期刊名称：Journal of Radiation Research and Applied Sciences
印刷版ISSN：1687-8507
出版年度：2021
卷号：14
期号：1
页码：159-170
DOI：10.1080/16878507.2021.1888243
出版社：Elsevier B.V.
摘要：This study aims to evaluate the dose accuracy of synthetic CT based bulk relative electron density (rED) assignment for application in 1.5 T MR-Linac for cervical carcinoma patients. Five cervix patients previously treated on 1.5 T MR-Linac were retrospectively investigated. Two sCTs were generated assigning bulk values to the different bone regions: the sCT FH was generated with delineation of femoral head, and the sCT AB was generated with the delineation of all the bone regions. The rest tissue of the patient data was set to mean rED values of the region of interests in CT. The same treatment plan based on original CT was recalculated or reoptimized on the sCT FH and sCT AB . The result of gamma analysis showed that gamma passing rate of treatment plans based on sCT AB was higher than plans based on sCT FH . And the differences of dose volume parameters between plans on sCTs and original CT showed that the differences for plan based on sCT AB were much smaller than sCT FH . The sCT generated with bulk rED assignment approach guarantees an acceptable level of dose accuracy for cervix carcinoma patients with 1.5 T MR-Linac. The accuracy can be improved by using complete delineation of the pelvic bone regions.
关键词：MR-guided radiotherapy MR-Linac synthetic CT bulk ED assignment cervical carcinoma
