原发性巨大肝癌与小肝癌立体定向放射治疗计划比较

The comparison of the treatment plan for huge and small primary liver cancer treated by stereotactic radiotherapy

目的比较原发性巨大肝癌与小肝癌立体定向放射治疗计划的设计。方法采用γ射线立体定向放射治疗原发性肝癌患者:A组43例患者,计划靶区体积(vptv)均≥300cm3;B组28例患者,31个vptv均≤100cm3。设计不同的立体定向放射治疗计划。结果 A组PTV均由50%～55%等剂量线包绕,PTV周边照射总剂量3200～3900cGy,分割处方剂量300～350cGy,每一计划需14～22个射野,靶区剂量均匀指数1.60～1.72;B组PTV均由70%～90%等剂量线包绕,PTV周边照射总剂量4000～5400cGy,分割处方剂量400～600cGy,每一计划至多需3个射野,靶区剂量均匀指数1.06～1.43。两组计划无正常组织受照剂量超过相应的耐受剂量。结论设计出合格的原发性巨大肝癌与小肝癌的立体定向放射治疗计划是可能的,然而,原发性巨大肝癌治疗计划所需射野数明显多于小肝癌治疗计划,小肝癌立体定向放射治疗计划靶区剂量均匀性优于巨大肝癌。

Objective To study the treatment plan for huge and small primary liver cancer treated by stereotactic radiotherapy.Methods The patients with primary liver cancer were treated with γ-ray stereotatic radiotherapy（SRT）.43 patients in group A,their planning target volume was no less than 300cm3（vptv≥300cm3）;28 patients with 31 targets in group B,their planning target volume was no more than 100 cm3（vptv≤100cm3）;Results In group A,PTVs were surrounded by 50%～55% isodose curve,the minimum dose of 3200～3900cGy were delivered to PTVs with the fraction dose of 300～350cGy,14～22 fields were needed in each treatment plan,and the index of dose homogeneity of target was 1.60～1.72;In group B,PTVs were surrounded by 70%～90% isodose curve,the minimum dose of 4000～5400cGy were delivered to PTVs with the fraction dose of 400～600cGy,3 fields were needed at most in each treatment plan,and the index of dose homogeneity of target was 1.06～1.43;There was no normal tissue that couldn＇t tolerate the irradiation in the two groups.Conclusions Qualified treatment plan for both huge and small primary liver cancer treated by γ-ray stereotactic radiotherapy could be designed,but much more fields are needed in huge liver cancer than in small liver cancer.Dose in small liver cancer is more homogeneous than in huge liver cancer.