霍奇金淋巴瘤斗篷野常规放疗与调强放疗计划剂量学研究

目的 对Ⅰ、Ⅱ期霍奇金淋巴瘤斗篷野常规放疗和4种不同设野IMRT计划剂量学进行比较,评估不同照射方法的优缺点.方法 选择10例病理证实的Ⅰ、Ⅱ期淋巴瘤患者行CT定位,用ECLIPS治疗计划系统对每例患者分别作出常规和4种不同布野的IMRT计划,分析各治疗计划PTV的CI、HI、D95、V95、Dmax、Dmean、Dmin,肺V5、V10、V20、V30,脊髓最大受量Dmax.结果 IMRT在PTV靶区剂量、适形性和均匀性方面均优于常规计划.4种IMRT计划之间PTV靶区覆盖、靶区剂量、适形性和均匀性方面相近;肺V30均低于常规放疗,但肺低剂量受照体积较常规放疗高,IMRT子野数越多可能使肺V20、V30越小而V5、V10越大;脊髓Dmax均低于常规放疗计划.结论 IMRT在靶区适形度、均匀性和靶区剂量、保护脊髓、降低肺高剂量受照体积方面均优于常规放疗,但肺低剂量照射体积大于常规放疗,而斗篷野IMRT可考虑选用7个野IMRT计划.

Dosimetric study on conventional mantle-field irradiation and intensity-modulated radiotherapy for Hodgkin's lymphoma

Objective To compare the dose distribution of mantle-field radiotherapy using conven-tional radiotherapy(CRT) and four intensity-modulated radiotherapy(IMRT) techniques in stage Ⅰ and Ⅱ Hodgkin's lymphoma(HL). Methods Ten patients with patholocally proved early stage HL underwent CT simulation. Then both CRT and IMRT planning performed using ECLIPS treatment planning system(TPS). The dosimetric parameters of different irradiation plans were analyzed, including conformal index (CI), homo-geneity index (HI), D95 and V95 of planning target volume (PTV), Dmax,Dmean,Dmin,V5,V10,V20 and V30 of the lung, as well as Dmax of the spinal cord. Results The isodose distribution and homogeneity of PTV were better in IMRT plans when compared with CRT plans. Target coverage, target dose conformity and homogene-ity were similar among all the four IMRT techniques. The V30 of the lung using IMRT was lower than using CRT,but the low-dose volume of the lung was higher. Among the four IMRT technique plans,the lung V20 and V30 were lower in plans with more-field technique,but the V5 and V10 were higher. The Dmax of the spinal cord using IMRT was all lower than that using CRT. Conclusions IMRT is better than CRT in target cov-erage, conformity, homogeneity and normal tissue sparing, especially in protecting the spinal cord and decrea-sing high-dose lung volume,though the low-dose lung volume is higher. Seven-field IMRT technique for man-de-field radiotherapy is recommanded.