|تعداد مشاهده مقاله||12,794,654|
|تعداد دریافت فایل اصل مقاله||6,126,815|
Evaluation of Interfractional Setup Uncertainties and Calculation of Adequate CTV-PTV Margin for Head and Neck Radiotherapy using Electronic Portal Imaging Device
|Journal of Biomedical Physics and Engineering|
|مقالات آماده انتشار، اصلاح شده برای چاپ، انتشار آنلاین از تاریخ 03 مهر 1402 اصل مقاله (1.12 M)|
|نوع مقاله: Original Research|
|شناسه دیجیتال (DOI): 10.31661/jbpe.v0i0.2211-1565|
|Elham Ahmadi1؛ Azam Eskandari1؛ Mohammad Mohammadi2؛ Maryam Naji3؛ Shahrokh Naseri1، 4؛ Hamid Gholamhosseinian* 1، 4|
|1Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran|
|2Royal Adelaide Hospital, Department of Medical Physics, Adelaide, Australia|
|3Department of Radiation Oncology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran|
|4Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran|
|Background: The evaluation of treatment-associated errors is important in the radiotherapy process, particularly those resulting related to patient setup.|
Objective: This research aimed to assess the interfractional setup errors and determine the Clinical Target Volume to Planning Target Volume (CTV to PTV) margin in patients undergoing 3-Dimensional Conformal Radiation Therapy (3DCRT) for head and neck cancer by means of electronic portal imaging device.
Material and Methods: In this analytical study, 300 portal images were acquired from 50 patients undergoing 3DCRT for head and neck cancer. Using the portal images of Lateral (LAT) and Antero-Posterior (AP) fields, population systematic (∑) and random (σ) errors were obtained in the lateral, longitudinal, and vertical directions. Finally, based on the International Commission on Radiation Units and Measurements (ICRU) Report 62’s, Stroom’s and Van Herk’s methods, Planning target volume margins were determined.
Results: The translational shift ranges were 0-8.1 mm in the ML, 0-9 mm in the SI (AP), 0-8.8 mm in the SI (LAT), and 0-10 mm in the AP directions. The population systematic and random errors were respectively 3.230, 2.753, and 2.997 mm, and 1.476, 1.853, and 1.715 mm in X, Y, and Z directions. The calculated PTV margins using the ICRU-62, Stroom’s, and Van Herk’s formulae were ranging from 3.236-3.551, 6.605-7.493, and 7.932-9.108 mm, respectively.
Conclusion: A PTV margin of 7.5-9.5 mm seems safe for ensuring adequate treatment volume coverage. In addition, the EPID is an effective equipment for verifying patient positioning and reducing treatment setup errors.
|Head and Neck Cancer؛ Radiotherapy؛ Patient Positioning؛ Setup Errors؛ Systematic Error|
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