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Wang Y, Ma K, Kang M, Yan D, Niu N, Yan S, Sun P, Zhang L, Sun L, Wang D, Tan H, Tang BZ. A new era of cancer phototherapy: mechanisms and applications. Chem Soc Rev 2024; 53:12014-12042. [PMID: 39494674 DOI: 10.1039/d4cs00708e] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2024]
Abstract
The past decades have witnessed great strides in phototherapy as an experimental option or regulation-approved treatment in numerous cancer indications. Of particular interest is nanoscale photosensitizer-based phototherapy, which has been established as a prominent candidate for advanced tumor treatment by virtue of its high efficacy and safety. Despite considerable research progress on materials, methods and devices in nanoscale photosensitizing agent-based phototherapy, their mechanisms of action are not always clear, which impedes their practical application in cancer treatment. Hence, from a new perspective, this review elaborates the working mechanisms, involving impairment and moderation effects, of diverse phototherapies on cells, organelles, organs, and tissues. Furthermore, the most current available phototherapy modalities are categorized as photodynamic, photothermal, photo-immune, photo-gas, and radio therapies in this review. A comprehensive understanding of the inferiority and superiority of various phototherapies will facilitate the advent of a new era of cancer phototherapy.
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Affiliation(s)
- Yuanwei Wang
- Center for Child Care and Mental Health (CCCMH) Shenzhen Children's Hospital, Shenzhen 518026, P. R. China.
| | - Ke Ma
- Center for Child Care and Mental Health (CCCMH) Shenzhen Children's Hospital, Shenzhen 518026, P. R. China.
| | - Miaomiao Kang
- Center for AIE Research, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering Shenzhen University, Shenzhen 518060, P. R. China.
| | - Dingyuan Yan
- Center for AIE Research, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering Shenzhen University, Shenzhen 518060, P. R. China.
| | - Niu Niu
- Center for AIE Research, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering Shenzhen University, Shenzhen 518060, P. R. China.
| | - Saisai Yan
- Center for AIE Research, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering Shenzhen University, Shenzhen 518060, P. R. China.
| | - Panpan Sun
- Center for AIE Research, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering Shenzhen University, Shenzhen 518060, P. R. China.
| | - Luzhi Zhang
- Center for Child Care and Mental Health (CCCMH) Shenzhen Children's Hospital, Shenzhen 518026, P. R. China.
| | - Lijie Sun
- Center for Child Care and Mental Health (CCCMH) Shenzhen Children's Hospital, Shenzhen 518026, P. R. China.
| | - Dong Wang
- Center for AIE Research, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering Shenzhen University, Shenzhen 518060, P. R. China.
| | - Hui Tan
- Center for Child Care and Mental Health (CCCMH) Shenzhen Children's Hospital, Shenzhen 518026, P. R. China.
| | - Ben Zhong Tang
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong Shenzhen, (CUHK-Shenzhen), Guangdong 518172, China.
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Maksim R, Buczyńska A, Sidorkiewicz I, Krętowski AJ, Sierko E. Imaging and Metabolic Diagnostic Methods in the Stage Assessment of Rectal Cancer. Cancers (Basel) 2024; 16:2553. [PMID: 39061192 PMCID: PMC11275086 DOI: 10.3390/cancers16142553] [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: 06/10/2024] [Revised: 07/04/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
Rectal cancer (RC) is a prevalent malignancy with significant morbidity and mortality rates. The accurate staging of RC is crucial for optimal treatment planning and patient outcomes. This review aims to summarize the current literature on imaging and metabolic diagnostic methods used in the stage assessment of RC. Various imaging modalities play a pivotal role in the initial evaluation and staging of RC. These include magnetic resonance imaging (MRI), computed tomography (CT), and endorectal ultrasound (ERUS). MRI has emerged as the gold standard for local staging due to its superior soft tissue resolution and ability to assess tumor invasion depth, lymph node involvement, and the presence of extramural vascular invasion. CT imaging provides valuable information about distant metastases and helps determine the feasibility of surgical resection. ERUS aids in assessing tumor depth, perirectal lymph nodes, and sphincter involvement. Understanding the strengths and limitations of each diagnostic modality is essential for accurate staging and treatment decisions in RC. Furthermore, the integration of multiple imaging and metabolic methods, such as PET/CT or PET/MRI, can enhance diagnostic accuracy and provide valuable prognostic information. Thus, a literature review was conducted to investigate and assess the effectiveness and accuracy of diagnostic methods, both imaging and metabolic, in the stage assessment of RC.
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Affiliation(s)
- Rafał Maksim
- Department of Radiotherapy, Maria Skłodowska-Curie Białystok Oncology Center, 15-027 Bialystok, Poland;
| | - Angelika Buczyńska
- Clinical Research Centre, Medical University of Bialystok, 15-276 Bialystok, Poland; (A.B.); (A.J.K.)
| | - Iwona Sidorkiewicz
- Clinical Research Support Centre, Medical University of Bialystok, 15-276 Bialystok, Poland;
| | - Adam Jacek Krętowski
- Clinical Research Centre, Medical University of Bialystok, 15-276 Bialystok, Poland; (A.B.); (A.J.K.)
- Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, 15-276 Bialystok, Poland
| | - Ewa Sierko
- Department of Oncology, Medical University of Bialystok, 15-276 Bialystok, Poland
- Department of Radiotherapy I, Maria Sklodowska-Curie Bialystok Oncology Centre, 15-027 Bialystok, Poland
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Hayman CV, Vyas D. Screening colonoscopy: The present and the future. World J Gastroenterol 2021; 27:233-239. [PMID: 33519138 PMCID: PMC7814366 DOI: 10.3748/wjg.v27.i3.233] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/10/2020] [Accepted: 12/11/2020] [Indexed: 02/06/2023] Open
Abstract
In the United States, colorectal cancer (CRC) is the second leading cause of mortality in men and women. We are now seeing an increasing number of patients with advanced-stage diagnosis and mortality from colorectal cancer before 50 years of age, which requires earlier screening. With the increasing need for CRC screening through colonoscopy, and thus endoscopists, easier and simpler techniques are needed to train proficient endoscopists. The most widely used approach by endoscopists is air insufflation colonoscopy, where air distends the colon to allow visualization of the colonic mucosa. This technique is un-comfortable for patients and requires an anesthetist to administer sedation. In addition, patients commonly complain about discomfort post-op as air escapes into the small bowel and cannot be adequately removed. Current research into the use of water insufflation colonoscopies has proved promising in reducing the need for sedation, decreasing discomfort, and increasing the visibility of the colonic mucosa. Future direction into water insufflation colonoscopies which have shown to be simpler and easier to teach may increase the number of proficient endoscopists in training to serve our aging population.
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Affiliation(s)
- Chelsea V Hayman
- College of Medicine, California Northstate University, Elk Grove, CA 95757, United States
| | - Dinesh Vyas
- College of Medicine, California Northstate University, Elk Grove, CA 95757, United States
- Department of Surgery, San Joaquin General Hospital, French Camp, CA 95231, United States
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Chen J, Ning C, Zhou Z, Yu P, Zhu Y, Tan G, Mao C. Nanomaterials as photothermal therapeutic agents. PROGRESS IN MATERIALS SCIENCE 2019; 99:1-26. [PMID: 30568319 PMCID: PMC6295417 DOI: 10.1016/j.pmatsci.2018.07.005] [Citation(s) in RCA: 420] [Impact Index Per Article: 70.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Curing cancer has been one of the greatest conundrums in the modern medical field. To reduce side-effects associated with the traditional cancer therapy such as radiotherapy and chemotherapy, photothermal therapy (PTT) has been recognized as one of the most promising treatments for cancer over recent years. PTT relies on ablation agents such as nanomaterials with a photothermal effect, for converting light into heat. In this way, elevated temperature could kill cancer cells while avoiding significant side effects on normal cells. This theory works because normal cells have a higher heat tolerance than cancer cells. Thus, nanomaterials with photothermal effects have attracted enormous attention due to their selectivity and non-invasive attributes. This review article summarizes the current status of employing nanomaterials with photothermal effects for anti-cancer treatment. Mechanisms of the photothermal effect and various factors affecting photothermal performance will be discussed. Efficient and selective PTT is believed to play an increasingly prominent role in cancer treatment. Moreover, merging PTT with other methods of cancer therapies is also discussed as a future trend.
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Affiliation(s)
- Junqi Chen
- College of Material Science and Engineering, South China University of Technology, Guangzhou 510641, China
- Guangdong Key Laboratory for Biomedical Engineering, Guangzhou 510641, China
| | - Chengyun Ning
- College of Material Science and Engineering, South China University of Technology, Guangzhou 510641, China
- Guangdong Key Laboratory for Biomedical Engineering, Guangzhou 510641, China
| | - Zhengnan Zhou
- College of Material Science and Engineering, South China University of Technology, Guangzhou 510641, China
- Guangdong Key Laboratory for Biomedical Engineering, Guangzhou 510641, China
| | - Peng Yu
- College of Material Science and Engineering, South China University of Technology, Guangzhou 510641, China
- Guangdong Key Laboratory for Biomedical Engineering, Guangzhou 510641, China
| | - Ye Zhu
- Department of Chemistry & Biochemistry, Stephenson Life Sciences Research Center, Institute for Biomedical Engineering, Science and Technology, University of Oklahoma, Oklahoma, United States
| | - Guoxin Tan
- Institute of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Chuanbin Mao
- Department of Chemistry & Biochemistry, Stephenson Life Sciences Research Center, Institute for Biomedical Engineering, Science and Technology, University of Oklahoma, Oklahoma, United States
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
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Bianchi F, Ciuti G, Koulaouzidis A, Arezzo A, Stoyanov D, Schostek S, Oddo CM, Menciassi A, Dario P. An innovative robotic platform for magnetically-driven painless colonoscopy. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:421. [PMID: 29201873 DOI: 10.21037/atm.2017.09.15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Colorectal cancer (CRC) represents a significant medical threat with a dramatic impact on the healthcare system with around 1.3 million patients worldwide, causing more than 700 thousand deaths annually. A key-aspect to successful and cost-effective disease management is represented by the early detection of CRC at asymptomatic stage. For this reason, population screening is highly recommended for patients older than 50 years or at high risk for familiarity. Currently, the standard endoscopic techniques do not meet this need. In recent years, innovative endoscopic robotic techniques and active locomotion devices have been developed as alternatives to conventional colonoscopy. The magnetically-driven robotic platform, presented by the authors, is conceived to perform less invasive and more comfortable colonoscopy with the aim to promote screening campaigns for detection of early colorectal neoplasm.
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Affiliation(s)
- Federico Bianchi
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Gastone Ciuti
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Alberto Arezzo
- Department of Surgical Sciences, University of Torino, Torino, Italy
| | - Danail Stoyanov
- Centre for Medical Image Computing and the Department of Computer Science, University College London, London, UK
| | | | | | | | - Paolo Dario
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
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Power SP, Moloney F, Twomey M, James K, O’Connor OJ, Maher MM. Computed tomography and patient risk: Facts, perceptions and uncertainties. World J Radiol 2016; 8:902-915. [PMID: 28070242 PMCID: PMC5183924 DOI: 10.4329/wjr.v8.i12.902] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/29/2016] [Accepted: 10/24/2016] [Indexed: 02/06/2023] Open
Abstract
Since its introduction in the 1970s, computed tomography (CT) has revolutionized diagnostic decision-making. One of the major concerns associated with the widespread use of CT is the associated increased radiation exposure incurred by patients. The link between ionizing radiation and the subsequent development of neoplasia has been largely based on extrapolating data from studies of survivors of the atomic bombs dropped in Japan in 1945 and on assessments of the increased relative risk of neoplasia in those occupationally exposed to radiation within the nuclear industry. However, the association between exposure to low-dose radiation from diagnostic imaging examinations and oncogenesis remains unclear. With improved technology, significant advances have already been achieved with regards to radiation dose reduction. There are several dose optimization strategies available that may be readily employed including omitting unnecessary images at the ends of acquired series, minimizing the number of phases acquired, and the use of automated exposure control as opposed to fixed tube current techniques. In addition, new image reconstruction techniques that reduce radiation dose have been developed in recent years with promising results. These techniques use iterative reconstruction algorithms to attain diagnostic quality images with reduced image noise at lower radiation doses.
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Bressan AK, Ouellet JF, Tanyingoh D, Dixon E, Kaplan GG, Grondin SC, Myers RP, Mohamed R, Ball CG. Temporal trends in the use of diagnostic imaging for inpatients with pancreatic conditions: How much ionizing radiation are we using? Can J Surg 2016; 59:188-96. [PMID: 27240285 DOI: 10.1503/cjs.006015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Low-dose ionizing radiation from medical imaging has been indirectly linked with subsequent cancer and increased costs. Computed tomography (CT) is the gold standard for defining pancreatic anatomy and complications. Our primary goal was to identify the temporal trends associated with diagnostic imaging for inpatients with pancreatic diseases. METHODS Data were extracted from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS) database from 2000 to 2008. Pancreas-related ICD-9 diagnostic codes were matched to all relevant imaging modalities. RESULTS Between 2000 and 2008, a significant increase in admissions (p < 0.001), but decrease in overall imaging procedures (p = 0.032), for all pancreatic disorders was observed. This was primarily a result of a reduction in the number of CT and endoscopic retrograde cholangiopancreatography examinations (i.e., reduced radiation exposure, p = 0.008). A concurrent increase in the number of inpatient magnetic resonance cholangiopancreatography/magnetic resonance imaging performed was observed (p = 0.040). Intraoperative cholangiography and CT remained the dominant imaging modality of choice overall (p = 0.027). CONCLUSION Inpatients with pancreatic diseases often require diagnostic imaging during their stay. This results in substantial exposure to ionizing radiation. The observed decrease in the use of CT may reflect an improved awareness of potential stochastic risks.
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Affiliation(s)
- Alexsander K Bressan
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Jean-Francois Ouellet
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Divine Tanyingoh
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Elijah Dixon
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Gilaad G Kaplan
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Sean C Grondin
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Robert P Myers
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Rachid Mohamed
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
| | - Chad G Ball
- From the Department of Surgery, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Bressan, Ouellet, Tanyingoh, Dixon, Grondin, Ball); and the Department of Medicine, University of Calgary, Foothills Medical Centre, Calgary, Alta. (Kaplan, Tanyingoh, Myers, Mohamed)
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Ball CG, Correa-Gallego C, Howard TJ, Zyromski NJ, House MG, Pitt HA, Nakeeb A, Schmidt CM, Akisik F, Lillemoe KD. Radiation dose from computed tomography in patients with necrotizing pancreatitis: how much is too much? J Gastrointest Surg 2010; 14:1529-35. [PMID: 20824381 DOI: 10.1007/s11605-010-1314-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 08/09/2010] [Indexed: 01/31/2023]
Abstract
OBJECTIVES Low-dose ionizing radiation from medical imaging has been indirectly linked with subsequent cancer. Computed tomography (CT) is the gold standard for defining pancreatic necrosis. The primary goal was to identify the frequency and effective radiation dose of CT imaging for patients with necrotizing pancreatitis. METHODS All patients with necrotizing pancreatitis (2003-2007) were retrospectively analyzed for CT-related radiation exposure. RESULTS Necrosis was identified in 18% (238/1290) of patients with acute pancreatitis (mean age = 53 years; hospital/ICU length of stay = 23/7 days; mortality = 9%). A median of five CTs/patient [interquartile range (IQR) = 4] were performed during a median 2.6-month interval. The average effective dose was 40 mSv per patient (equivalent to 2,000 chest X-rays; 13.2 years of background radiation; one out of 250 increased risk of fatal cancer). The actual effective dose was 63 mSv considering various scanner technologies. CTs were infrequently (20%) followed by direct intervention (199 interventional radiology, 118 operative, 12 endoscopic) (median = 1; IQR = 2). Magnetic resonance imaging did not have a CT-sparing effect. Mean direct hospital costs increased linearly with CT number (R = 0.7). CONCLUSIONS The effective radiation dose received by patients with necrotizing pancreatitis is significant. Management changes infrequently follow CT imaging. The ubiquitous use of CT in necrotizing pancreatitis raises substantial public health concerns and mandates a careful reassessment of its utility.
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Affiliation(s)
- Chad G Ball
- Department of Surgery, Indiana University, 545 Barnhill Drive, Emerson Hall 203, Indianapolis, IN 46202, USA.
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A simple image processing approach for electronic cleansing in computed tomographic colonography. Biomed Imaging Interv J 2009; 5:e28. [PMID: 21611057 PMCID: PMC3097783 DOI: 10.2349/biij.5.3.e28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 05/01/2009] [Indexed: 12/12/2022] Open
Abstract
The prevalence of colon cancer has seen strong demand in screening for colorectal neoplasia, and this has drawn considerable attention to the technological advances in Computed Tomographic Colonography (CTC). With the assistance of an oral contrast agent, an imaging technique known as Electronic Cleansing (EC), can affect virtual cleaning of the computed tomography (CT) images, to remove fecal material that is tagged by the agent. Technical problems can arise with electronic cleansing however, when the air lumen causes distortions to the tagged regions which result in partial volume effects. Combining the simple image arithmetic of an electronic cleansing algorithm, with a vertical motion filter at the fluid level of the bowel, artifacts such as those caused by an air lumen are eliminated. Essentially, the filter becomes a vector for that carries the measurement of vertical motion to neutralise the artifact that is causing partial volume effects. Results demonstrate that despite its simplicity, this technique offers accuracy and is able to successfully maintain the normal intra-colonic structure, while supporting digital leaning of tagged residual material appearing on the colon wall.
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Liedenbaum MH, Venema HW, Stoker J. Radiation dose in CT colonography--trends in time and differences between daily practice and screening protocols. Eur Radiol 2008; 18:2222-30. [PMID: 18491095 DOI: 10.1007/s00330-008-0994-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 02/25/2008] [Accepted: 02/29/2008] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to evaluate the currently used effective doses in CT colonography (CTC) and to search for trends in time. A Pubmed search for articles and a search for congress abstracts concerning CTC was performed. Research institutions were sent a CTC dose questionnaire concerning the type of CT system employed and the CT parameters used. With the ImPACT CT Dosimetry Spreadsheet effective doses were calculated. Of 83 institutions, 34 returned a complete questionnaire; 21 (62%) used 64-detector row CT and 17 (50%) used dose modulation. The median effective dose per institution was 5.7 mSv (2.8 mSv supine; 2.5 mSv prone) for screening protocols and 9.1 mSv (5.2 and 3.0 mSv, respectively) for daily practice protocols (p<0.05). Doses did not differ significantly between CT machines with different numbers of detector rows. In 17 institutions incorporated in a study in 2004 as well, the median dose for daily practice protocols changed from 11 mSv in 2004 to 9.7 mSv now (n.s.). Median effective dose for CTC is significantly lower for screening than for daily practice protocols. Although the number of CTC protocols with dose modulation increased substantially since 2004, no significant decrease in effective dose was found.
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Affiliation(s)
- M H Liedenbaum
- Department of Radiology, Academic Medical Center, University of Amsterdam, Postbus 22660, 1100 DD Amsterdam, The Netherlands.
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Affiliation(s)
- David J Brenner
- Center for Radiological Research, Columbia University Medical Center, New York, NY 10032, USA.
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