Feasibility Study of Vertical Multileaf Collimator for Determination of Irradiation Size.
- Author:
Chang Yeol LEE
1
;
Kihong SON
;
Sang Hun SHIN
;
Seungwoo PARK
;
Donghan LEE
;
Haijo JUNG
;
Munsik CHOI
;
Won Young OH
;
Kum Bae KIM
;
Gwang Mo YANG
;
Young Hoon JI
Author Information
1. Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul, Korea.
- Publication Type:Original Article
- Keywords:
Vertical Multileaf Collimator;
Lead block;
Penumbra size
- MeSH:
Axis, Cervical Vertebra;
Feasibility Studies;
Glass
- From:Korean Journal of Medical Physics
2011;22(1):3-11
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The purpose of this study was to evaluate feasibility of Vertical Multileaf Collimator for determination of irradiation size using Vertical Multileaf Collimator and lead block to determine 4 different irradiation shape in case of Co-60 gamma-ray and 6 MV X-ray. We chose ion chamber, glass dosimeter and EBT chromic film to compare with Vertical Multileaf Collimator results and lead block results. In case of Co-60 gamma-ray and 6 MV X-ray, the central axis point dose normalized at reference field of lead block with ion chamber results for Vertical Multileaf Collimator were estimated higher than lead block about 5.1%, 4.2%. In case of Co-60 gamma-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 2.2%, 7.8%, 7.2%, 4.0% for reference, circle, triangle, cross field, respectively. In case of 6 MV X-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 6.7%, 6.2%, 3.8%, 6.2% for reference, circle, triangle, cross field, respectively. The results of EBT chromic film, Vertical Multileaf Collimator of penumbra size for all irradiation shape was smaller than lead block of those size that 2.0~3.5 mm for Co-60 gamma-ray, 0.5~1.0 mm for 6 MV X-ray. The results from this study, radiation treatment volume that results in shielding block can be minimized. In addition, during radiation treatment for 2, 3-dimensional radiation therapy using a Vertical Multileaf Collimator of this survey can be used to determine variety of irradiation fields.
