乳腺癌根治术后胸壁放疗技术的选择

The selection of radiotherapy on chest wall of patients with breast carcinoma after radical mastectomy

目的:探讨乳腺癌根治术后胸壁放射治疗的最合理方式。方法:对20例乳腺癌根治术后患者采用三维适形放疗(3D-CRT)和调强放疗(IMRT)2种技术,同时设计胸壁治疗计划,通过三维治疗计划系统(3D-TPS),用剂量-体积直方图(DVH)比较2种治疗计划中照射野的数目、肿瘤靶体积的剂量、适形指数(CI)、剂量不均匀指数(HI)及心、肺、肝等重要组织器官的照射量。结果:IMRT技术靶区的适形度、剂量分布均匀,心、肺、肝正常组织器官的照射量分别为0.21、1.19、2.75、9.797、.68 Gy,优于3D-CRT,二者差异有统计学意义(P<0.01)。2种治疗技术中肿瘤靶区内剂量分布基本相似,差异无统计学意义。结论:IMRT可以提高靶区内剂量分布的均匀性,减少胸壁出现高剂量区;能减少心、肺、肝等器官的照射容积和受照剂量。

Objective： To evaluate the rational way of radiotherapy onchest wall after mastectomy. Methods： Twenty patients after mastectomy with breast cancer respectively received two different methods of planning including intensity modulated radiaton therapy （IMRT） and three-dimensional conformal radiation therapy （3D-CRT） according to three-dimensional radiation treatment planning system （3D-TPS）. Dosevolume histogram （DVH） was used to assess the total number monitor units, target volume distribution, conformity index （CI）, heterogeneity index （HI）, dose of normal organs： lung, heart and liver. Results： Using IMRT, target conformity, target heterogeneity and the doses of normal tissue such as lung, heart, liver are respectively 0.21, 1.19, 2.75, 9.79, 7.68 Gy. These are superior to those using 3D-CRT. But target volume distribution does not differ significantly between two ways. Conclusion： Compared with 3D- CRT, Target volume dosimetric distribution of IMRT is more precise. The IMRT plans increased the target heterogenetity and decrease the radiation volumes and doses of normal tissue.