摘要
Abstract
[Objective]To investigate the dosimetric advantages of partial beam avoidance volume rotation intensity modulation in radiotherapy after radical mastectomy for left breast cancer.[Methods]A total of 45 female patients(aged 38 to 68 years,median age 50.1 years)with left breast cancer who underwent modified radical mastectomy and radiotherapy were selected.Beam avoidance group A plans and non-beam avoidance group B plans were designed for each patient to assess the dosimetric differences and machine hops between the two groups of plans in target conformity index and uniformity index,unaffected breast,bilateral lung,and heart.[Results]All patients met the clinical prescribed dose requirements in both groups,D2%of planning target volume(PTV)in group A was significantly higher than that in group B(P=0.001);there were no significant differences in conformity index(CI)and homogeneity index(HI)(1.12±0.04 vs.1.10±0.02,P=0.192;0.13±0.02 vs.0.10±0.03,P=0.426).The mean dose Dmean of the affected lung was similar between the two groups(P=0.549),and V30Gy in group A was significantly higher than that in group B(P<0.05),but V5Gy,V10Gy,and V20Gy were correspondingly reduced compared with group B(P>0.05).Group A significantly reduced Dmean,V5Gy,and V10Gy in the unaffected lung compared with group B,with mean values of 51.5%(P<0.05),36.4%(P<0.05),80.2%(P<0.05),and 70.4%(P<0.05),respectively.The mean values of all assessed parameters of the unaffected breast and heart in group A were lower than those in group B,in which there were significant differences in the mean values of Dmean,V5Gy and cardiac Dmean,V5Gy,and V10Gy in the unaffected breast(P<0.05),and the mean dose to the heart was reduced by 26.3%compared with group B.The mean number of machine units in group A was significantly lower than that in group B(P<0.05).[Conclusion]Multi-arc volumetric rotational intensity modulated radiation therapy with partial beam avoidance can not only fully ensure the target dose,but also effectively reduce the low-dose irradiation of the unaffected lung,unaffected breast and heart in patients undergoing radiotherapy after radical resection of left breast cancer,thereby reducing the risk of radiation-induced second cancer.关键词
容积旋转调强/左乳癌根治术/低剂量体积/部分射束回避Key words
volume rotation intensity modulation/radical mastectomy for left breast cancer/low-dose volume/partial beam avoidance分类
临床医学
