การตรวจสอบปริมาณรังสีของอุปกรณ์ปรับแต่งลำรังสีรูปลิ่มแบบไดนามิกโดยใช้อุปกรณ์รับภาพอิเล็กทรอนิกส์

Saiyo N; Phongphiriyadecha K; Thongsawad S; Changphong P; Khotsawan T; Nilsetkurawat N

Authors

Saiyo N School of Radiological Technology, Faculty of Health Science Technology, Radiation Oncology Department, Chulabhorn Hospital, HRH Princess Chulabhorn College of medical Science, Chulabhorn Royal Academy, Thailand
Phongphiriyadecha K Radiological Technology Division, Faculty of Science, Ramkhamhaeng University, Thailand
Thongsawad S Medical Physics Program, Faculty of Medicine and Public Health, Radiation Oncology Department, Chulabhorn Hospital, HRH Princess Chulabhorn College of medical Science, Chulabhorn Royal Academy, Thailand
Changphong P Radiological Technology Division, Faculty of Science, Ramkhamhaeng University, Thailand
Khotsawan T Radiological Technology Division, Faculty of Science, Ramkhamhaeng University, Thailand
Nilsetkurawat N Radiological Technology Division, Faculty of Science, Ramkhamhaeng University, Thailand

Keywords:

Electronic Portal Imaging Device, Enhance Dynamic Wedges, Beam Profile Verification

Abstract

Objectives The purpose of this study was to verify the 80% enhanced dynamic wedge (EDW) beam profile using an electronic portal imaging device (EPID).

Methods This study investigated symmetric and asymmetric field sizes using a 6 MV photon beam. Verification of the wedge output factor with an 80% beam profile was performed by comparing EPID measurements and treatment planning systems (TPS) calculations in both symmetric and asymmetric field sizes at different wedge angles (15, 30, 45, and 60 degrees).

Results For the symmetric field size, the average difference between the measured and calculated beam profile was less than 2% (range 0.57-1.12%). For the asymmetric field size, the difference was also less than 2% (range 0.3-0.52%).

Conclusion This study indicates that EPID can be used to verify the 80% enhanced dynamic wedge beam profile at different field sizes and wedge angles. The difference in beam profiles was less than 2% which is in accordance with AAPM TG no.142 recommendations.

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