A Study on Radiation Level at the Treatment Plane Due to Induced Activity in Linear Accelerator Head.

IF 0.7 Q4 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Journal of Medical Physics Pub Date : 2024-07-01 Epub Date: 2024-09-21 DOI:10.4103/jmp.jmp_16_24

Sonal Varshney, Lalit Kumar, Umesh K Dwivedi, Pradeep Narayan

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引用次数: 0

Abstract

Background: The induced activity is produced in the target, monitor chamber, flattening filter (FF), collimating jaws, etc., when a high-energy photon beam is utilized for radiation therapy. This may result in add-on exposure to radiation professionals.

Objective: This study aims to measure the radiation level (RL) at the treatment plane due to induced activity in the linear accelerator head.

Materials and methods: In this study, RLs were measured close to the isocenter (I), LINAC head (H), and 0.5 m lateral to the isocenter (L) inside the radiation bunker. The RLs were measured for field sizes (FS) 5 cm × 5 cm, 10 cm × 10 cm, 20 cm × 20 cm, 30 cm × 30 cm, and 40 cm × 40 cm, using 50, 100, 200, 300, 400, 500, and 1000 monitor units (MUs) at above said locations inside the bunker using 10 mega-voltage (MV), 10 MV FF free, and 15 MV radiation beam.

Results: RL increases with an increase in FS and MUs at all mentioned locations inside the bunker, except for 40 cm × 40 cm FS. The present study shows that RL increases with an increase in radiation beam energy, and there was significant RL inside the bunker at the mentioned location, even after the 1 min of high-energy radiation exposure.

Conclusion: Therefore, treatment with a high-energy beam should be scheduled in the later evening of the working day and the jaw should be closed to a minimum before entering the bunker and a sufficient time gap should be followed to minimize the additional exposure due to induced activation in high-energy treatment.

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直线加速器头部诱导活动导致治疗平面辐射水平的研究。

背景：当利用高能光子束进行放射治疗时，靶、监测室、平整过滤器（FF）、准直钳口等处会产生诱导活度。这可能会导致辐射专业人员受到额外的照射：本研究旨在测量直线加速器头部诱导活动导致的治疗平面辐射水平（RL）：在这项研究中，对辐射掩体内靠近等中心（I）、LINAC 头（H）和等中心（L）外侧 0.5 米处的辐射水平进行了测量。使用 50、100、200、300、400、500 和 1000 个监测单元（MUs），使用 10 MV、10 MV FF free 和 15 MV 辐射束，在掩体内的上述位置测量了 5 厘米×5 厘米、10 厘米×10 厘米、20 厘米×20 厘米、30 厘米×30 厘米和 40 厘米×40 厘米的磁场尺寸（FS）：除 40 厘米 × 40 厘米 FS 外，掩体内所有上述位置的 RL 都随着 FS 和 MU 的增加而增加。本研究表明，RL 会随着辐射束能量的增加而增加，即使在高能辐射照射 1 分钟后，沙坑内上述位置的 RL 也会显著增加：因此，高能射线治疗应安排在工作日的傍晚进行，进入掩体前应尽量闭合下颌，并保持足够的时间间隔，以尽量减少高能治疗中诱导活化引起的额外照射。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Medical Physics RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING-

CiteScore

1.10

自引率

11.10%

发文量

审稿时长

30 weeks

期刊介绍： JOURNAL OF MEDICAL PHYSICS is the official journal of Association of Medical Physicists of India (AMPI). The association has been bringing out a quarterly publication since 1976. Till the end of 1993, it was known as Medical Physics Bulletin, which then became Journal of Medical Physics. The main objective of the Journal is to serve as a vehicle of communication to highlight all aspects of the practice of medical radiation physics. The areas covered include all aspects of the application of radiation physics to biological sciences, radiotherapy, radiodiagnosis, nuclear medicine, dosimetry and radiation protection. Papers / manuscripts dealing with the aspects of physics related to cancer therapy / radiobiology also fall within the scope of the journal.