调强放疗与容积弧形调强放疗技术对乳腺癌患者分次内位移误差的影响研究OACSTPCD

Objective To compare the intra-fractional errors of breast cancer patients after breast-conserving surgery when applying intensity modulated radiation therapy(IMRT)and volumetric modulated arc therapy(VMAT),and to investigate whether adding an abdominal thermoplastic during position fixation can reduce intra-fractional errors or not.Methods A total of 60 female patients who received radiation therapy after breast conserving surgery from October 2022 to March 2023 were selected as the study objects,and randomly divided into IMRT group(n=30)and VMAT group(n=30)according to different treatment techniques.A total of 15 patients in each of the 2 groups were randomly selected to add thermoplastic film to the abdomen when the body position was fixed,and were divided into the conventional group and the peritoneal group according to whether the attachment was fixed with thermoplastic film.With the planned target volume as the main registration area,the intra-fractional errors of IMRT group and VMAT group,conventional group and peritoneal group were compared by the cone-beam CT gray scale registration algorithm.Results According to independent sample t-test,the treatment duration of VMAT group was significantly smaller than that of IMRT group[(4.17±0.86)min vs.(9.69±1.13)min],and the difference was statistically significant(P<0.05).According to Wilcoxon rank sum test,the intra-fractional errors in the left and right(x),head and foot(y),anterior-posterior(z)directions in VMAT group were smaller than those in IMRT group,with statistical significance(P<0.05).According to independent sample t-test,there was no significant difference in the treatment duration between the conventional group and the peritoneal group(P>0.05).According to Wilcoxon rank sum test,the intra-fractional error in x and y directions in peritoneal group was smaller than that in conventional group,the difference was statistically significant(P<0.05),but there was no statistically significant difference in z direction(P>0.05).Conclusion The application of VMAT technique results in smaller intra-fractional errors compared to IMRT for breast cancer patients after breast-conserving surgery.The addition of abdominal thermoplastic film in the body position fixation can reduce the intra-fractionated error in x and y directions.