肿瘤腹主动脉旁淋巴结转移三维适形和调强放射治疗计划的剂量学比较

Dosimetry Comparison of 3-dimensional Conformal Radiation Therapy and Intensity Modulated Radiation Therapy Plans for Para-aortic Lymph Node Tumor Metastasis

目的:比较腹主动脉旁淋巴结肿瘤转移的3D-CRT和IMRT放射治疗计划的剂量学差异。方法:设计常规四野(3D-CRT)和调强放疗(IMRT)计划,通过剂量-体积直方图比较二者的放射物理参数,并评价其应用价值。结果:IMRT计划中靶区最大剂量明显低于3D-CRT计划中的相应值,其靶区适形度也明显占优。同时,IMRT计划中的肾脏高剂量区明显低于3D-CRT计划中的高剂量区,并且其肠道剂量D5、D10、D20、D30和平均剂量均明显低于3D-CRT计划中的相应值,差异有统计学意义。结论:就腹主动脉旁淋巴结肿瘤转移的放射治疗,IMRT技术有效地将肿瘤靶区与周围正常危险器官分割开,从而在提高肿瘤放射剂量的同时最大限度减少危险器官的照射剂量,应该更广泛地应用于临床。

Objective： To compare dosimetry of 3D-CRT and IMRT plan for para-aortic lymph node tumor metastasis. Methods： For 12 patients, 3D-CRT and IMRT plans were performed, and plans were compared according to dose-volume histogram. Results： The Dmax for GTV in IMRT plan and the conformity index were better than those in 3D-CRT plan. Also, the D5 of kidneys in IMRT plan were statistically lower than those in 3D-CRT plan. In dose study of intestine, D5,D10,D20,D30 and Dmean, were all statistically lower in IMRT plan than the parameters in 3D-CRT plan. Conclusions： In radiotherapy for para-aortic lymph node tumor metastasis, IMRT effectively separated GTV and the organs at risk, escalating the dose for tumor and limiting the dose for these organs as could as possible. IMRT should be applied in clinic more widely.