自动勾画技术在全乳内侧瘤床同步推量中的应用

AClinical Application of automatic delineation in whole breast radiotherapy with simultaneous integrated boost to the medial tumor beds

目的 通过比较自动勾画(auto-segmentation, AS)与人工勾画(manually segmented, MS)结构的几何、剂量和工作时间差异,以评估自动勾画在全乳放疗内侧瘤床同步推量中应用的可行性与有效性。方法 选取遵义市第一人民医院收治的左侧乳腺癌保乳术后行单纯全乳大分割放疗内侧瘤床同期推量患者30例,采用戴斯系数(DSC)、95%豪斯多夫距离(95HD)评估软件AccuContour自动勾画的全乳计划靶区(PTV)和心肺结构几何差异;然后比较两组对应放疗计划PlanA和PlanM靶区和心肺剂量学差异;最后比较两组花费时间。结果 自动勾画实现了肿瘤计划靶区(PGTV)、PTV、肺和心脏DSC分别为0.94(0.91,0.96)、0.88(0.86,0.91)、0.98(0.97,0.98)和0.94(0.93,0.95),95HD(cm)分别为0.25(0.20,0.33)、0.99(0.56,1.20)、0.29(0.25,0.35)和0.50(0.50,0.59);剂量学结果显示AS组PGTV和PTV的V95、D95和Dmean明显低于人工勾画组(P <0.05),而左肺的V20和MLD明显增大(P <0.05),心脏剂量参数差异无统计学意义;两组PGTV和心肺的剂量参数平均绝对差异小于1 Gy/1%;工作效率上,自动勾画组中能在2 d内完成对超过70%的患者勾画和计划,时间大幅缩短。结论 与人工勾画相比,在全乳放疗内侧瘤床推量中自动勾画靶区和心肺的几何和剂量参数差异较小。如果在计划优化前对PTV人工略微修改,或可使工作效率显著提高。

Objective To assess the viability and efficacy of employing automated segmentation for whole breast radiotherapy with simultaneous integrated boost to the medial tumor beds,a comparative analysis was conducted on the disparities in geometry,dosimetry,and working time between the auto-segmentation(AS)and manual segmentation(MS)groups.Methods A total of 30 patients with early breast cancer,who had undergone conserving surgery and received hypofractionated radiotherapy with a boost to the medial tumor bed,were enrolled from the First People's Hospital of Zunyi.AccuContour software was used in the AS group to obtain the whole breast planning target volume and cardiopulmonary structure.Geometric differences between AS and MS groups were assessed using Dice similarity coefficient(DSC)and 95%Hausdorff distance(95HD).Subsequently,a comparison was made between the two groups regarding target and cardiopulmonary dosimetry for PlanA and PlanM.Additionally,the time spent by each group was also compared.Results The DSC of PGTV,PTV,lung,and heart were 0.94(0.91,0.96),0.88(0.86,0.91),0.98(0.97,0.98)and 0.94(0.93,0.95),respectively.And the 95 HD(cm)were 0.25(0.20,0.33),0.99(0.56,1.20),0.29(0.25,0.35)and 0.50(0.50,0.59)respectively.The dosimetric results showed that the V95,D95,and Dmean of PGTV and PTV in the AS group were significantly lower than those in the MS group(P<0.05);while the V20 and MLD of the left lung were significantly higher(P<0.05).No significant difference was observed in cardiac dose between the two groups.The mean absolute differences of PGTV and cardiopulmonary dose parameters between the two groups were less than 1 Gy/1%,respec-tively.In terms of work efficiency,the AS approach substantially reduced contouring and planning time with over 70%of cases approved within two days.Conclusions The differences in geometric and dosimetric parameters between the auto-segmentation and manual segmentation groups were found to be negligible for whole breast radiotherapy with medial tumor bed boost patients.It is recommended that the PTV be manually modified prior to plan optimiza-tion,leading to a significant improvement in work efficiency.