Abstract

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Title:: Dosimetric comparison among split-field, fixed-jaw and rotating multi-leaf collimator in the radiotherapy of gastric carcinoma

Author(s):: JIANG Dazhen; LIU Hui; DAI Jing; ZHOU Fuxiang; XIE Conghua; WANG Xiaoyong; Department of Radiation Oncology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China

Keywords:: ; Keywords: gastric carcinoma; multi-leaf collimator; fixed-jaw plan; split-field plan; intensity-modulated radiotherapy

Abstract:: Abstract: Objective To compare the dosimetric differences among split-field, fixed-jaw and rotating multi-leaf collimator (RMLC) used in intensity-modulated radiotherapy of gastric carcinoma for providing reference for the selection of treatment strategy. Methods Ten patients with gastric carcinoma was enrolled in this study, and 3 plans, namely fixed-jaw plan (9-field), split-field plan and RMLC plan, were designed for each patient. Several dosimetric parameters, including monitor units, the conformity index, homogeneity index, Dmax, Dmean, V45 of target areas, and the V5, V10, V20, V30, V40, V45, Dmax, Dmean of the body, liver, small intestine, spinal cord and kidneys were compared. Results All 3 plans met clinical requirements. The V5, V10, V20 and V30 of the body in fixed-jaw plan were significantly lower than those in split-field plan and RMLC plan, and meanwhile, there were some decreases in the low-dose volume of the kidney, liver and small intestine, with statistical differences. The Dmax of the body (planning target volume) in split-field plan was lower than that in fixed-jaw plan and RMLC plan, with statistical differences. Conclusion Compared with split-field plan and RMLC plan, fixed-jaw plan achieves a better organs-at-risk protection and reduces low-dose volume.