半野技术结合非共面照射技术在乳腺癌胸锁联合照射中的应用  

A Study of Using Half-beam Irradiation Technique Combined with Non-coplanar Irradiation Technique for Breast Cancer Radiotherapy

作　　者：白雪[1] 杜向慧[1] 王升晔[1] 王健[1] 翁邓胡[1] 李剑龙[1] 李浦[1] 陈维军[1] 

机构地区：[1]浙江省肿瘤医院放疗科浙江省胸部肿瘤重点实验室,浙江杭州310022

出　　处：《中国医学物理学杂志》2014年第3期4849-4852,共4页Chinese Journal of Medical Physics

基　　金：浙江省卫生厅A类项目(编号320-67)

摘　　要：目的:介绍一种乳腺癌适形放疗中新的射野衔接技术,以保证乳腺癌患者放疗时锁骨上区域与胸壁区域靶区剂量均匀衔接,并降低治疗计划设计与实施中的操作复杂度。方法:选取一例乳腺癌胸锁联合照射病人,锁骨上靶区采用半野照射技术,胸壁靶区采用非共面切线野照射技术,使上下两组照射野在射野衔接处相切。使用直线加速器6 MV-X射线照射靶区,处方剂量设置为50 Gy包绕95%靶区体积,使用治疗计划系统计算三维剂量分布。结果:半野照射技术结合非共面照射技术应用于乳腺癌胸锁联合照射时,在治疗计划系统上显示处方剂量在射野衔接处均匀衔接,50 Gy处方剂量等剂量线平滑,剂量线未见明显的凹陷和突出现象,无剂量冷热点出现。结论:半野照射技术联合非共面照射技术用于乳腺癌胸锁联合照射,在TPS上演示显示使用该方法能够使相邻射野剂量均匀衔接,适用于胸壁部分靶区头脚方向长度大于20 cm的患者放射治疗需求,且使用方法较传统方法更加简单易行,值得推广,临床实际使用中建议使用验证手段来保障该技术的可靠性。Objective：Introduce a new radiotherapy method for breast cancer, which can get a good dose junction between supr- aclavicular area and breast area and easy to execute. Meth0ds：For the breast cancer which required radiotherapy, half-beam ir- radiation technique was used to the beam group which irradiating the target located at supraclavicular area and non-eoplanar technique was used to the beam group which irradiating the target located at breast area to ensure two beam group tangent on junction boundary. Treatment was delivered by a standard 6 MV X-ray on linear accelerator. PTV was prescribed by 50 Gy to 95% volume. The dose distribution was calculated on treatment planning system.Results： The dose distribution displayed on treatment planning system shows that prescription dose linked well on the beam boundary by using half-beam irradiation tech- nique to irradiate supraclavicular area and using non-coplanar irradiation technique to irradiate breast area. No dose hot point or cold point appeared on beam boundary. Conclusions： The half-beam irradiation technique combined with the non-coplanar ir- radiation technique is fitful for the breast cancer radiotherapy, especially fitful for PTV maximum size bigger than 20 cm in the cephalocaudal direction, dose displayed on treatment planning system demonstrates that breast cancer radiotherapy executed with this method can get a good dose link between supraclavicular area and breast area and it is easy to execute.

关 键 词：放射治疗 乳腺癌 剂量衔接 

分 类 号：R730.55[医药卫生—肿瘤]