Open AccessDosimetric effects related to collimator angle optimization in intensity‐modulated radiotherapy planning for gastric cancer
Author(s) -
Su Huanfan,
Zhao Man,
Zhang Jun,
Dai Zhitao
Publication year - 2021
Publication title -
precision radiation oncology
Language(s) - English
Resource type - Journals
ISSN - 2398-7324
DOI - 10.1002/pro6.1108
Subject(s) - collimator , nuclear medicine , dosimetry , radiation therapy , radiation treatment planning , intensity (physics) , cancer , radiation , medicine , optics , physics , radiology
Abstract Objective To investigate the dosimetric impact of different collimator angle optimization methods in intensity‐modulated radiotherapy of gastric cancer. Methods A total of 10 gastric cases were retrospectively selected in this study. Three sets of plans were generated with different collimator angle optimization: setting the collimator angle to 0° (CL 0 ), applying Eclipse automatic collimator angle optimization (CL A ), and setting the collimator angle corresponding to the minimum X‐jaw gap (CL X ). Different dosimetric metrics were applied in comparison of the target volume and normal tissues. Delivery efficiency was accessed in terms of control points, split fields, monitor units, and treatment time. All plans were verified using the 2‐D array MatriXX, and the γ‐index analysis was carried out by using different criteria. Results There was no significant difference in dosimetric comparison of planning target volume and organs at risk. Compared with CL 0 , Both CL A and CL X can significantly reduce control points, split fields, and monitor units, except that CL A increased treatment time. For dose verification, the γ passing rate showed a tendency of CLx > CL A > CL 0 . Conclusion For intensity‐modulated radiotherapy for gastric cancer, CL A and CL X can obtain comparable dosimetry distribution in respect to CL 0. However, CL X can significantly increase the dose delivery efficiency and verification passing rates. It was suggested that CLx was beneficial in intensity‐modulated radiotherapy for gastric cancer.