三维适形与简化调强放疗技术在非小细胞肺癌放疗中的剂量学比较

目的 用剂量学方法比较三维适形(3D-CRT)和简化调强放疗(sIMRT)技术用于治疗非小细胞肺癌(NSCLC)的差异.方法 选择接受放疗的10例NSCLC患者进行研究.对每例患者进行3D-CRT和sIMRT的治疗计划设计,处方剂量为60 Gy(2 Gy/次),所有计划都使95%靶区体积达到处方剂量要求.并用ADAC Pinnacle3计划系统提供的卷积或迭加算法对两种放疗技术的治疗计划进行剂量计算,比较靶区剂量分布均匀性和适形性,以及危及正常组织剂量体积直方图参数.结果 3D-CRT与sIMRT放疗计划的等剂量线和DVH相近,sIMRT计划的靶区剂量均匀性和适形性略优于3D-CRT计划,sIMRT放疗计划中肺的平均剂量、V5、V10、V20别比3D-CRT降低14.81%、17.88%、19.15%、27.78%,而食管、心脏、脊髓等危及器官的受量基本相同.结论 对于NSCLC,sIMRT放疗技术在某些方面具有3D-CRT无法替代的优势,值得在临床推广应用.

Dosimetric comparison of three-dimensional conformal radiotherapy and simplified intensity-modulated radiotherapy for non-small cell lung cancer

Objective To compare dosimetrie difference of treatment planning of three-dimensional conformal radiotherapy (3D-CRT) and simplified intensity-modulated radiotherapy (slMRT) for non-small cell lung cancer (NSCLC). Methods Ten NSCLC patients treaded by radiotherapy were investigated. 3D-CRT and slMRT plannings were designed for each patient. The prescribed dose was 60 Gy(2 Gy/f), the 95 % of the planning target volume was received with this dose for each patient. The dose was computed with treatment planning system of ADAC Pinnacle3 using convolution/superpasition algorithm. Two plans were compared according to the homogeneity index (HI) and conformity index (CI) of dosimetry in the planning target volume and the parameters of dose-volume histogram (DVH) in normal tissue. Results In the terms of HI and CI, sIMRT had slight vantages over 3D-CRT. In the terms of DVH, compared with 3D-CRT, mean lung dose, V5, V10 and V20 of slMRT reduced by 14.81 %, 17.88 %, 19.15 % and 27.78 %, respectively. The dosimetric differences were not statistically significant between 3D-CRT and sIMRT in terms of esophagus, heart and spinal cord. Conclusions For NSCLC, sIMRT has some irreplaceable advantages over 3D-CRT and is worth spreading in clinical work.