Accurate pre-treatment dose prediction is essential for efficient radiotherapy planning. Although deep learning models have advanced automated dose distribution, comprehensive multi-tumor analyses remain scarce. This study assesses deep learning models for dose prediction across diverse tumor types, combining objective and subjective evaluation methods.

We included 622 patients with planning data across various tumor sites: nasopharyngeal carcinoma (n = 29), esophageal carcinoma (n = 82), left-sided breast carcinoma (n = 107), right-sided breast carcinoma (n = 95), cervical carcinoma treated with radical radiotherapy (n = 84), postoperative cervical carcinoma (n = 122), and rectal carcinoma (n = 103). Dose predictions were generated using U-Net, Flex-Net, and Highres-Net models, with data split into training (60%), validation (20%), and testing (20%) sets. Quantitative comparisons used normalized dose difference (NDD) and dose-volume histogram (DVH) metrics, and qualitative assessments by radiation oncologists were performed on the testing set.

Predicted and clinical doses correlated well, with NDD values under 3% for tumor targets in nasopharyngeal, breast, and postoperative cervical cancer. Qualitative assessments revealed that U-Net, Flex-Net, and Highres-Net achieved the highest accuracy in cervical radical, breast/rectal/postoperative cervical, and nasopharyngeal/esophageal cancers, respectively. Among the test cases (n = 123), 53.7% were deemed clinically acceptable and 32.5% required minor adjustments. The "Best Selection" approach, combining strengths of all three models, raised clinical acceptance to 62.6%.

This study demonstrates that automated dose prediction can provide a robust starting point for rapid plan generation. Leveraging model-specific strengths through the "Best Selection" approach enhances prediction accuracy and shows potential to improve clinical efficiency across multiple tumor types.

This study aimed to assess the effect of plan complexity on dosimetric alterations induced by multileaf collimator (MLC) misplacements in volumetric modulated arc therapy (VMAT).

Volumetric modulated arc therapy plans for 14 cervical and 10 lung cancer cases were reoptimized utilizing 3 distinct aperture shape controller (ASC) settings (none, very high, and very low), resulting in 3 plan groups: ASC-none, ASC-vh, and ASC-vl. Four types of MLC position errors were simulated: total shifts (Type 1), open/closed (Type 2), right-side shifts (Type 3), and left-side shifts (Type 4). Plan complexity was assessed using the small aperture score (SAS). Dose deviations resulting from various MLC positioning errors and SAS values were calculated and compared among the 3 ASC groups.

The variations in planning target volume (PTV) D95% for cervical cancer were approximately 0.6%, 3.7%, 1.9%, and 1.8% per millimetre for Types 1-4 errors, respectively. In the case of lung cancer, the changes were 2.3%, 9.3%, 5.3%, and 4.6% per millimetre. The ASC-vh and ASC-vl groups exhibited significantly reduced dose changes and SAS values in response to MLC errors, as compared to the ASC-none group (P < .05).

Highly complex plans exhibit greater dose sensitivity to MLC positional errors. The application of ASC proves effective in reducing plan complexity and mitigating the influence of MLC errors on dose deviation.

By elucidating the relationship between dosimetric impacts from MLC errors and plan complexity, this study offers valuable guidance for the design of radiotherapy plans, helping to enhance the accuracy and effectiveness of VMAT treatments.

We quantify dosimetric differences between 3-dimensional (3D) planning and volumetric modulated arc therapy (VMAT) in breast cancer patients requiring comprehensive regional nodal irradiation (CRNI). Target volume dose, prescription isodose conformality to target volumes, plan hotspots, normal tissue dose-volume metrics, and back and shoulder dose were compared for VMAT and 3D plans of 50 patients. Metrics used to compare VMAT plans with 3D plans included the percentage of primary clinical target volumes (CTVs) receiving 98% of a prescription dose of 5000 cGy, CTV dose hotspots, the extra treatment volume (ETV), and the portion of the patient's body receiving 90% of the CTV prescription dose (excluding the primary target volume). Superior values for these metrics were found for VMAT plans when compared to 3D plans. The mean percentage of the target volume receiving 98% of the prescription dose of 3D plans was 95.4% versus 98.9% among VMAT plans (P < .01). The mean target volume hotspot of 3D plans was 7200 cGy versus 5450 cGy for VMAT plans (P < .01). A mean ETV found for 3D plans was nearly double that found among VMAT plans (5.3% vs 2.7%, P < .01). VMAT plans resulted in lower doses to the shoulder and back. Mean total body volumes of VMAT plans were lower for dose thresholds of 100% to 130% of the prescription. VMAT plans generally had superior values for institutional normal tissue dose constraints. VMAT is superior to 3D planning across multiple metrics for breast cancer patients requiring CRNI. Insurance coverage for VMAT should not require 3D comparison plans.

Patients with node-positive (LN+) uterine or cervical cancer often require postoperative radiation therapy (RT) to the pelvis and para-aortic nodes. A prospective phase 2 study was conducted to evaluate the efficacy of proton beam RT for LN+ uterine or cervical cancer.

Patients with IIIC uterine and cervical cancer post hysterectomy and lymphadenectomy were eligible. Patients received 45 Gy(relative biological effectiveness) in 25 fractions with pencil beam scanning proton therapy (PBS-PT). Primary endpoints included comparing dose-volume histogram and toxicity (National Cancer Institute Common Terminology Criteria for Adverse Events v4.02) between PBS-PT and intensity modulated RT or 3-dimensional conformal RT. Secondary endpoints included progression-free survival, overall survival, patterns of recurrence, and quality of life (QOL using Functional Assessment of Cancer Therapy-Endometrial/Cervix Version 4, FACT-En/Cx V4).

Twenty-one patients completed RT between October 2013 and October 2018. Median follow-up was 60.6 months (range, 11.2-68.8). There were 15 uterine and 6 cervical cancer patients. Four received pelvic and 17 received extended-field RT. Dose-volume histogram comparisons showed significantly less volume treated with PBS-PT compared to 3-dimensional conformal RT and intensity modulated RT for bowel, bone marrow, and kidney (all P < .05) at all dose levels except V45 bladder and bowel. Acute and late grade 3 gastrointestinal toxicity were 14% and 4.7%, respectively. There were no acute or late grade 3 genitourinary toxicities. Acute and late grade 3 hematologic toxicities were 24% and 4.7%, respectively. There was 1 late grade 3 lymphedema. The 2- and 5-year progression-free survival were 81% (95% CI, 56%-92%) and 76% (95% CI, 51%-89%). There were no in-field recurrences. The 2- and 5-year overall survival were 86% (95% CI, 62%-95%) and 80% (95% CI, 55%-92%). QOL increased significantly over time with an average increase of 10.7 points from baseline to 5 years (95% CI, 0.9-20.4, P = .032).

Compared to photon RT, PBS-PT treats significantly less normal tissue volume. PBS-PT appears effective in preventing local-regional recurrence in LN+ patients with minimal acute and late toxicity. QOL significantly improved from baseline to 5 years.

This study aimed to evaluate the dosimetric and clinical outcomes of flattening filter (FF) versus flattening filter-free (FFF) beams in head and neck cancer (HNC) patients treated with volumetric modulated arc therapy (VMAT). Twenty-four patients with 70/59.4/54 Gy dose prescribed in 33 fractions with simultaneous integrated boost treatment were retrospectively analyzed to compare treatment delivery efficiency, target coverage, sparing of organs at risk (OARs), and remaining volume at risk (RVR) in two HNC groups (nasopharyngeal and oropharyngeal). Study findings indicate that FFF beams significantly reduce conformity index (CI) and homogeneity index (HI) by p-values (0.008, < 0.001, 0.002, 0.015) for PTV70 CI, PTV70 HI, PTV60 HI, and PTV54 HI, respectively. Gradient dose was significantly improved in FFF mode, and monitor units (MU) were increased (p < 0.001). In terms of OARs, the study revealed superior performance of FFF in most of structures and RVR especially in the oropharyngeal group. OARs sparing is notably enhanced for structures distant from the target (eyes, lenses, and optic pathway). Additionally, brainstem sparing shows significant improvement in oropharyngeal cases when using FFF plans (p = 0.046); however, FF plans demonstrate superior results in nasopharyngeal cases (p = 0.026). It is concluded that both FF and FFF photon beams are effective for treating HNC patients. VMAT plans using FFF mode offer clinically acceptable outcomes, demonstrating a significant reduction in gradient and integral dose. However, FF plans exhibit superior target homogeneity and reduced MU requirements. Therefore, the choice between these techniques should be based on a comprehensive evaluation of all relevant parameters.

This study aimed to assess the dosimetric advantages of dual arc increments in head and neck volumetric-modulated arc therapy (VMAT) in the Monaco treatment planning system (TPS).

Three VMAT plans were created for each of the 10 patients by prescribing 70 Gy in 35 fractions with arc increment combinations of 30°/30°, 15°/15°, and 30°/15° in the Monaco TPS. The dose to 0.03 cm3 volume (D0.03cc), conformity number, and homogeneity and gradient indices was compared for the planning target volume (PTV), and the D0.03cc and mean dose (Dmean) of the spinal cord, brain stem, parotid glands were compared. For plan complexity evaluation, the monitor unit and various related metrics were compared. Wilcoxon signed-rank tests were performed across plans for the evaluated indicators.

For PTV, plans with 30°/15° showed comparable D0.03cc and homogeneity and gradient indices to those of plans with 30°/30° and 15°/15° while exhibiting a better conformity number. The D0.03cc for spinal cord and brain stem for plans with 30°/15° were 26.0% and 20.8% less than those with 30°/30° and 16.8% and 19.0% less than those with 15°/15°, respectively. The Dmean for the left and right parotid glands under plans with 30°/15° were 17.4% and 13.2% less than those with 30°/30° and 14.0% and 9.8% less than those with 15°/15°, respectively. The total monitor unit in plans with 30°/15° was less than that in other plans but with no significance. The plans with 30°/15° showed higher modulation complexity and plan-averaged irregularity, while no significant differences observed in both plan-averaged area and modulation compared with other plans.

In head and neck VMAT, a dual arc increment of 30°/15° seems advisable because it can substantially reduce doses to normal tissues with comparable delivery efficiency while maintaining target dose coverage.

Palliative radiotherapy is frequently applied for various indications, with hemostasis being a quite common one. However, while bleeding can occur at different sites and arise from various primary tumor types, clear guidelines for administering hemostatic radiotherapy are lacking. Additionally, most available data on hemostatic radiotherapy are retrospective, and often studies do not focus on hemostasis specifically. This review provides an overview of the most recent data on hemostatic radiotherapy to identify any research trends and focus areas for this specific topic.

This review confirms the value of radiation for tumor bleeding. Unfortunately, research in hemostatic radiotherapy predominantly continues to focus on retrospective analyses of treated patients. However, at least two prospective trials specifically investigating hemostasis have been published recently, both conducted in low-income countries.

Radiotherapy is an effective and well-tolerated treatment for bleeding tumors. As the incidence of advanced cancer rises in low- and middle-income countries, where resources are limited, further research should focus on hypofractionated regimens. Additionally, there is a need for comprehensive descriptions of contouring and treatment planning to optimize outcomes in these settings.

Surface Guided Radiation Treatment (SGRT) is a new method of positioning and monitoring patients on the linear accelerator's couch, using visual light cameras to monitor the skin's surface. The purpose of this study was to compare the SGRT with the conventional method, based on lasers and tattoos, in terms of accuracy and time expenditure, on patients with pelvic malignancies.

A group of 34 patients were enrolled in this study, 24 males who underwent radiotherapy prostate treatment and 10 females who underwent gynecological radiation therapy. They were divided into two groups: Group A consisted of 17 (12 males and 5 females) patients positioned using tattoos/laser technique. Group Β also consisted of 17 (12 males and 5 females) patients positioned using the SGRT technique. For the verification of their position, all patients underwent cone beam computed tomography (CBCT) before each session. The corrections in the three directions recorded by the CBCT system were acquired for 419 and 358 sessions for groups A and B, respectively. The total corrections were also calculated. The positioning time was measured for 7 treatment sessions for each patient. The above corrections, along with the positioning duration, were statistically compared between the two groups.

The Mann-Whitney U test shows that the corrections for Group B were significantly smaller (p < 0.05) than those for Group A. The comparison of the median values of each dataset shows that the corrections improved by 16.6% for the vertical direction, 36.7% for the lateral direction, and 33.3% for the longitudinal direction, while the total correction improved by 29.2%. The SGRT method also seems more consistent, as the average interquartile range (IQR) of the correction values of Group B was 0.25 cm, while the same value was 0.38 cm for Group A. The median positioning time was 1.6 ± 0.4 min for Group A and 2.0 ± 0.6 min for Group B. The positioning duration of patients in Group B was significantly elevated (Mann-Whitney U test, p < 0.001) in respect to that related to patients of Group A.

The above results show that SGRT increases the setup time compared to the conventional approach but it provides a more accurate positioning of patients subjected to VMAT for pelvic malignancies.

There has been an uptake in hypofractionation radiotherapy schedules (> 2.45 Gy per fraction) worldwide over the last decade. The aim of this paper was to evaluate the change in fractionation schedules for patients undergoing radiotherapy in regional Queensland. The influence of treatment site, intent and patient social circumstances was assessed, identifying any current gaps in practice.

This retrospective clinical audit, included patients who underwent radiotherapy in 2012, 2019 and 2022 at a large regional department. This allowed a 10-year analysis and an evaluation of any impact of COVID-19. Demographic data and treatment information was collected and analysed using descriptive statistics.

There was a notable trend favouring hypofractionation for patients treated for breast and prostate cancer. In 2012, 62.7% of breast cancer patients were treated with conventional fractionation and 37.3% were treated with hypofractionation, versus 2.4% and 92.1%, respectively, in 2022. Prostate cancer fractionation changed from 99.4% of patients treated with conventional fractionation and 0.6% with hypofractionation in 2012 to 23.2% and 74.1%, respectively, in 2022. The standard of care also shifted for palliative intent, with lung, brain and bone metastases in 2022 being treated with increased hypofractionated and ultra-hypofractionated radiotherapy (> 5 Gy per fraction). This coincides with more complex and modulated treatments being readily available, such as stereotactic radiotherapy and volumetric modulated arc therapy. Hypofractionated treatments, however, were not influenced by the social factors of patients, having no distinct relationship with Indigenous status, age and patients' distance to treatment.

This study has validated the increase in hypofractionated treatments over a range of cancer sites and treatment intents, with increased treatment complexity. This has a direct impact on both departmental resources and patient-centred care, offering value-based radiotherapy.

Objective The dosimetric characteristics and treatment efficiency of VMAT plans using two linear accelerator platforms, Halcyon and Infinity, in conventional radiotherapy for non-small cell lung cancer (NSCLC) are compared to provide data for selecting clinical equipment. The study also explores potential confounding factors that may influence treatment outcomes. Methods This retrospective cohort study aims to compare the dosimetric characteristics and treatment efficiency of VMAT plans delivered using Halcyon and Infinity linear accelerator platforms in patients with NSCLC. A retrospective analysis was performed on 60 NSCLC patients receiving conventional fractionated radiotherapy with VMAT plans developed for both Halcyon and Infinity. These plans were optimized with RayStation 9A with identical dose constraints and optimization parameters. The groups were compared in terms of target dose coverage, normal tissue sparing, plan complexity, and treatment efficiency. The dosimetric parameters included D98%, D2%, and Dmean for both the CTV and PTV and dose distributions for organs at risk (OARs), including the heart, lungs, and spinal cord. Logistic regression was performed to account for potential confounding factors, such as PTV volume, tumor stage, and tumor location. Results The VMAT plans of both platforms met the clinical dosimetric requirements. Halcyon showed superior protection of normal tissues in low-dose areas (e.g., Lungs V5Gy and Heart V30Gy), whereas Infinity excelled in controlling hot spots and achieving rapid dose fall-off at the target margins. Furthermore, Halcyon has fewer plan monitoring units and lower complexity than Infinity and reduced treatment time by 24.0%. Logistic regression analysis revealed that PTV volume was a significant predictor for dose metric differences, while tumor stage and tumor location had variable effects depending on the dose metric, highlighting the need to account for these factors in clinical comparisons. Overall, there was no significant difference in target dose coverage or uniformity between the platforms; each demonstrated specific strengths in protecting different OARs and in treatment execution efficiency. Conclusion Halcyon and Infinity offer distinct advantages in radiotherapy for NSCLC. Halcyon provides better protection of normal tissues and performance in low-dose regions, whereas Infinity offers greater treatment efficiency and superior control in high-dose regions. The study also highlights that PTV volume is an important factor influencing dosimetric outcomes. In choosing optimal radiotherapy equipment in clinical practice, the study results suggest that treatment planning should leverage the unique technical features of different accelerators to achieve the best individualized outcomes. Future studies should increase the sample size and employ prospective research designs to confirm the clinical relevance of these findings.

Background and Objectives: The utilization of non-metallic pedicle screws and rods has become a favored approach in the management of spinal tumors. An abundance of metal artifacts improves postoperative imaging and allows for precise radiation treatment planning. Under certain conditions, a vertebral body replacement (VBR) is necessary in addition to dorsal fixation. For a long time, VBR hardware was available as titanium implants only. Recently, other non-titanium products were introduced into the market. This study compares radiotherapy planning after VBR with titanium and non-titanium materials. Materials and Methods: This is a retrospective cohort study in a single academic center setting. VBR was performed for thoracic spinal metastatic disease. Radiation plan quality was evaluated according to the criteria of the International Commission on Radiation Units and Measurements, based on postoperative CT imaging. Results: Six patients with dorsal fixation and VBR were included, half of which were treated with titanium VBR and the other half with a minimum metallic implant. In addition, patients received different dorsal fixation hardware. No difference was found in terms of radiation plan quality. With non-titanium materials, visual demarcation during radiation planning was superior. Conclusions: This is the first study in the field to comprehensively compare radiation treatment planning after VBR using different materials. With minimum metallic implants, radiotherapy planning is equal in terms of planning but superior in terms of visual demarcation in comparison to standard titanium VBR, potentially enabling more precise radiotherapy approaches.

Radiotherapy for head and neck cancer can trigger or worsen obstructive sleep apnea (OSA) due to factors such as neurological impairment, muscle atrophy, edema, and xerostomia. We present a case in which a patient developed severe OSA 3 months after undergoing radiochemotherapy and neck dissection for squamous cell carcinoma of the right lingual tonsil with regional metastasis. Polysomnography confirmed severe OSA. Unfortunately, the patient did not adhere to the recommended treatment. The symptoms persisted for 6 months but then, unexpectedly, resolved completely. A follow-up polysomnography conducted 1 year after radiotherapy showed no evidence of OSA. This case suggests that a recent diagnosis of OSA following head and neck radiotherapy may not be permanent and should not necessarily lead to a lifelong prognosis of sleep-related breathing disorders.

Palma VM, Silva POT, Formigoni GGS, Sennes LU, Cahali MB. Transient radiation-induced severe obstructive sleep apnea. J Clin Sleep Med. 2025;21(2):427-429.

This study investigates scintillation dosimetry coupled with Cherenkov imaging for in vivo dose monitoring during whole breast radiation therapy (WBRT). Given recent observations of excess dose to the contralateral breast (CB), in vivo dosimetry (IVD) could help ensure accurate dose delivery and decrease risks of secondary cancer. This work presents a rapid, streamlined alternative to traditional IVD, providing direct visualization of measurement location relative to the treatment field on the patient.

Ten WBRT patients consented under an institutional review board-approved protocol were monitored with scintillation dosimetry and always-on Cherenkov imaging, on both their treated and CB for 1 to 3 fractions. Scintillator dosimeters, small plastic discs 1 mm thick and 15 mm in diameter, were calibrated against optically stimulated luminescent dosimeters (OSLDs) to generate an integral output-to-dose conversion, where integral output is measured in postprocessing through a custom fitting algorithm. The discs have been extensively characterized in a previous study for various treatment conditions including beam energy and treatment geometry.

A total of 44 dosimetry measurements were evaluated, including 22 treated breast and 22 CB measurements. After integral output-to-dose calibration, in vivo scintillator dosimeters exhibited high linearity (R2 = 0.99) with paired OSLD readings across all patients. The difference between scintillation and OSLD dose measurements averaged 2.8% of the prescribed dose, or an absolute dose difference of approximately 7 cGy.

Integration of scintillation dosimetry with Cherenkov imaging offers an accurate, rapid alternative for in vivo dose verification in WBRT, circumventing the limitations of conventional point dosimeters. The additional benefit of visualizing measurement locations relative to the treatment field provides users an enhanced understanding of results and allows for detection of high dose gradients. Future work will explore the applicability of this technique across a broader range of radiation therapy treatments, aiming to streamline IVD practices.

The evolution of radiation therapy in Uganda has been a journey marked by significant milestones and persistent challenges. Since the inception of radiotherapy services in 1988-1989, there has been a concerted effort to enhance cancer treatment services. The early years were characterized by foundational developments, such as the installation of the first teletherapy units, low-dose-rate brachytherapy units, and conventional simulators, and the recognition of radiation oncologists and medical physicist professionals laid the groundwork for radiotherapy treatment modalities. With more support from the International Atomic Energy Agency, the acquisition of dosimetry equipment, treatment planning systems, and additional professional training signaled a new era in the fight against cancer. As we entered the second decade of the millennium, the Uganda Cancer Institute (UCI) witnessed a progression in sophisticated radiotherapy services, including high-dose-rate brachytherapy, initiation of intensity modulated radiation therapy (IMRT)/volumetric modulated arc therapy (VMAT), and use of artificial intelligence. These advancements improved the efficiency/precision of treatments and the time patients spent undergoing therapy. Around the second decade of radiotherapy services, about 600 new patients with cancer were annually treated compared with about 2,600 in 2023. Currently, an average of 1,440 brachytherapy insertions are done annually compared with 300 insertions for the first 20 years. Despite the technological strides, the UCI faced numerous obstacles, including limited equipment, knowledge gaps in appropriate tumor/organs at risk segmentations, treatment planning, and protocols. However, international support and collaboration efforts have led to significant improvement in the precision and effectiveness of treatments. Currently, about 51% of all patients are treated with image-guided techniques-IMRT/VMAT (42%) and three-dimensional conformal radiation treatment (10%). The Government has commenced the decentralization of radiotherapy services to other regions. This review can be a learning lesson for the more than 25 countries in Africa and other low-middle-income countries globally that do not have access to radiotherapy and/or are in the process of starting such facilities.

Recently, neoadjuvant short-course radiation therapy (SCRT) has emerged as a valid treatment option for patients with locally advanced rectal cancer (LARC). We assessed SCRT plans using volumetric-modulated arc therapy (VMAT) with Halcyon and Infinity medical linear accelerators (Linacs) and compared the plan quality and delivery efficiency across all cases. Thirty patients who underwent preoperative SCRT for LARC at the hospital were randomly selected. Treatment plans were designed using the Halcyon and Infinity linac platforms, generating Halcyon VMAT plans (Group H) and Infinity VMAT plans (Group I). The target coverage, organ at risk (OAR) dose distribution, number of monitor units, treatment delivery time, and planning complexity of the two groups were compared and analyzed. Plan quality assurance was performed on the ArcCheck phantom. The overall plan quality regarding target volume and OARs was comparable for plans delivered on Halcyon and Infinity Agility machines, with each platform having advantages. Therefore, both radiotherapy platforms are very good options when selecting which technique to use in the clinic.

This study aimed to investigate the effect of couch rotation angles on non-coplanar volumetric modulated arc therapy (ncVMAT) plan for stereotactic body radiotherapy (SBRT) in lung cancer patients and to evaluate the feasibility of clinically applying ncVMAT for SBRT.

Twenty-four lung cancer patients with a single lesion eligible for SBRT were enrolled in the study. Seven dual partial-arc VMAT plans with varying couch angles were designed for every patient. These plans utilized two partial arcs, with the same first arc set at a fixed 0° couch angle in all plans. The second arc's couch angle varies at 15° intervals, ranging from 0° to 90°. The plans are designated as C0, NC15, NC30, NC45, NC60, NC75, and NC90, respectively. Plan evaluation included assessment of the maximum dose (Dmax), the mean dose (Dmean), homogeneity index (HI), conformity index (CI), and the ratio of the 50% isodose volume to the planning target volume (R50%). Dosimetric parameters for organs at risk such as the ipsilateral lung, contralateral lung, bilateral lungs, esophagus, trachea, chest wall, heart, and spinal cord were analyzed. Additionally, plan complexity-related metrics included modulation degree (MD), delivery time (DT), and monitor unit (MU) were assessed.

As the couch rotation angle increased, parameters such as Dmax, Dmean, HI, CI, R50%, V20Gy, V25.75Gy and V30Gy of the ipsilateral lung and bilateral lungs, V10Gy of the contralateral lung and Dmean of the chest wall varied, while MD, MU, and DT increased. Compared to C0, the Dmax, Dmean, and HI of the planning target volume (PTV) decreased from 6728.35 ± 209.56cGy, 5743.04 ± 93.45cGy, and 0.281 ± 0.032 to 6500.48 ± 225.26cGy, 5654.81 ± 109.23cGy, and 0.245 ± 0.031, respectively, when the couch was rotated to 90°. The CI increased from 0.859 ± 0.031 to 0.876 ± 0.024. Decreases in R50% were 1.4%, 4.9%, 9%, 13.5%, 16.8%, and 18.4% for NC15, NC30, NC45, NC60, NC75, and NC90, respectively.

In the treatment of lung cancer using SBRT, ncVMAT plans demonstrate superior dose distribution and deliver lower doses to certain OARs compared to cVMAT plans. This advantage becomes more pronounced with increasing couch rotation angles. Our study offers theoretical support for the preferential use of ncVMAT plans in lung cancer SBRT and provides empirical evidence to guide the selection of optimal couch rotation angles.

Radiation injuries, particularly those resulting from therapeutic or accidental exposure, present complex challenges for medical management. These injuries can manifest localized skin damage or extend to deeper tissues, presenting as various clinical entities that require treatment strategies, ranging from conservative management to complex surgical interventions. Radiation treatment constitutes a fundamental component of neoplastic management, with nearly two out of three oncological instances undergoing it as an element of their therapeutic strategy. The therapeutic approach to radiation injury consists of expanding prophylactic measures while maintaining the efficacy of treatment, such as conservative treatment or local debridement followed by reconstruction. The armamentarium of reconstructive methods available for plastic surgeons, from secondary healing to free tissue transfer, can be successfully applied to radiation injuries. However, the unique pathophysiological changes induced by radiation necessitate a careful and specialized approach for their application, considering the altered tissue characteristics and healing dynamics. The therapeutic strategy is guided by both the severity and progression of the injury, with the primary aim of restoring functionality and aesthetic aspects while simultaneously minimizing the risk of complications. This paper explores the various conditions encompassed by the term "radiation injury," reviews both non-surgical and surgical therapeutic strategies for managing these injuries, and highlights the unique challenges associated with treating irradiated tissues within specific oncological contexts.

To evaluate the feasibility and accuracy of radiomics, dosiomics, and deep learning (DL) in predicting Radiation Pneumonitis (RP) in lung cancer patients underwent volumetric modulated arc therapy (VMAT) to improve radiotherapy safety and management.

Total of 318 and 31 lung cancer patients underwent VMAT from First Affiliated Hospital of Wenzhou Medical University (WMU) and Quzhou Affiliated Hospital of WMU were enrolled for training and external validation, respectively. Models based on radiomics (R), dosiomics (D), and combined radiomics and dosiomics features (R+D) were constructed and validated using three machine learning (ML) methods. DL models trained with CT (DLR), dose distribution (DLD), and combined CT and dose distribution (DL(R+D)) images were constructed. DL features were then extracted from the fully connected layers of the best-performing DL model to combine with features of the ML model with the best performance to construct models of R+DLR, D+DLD, R+D+DL(R+D)) for RP prediction.

The R+D model achieved a best area under curve (AUC) of 0.84, 0.73, and 0.73 in the internal validation cohorts with Support Vector Machine (SVM), XGBoost, and Logistic Regression (LR), respectively. The DL(R+D) model achieved a best AUC of 0.89 and 0.86 using ResNet-34 in training and internal validation cohorts, respectively. The R+D+DL(R+D) model achieved a best performance in the external validation cohorts with an AUC, accuracy, sensitivity, and specificity of 0.81(0.62-0.99), 0.81, 0.84, and 0.67, respectively.

The integration of radiomics, dosiomics, and DL features is feasible and accurate for the RP prediction to improve the management of lung cancer patients underwent VMAT.

Volumetric-modulated arc therapy (VMAT) is a radiotherapy technique used to treat patients with localized prostate cancer, which is frequently associated with acute adverse events (AEs) that can affect subsequent treatment. Notably, the radiation dose of VMAT can be tailored to each patient. In the present study, a retrospective analysis was performed to predict acute AEs in response to a therapeutic high radiation dose rate based on urinary metabolomic molecules, which are easily collected as noninvasive biosamples. Urine samples from 11 patients with prostate cancer who were treated with VMAT (76 Gy/38 fractions) were collected. The study found that seven patients (~64%) exhibited genitourinary toxicity (Grade 1) and four patients had no AEs. A total of 630 urinary metabolites were then analyzed using a mass spectrometer (QTRAP6500+; AB SCIEX), and 234 relevant molecules for biological and clinical applications were extracted from the absolute quantified metabolite values using the MetaboINDICATOR tool. In the Grade 1 acute AE group, there was a significant negative correlation (rs=-0.297, P<0.05) between the number of VMAT fractions and total phospholipase A2 activity in the urine. Additionally, patients with Grade 1 AEs exhibited a decrease in PC aa C40:1, a phospholipid. These findings suggested that specific lipids found in urinary metabolites may serve as predictive biomarkers for acute AEs in response to external radiotherapy.

Modern radiotherapeutic techniques, such as intensity-modulated radiation therapy or stereotactic body radiotherapy, require high-dose delivery precision. However, the precise localization of tumors during patient respiration remains a challenge. Therefore, it is essential to investigate effective methods for monitoring respiration to minimize potential complications. Despite several systems currently in clinical use, there are drawbacks, including the complexity of the setup, the discomfort to the patient, and the high cost.

This study investigated the feasibility of using a novel pressure sensor array (PSA) as a tool to monitor respiration during radiotherapy treatments. The PSA was positioned between the treatment couch and the back of the patient lying on it and was intended to overcome some limitations of current methods. The main objectives included assessing the PSA's capability in monitoring respiratory behavior and to investigate prospective applications that extend beyond respiratory monitoring.

A PSA with 31 pressure-sensing elements was used in 12 volunteers. The participants were instructed to breathe naturally while lying on a couch without any audio or visual guidance. The performance of the PSA was compared to that of a camera-based respiratory monitoring system (RPM, Varian, USA), which served as a reference. Several metrics, including pressure distribution, weight sensitivity, and correlations between PSA and RPM signals, were analyzed. The PSA's capacity to provide information on potential applications related to patient stability was also investigated.

The linear relationship between the weight applied to the PSA and its output was demonstrated in this study, confirming its sensitivity to pressure changes. A comparison of PSA and RPM curves revealed a high correlation coefficient of 0.9391 on average, indicating consistent respiratory cycles. The PSA also effectively measured the weight distribution at the volunteer's back in real-time, which allows for monitoring the patient's movements during the radiotherapy.

PSA is a promising candidate for effective respiratory monitoring during radiotherapy treatments. Its performance is comparable to the established RPM system, and its additional capabilities suggest its multifaceted utility. This paper shows the potential use of PSA for patient monitoring in radiotherapy and suggests possibilities for further research, including performance comparisons with other existing systems and real-patient applications with respiratory training.

Nuclear protein of the testis carcinoma is an exceedingly rare and poorly differentiated carcinoma characterized by BDR4::NUTM1 gene translocation. Typically, the tumor affects young adults, and no standardized recommendations for therapeutic management have been available since 2022; the clinical course remains mostly dismal. We report the successful multimodal treatment of a 13-year-old boy affected by a primary chest NUT-carcinoma with a novel NUTM1 rearrangement that remains in complete continuous remission at 30 months from diagnosis.

(1) Background: Head and neck cancer treatment, including advanced techniques like Volumetric Modulated Arc Therapy (VMAT), presents challenges for maintaining patient quality of life (QoL). Thus, thoroughly investigating how radiation therapy (RT) affects patients has been proved essential. Derived by that, this study aims to understand the complex interactions between not only RT and QoL but also symptom severity, and treatment-related toxicities in three distinct time points of patient's treatment; (2) Methods: To achieve that, EORTC-QLQ-C30 and EORTC QLQ-H&N35 questionnaires were used in combination with EORTC_RTOG scoring criteria and Spearman's rho statistical analysis for 74 patients with cancer undergoing VMAT radiation therapy; (3) Results: The results revealed a significant improvement in the Overall Health Index post-treatment, indicating a temporary decline during therapy followed by subsequent recovery, often surpassing pre-treatment QoL levels. Concurrently a reduction in symptomatology was observed, notably in pain, swallowing difficulties, and dry mouth, aligning with prior research indicating decreased symptom burden post-treatment. However, Spearman's correlation coefficient analysis at two distinct time points during therapy uncovered varying degrees of correlation between dosimetric data at Organs at Risk (OARs) and reported symptoms, highlighting potential limitations in using QoL questionnaires as sole indicators of treatment efficacy. Our investigation into the correlation between dosimetric data, toxicity, and symptoms focused on the relationship between radiation doses and oral mucositis levels, a common toxicity in head and neck cancer patients. Significant associations were identified between toxicity levels and dosimetric parameters, particularly with OARs such as the parotid glands, oral cavity, and swallowing muscles, underlining the utility of the EORTC method as a reliable toxicity assessment tool; (4) Conclusions: To summarize, current research attempts to underscore the importance of refining QoL assessments for enhanced patient care. The integration of dosimetric data, symptom severity, and treatment-related toxicities in the QoL outcomes of head and neck cancer patients undergoing VMAT radiation therapy, can lead towards the optimization of treatment strategies and the improvement of patient outcomes in future patient-centered radiation therapy practices.

This study aimed to analyze the effect of different gantry angles on portal imaging in terms of isocenter shifts and their dosimetric impact on dose delivery.

Thirty patients with head and neck cancers were prospectively selected for this study. The reference anterior to posterior (AP) digitally reconstructed reference radiograph image was obtained at a gantry angle of 0°. The AP portal images were acquired at angles of 0°, 0.5°, 1°, 1.5°, and 2.0°. The average deviation of the isocenter shift with respect to the zero-gantry angle was calculated. To check the dosimetric effects, the reference fluence was compared with different fluences measured at different isocenter shifts.

The average isocenter shift differences in the lateral direction were 0.7 mm, 1.3 mm, 1.9 mm, and 2.5 mm. The average difference was <±0.1 mm for isocenter shift in the longitudinal direction. The results of the statistical analysis showed that the average isocenter shift and gamma pass rate with respect to the different isocenter position errors were significant in the lateral direction.

The results of this study showed that as the gantry angle increased, the isocenter shifted and the percentage of deviation in the lateral direction increased.

To evaluate the toxicity of prophylactic extended-field radiation therapy (EFRT) combined with volumetric modulated arc therapy (VMAT) in combination with cisplatin chemotherapy for locally advanced stage IIIC1r cervical cancer [2018 International Federation of Gynecology and Obstetrics (FIGO)].

Thirty patients with stage IIIC1r cervical cancer were treated with EFRT combined with concurrent cisplatin. Acute toxicities were evaluated according to the common terminology criteria for adverse events (CTCAE v.5). Delayed toxicities were evaluated according to the classification criteria of radiation damage toxicity of the Radiation Therapy Oncology Group (RTOG). The efficacy of the regimens was evaluated using response evaluation criteria in solid tumors (RECIST v1.1). Spearman correlation was used to analyze the correlation between acute gastrointestinal toxicity (nausea) and the small bowel V45. Predictive value analysis was performed using a receiver operating characteristic (ROC) curve.

There were no grade ≥ 3 acute toxicities. The most common acute toxicity observed was nausea (grade 2 in 40%), which was positively correlated with the volume of the small intestine receiving 45 Gy. When the V45 of the small intestine was > 83.2 cc, the risk of grade 2 acute upper digestive tract toxicity (nausea) increased. The major late toxicities had the following distributions: Grade 1 diarrhea, 36.7%; Grade 1 abdominal pain, 13.3%; and Grade 1 radiation cystitis. No grade ≥ 2 late toxicities were observed.

Treatment of locally advanced stage IIIC1r cervical cancer with EFRT combined with VMAT and concurrent cisplatin chemotherapy was well tolerated, and the acute toxicity profile was acceptable. Significant grade 3 acute/delayed toxicities were not observed.

Multi-criteria optimization (MCO) function has been available on commercial radiotherapy (RT) treatment planning systems to improve plan quality; however, no study has compared Eclipse and RayStation MCO functions for prostate RT planning. The purpose of this study was to compare prostate RT MCO plan qualities in terms of discrepancies between Pareto optimal and final deliverable plans, and dosimetric impact of final deliverable plans. In total, 25 computed tomography datasets of prostate cancer patients were used for Eclipse (version 16.1) and RayStation (version 12A) MCO-based plannings with doses received by 98% of planning target volume having 76 Gy prescription (PTV76D98%) and 50% of rectum (rectum D50%) selected as trade-off criteria. Pareto optimal and final deliverable plan discrepancies were determined based on PTV76D98% and rectum D50% percentage differences. Their final deliverable plans were compared in terms of doses received by PTV76 and other structures including rectum, and PTV76 homogeneity index (HI) and conformity index (CI), using a t-test. Both systems showed discrepancies between Pareto optimal and final deliverable plans (Eclipse: -0.89% (PTV76D98%) and -2.49% (Rectum D50%); RayStation: 3.56% (PTV76D98%) and -1.96% (Rectum D50%)). Statistically significantly different average values of PTV76D98%,HI and CI, and mean dose received by rectum (Eclipse: 76.07 Gy, 0.06, 1.05 and 39.36 Gy; RayStation: 70.43 Gy, 0.11, 0.87 and 51.65 Gy) are noted, respectively (p < 0.001). Eclipse MCO-based prostate RT plan quality appears better than that of RayStation.

Compared to photon beam, carbon-ion radiotherapy (CIRT) has both physical and biological advantages.

To examine whether two-dimensional (2D) CIRT is dosimetrically superior to photon beam volume-modulated arc therapy (VMAT) in protecting the normal tissues for stage III non-small-cell lung cancer (NSCLC).

A retrospective study was conducted. Thirteen patients with stage III NSCLC treated in our center with curative CIRT and a sham photon beam VMAT treatment planning with the same normal tissue dose constraints were included for analysis. Target dose distributions and the homogeneity index (HI) within the planning target volumes were compared.

Both CIRT and VMAT plans have good tumor coverage with no significant differences in D98, D95, and D50 of Planning target volume 1 (PTV1) between the two plans. The HIs between the two plans are similar. The HI of PTV2 is superior in the CIRT plan (CIRT vs. VMAT: 0.08 vs. 0.16, P < 0.05). In general, CIRT results in a lower dose of the organ-at-risk (OAR) than the photon plans. The V5, V10, V20, V30, V40, and Dmean of the contralateral lung in the CIRT plan are significantly lower than that of the photon VMAT. For the ipsilateral lung, the V5 of CIRT is significantly lower. The CIRT also had significantly lower spinal cord Dmax, esophageal Dmean and V50, V10 and V30 of bone, and V50 of the trachea and bronchial tree.

Compared with photon VMAT, 2D-CIRT using the passive beam scanning technique significantly reduces the radiation dose to the OARs in curative radiotherapy of stage III NSCLC, suggesting a better protection of the normal tissues.

Localized extra-mammary Paget's disease (EMPD) is mainly treated with surgical resection. Curative radiation therapy (CRT) is an alternative to surgery. Electron beams and conventional X-ray methods have been used in patients with EMPD for radiotherapy. The present report describes the case of a very elderly patient with perineal EMPD who was treated with definitive radiotherapy consisting of 60 Gy in 30 fractions. Surgery was deemed too difficult because of his age and comorbidities. We adopted volumetric modulated arc therapy as the radiotherapy modality, a recent, advanced form of intensity-modulated radiation therapy. Grade 3 dermatitis was observed as an acute phase adverse event, and he achieved a complete response and maintained remission for over one-year post-treatment. Our radiotherapy treatment protocol resulted in good clinical outcomes; therefore, it may be a candidate for inoperable patients with EMPD.

Purpose: This study aims to develop a data-collecting package ExpressMLC and investigate the applicability of MapCHECK2 for multileaf collimator (MLC) modeling and commissioning for complex radiation treatment plans. Materials and methods: The MLC model incorporates realistic parameters to account for sophisticated MLC features. A set of 8 single-beam plans, denoted by ExpressMLC, is created for the determination of parameters. For the commissioning of the MLC model, 4 intensity modulated radiation therapy (IMRT) plans specified by the AAPM TG 119 report were transferred to a computed tomography study of MapCHECK2, recalculated, and compared to measurements on a Varian accelerator. Both per-beam and composite-beam dose verification were conducted. Results: Through sufficient characterization of the MLC model, under 3%/2 mm and 2%/2 mm criteria, MapCHECK2 can be used to accurately verify per beam dose with gamma passing rate better than 90.9% and 89.3%, respectively, while the Gafchromic EBT3 films can achieve gamma passing rate better than 89.3% and 85.7%, respectively. Under the same criteria, MapCHECK2 can achieve composite beam dose verification with a gamma passing rate better than 95.9% and 90.3%, while the Gafchromic EBT3 films can achieve a gamma passing rate better than 96.1% and 91.8%; the p-value from the Mann Whitney test between gamma passing rates of the per beam dose verification using full MapCHECK2 package calibrated MLC model and film calibrated MLC model is .44 and .47, respectively; the p-value between those of the true composite beam dose verification is .62 and .36, respectively. Conclusion: It is confirmed that the 2-dimensional (2D) diode array MapCHECK2 can be used for data collection for MLC modeling with the combination of the ExpressMLC package of plans, whose doses are sufficient for the determination of MLC parameters. It could be a fitting alternative to films to boost the efficiency of MLC modeling and commissioning without sacrificing accuracy.

The aim of this planning study was to compare the dosimetric outcomes of Volumetric Modulated Arc Therapy (VMAT), Proton Beam Therapy (PBT), and conventional External Beam Radiation Therapy (cEBRT) in the treatment of thoracic spinal metastases originating from breast or prostate cancer. Our study utilized data from 30 different treatment plans and evaluated target coverage and doses to vital organs at risk (OARs), such as the spinal cord, heart, esophagus, and lungs. The results showed that VMAT and PBT achieved superior target coverage and significantly lower doses to the spinal cord compared to cEBRT (target: median PTVD95%: 75.2 for cEBRT vs. 92.9 and 91.7 for VMAT (p < 0.001) and PBT (p < 0.001), respectively; spinal cord: median Dmax%: 105.1 for cEBRT vs. 100.4 and 103.6 for VMAT (p < 0.001) and PBT (p = 0.002), respectively). Specifically, VMAT was notable for its superior target coverage and PBT for significantly lower doses to heart, lungs, and esophagus. However, VMAT resulted in higher lung doses, indicating potential trade-offs among different techniques. The study demonstrated the relative advantages of VMAT and PBT over traditional RT in the palliative treatment of spinal metastases using conventional fractionation. These findings underscore the potential of VMAT and PBT to improve dosimetric outcomes, suggesting that they may be more suitable for certain patient groups for whom the sparing of specific OARs is especially important.

Automatic patient-specific quality assurance (PSQA) is recently explored using artificial intelligence approaches, and several studies reported the development of machine learning models for predicting the gamma pass rate (GPR) index only.

To develop a novel deep learning approach using a generative adversarial network (GAN) to predict the synthetic measured fluence.

A novel training method called "dual training," which involves the training of the encoder and decoder separately, was proposed and evaluated for cycle GAN (cycle-GAN) and conditional GAN (c-GAN). A total of 164 VMAT treatment plans, including 344 arcs (training data: 262, validation data: 30, and testing data: 52) from various treatment sites, were selected for prediction model development. For each patient, portal-dose-image-prediction fluence from TPS was used as input, and measured fluence from EPID was used as output/response for model training. Predicted GPR was derived by comparing the TPS fluence with the synthetic measured fluence generated by the DL models using gamma evaluation of criteria 2%/2 mm. The performance of dual training was compared against the traditional single-training approach. In addition, we also developed a separate classification model specifically designed to detect automatically three types of errors (rotational, translational, and MU-scale) in the synthetic EPID-measured fluence.

Overall, the dual training improved the prediction accuracy of both cycle-GAN and c-GAN. Predicted GPR results of single training were within 3% for 71.2% and 78.8% of test cases for cycle-GAN and c-GAN, respectively. Moreover, similar results for dual training were 82.7% and 88.5% for cycle-GAN and c-GAN, respectively. The error detection model showed high classification accuracy (>98%) for detecting errors related to rotational and translational errors. However, it struggled to differentiate the fluences with "MU scale error" from "error-free" fluences.

We developed a method to automatically generate the synthetic measured fluence and identify errors within them. The proposed dual training improved the PSQA prediction accuracy of both the GAN models, with c-GAN demonstrating superior performance over the cycle-GAN. Our results indicate that the c-GAN with dual training approach combined with error detection model, can accurately generate the synthetic measured fluence for VMAT PSQA and identify the errors. This approach has the potential to pave the way for virtual patient-specific QA of VMAT treatments.

The Mobius3D software addresses limitations lacking in measurement-based methods in patient-specific quality assurance (QA). The objective of this study was to validate its dosimetric performance against conventionally used portal dose measurements using gamma analysis and confidence limits.

A total of 240 patient-specific QA plans for the Varian Halcyon linear accelerator were collected. The Mobius3D software was commissioned through beam data and plan verification. All plans underwent QA through the electronic portal imaging device, coupled with the Portal Dosimetry software, and the Mobius3D. Data were assessed using >95% gamma pass. Portal measurements were evaluated using 3%/2 mm and 3%/3 mm criteria, whereas Mobius3D was analyzed at 3%/3 mm and 5%/3 mm, at the 10% threshold.

Mobius 5%/3 mm mean gamma passes were 99.89% for volumetric-modulated arc therapy (VMAT) and 99.31% for intensity-modulated radiotherapy (IMRT), and correspondingly, the data for portal 3%/2 mm were 99.99% and 99.96%. The Mobius3D at 5%/3 mm can perform like Portal 3%/2 mm for VMAT plans at 0.1% difference, especially for head/neck and pelvic/abdominal cases. In IMRT-based treatments, at 0.7% difference in Mobius3D 5%/3 mm and Portal 3%/2 mm, the performance and error identification in IMRT plans should be applied more carefully due to the amount of failed plans, particularly the chest region. The confidence limits for VMAT plans for Portal 3%/2 mm and Mobius 5%/3 mm are 99.93% and 99.42%, respectively, while for IMRT plans are 99.69% and 97.43%, respectively.

At a 5%/3 mm criterion, the Mobius3D may yield percentage gamma pass rates like measurements obtained by Portal Dosimetry 3%/3 mm and Portal Dosimetry 3%/2 mm. As the software is largely dependent on commissioned data, rigorous commissioning and a comprehensive QA program should be implemented.

A recent approach to radiotherapy for prostate cancer is the administration of high doses of radiation to the prostate while minimizing the risk of side effects. Thus, image-guided radiotherapy utilizes advanced imaging techniques and is a feasible strategy for increasing the radiation dose. New radioactive particles are another approach to achieving high doses and safe procedures. Prostate brachytherapy is currently considered as a combination therapy. Spacers are useful to protect adjacent organs, specifically the rectum, from excessive radiation exposure.

The present study was implemented to compare the dosimetric parameters of the target dose coverage and critical structures in the treatment planning of four radiotherapy techniques [namely, three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), hybrid IMRT (h-IMRT) and volumetric-modulated arc therapy (VMAT)] for stage III non-small cell lung cancer (NSCLC) qualified plans for medical physicists, therapists and physicians. A total of 40 patients confirmed to have stage IIIA or IIIB NSCLC were enrolled, and four plans were designed for each patient. The prescription dose to the planning target volume (PTV) was assigned as 60 Gy in 30 fractions. The conformity index (CI), heterogeneity index (HI) and parameters of organs at risk (OARs) were calculated. For the PTV, the CI for VMAT was found to be the highest of all the four techniques (P<0.05), whereas the HI for the h-IMRT technique was found to be the lowest (P<0.05). Concerning the OARs, for the percentage of lung volume receiving a dose >5 Gy (lung V₅), the highest value was obtained with VMAT (P<0.05), whereas for lung V₃₀ and heart V₃₀, the VMAT and IMRT techniques were found to be better compared with 3D-CRT and h-IMRT (P<0.05). For esophagus V₅₀, the maximal dose (D_max) and mean dose for the IMRT technique displayed the best results (P<0.05), and in the case of the spinal cord, the D_max with VMAT showed a significant advantage over the other techniques (P<0.05). The treatment monitor units (MUs) in IMRT were found to be the largest (P<0.05), whereas the treatment time with VMAT was the shortest (P<0.05). For smaller PTVs, VMAT was the technique that provided the optimal dose distribution and sparing of the heart. Compared with 3D-CRT alone, adding 20% IMRT to the 3D-CRT base plan was shown to improve the plan quality, and IMRT and VMAT, as techniques, had better dose coverage and sparing of OARs. Furthermore, for patients in whom the lung V5 could be kept low enough, VMAT potentially offered a good alternative to the technique to IMRT, thereby offering additional possibilities for sparing of other OARs, and decreasing the MUs and treatment time.