鼻咽癌调强放射治疗和三维适形放射治疗计划比较分析

目的:探讨调强放射治疗(IMRT)鼻咽癌的优势,以改进放射治疗技术。方法:对7例T2~3N1~3期鼻咽癌进行IMRT和三维适形放射治疗(3D-CRT)计划的比较,每一例各设计一个IMRT和3D-CRT治疗计划,给予95%计划靶体积(PTV)50 Gy的处方剂量,用等剂量分布曲线和剂量-体积直方图(DVH)评价治疗计划,评价参数包括平均剂量、适形指数(CI)、剂量不均匀性指数(HI)、D5%、V95%和各重要器官受量等。结果:IMRT和3D-CRT各参数值:平均剂量分别为(54.0±1.5)Gy和(55.1±0.5)Gy,CI分别为0.85±0.01、0.61±0.03,HI分别为1.15±0.05、1.23±0.05,D5%分别为(57.3±0.2)Gy和(60.7±1.2)Gy,V95%分别为(98.8±0.53)%和(96.8±2.01)%,PTV靶区剂量除平均剂量和V95%外,其它各项参数差异均有统计学意义(P<0.05)。重要器官受量:脊髓最大剂量分别为(41.7±2.5)Gy和(46.4±2.7)Gy,差异有统计学意义(P<0.01),其它参数均较接近,差异无统计学意义。结论:鼻咽癌IMRT计划优于CRT,是治疗鼻咽癌的理想选择。

Comparison of plans of intensity-modulated radiotherapy with 3D-conformal radiotherapy for nasopharyngeal carcinoma

Objective: To investigate superiority of intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma, in order to improve technology of radiotherapy for nasopharyngeal carcinoma. Methods: IMRT and CRT plans were compared for seven patients with nasopharyngeal carcinoma with staging of T_(2~3)N_(1~3). For each patient, one IMRT and one CRT plans were designed with a prescribed dose of 50 Gy to at least 95% of plan target volume (PTV). The following parameters of these plans in each patient were compared: isodose distributions line, dose-volume histogram (DVH), D_(5%), V_(95%) and the dose of protective organs, etc. Results: For IMRT and one CRT, ,CI was 0.85 and 0.61, HI was 1.15 and 1.25, D_(5%) was 57.5 Gy and 60.7 Gy, V_(95%) was 98.8% and 96.8%, respectively all P<0.05, except average dose and D_(95%). Maximum dose for spinal cord was 41.7 Gy and 46.4 Gy, (P<0.01),respectively. Conclusion: Plans of IMRT is superior to CRT for the treatment of nasopharymgeal carcinoma, At present, IMRT is an ideal selection for the treatment of nasopharymgeal carcinoma.