经肝动脉灌注90Y微球治疗肝癌的剂量计算

目的 计算经肝动脉灌注^90Y微球治疗肝癌后肿瘤及正常组织内的吸收剂量分布情况。方法 用Campbell AM等人的肝癌病人经^90Y微球治疗后的肿瘤切实实验结果进行微球的分布模拟，然后计算肿瘤及正常组织的吸收剂量并画出吸收剂量自肿瘤中心沿径向的分布图，并与其他微球分布模型的计算结果进行比较。结果 用本文中的微球分布计算所得的总微球数接近于实际注入肝脏部位的微球数，以此分布为基础的剂量计算结果表明：治疗后绝大部分正常组织的有收剂量均小于其耐受剂量但同时在肿瘤中心部位也存在欠剂量区，此结果要较相同治疗活度下其他两种微球分布模型计算的结果更接近于实际情况；相同治疗活度及微球分布时^90Y微球治疗后的剂量均匀性较^32P的略优。结论 ^90Y微球治疗肝癌后的剂量计算最好采用微球的不均匀分布模型才能正确反映实际剂量分布并解释临床实际疗效。

Dose calculation after radiation therapy for liver malignancy with intraarterial infusion of 90Y microspheres

Objective To calculate the dose distribution in tumor and normal tissue of the liver after radiotherapy for liver malignancy with intraarterial infusion of 90 Y microspheres 90 Y -IIT. Methods With the experiment results of microspheres distribution data of Campbell AM et al.in the resected sample of a patients liver after 90 Y-IIT, we simulated the distribution of microspheres.Then using this simulation and the other two distribution models of the mocrospheres,the dose in the tumor and the normal tissue would be calculated and the relationship between dose and distance from the tumor center would be revealed. Results The numbers of microspheres calculated with the simulation was closer to the actual numbers of microspheres infused to the liver.The dose distribution calculated by this simulation show that: most of the normal tissues dose was less than their tolerance dose and at the same time the dose of some tumor parts could not get enough tumoricidal dose.This result was fitter to the actual results than that calculated by other two distribution models. Conclusion In order to get the dose distribution which coincides with the actual result in clinics after 90 Y IIT,the heterogeneity distribution model of the microspheres should be used. ;