Dosimetric comparison of anal sphincter and its substructures with different radiotherapy techniques for rectal cancer
10.19745/j.1003-8868.2024155
- VernacularTitle:直肠癌不同放疗技术下肛门括约肌及其亚结构的剂量学比较
- Author:
Geng LI
1
;
Fei DENG
;
Yong-Jun LI
;
Da-Li FENG
;
Xin LI
;
Zhuo KONG
;
Ji-Ping WANG
;
Min ZOU
Author Information
1. 三峡大学附属第二人民医院/宜昌市第二人民医院肿瘤放射治疗中心,湖北宜昌 443000
- Keywords:
rectal cancer;
volume modulated arc therapy;
intensity modulated radiation therapy;
anal sphincter;
dosimetry
- From:
Chinese Medical Equipment Journal
2024;45(8):63-67
- CountryChina
- Language:Chinese
-
Abstract:
Objective To compare the dosimetric effects of volume modulated arc therapy(VMAT)and intensity modulated radiation therapy(I M RT)on the anal sphincter(AS)and its sub-structures in neoadjuvant radiotherapy for rectal cancer to facilitate the selection of radiotherapy techniques.Methods Fifty rectal cancer patients receiving neoadjuvant radiotherapy were selected,and 2 types of radiotherapy plans,including coplanar double full-arc VMAT and coplanar seven-field homo-geneous IMRT,were designed based on the CT images of the patients,respectively.Under the premise of ensuring that the irradiated doses to the target area and the major organs at risk reached the standard and met the clinical requirements,AS and its substructures were added as the organs at risk for dosimetric evaluation.The absolute dose parameters and relative dose parameters of AS and its substructures were counted by dose-volume histograms.Statistical analysis was performed using IBM SPSS 22.0 software.Results The VMAT plan had the relative dose parameters V20,V30,and V40 of AS and its substructures lower those of the IMRT plan,the differences were statistically significant(P＜0.05),while the differences in V5 and V 10 were not statistically significant(P＞0.05).The VMAT plan had the absolute dose parameterDmeanlower while the D2％slightly higher than those of the IMRT plan,the differences were statistically significant(P＜0.05).The difference in D98％between the two plans was not statistically significant(P＞0.05).Conclusion During rectal cancer radiotherapy VMAT generally behaves better than IMRT in protecting AS and its sub-structures and decreasing injuries of AS and its sub-structures dosimetrically.[Chinese Medical Equipment Journal,2024,45(8):63-67]
