be <10 minutes. Compared to clinical TrueBeam HyperArc, Halcyon SRT plans provided similar plan quality and treatment delivery accuracy with a potentially faster overall treatment using fully automated patient setup and verification. Rapid delivery of recurrent HNC SRT may reduce intrafraction motion errors while also improving patient compliance and comfort. To provide high-quality of HNC SRT similar to HyperArc, we recommend Halcyon users consider commissioning this novel method. This method will be useful for remote and underserved patient cohorts including Halcyon-only clinics as well.
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Affiliation(s)
- Damodar Pokhrel
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA.
| | - Josh Misa
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Shane McCarthy
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Eddy S Yang
- Department of Radiation Medicine, Medical Physics Graduate Program, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
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Huang Y, Liu Z. Dosimetric performance evaluation of the Halcyon treatment platform for stereotactic radiotherapy: A pooled study. Medicine (Baltimore) 2023; 102:e34933. [PMID: 37682167 PMCID: PMC10489306 DOI: 10.1097/md.0000000000034933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/04/2023] [Indexed: 09/09/2023] Open
Abstract
With the advancement of radiotherapy equipment, stereotactic radiotherapy (SRT) has been increasingly used. Among the many radiotherapy devices, Halcyon shows promising applications. This article reviews the dosimetric performance such as plan quality, plan complexity, and gamma passing rates of SRT plans with Halcyon to determine the effectiveness and safety of Halcyon SRT plans. This article retrieved the last 5 years of PubMed studies on the effectiveness and safety of the Halcyon SRT plans. Two authors independently reviewed the titles and abstracts to decide whether to include the studies. A search was conducted to identify publications relevant to evaluating the dosimetric performance of SRT plans on Halcyon using the key strings Halcyon, stereotactic radiosurgery, SRT, stereotactic body radiotherapy, and stereotactic ablative radiotherapy. A total of 18 eligible publications were retrieved. Compared to SRT plans on the TrueBeam, the Halcyon has advantages in terms of plan quality, plan complexity, and gamma passing rates. The high treatment speed of SRT plans on the Halcyon is impressive, while the results of its plan evaluation are also encouraging. As a result, Halcyon offers a new option for busy radiotherapy units while significantly improving patient comfort in treatment. For more accurate results, additional relevant publications will need to be followed up in subsequent studies.
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Affiliation(s)
- Yangyang Huang
- Department of Radiotherapy, the Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zongwen Liu
- Department of Radiotherapy, the Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Kawata K, Hirashima H, Tsuruta Y, Sasaki M, Matsushita N, Fujimoto T, Nakamura M, Nakata M. Applicability evaluation of the TRS-483 protocol for the determination of small-field output factors using different multi-leaf collimator and field-shaping types. Phys Med 2023; 113:102664. [PMID: 37573811 DOI: 10.1016/j.ejmp.2023.102664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 08/06/2023] [Accepted: 08/07/2023] [Indexed: 08/15/2023] Open
Abstract
PURPOSE To evaluate the applicability of TRS-483 output correction factors (CFs) for small-field output factors (OFs) using different multi-leaf collimators (MLC) and field-shaping types. METHODS All measurements were performed on TrueBeam, TrueBeam STx, and Halcyon using 6 MV flattening filter-free energy. Four detectors, including CC01, CC04, microDiamond, and EDGE, were used. Nominal field sizes ranging from 1 × 1 to 4 × 4, and 10 × 10 cm2 were used to measure small-field OFs at source-to-axis distance of 100 cm with a 0° gantry angle in a 3D water phantom. Further, the field-shaping types were defined using jaw collimator or MLC (five different configurations). A field size of 10 × 10 cm2 was used as the reference for calculation of OFs obtained as ratio of detector readings (OFdet). The percentage difference and coefficient of variation of OFdet and OFdet corrected by applying CF were compared for each field size and configuration. RESULTS For OFdet corrected by applying CF, the ranges of percentage difference and coefficient of variation in all configurations for ≥ 2 × 2 cm2 fields were reduced from 1.2-2.2 to 0.8-1.3 percentage points (%pt) and from 0.5-1.0 to 0.4-0.7%, respectively. For 1 × 1 cm2 field, the ranges of percentage difference and coefficient of variation were reduced from 3.3-5.7 to 1.2-2.2 %pt and from 2.2-3.7 to 0.8-1.1%, respectively. CONCLUSIONS The CFs described in TRS-483 dosimetry protocol have broad applicability in reducing OF variations between detectors under different MLC and field-shaping types.
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Affiliation(s)
- Kohei Kawata
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
| | - Hideaki Hirashima
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
| | - Yusuke Tsuruta
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan; Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Makoto Sasaki
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
| | - Norimasa Matsushita
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
| | - Takahiro Fujimoto
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan; Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Manabu Nakata
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
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Pokhrel D, Smith M, Volk A, Bernard ME. Benchmarking halcyon ring delivery system for hypofractionated breast radiotherapy: Validation and clinical implementation of the fast-forward trial. J Appl Clin Med Phys 2023; 24:e14047. [PMID: 37221949 PMCID: PMC10476987 DOI: 10.1002/acm2.14047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/01/2023] [Accepted: 05/11/2023] [Indexed: 05/25/2023] Open
Abstract
PURPOSE The aim of this study was to demonstrate the feasibility and efficacy of an iterative CBCT-guided breast radiotherapy with Fast-Forward trial of 26 Gy in five fractions on a Halcyon Linac. This study quantifies Halcyon plan quality, treatment delivery accuracy and efficacy by comparison with those of clinical TrueBeam plans. MATERIALS AND METHODS Ten accelerated partial breast irradiation (APBI) patients (four right, six left) who underwent Fast-Forward trial at our institute on TrueBeam (6MV beam) were re-planned on Halcyon (6MV-FFF). Three site-specific partial coplanar VMAT arcs and an Acuros-based dose engine were used. For benchmarking, PTV coverage, organs-at-risk (OAR) doses, beam-on time, and quality assurance (QA) results were compared for both plans. RESULTS The average PTV was 806 cc. Compared to TrueBeam plans, Halcyon provided highly conformal and homogeneous plans with similar mean PTVD95 (25.72 vs. 25.73 Gy), both global maximum hotspot < 110% (p = 0.954) and similar mean GTV dose (27.04 vs. 26.80 Gy, p = 0.093). Halcyon provided lower volume of ipsilateral lung receiving 8 Gy (6.34% vs. 8.18%, p = 0.021), similar heart V1.5 Gy (16.75% vs. 16.92%, p = 0.872), V7Gy (0% vs. 0%), mean heart dose (0.96 vs. 0.9 Gy, p = 0.228), lower maximum dose to contralateral breast (3.2 vs. 3.6 Gy, p = 0.174), and nipple (19.6 vs. 20.1 Gy, p = 0.363). Compared to TrueBeam, Halcyon plans provided similar patient-specific QA pass rates and independent in-house Monte Carlo second check results of 99.6% vs. 97.9% (3%/2 mm gamma criteria) and 98.6% versus 99.2%, respectively, suggesting similar treatment delivery accuracy. Halcyon provided shorter beam-on time (1.49 vs. 1.68 min, p = 0.036). CONCLUSION Compared to the SBRT-dedicated TrueBeam, Halcyon VMAT plans provided similar plan quality and treatment delivery accuracy, yet potentially faster treatment via one-step patient setup and verification with no patient collision issues. Rapid delivery of daily APBI on Fast-Forward trial on Halcyon with door-to-door patient time < 10 min, could reduce intrafraction motion errors, and improve patient comfort and compliance. We have started treating APBI on Halcyon. Clinical follow-up results are warranted. We recommend Halcyon users consider implementing the protocol to remote and underserved APBI patients in Halcyon-only clinics.
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Affiliation(s)
- Damodar Pokhrel
- Department of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Mason Smith
- Department of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Alexander Volk
- Department of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Mark E. Bernard
- Department of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
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10
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Razinskas G, Schindhelm R, Sauer OA, Wegener S. Sensitivity and specificity of Varian Halcyon's portal dosimetry for plan-specific pre-treatment QA. J Appl Clin Med Phys 2023; 24:e14001. [PMID: 37086428 PMCID: PMC10402680 DOI: 10.1002/acm2.14001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/06/2023] [Accepted: 04/03/2023] [Indexed: 04/23/2023] Open
Abstract
PURPOSE Developed as a plan-specific pre-treatment QA tool, Varian portal dosimetry promises a fast, high-resolution, and integrated QA solution. In this study, the agreement between predicted fluence and measured cumulative portal dose was determined for the first 140 patient plans at our Halcyon linear accelerator. Furthermore, the capability of portal dosimetry to detect incorrect plan delivery was compared to that of a common QA phantom. Finally, tolerance criteria for verification of VMAT plan delivery with Varian portal dosimetry were derived. METHODS All patient plans and the corresponding verification plans were generated within the Eclipse treatment planning system. Four representative plans of different treatment sites (prostate, prostate with lymphatic drainage, rectum, and head & neck) were intentionally altered to model incorrect plan delivery. Investigated errors included both systematic and random errors. Gamma analysis was conducted on both portal dose (criteria γ2%/2 mm , γ2%/1 mm , and γ1%/1 mm ) and ArcCHECK measurements (criteria γ3%/3 mm , γ3%/2 mm , and γ2%/2 mm ) with a 10% low-dose threshold. Performance assessment of various acceptance criteria for plan-specific treatment QA utilized receiver operating characteristic (ROC) analysis. RESULTS Predicted and acquired portal dosimetry fluences demonstrated a high agreement evident by average gamma passing rates for the clinical patient plans of 99.90%, 96.64%, and 91.87% for γ2%/2 mm , γ2%/1 mm , and γ1%/1 mm , respectively. The ROC analysis demonstrated a very high capability of detecting erroneous plan delivery for portal dosimetry (area under curve (AUC) > 0.98) and in this regard outperforms QA with the ArcCHECK phantom (AUC ≈ 0.82). With the suggested optimum decision thresholds excellent sensitivity and specificity is simultaneously possible. CONCLUSIONS Owing to the high achievable spatial resolution, portal dosimetry at the Halcyon can reliably be deployed as plan-specific pre-treatment QA tool to screen for errors. It is recommended to support the fluence integrated portal dosimetry QA by independent phantom-based measurements of a random sample survey of treatment plans.
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Affiliation(s)
- Gary Razinskas
- Department of Radiation OncologyUniversity Hospital WurzburgWurzburgGermany
| | - Robert Schindhelm
- Department of Radiation OncologyUniversity Hospital WurzburgWurzburgGermany
| | - Otto A. Sauer
- Department of Radiation OncologyUniversity Hospital WurzburgWurzburgGermany
| | - Sonja Wegener
- Department of Radiation OncologyUniversity Hospital WurzburgWurzburgGermany
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11
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Comparison of ArcCHECK and portal dosimetry in dose verification for intensity modulated radiotherapy plan for craniospinal irradiation. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2023. [DOI: 10.1016/j.jrras.2023.100534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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12
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Shen C, Chen L, Zhong X, Gonzalez Y, Visak J, Meng B, Inam E, Parsons D, Godley A, Jiang S, Cai B, Lin MH. Clinical experience on patient-specific quality assurance for CBCT-based online adaptive treatment plan. J Appl Clin Med Phys 2023; 24:e13918. [PMID: 36729373 PMCID: PMC10113688 DOI: 10.1002/acm2.13918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 02/03/2023] Open
Abstract
PURPOSE Ethos CBCT-based adaptive radiotherapy (ART) system can generate an online adaptive plan by re-optimizing the initial reference plan based on the patient anatomy at the treatment. The optimization process is fully automated without any room for human intervention. Due to the change in anatomy, the ART plan can be significantly different from the initial plan in terms of plan parameters such as the aperture shapes and number of monitor units (MUs). In this study, we investigated the feasibility of using calculation-based patient specific QA for ART plans in conjunction with measurement-based and calculation-based QA for initial plans to establish an action level for the online ART patient-specific QA. METHODS A cohort of 98 cases treated on CBCT-based ART system were collected for this study. We performed measurement-based QA using ArcCheck and calculation-based QA using Mobius for both the initial plan and the ART plan for analysis. For online the ART plan, Mobius calculation was conducted prior to the delivery, while ArcCheck measurement was delivered on the same day after the treatment. We first investigated the modulation factors (MFs) and MU numbers of the initial plans and ART plans, respectively. The γ passing rates of initial and ART plan QA were analyzed. Then action limits were derived for QA calculation and measurement for both initial and online ART plans, respectively, from 30 randomly selected patient cases, and were evaluated using the other 68 patient cases. RESULTS The difference in MF between initial plan and ART-plan was 12.9% ± 12.7% which demonstrates their significant difference in plan parameters. Based on the patient QA results, pre-treatment calculation and measurement results are generally well aligned with ArcCheck measurement results for online ART plans, illustrating their feasibility as an indicator of failure in online ART QA measurements. Furthermore, using 30 randomly selected patient cases, the γ analysis action limit derived for initial plans and ART plans are 89.6% and 90.4% in ArcCheck QA (2%/2 mm) and are 92.4% and 93.6% in Mobius QA(3%/2 mm), respectively. According to the calculated action limits, the ArcCheck measurements for all the initial and ART plans passed QA successfully while the Mobius calculation action limits flagged seven and four failure cases respectively for initial plans and ART plans, respectively. CONCLUSION An ART plan can be substantially different from the initial plan, and therefore a separate session of ART plan QA is needed to ensure treatment safety and quality. The pre-treatment QA calculation via Mobius can serve as a reliable indicator of failure in online ART plan QA. However, given that Ethos ART system is still relatively new, ArcCheck measurement of initial plan is still in practice. It may be skipped as we gain more experience and have better understanding of the system.
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Affiliation(s)
- Chenyang Shen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Liyuan Chen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Xinran Zhong
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yesenia Gonzalez
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Justin Visak
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Boyu Meng
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Enobong Inam
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - David Parsons
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Andrew Godley
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Steve Jiang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Bin Cai
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mu-Han Lin
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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13
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Henke LE, Fischer-Valuck BW, Rudra S, Wan L, Samson PS, Srivastava A, Gabani P, Roach MC, Zoberi I, Laugeman E, Mutic S, Robinson CG, Hugo GD, Cai B, Kim H. Prospective imaging comparison of anatomic delineation with rapid kV cone beam CT on a novel ring gantry radiotherapy device. Radiother Oncol 2023; 178:109428. [PMID: 36455686 DOI: 10.1016/j.radonc.2022.11.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 11/22/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022]
Abstract
INTRODUCTION A kV imager coupled to a novel, ring-gantry radiotherapy system offers improved on-board kV-cone-beam computed tomography (CBCT) acquisition time (17-40 seconds) and image quality, which may improve CT radiotherapy image-guidance and enable online adaptive radiotherapy. We evaluated whether inter-observer contour variability over various anatomic structures was non-inferior using a novel ring gantry kV-CBCT (RG-CBCT) imager as compared to diagnostic-quality simulation CT (simCT). MATERIALS/METHODS Seven patients undergoing radiotherapy were imaged with the RG-CBCT system at breath hold (BH) and/or free breathing (FB) for various disease sites on a prospective imaging study. Anatomy was independently contoured by seven radiation oncologists on: 1. SimCT 2. Standard C-arm kV-CBCT (CA-CBCT), and 3. Novel RG-CBCT at FB and BH. Inter-observer contour variability was evaluated by computing simultaneous truth and performance level estimation (STAPLE) consensus contours, then computing average symmetric surface distance (ASSD) and Dice similarity coefficient (DSC) between individual raters and consensus contours for comparison across image types. RESULTS Across 7 patients, 18 organs-at-risk (OARs) were evaluated on 27 image sets. Both BH and FB RG-CBCT were non-inferior to simCT for inter-observer delineation variability across all OARs and patients by ASSD analysis (p < 0.001), whereas CA-CBCT was not (p = 0.923). RG-CBCT (FB and BH) also remained non-inferior for abdomen and breast subsites compared to simCT on ASSD analysis (p < 0.025). On DSC comparison, neither RG-CBCT nor CA-CBCT were non-inferior to simCT for all sites (p > 0.025). CONCLUSIONS Inter-observer ability to delineate OARs using novel RG-CBCT images was non-inferior to simCT by the ASSD criterion but not DSC criterion.
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Affiliation(s)
- Lauren E Henke
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Benjamin W Fischer-Valuck
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Soumon Rudra
- Department of Radiation Oncology, Emory University, Atlanta, GA, United States
| | - Leping Wan
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Pamela S Samson
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Amar Srivastava
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Prashant Gabani
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | | | - Imran Zoberi
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Eric Laugeman
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Sasa Mutic
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States; Varian Medical Systems, Palo Alto, California, USA
| | - Clifford G Robinson
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Geoffrey D Hugo
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States
| | - Bin Cai
- Department of Radiation Oncology, University of Texas Southwestern School of Medicine, Dallas, TX, United States
| | - Hyun Kim
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, United States.
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Kubo K, Tamura M, Matsumoto K, Otsuka M, Monzen H. Independent monitor unit verification for dynamic flattened beam plans on the Halcyon linac. J Appl Clin Med Phys 2022; 24:e13807. [PMID: 36265085 PMCID: PMC9859998 DOI: 10.1002/acm2.13807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/17/2022] [Accepted: 09/22/2022] [Indexed: 01/26/2023] Open
Abstract
Independent monitor unit verification (MUV) methods for the dynamic beam-flattening (DBF) technique have not been established. The purpose of this study was to clarify whether MU values for the DBF technique can be calculated using in-air and in-water output ratios (Sc and Scp ). Sc and Scp were measured in the DBF mode, and the phantom scatter factor (Sp ) was calculated. The difference between calculated and planned MUs with square and rectangle fields and clinical plans for different treatment sites was also evaluated. Sc values for the 4 × 4 to 24 × 24 cm2 fields of the distal multi-leaf collimator (MLC) layer at 2-cm intervals were 0.887, 0.815, 0.715, 0.716, 0.611, 0.612, 0.511, 0.373, 0.374, 0.375, and 0.374, respectively. No collimator exchange effect was observed. Sc also depends slightly on the field size of the distal MLC layer. If the distal-MLC-layered field size was less than 20% of the corresponding MLC sequence size in the proximal MLC layer, Sc was affected by >1%, which was compensated using a correction factor (CF). Sp increased as the field sizes of the MLC sequence and distal MLC leaves increased. MUs calculated using measured Sc , Sp , and CF for square and rectangle fields agreed with planned MUs within ±1.2%. A larger difference (-1.5%) between calculated and planned MUs was observed for clinical plans, whereas differences in MUs were within 2 MU for most fields (56 out of 64 fields). MU calculation for the DBF technique can be performed with Sc , Sp , and CF for independent MUV.
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Affiliation(s)
- Kazuki Kubo
- Department of Medical PhysicsGraduate School of Medical SciencesKindai UniversityOsaka‐sayamaOsakaJapan
| | - Mikoto Tamura
- Department of Medical PhysicsGraduate School of Medical SciencesKindai UniversityOsaka‐sayamaOsakaJapan
| | - Kenji Matsumoto
- Department of Radiology CenterKindai University HospitalOsaka‐sayamaOsakaJapan
| | - Masakazu Otsuka
- Department of Radiology CenterKindai University HospitalOsaka‐sayamaOsakaJapan
| | - Hajime Monzen
- Department of Medical PhysicsGraduate School of Medical SciencesKindai UniversityOsaka‐sayamaOsakaJapan
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15
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Schiff JP, Price AT, Stowe HB, Laugeman E, Chin RI, Hatscher C, Pryser E, Cai B, Hugo GD, Kim H, Badiyan SN, Robinson CG, Henke LE. Simulated computed tomography-guided stereotactic adaptive radiotherapy (CT-STAR) for the treatment of locally advanced pancreatic cancer. Radiother Oncol 2022; 175:144-151. [PMID: 36063981 DOI: 10.1016/j.radonc.2022.08.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 01/18/2023]
Abstract
BACKGROUND AND PURPOSE We conducted a prospective, in silico imaging clinical trial to evaluate the feasibility and potential dosimetric benefits of computed tomography-guided stereotactic adaptive radiotherapy (CT-STAR) for the treatment of locally advanced pancreatic cancer (LAPC). MATERIALS AND METHODS Eight patients with LAPC received five additional CBCTs on the ETHOS system before or after their standard of care radiotherapy treatment. Initial plans were created based on their initial simulation anatomy (PI) and emulated adaptive plans were created based on their anatomy-of-the-day (PA). The prescription was 50 Gy/5 fractions. Plans were created under a strict isotoxicity approach, in which organ-at-risk (OAR) constraints were prioritized over planning target volume coverage. The PI was evaluated on the patient's anatomy-of-the-day, compared to the daily PA, and the superior plan was selected. Feasibility was defined as successful completion of the workflow in compliance with strict OAR constraints in ≥80% of fractions. RESULTS CT-STAR was feasible in silico for LAPC and improved OAR and/or target dosimetry in 100% of fractions. Use of the PI based on the patient's anatomy-of-the-day would have yielded a total of 94 OAR constraint violations and ≥1 hard constraint violation in 40/40 fractions. In contrast, 39/40 PA met all OAR constraints. In one fraction, the PA minimally exceeded the large bowel constraint, although dosimetrically improved compared to the PI. Total workflow time per fraction was 36.28 minutes (27.57-55.86). CONCLUSION CT-STAR for the treatment of LAPC cancer proved feasible and was dosimetrically superior to non-adapted CT-stereotactic body radiotherapy.
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Affiliation(s)
- Joshua P Schiff
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Alex T Price
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Hayley B Stowe
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Eric Laugeman
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Re-I Chin
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Casey Hatscher
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Eleanor Pryser
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Bin Cai
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, 2280 Inwood Road, Dallas, TX 75390, USA.
| | - Geoffrey D Hugo
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Hyun Kim
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Shahed N Badiyan
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Clifford G Robinson
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
| | - Lauren E Henke
- Department of Radiation Oncology, Washington University School of Medicine in St. Louis, 4921 Parkview Place, Campus Box 8224, St. Louis, MO 63110, USA.
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Wang GY, Zhu QZ, Zhu HL, Jiang LJ, Zhao N, Liu ZK, Zhang FQ. Clinical performance evaluation of O-Ring Halcyon Linac: A real-world study. World J Clin Cases 2022; 10:7728-7737. [PMID: 36158510 PMCID: PMC9372831 DOI: 10.12998/wjcc.v10.i22.7728] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/07/2022] [Accepted: 06/17/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Radiation therapy, especially the development of linear accelerators, plays a key role in cancer management. The fast-rotating coplanar O-ring Halcyon Linac has demonstrated many advantages. The previous literature has mainly focused on the machine parameters and plan quality of Halcyon, with a lack of relevant research on its clinical application.
AIM To evaluate the clinical performance of the O-ring Halcyon treatment system in a real-world application setting.
METHODS Data from sixty-one patients who were treated with the Halcyon system throughout the entire radiotherapy process in Peking Union Medical College Hospital between August 2019 and September 2020 were retrospectively reviewed. We evaluated the target tumour response to radiotherapy and irradiation toxicity from 1 to 3 mo after treatment. Dosimetric verification of Halcyon plans was performed using a quality assurance procedure, including portal dosimetry, ArcCHECK and point dose measurements for verification of the system delivery accuracy.
RESULTS Of the 61 patients in the five groups, 16, 12, 7 and 26 patients had complete response, partial response, progressive disease and stable disease, respectively. No increase in the irradiated target tumour volume was observed when separately evaluating the local response. Regarding irradiation toxicity, no radiation-induced deaths were observed. Thirty-eight percent (23/61 patients) had no radiation toxicity after radiotherapy, 56% (34/61 patients) experienced radiation toxicity that resolved after treatment, and 6% (4/61 patients) had irreversible adverse reactions. The average gamma passing rates with a 2% dose difference and 2-mm distance to agreement for IMRT/VMAT/SRT plans were ArcCHECK at 96.4% and portal dosimetry at 96.7%, respectively. All of the validated clinical plans were within 3% for point dose measurements, and Halcyon’s ArcCHECK demonstrated a high pass rate of 99.1% ± 1.1% for clinical gamma passing criteria of 3%/3 mm.
CONCLUSION The O-ring Halcyon Linac could achieve a better therapeutic effect on the target volume by providing accurate treatment delivery plans with tolerable irradiation toxicity.
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Affiliation(s)
- Guang-Yu Wang
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Qi-Zhen Zhu
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - He-Ling Zhu
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Ling-Juan Jiang
- Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, China
| | - Nan Zhao
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Zhi-Kai Liu
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Fu-Quan Zhang
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
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Pokhrel D, Webster A, Mallory R, Visak J, Bernard ME, McGarry RC, Kudrimoti M. Feasibility of using ring‐mounted Halcyon Linac for single‐isocenter/two‐lesion lung stereotactic body radiation therapy. J Appl Clin Med Phys 2022; 23:e13555. [PMID: 35128795 PMCID: PMC9121043 DOI: 10.1002/acm2.13555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 01/14/2022] [Accepted: 01/26/2022] [Indexed: 11/07/2022] Open
Affiliation(s)
- Damodar Pokhrel
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Aaron Webster
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Richard Mallory
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Justin Visak
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Mark E. Bernard
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Ronald C. McGarry
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Mahesh Kudrimoti
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKentuckyUSA
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Uehara T, Monzen H, Tamura M, Inada M, Otsuka M, Doi H, Matsumoto K, Nishimura Y. Feasibility study of volumetric modulated arc therapy with Halcyon™ linac for total body irradiation. Radiat Oncol 2021; 16:236. [PMID: 34906180 PMCID: PMC8670260 DOI: 10.1186/s13014-021-01959-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/29/2021] [Indexed: 01/11/2023] Open
Abstract
Background The use of total body irradiation (TBI) with linac-based volumetric modulated arc therapy (VMAT) has been steadily increasing. Helical tomotherapy has been applied in TBI and total marrow irradiation to reduce the dose to critical organs, especially the lungs. However, the methodology of TBI with Halcyon™ linac remains unclear. This study aimed to evaluate whether VMAT with Halcyon™ linac can be clinically used for TBI. Methods VMAT planning with Halcyon™ linac was conducted using a whole-body computed tomography data set. The planning target volume (PTV) included the body cropped 3 mm from the source. A dose of 12 Gy in six fractions was prescribed for 50% of the PTV. The organs at risk (OARs) included the lens, lungs, kidneys, and testes. Results The PTV D98%, D95%, D50%, and D2% were 8.9 (74.2%), 10.1 (84.2%), 12.6 (105%), and 14.2 Gy (118%), respectively. The homogeneity index was 0.42. For OARs, the Dmean of the lungs, kidneys, lens, and testes were 9.6, 8.5, 8.9, and 4.4 Gy, respectively. The V12Gy of the lungs and kidneys were 4.5% and 0%, respectively. The Dmax of the testes was 5.8 Gy. Contouring took 1–2 h. Dose calculation and optimization was performed for 3–4 h. Quality assurance (QA) took 2–3 h. The treatment duration was 23 min. Conclusions A planning study of TBI with Halcyon™ to set up VMAT-TBI, dosimetric evaluation, and pretreatment QA, was established. Supplementary Information The online version contains supplementary material available at 10.1186/s13014-021-01959-3.
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Affiliation(s)
- Takuya Uehara
- Department of Radiation Oncology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Hajime Monzen
- Department of Medical Physics, Graduate School of Medical Science, Kindai University, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan.
| | - Mikoto Tamura
- Department of Medical Physics, Graduate School of Medical Science, Kindai University, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan
| | - Masahiro Inada
- Department of Radiation Oncology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Masakazu Otsuka
- Department of Medical Physics, Graduate School of Medical Science, Kindai University, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan
| | - Hiroshi Doi
- Department of Radiation Oncology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Kenji Matsumoto
- Department of Medical Physics, Graduate School of Medical Science, Kindai University, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Faculty of Medicine, Kindai University, Osaka, Japan
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Pokhrel D, Stephen J, Webster A, Bernard ME. Double-vertebral segment SBRT via novel ring-mounted Halcyon Linac: Plan quality, delivery efficiency and accuracy. Med Dosim 2021; 47:20-25. [PMID: 34412963 DOI: 10.1016/j.meddos.2021.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/21/2021] [Accepted: 07/14/2021] [Indexed: 10/20/2022]
Abstract
To evaluate the plan quality, treatment delivery efficiency, and accuracy of single-isocenter/multi-target (SIMT) volumetric modulated arc therapy (VMAT) of double-vertebral segments stereotactic body radiation therapy (SBRT) on Halcyon ring delivery system (RDS). In-house multi-target end-to-end phantom testing and independent dose verification using the MD Anderson's single-isocenter/multi-target (lung/spine targets) thorax phantom were completed. Six previously treated patients with 2-vertebral segments on thoracic and/or lumber spine were replanned on Halcyon RDS with 6MV-FFF beam using a single-isocenter placed between the vertebral segments. Three full VMAT arcs with 0° and ±10° collimator angles and advanced Acuros-based dose engine for heterogeneity corrections were used. Prescription was 35 Gy in 5 fractions to each vertebral-segment, simultaneously. For comparison, Halcyon VMAT-SBRT plans were retrospectively created on SBRT-dedicated Truebeam with a 6MV-FFF beam using identical planning geometry and optimization objectives. Target coverage, conformity index (CI), heterogeneity index (HI), gradient index (GI), dose to 2-cm away from each target (D2-cm), and dose to adjacent organs-at-risk (OAR) were evaluated per NRG-BR002 protocol. Treatment delivery parameters were evaluated for both plans. In-house phantom measurements showed acceptable spatial accuracy (< 1mm within 5-cm from the isocenter) of conebeam CT-guided Halcyon SBRT treatments. The MD Anderson phantom irradiation credentialing results met IROC requirements for protocol patients. Mean isocenter-to-tumor center distance was 3.3 ± 0.6-cm (range 2.4 to 4.3-cm). Mean combined PTV was 57.3 ± 31.3 cc (range 20.1 to 99.9 cc). Both Halcyon and Truebeam SIMT-VMAT plans met NRG-BR002 compliance criteria and show similar CI, HI, GI, D2-cm. Maximal and volumetric doses to adjacent OAR including dose to partial spinal cord were lower with Halcyon RDS. Average total monitor units, modulation, and overall treatment time were lower with Halcyon plans by 130 MU, 0.2, 3.8 min, respectively, with similar beam-on time. Average pre-treatment patient-specific portal-dosimetry QA results on Halcyon showed a high pass rate of 99.6%, compared to SBRT-dedicated Truebeam pass rate of 96.8%, for 2%/2 mm clinical gamma passing criteria, suggesting more accurate treatment delivery on Halcyon RDS. SBRT treatment of double-vertebral segments via SIMT-VMAT plans on Halcyon for selected patients is feasible and dosimetrically superior to Truebeam Linac. Faster treatment delivery (<10 min) of double-vertebral segment SBRT on Halcyon could reduce patient intolerance due to severe back pain, potentially reduce intra-fraction motion errors, and improve patient throughput, and clinic workflow.
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Affiliation(s)
- Damodar Pokhrel
- University of Kentucky, Department of Radiation Medicine, Lexington, KY, USA.
| | - Joseph Stephen
- University of Kentucky, Department of Radiation Medicine, Lexington, KY, USA
| | - Aaron Webster
- University of Kentucky, Department of Radiation Medicine, Lexington, KY, USA
| | - Mark E Bernard
- University of Kentucky, Department of Radiation Medicine, Lexington, KY, USA
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Pokhrel D, Webster A, Stephen J, St Clair W. SBRT treatment of abdominal and pelvic oligometastatic lymph nodes using ring-mounted Halcyon Linac. J Appl Clin Med Phys 2021; 22:162-171. [PMID: 34032367 PMCID: PMC8200515 DOI: 10.1002/acm2.13268] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/18/2021] [Accepted: 04/14/2021] [Indexed: 12/31/2022] Open
Abstract
PURPOSE/OBJECTIVES This work seeks to evaluate the plan quality, treatment delivery efficiency, and accuracy of single-isocenter volumetric modulated arc therapy (VMAT) of abdominal/pelvic oligometastatic lymph nodes (LNs) stereotactic body radiation therapy (SBRT) on Halcyon Linac. MATERIALS AND METHODS After completing the in-house multitarget end-to-end phantom testing and independent dose verification using MD Anderson's single-isocenter/multi-target (lung and spine target inserts) thorax phantom, eight patients with two to three abdominal/pelvic oligometastatic LNs underwent highly conformal single-isocenter VMAT-SBRT treatment using the Halcyon Linac 6MV flattening filter free (FFF) beam. Targets were identified using an Axumin PET/CT scan co-registered with planning CT images and a single-isocenter was placed between/among the targets. Doses between 25 and 36.25 Gy in 5 fractions were delivered. Patients were treated every other day. Plans were calculated in Eclipse with advanced AcurosXB algorithm for heterogeneity corrections. For comparison, Halcyon VMAT-SBRT plans were retrospectively generated for SBRT-dedicated TrueBeam with a 6MV-FFF beam using identical planning geometry and objectives. Target coverage, conformity index (CI), dose to 2 cm away from each target (D2cm) and dose to adjacent organs-at-risk (OAR) were evaluated. Additionally, various treatment delivery parameters including beam-on time were recorded. RESULTS Phantom measurements showed acceptable spatial accuracy of conebeam CT-guided Halcyon SBRT treatments including compliance with MD Anderson's single-isocenter/multi-targets phantom credentialing results. For patients, the mean isocenter to tumor center distance was 3.4 ± 1.2 cm (range, 1.5-4.8 cm). The mean combined PTV was 18.9 ± 10.9 cc (range, 5.6-39.5 cc). There was no clinically significant difference in dose to LNs, CI, D2cm and maximal doses to OAR between single-isocenter Halcyon and Truebeam VMAT-SBRT plans, although, Halcyon plans provided preferably lower maximal dose to adjacent OAR. Additionally, total monitor units, beam-on time and overall treatment time was lower with Halcyon plans. Halcyon's portal dosimetry demonstrated a high pass rate of 98.1 ± 1.6% for clinical gamma passing criteria of 2%/2 mm. CONCLUSION SBRT treatment of abdominal/pelvic oligometastatic LNs with single-isocenter VMAT on Halcyon was dosimetrically equivalent to TrueBeam. Faster treatment delivery to oligometastatic LNs via single-isocenter Halcyon VMAT can improve clinic workflow and patient compliance, potentially reducing intrafraction motion errors for well-suited patients. Clinical follow-up of these patients is ongoing.
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Affiliation(s)
- Damodar Pokhrel
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKYUSA
| | - Aaron Webster
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKYUSA
| | - Joseph Stephen
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKYUSA
| | - William St Clair
- Medical Physics Graduate ProgramDepartment of Radiation MedicineUniversity of KentuckyLexingtonKYUSA
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21
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Tattenberg S, Hyde D, Milette MP, Parodi K, Araujo C, Carlone M. Assessment of the Sun Nuclear ArcCHECK to detect errors in 6MV FFF VMAT delivery of brain SABR using ROC analysis. J Appl Clin Med Phys 2021; 22:35-44. [PMID: 34021691 PMCID: PMC8200516 DOI: 10.1002/acm2.13276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 03/24/2021] [Accepted: 04/19/2021] [Indexed: 11/11/2022] Open
Abstract
Institutions use a range of different detector systems for patient-specific quality assurance (QA) measurements conducted to assure that the dose delivered by a patient's radiotherapy treatment plan matches the calculated dose distribution. However, the ability of different detectors to detect errors from different sources is often unreported. This study contains a systematic evaluation of Sun Nuclear's ArcCHECK in terms of the detectability of potential machine-related treatment errors. The five investigated sources of error were multileaf collimator (MLC) leaf positions, gantry angle, collimator angle, jaw positions, and dose output. The study encompassed the clinical treatment plans of 29 brain cancer patients who received stereotactic ablative radiotherapy (SABR). Six error magnitudes were investigated per source of error. In addition, the Eclipse AAA beam model dosimetric leaf gap (DLG) parameter was varied with four error magnitudes. Error detectability was determined based on the area under the receiver operating characteristic (ROC) curve (AUC). Detectability of DLG errors was good or excellent (AUC >0.8) at an error magnitude of at least ±0.4 mm, while MLC leaf position and gantry angle errors reached good or excellent detectability at error magnitudes of at least 1.0 mm and 0.6°, respectively. Ideal thresholds, that is, gamma passing rates, to maximize sensitivity and specificity ranged from 79.1% to 98.7%. The detectability of collimator angle, jaw position, and dose output errors was poor for all investigated error magnitudes, with an AUC between 0.5 and 0.6. The ArcCHECK device's ability to detect errors from treatment machine-related sources was evaluated, and ideal gamma passing rate thresholds were determined for each source of error. The ArcCHECK was able to detect errors in DLG value, MLC leaf positions, and gantry angle. The ArcCHECK was unable to detect the studied errors in collimator angle, jaw positions, and dose output.
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Affiliation(s)
- Sebastian Tattenberg
- Department of Medical Physics, Ludwig Maximilian University of Munich, Garching, Germany.,Irving K. Barber Faculty of Science, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada
| | - Derek Hyde
- Irving K. Barber Faculty of Science, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada.,Centre for the Southern Interior, Department of Medical Physics, BC Cancer Agency, Kelowna, BC, Canada
| | - Marie-Pierre Milette
- Irving K. Barber Faculty of Science, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada.,Centre for the Southern Interior, Department of Medical Physics, BC Cancer Agency, Kelowna, BC, Canada
| | - Katia Parodi
- Department of Medical Physics, Ludwig Maximilian University of Munich, Garching, Germany
| | - Cynthia Araujo
- Irving K. Barber Faculty of Science, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada.,Centre for the Southern Interior, Department of Medical Physics, BC Cancer Agency, Kelowna, BC, Canada
| | - Marco Carlone
- Irving K. Barber Faculty of Science, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada.,Centre for the Southern Interior, Department of Medical Physics, BC Cancer Agency, Kelowna, BC, Canada
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Hernandez V, Saez J, Angerud A, Cayez R, Khamphan C, Nguyen D, Vieillevigne L, Feygelman V. Dosimetric leaf gap and leaf trailing effect in a double-stacked multileaf collimator. Med Phys 2021; 48:3413-3424. [PMID: 33932237 DOI: 10.1002/mp.14914] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 04/02/2021] [Accepted: 04/23/2021] [Indexed: 01/21/2023] Open
Abstract
PURPOSE To investigate (i) the dosimetric leaf gap (DLG) and the effect of the "trailing distance" between leaves from different multileaf collimator (MLC) layers in Halcyon systems and (ii) the ability of the currently available treatment planning systems (TPSs) to approximate this effect. METHODS DICOM plans with transmission beams and sweeping gap tests were created in Python for measuring the DLG for each MLC layer independently and for both layers combined. In clinical Halcyon plans both MLC layers are interchangeably used and leaves from different layers are offset, thus forming a trailing pattern. To characterize the impact of such configuration, new tests called "trailing sweeping gaps" were designed and created where the leaves from one layer follow the leaves from the other layer at a fixed "trailing distance" t between the tips. Measurements were carried out on five Halcyons SX2 from different institutions and calculations from both the Eclipse and RayStation TPSs were compared with measurements. RESULTS The dose accumulated during a sweeping gap delivery progressively increased with the trailing distance t . We call this "the trailing effect." It is most pronounced for t between 0 and 5 mm, although some changes were obtained up to 20 mm. The dose variation was independent of the gap size. The measured DLG values also increased with t up to 20 mm, again with the steepest variation between 0 and 5 mm. Measured DLG values were negative at t = 0 (the leaves from both layers at the same position) but changed sign for t ≥ 1 mm, in line with the positive DLG sign usually observed with single-layer rounded-end MLCs. The Eclipse TPS does not explicitly model the leaf tip and, as a consequence, could not predict the dose reduction due to the trailing effect. This resulted in dose discrepancies up to +10% and -8% for the 5 mm sweeping gap and up to ±5% for the 10 mm one depending on the distance t . RayStation implements a simple model of the leaf tip that was able to approximate the trailing effect and improved the agreement with measured doses. In particular, with a prototype version of RayStation that assigned a higher transmission at the leaf tip the agreement with measured doses was within ±3% even for the 5 mm gap. The five Halcyon systems behaved very similarly but differences in the DLG around 0.2 mm were found across different treatment units and between MLC layers from the same system. The DLG for the proximal layer was consistently higher than for the distal layer, with differences ranging between 0.10 mm and 0.24 mm. CONCLUSIONS The trailing distance between the leaves from different layers substantially affected the doses delivered by sweeping gaps and the measured DLG values. Stacked MLCs introduce a new level of complexity in TPSs, which ideally need to implement an explicit model of the leaf tip in order to reproduce the trailing effect. Dynamic tests called "trailing sweeping gaps" were designed that are useful for characterizing and commissioning dual-layer MLC systems.
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Affiliation(s)
- Victor Hernandez
- Department of Medical Physics, Hospital Sant Joan de Reus, IISPV, 43204, Tarragona, Spain
| | - Jordi Saez
- Department of Radiation Oncology, Hospital Clínic de Barcelona, 08036, Barcelona, Spain
| | | | - Romain Cayez
- Department of Medical Physics, Oscar Lambret Center, 59000, Lille, France
| | - Catherine Khamphan
- Medical Physics Department, Institut Sainte-Catherine, 84000, Avignon, France
| | - Daniel Nguyen
- Centre de Radiothérapie de Mâcon, 71000, Mâcon, France
| | - Laure Vieillevigne
- Department of Medical Physics, Institut Claudius Regaud-Institut Universitaire du Cancer de Toulouse, 31059, Toulouse, France.,Centre de Recherche en Cancérologie de Toulouse UMR1037 INSERM, Université Toulouse 3-ERL5294 CNRS, Oncopole, 31037, Toulouse, France
| | - Vladimir Feygelman
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, 12902, Florida, USA
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Saini A, Tichacek C, Johansson W, Redler G, Zhang G, Moros EG, Qayyum M, Feygelman V. Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment. J Appl Clin Med Phys 2021; 22:21-34. [PMID: 33452738 PMCID: PMC7882119 DOI: 10.1002/acm2.13116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/10/2020] [Accepted: 11/16/2020] [Indexed: 01/08/2023] Open
Abstract
The Halcyon™ platform is self‐contained, combining a treatment planning (Eclipse) system TPS) with information management and radiation delivery components. The standard TPS beam model is configured and locked down by the vendor. A portal dosimetry‐based system for patient‐specific QA (PSQA) is also included. While ensuring consistency across the user base, this closed model may not be optimal for every department. We set out to commission independent TPS (RayStation 9B, RaySearch Laboratories) and PSQA (PerFraction, Sun Nuclear Corp.) systems for use with the Halcyon linac. The output factors and PDDs for very small fields (0.5 × 0.5 cm2) were collected to augment the standard Varian dataset. The MLC leaf‐end parameters were estimated based on the various static and dynamic tests with simple model fields and honed by minimizing the mean and standard deviation of dose difference between the ion chamber measurements and RayStation Monte Carlo calculations for 15 VMAT and IMRT test plans. Two chamber measurements were taken per plan, in the high (isocenter) and lower dose regions. The ratio of low to high doses ranged from 0.4 to 0.8. All percent dose differences were expressed relative to the local dose. The mean error was 0.0 ± 1.1% (TG119‐style confidence limit ± 2%). Gamma analysis with the helical diode array using the standard 3%Global/2mm criteria resulted in the average passing rate of 99.3 ± 0.5% (confidence limit 98.3%–100%). The average local dose error for all detectors across all plans was 0.2% ± 5.3%. The ion chamber results compared favorably with our recalculation with Eclipse and PerFraction, as well as with several published Eclipse reports. Dose distribution gamma analysis comparisons between RayStation and PerFraction with 2%Local/2mm criteria yielded an average passing rate of 98.5% ± 0.8% (confidence limit 96.9%–100%). It is feasible to use the Halcyon accelerator with independent planning and verification systems without sacrificing dosimetric accuracy.
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Affiliation(s)
- Amarjit Saini
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - Chris Tichacek
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - William Johansson
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - Gage Redler
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - Geoffrey Zhang
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - Eduardo G Moros
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
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Pokhrel D, Visak J, Critchfield LC, Stephen J, Bernard ME, Randall M, Kudrimoti M. Clinical validation of ring-mounted halcyon linac for lung SBRT: comparison to SBRT-dedicated C-arm linac treatments. J Appl Clin Med Phys 2020; 22:261-270. [PMID: 33342070 PMCID: PMC7856490 DOI: 10.1002/acm2.13146] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/19/2020] [Accepted: 12/04/2020] [Indexed: 12/31/2022] Open
Abstract
Stereotactic body radiotherapy (SBRT) of lung tumors via the ring‐mounted Halcyon Linac, a fast kilovoltage cone beam CT‐guided treatment with coplanar geometry, a single energy 6MV flattening filter free (FFF) beam and volumetric modulated arc therapy (VMAT) is a fast, safe, and feasible treatment modality for selected lung cancer patients. Four‐dimensional (4D) CT‐based treatment plans were generated using advanced AcurosXB algorithm with heterogeneity corrections using an SBRT board and Halcyon couch insert. Halcyon VMAT‐SBRT plans with stacked and staggered multileaf collimators produced highly conformal radiosurgical dose distribution to the target, lower intermediate dose spillage, and similar dose to adjacent organs at risks (OARs) compared to SBRT‐dedicated highly conformal clinical noncoplanar Truebeam VMAT plans following the RTOG‐0813 requirements. Due to low monitor units per fraction and less multileaf collimator (MLC) modulation, the Halcyon VMAT plan can deliver lung SBRT fractions with an overall treatment time of less than 15 min (for 50 Gy in five fractions), significantly improving patient comfort and clinic workflow. Higher pass rates of quality assurance results demonstrate a more accurate treatment delivery on Halcyon. We have implemented Halcyon for lung SBRT treatment in our clinic. We suggest others use Halcyon for lung SBRT treatments using abdominal compression or 4D CT‐based treatment planning, thus expanding the access of curative ultra‐hypofractionated treatments to other centers with only a Halcyon Linac. Clinical follow‐up results for patients treated on Halcyon Linac with lung SBRT is ongoing.
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Affiliation(s)
- Damodar Pokhrel
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Justin Visak
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Lana C Critchfield
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Joseph Stephen
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Mark E Bernard
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Marcus Randall
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Mahesh Kudrimoti
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
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25
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Pokhrel D, Tackett T, Stephen J, Visak J, Amin-Zimmerman F, McGregor A, Strup SE, St Clair W. Prostate SBRT using O-Ring Halcyon Linac - Plan quality, delivery efficiency, and accuracy. J Appl Clin Med Phys 2020; 22:68-75. [PMID: 33340388 PMCID: PMC7856496 DOI: 10.1002/acm2.13105] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/20/2020] [Accepted: 11/02/2020] [Indexed: 12/31/2022] Open
Abstract
Cone beam CT‐guided prostate stereotactic body radiotherapy (SBRT) treatment on the recently installed novel O‐ring coplanar geometry Halcyon Linac with a single energy 6MV‐flattening filter free (FFF) beam and volumetric modulated arc therapy (VMAT) is a fast, safe, and feasible treatment modality for early stage low‐ and intermediate‐risk prostate cancer patients. Following the RTOG‐0938 compliance criteria and utilizing two‐full arc geometry, VMAT prostate SBRT plans were generated for ten consecutive patients using advanced Acuros‐based algorithm for heterogeneity corrections with Halcyon couch insert. Halcyon VMAT plans with the stacked and staggered multileaf collimators (MLC) produced highly conformal SBRT dose distributions to the prostate, lower intermediate dose spillage and similar dose to adjacent organs‐at‐risks (OARs) compared to SBRT‐dedicated Truebeam VMAT plans. Due to lower monitor units per fraction and less MLC modulation through the target, the Halcyon VMAT plan can deliver prostate SBRT fractions in and overall treatment time of less than 10 minutes (for 36.25 Gy in five fractions), significantly improving patient compliance and clinic workflow. Pretreatment quality assurance results were similar to Truebeam VMAT plans. We have implemented Halcyon Linac for prostate SBRT treatment in our institution. We recommend that others use Halcyon for prostate SBRT treatments to expand the access of curative hypofractionated treatments to other clinics only equipped with a Halcyon Linac. Clinical follow‐up results for patients who underwent prostate SBRT treatment on our Halcyon Linac is underway.
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Affiliation(s)
- Damodar Pokhrel
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Tanner Tackett
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Joseph Stephen
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | - Justin Visak
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
| | | | - Andrew McGregor
- Lexington Clinic, University of Kentucky, Lexington, KY, USA
| | - Stephen E Strup
- Department of Urology, University of Kentucky, Lexington, KY, USA
| | - William St Clair
- Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA
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