前列腺癌调强放疗和三维适形放疗剂量学对比研究

A comparison between intensity modulated radiotherapy and three-dimensional conformal radiotherapy in dose distribution in prostate cancer

目的:通过对前列腺癌调强和适形放疗方案的比较,选择前列腺癌最佳放疗方案。方法:选取8例前列腺癌患者,经过增强CT模拟定位后参考盆腔磁共振结果勾画大体肿瘤体积,按统一标准外扩临床靶体积和PTV,应用三维治疗计划系统为每例患者设计调强适形放疗计划(IMRT)和三维适形放疗计划,在规定PTV至少达到95%处方剂量前提下根据剂量体积直方图比较两种计划靶区剂量分布及直肠、膀胱、股骨头等正常组织受量的差异。结果:调强放疗的靶区适形度指数、均匀性指数、处方剂量覆盖PTV百分比较好,减少了直肠、膀胱和股骨头剂量,差异均有统计学意义(P<0.05)。结论:前列腺癌采用IMRT是目前最佳的一种放疗方法。

Objective To find the optimal radiotherapy for prostate cancer through comparison of intensity modulated radiotherapy and three-dimensional conformal radiotherapy （3D-CRT） technique. Methods Eight patients with prostate cancer underwent CT simulation. GTV was contour on the CT image, referring the MRI, then CTV and plan target volume （PTV） were also defined using the same criteria. Intensity modulated radiotherapy and 3D-CRT were designed at the sameTPS. The difference of exposure doses between target area and critical organ was compared by dose volumehistogram with the PTV must reach 95% of the prescription dose. Results Compared with 3D-CRT, the target dose was well-distributed, and the absorbed dose and volume in rectum, bladder and femoral head were obviously reduced. Conclusion Intensity modulated radiotherapy is the optimal radiotherapy for prostate cancer.