PET-CT对晚期非小细胞肺癌精确放疗计划的影响

The Impact of PET-CT on Precise Radiotherapy Planning for Advanced Non-Small Cell Lung Cancer

目的探讨正电子发射计算机断层显像(PET-CT)对晚期非小细胞肺癌(NSCLC)靶区勾画及放疗计划的影响。方法对30例确诊的NSCLC患者进行PET-CT扫描,分别以CT图像和PET-CT图像勾画肿瘤靶区(GTV)并以相同参数制定放疗计划,比较2套计划GTV、计划靶区(PTV)和周围危及器官(OAR)的剂量变化。结果30例患者中PET-CT融合图像上勾画的GTV及其相应PTV体积增大者有8例,体积减小有22例。PET-CT图像改变了常规CT图像勾画的GTV及PTV大小,但在PlanPET-CT和PlanCT中的VGTV及VPTV之间的差异无统计学意义。与Planct比较,PlanPET-CT双肺V20降低(P<0.05),双肺V30、平均全肺受照射剂量(MLD)及脊髓、食管、心脏的相关参数比较差异均无统计学意义。结论应用PET-CT勾画靶区可减少放射性肺炎的发生,有利于提高靶区剂量。

Objective To investigate the impact of PET-CT on the target volume delineation and precise radiotherapy planning for patients with advanced non-small cell lung cancer （NSCLC）. Methods PET-CT scanning was performed in 30 histologically proved NSCLC patients. The gross tumor volume （GTV） was delineated, and radiotherapy planning was established with identical parameters based on the CT image and PET-CT fused image, respectively. The differences of doses between GTV, planning target volume （PTV） and organsat rise （OAR） were compared. Results PET-CT image results changed the target volume delineation in 30 patients with 8 increased and 22 decreased. There were no differences in GTV and PTV between the VGTV and VPTV statistically, although PET-CT image changed conventional CT image size sketch of GTV and PTV. The V20 of total lung decreased in the PlanPET-CT compared with that of PlanCT （P〈0.05）, but no differences were found in the V30 of total lung, mean lung dose （MLD）, the data of spinal cord, esophagus and heart. Conclusion PET-CT may reduce the radiation injuries in the lung and improve the target dose.