术后复发性膀胱癌PET/CT定位三维适形放疗的疗效分析

摘要

目的:对比研究术后复发性膀胱癌经18 FDG PET/CT定位适形放疗的疗效、不良反应及失败原因.方法:对46例术后局部复发性膀胱癌患者随机分为18FDG PET/CT定位适形放疗组(PET/CT组)和普通CT定位适形放疗组(普通CT组).PET/CT组用PET/CT扫描定位,将扫描数据输入三维治疗计划系统,将PET图像和CT图像融合后进行靶区(GTV与PTV)和重要脏器勾画、三维重建,制定计划后常规分割适形放疗40Gy左右,然后缩野放疗至总剂量60 - 66Gy；普通CT组用普通CT定位设野,三维适形放疗至相同剂量.结果:PET/CT组的平均PTV体积、膀胱V40、直肠V40分别比普通CT组小13.2cm3、5.8cm3、7.6cm3(P＜0.01)；放疗后6个月,两组CEA平均值分别下降为10.8ng/ml、11.7ng/ml(P ＜0.01)；PET/CT组的中位复发时间11.2个月,普通CT组的中位复发时间9.1个月(P＜0.01)；PET/CT组的胃肠道与膀胱放射性不良反应低于普通CT组(P＜0.05)；疗前GTV≤50cm3者预后好.结论:PET/CT定位三维适形放疗术后复发性膀胱癌可以优化放疗计划,联合化疗可以延长中位复发时间,分期早者预后好.%Objective:To analyse the effect of I8FDG PET/CT positioning three - dimensional conformal radiother-apy(3DCRT) for local recurrence in postoperative bladder carcinoma. Methods:All 46 cases of local recurrence in postoperative bladder carcinoma patients were randomly divided into 18FDG PET/CT positioning 3DCRT group (PET/ CT group) and the general CT positioning 3DCRT group (normal CT group). The location of PET/CT groups cases was determined by PET/CT and the data was transmitted to the treatment planning system (TPS) ,the PET image and CT image were fused together. The target volume and critical organs were determined and the treatment plan was worked out from the fused image,then conventional fraction's 3DCRT (40Gy or so) was followed to a total dose of radiotherapy 60 -66Gy by reduced radiation field. The location of normal CT groups cases was determined by normal CT and were treated by 3DCRT to the same dose. Results:The average PTVs volume,bladder's V40,rectums V40 of the PET/CT group were smaller than that of the normal CT group ( all P < 0. 05). There was significant difference between the average CEA before and after radiotherapy( P <0. 01). The median recurrence time of the PET/CT group was 11.2 months, and the median recurrence time of the normal CT group was 9. 1 months, there was significant difference between the two groups (P < 0. 01). The early trachea, esophagus and bladders reactions of the PET/CT group were lower than that of normal CT group (P < 0. 05). Multivariate analysis showed that early T stage lesions were better than that of others(P <0.01 ). Conclusion: PET/CT positioning 3DCRT can optimize the radiation treatment planning for local recurrence in postoperative bladder carcinoma, the patients with early stage lesions have better prognosis.