基于环形加速器的RapidPlan模块在宫颈癌容积调强放疗中的研究

The application of the RapidPlan module based on O-ring accelerator in volumetric modulated arc therapy for cervical cancer

目的研究基于Halcyon 2.0环形医用直线加速器的RapidPlan模块在宫颈癌术后容积旋转调强(VMAT)计划设计的临床可行性及优势。方法从数据库中选取98例临床宫颈癌病例,基于Halcyon 2.0设计VMAT人工放疗计划,导入到RapidPlan模块,训练得到优度较高的预测模型。另选取20例宫颈癌术后患者作为验证集,比较其人工计划与RapidPlan自动生成计划在剂量学、计划一致性、计划执行效率之间的差异。结果RapidPlan自动计划能够获得与人工计划质量相当的靶区和危及器官剂量分布。对股骨头的保护略逊于人工计划,对脊髓的保护优于人工计划,两者差异具有统计学意义(t=4.71,P<0.001)。RapidPlan计划MU平均值为687.46 MU,较人工计划的平均值815.34 MU低,两者差异具有统计学意义(t=6.09,P<0.05)。Portal Dosimetry验证1 mm/1%的γ通过率RapidPlan的平均值为89.48%,人工计划为88.22%,差异具有统计学意义(t=3.35,P<0.05)。结论基于Halcyon 2.0平台的RapidPlan自动计划可以满足宫颈癌VMAT计划的临床需求,且具备一定优势。

Objective To study the clinical feasibility and advantages of the RapidPlan module based on Halcyon 2.0 ring medical linear accelerator in the design of volumetric modulated arc therapy(VMAT)plans after cervical cancer surgery.Methods The data of 98 clinical cervical cancer cases were selected from the database,and VMAT artificial radiotherapy plans were designed based on Halcyon 2.0.Then,the designed plans were imported into the RapidPlan module to train the module for a prediction model with high goodness of fit.Another 20 patients after cervical cancer surgery were selected as the validation set to compare the differences in dosimetry,plan consistency,and plan execution efficiency between the manual plans and RapidPlan automatic plans.Results The RapidPlan automatic plans could obtain dose distribution of target volume and organs at risk with the same quality as the manual plans.The RapidPlan automatic plans provided slightly inferior protection of the femoral head but superior protection of the spinal cord compared to the manual plans,and the difference was statistically significant(t=4.71,P<0.001).The average MU of the RapidPlan automatic plans was 687.46,which was lower than that of the manual plan(815.34),and the difference was statistically significant(t=6.09,P<0.05).The portal dosimetry(PD)verification revealed that the averageγpassing rate(1 mm/1%)of the RapidPlan automatic plans was 89.48%and that of the manual plans was 88.22%,and the difference was statistically significant(t=3.35,P<0.05).Conclusion RapidPlan automatic plans based on the Halcyon 2.0 platform can meet the clinical needs of the VMAT program for cervical cancer and has certain advantages.