调强技术治疗非小细胞肺癌可能性分析及剂量评估

Dosimetry evaluation and feasibility of intensity-modulated radiotherapy for non-small-cell lung cancer

目的研究调强技术治疗非小细胞肺癌的可能性及对正常肺组织和胸部其他危及器官的保护。方法选择20例非小细胞肺癌病人，回顾性地分析三维适形和调强治疗计划。调强与适形计划都要求使95％的计划靶区接受64Gy的处方剂量，使肺、食管、心脏、脊髓接受大于耐受剂量的体积最小。根据计划靶区的等剂量分布、体积一剂量直方图以及其他的剂量学指标，比较两种不同治疗计划的优劣。结果与适形计划相比，调强治疗计划在临床认可的范围内降低了靶区剂量的均匀性，但剂量的适形性有显著提高；正常肺组织的V20值减少11％、平均剂量下降2Gy，但肺组织和危及器官的V5、V10值很难进一步改善。结论调强比适形放疗更适合非小细胞肺癌的治疗。

Objective To investigate the feasibility of intensity-modulated radiotherapy for non-smallcell lung cancer with respect to target-dose conformity ＆ heterogeneity and normal tissue sparing. Methods In order to compare intensity-modulated and three-dimensional conformal radiotherapy of twenty non-small-cell lung cancer patients with stage Ⅰ-Ⅳ, retrospective treatment planning study was performed. The two types of plans were designed to deliver 64 Gy to 95 % of the planning target volume and to minimize the volume of normal lung, esophagus, heart and spinal cord irradiated above their tolerance doses. All plans were compared according to the planning target volume coverage, dose-volume histogram and other dosimetrie parameters of normal tissues. Results Commparod with three-dimensional conformal radiotherapy, the intensity-modulated plan improved conformity without significantly sacrificing the heterogeneity with regard to planning target volume coverage. The V20 and mean dose lung of were reduced with a median reduction of 11% and 2 Gy. Conclusions It is indicated that intensity-modulated radiotherapy may be more applicable for non-small-cell lung cancer than three-dimensional conformal radiotherapy.