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

Autor: Sonal Varshney, Lalit Kumar, Umesh K. Dwivedi, Pradeep Narayan
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Journal of Medical Physics, Vol 49, Iss 3, Pp 480-486 (2024)
Druh dokumentu: article
ISSN: 0971-6203
1998-3913
DOI: 10.4103/jmp.jmp_16_24
Popis: 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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