18F-FDG PET-CT确定非小细胞肺癌淋巴结放疗靶区的初步探讨

目的探讨18F-FDG PET-CT确定非小细胞肺癌(NSCLC)患者区域淋巴结放疗靶区的价值。方法回顾性分析58例经根治性手术治疗的NSCLC患者,术前同期行PET-CT和CT检查。经盲法阅片后,由肿瘤放射治疗医师结合影像诊断结果分别在PET-CT和CT图像上勾画靶区,并与病理诊断结果进行对照。结果CT诊断纵隔淋巴结转移的灵敏度、特异度、准确率、阳性预测值及阴性预测值分别为56.0%、54.2%、54.8%、38.9%和70.3%,PET-CT分别为88.0%、85.4%、86.3%、75.9%和93.2%,两者差异均有统计学意义(P<0.05)。CT和PET-CT对诊断肺门区域淋巴结的差异无统计学意义。18F-FDG PET参与靶区勾画后,46.5%的患者淋巴结靶区改变,其靶区完全包含转移性淋巴结的准确率为75.9%,与单纯CT(48.3%)的准确率比较,差异有统计学意义(P<0.05)。结论18F-FDG PET-CT能更准确地估计NSCLC患者区域淋巴结转移的范围,从而指导放疗靶区的勾画。

Preliminary study of 18F-FDG PET-CT in defining lymph node radiation target volume for non-small-cell lung cancer patients

Objective To investigate the value of 18F-FDG PET-CT in detecting metastatic lymph node and radiation planning for patient with non-small-cell lung cancer (NSCLC). Methods The data of 58 NSCLC patients were retrospectively analyzed. Preoperatively, Both 18F-FDG PET-CT and CT scan were performed for all patients. Blinded interpretation of these images was then carried out. The gross tumor volume defined by radiation oncologist based on imaging results of either PET-CT or CT alone was compared with pathological results eventually. Results The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of detecting metastatic lymph node in the mediastinum was 56. 0% , 54.2% , 54.8% , 38.9% , 70.3% by CT alone, and 88.0% , 85.4% , 86.3% , 75.9% , 93.2% by PET-CT, respectively. There was a statisticalty significant difference between two methods(P<0.05). However, statisticalty no significant difference in detecting hilar lymph nodes was observed. The radiation target volume defined by CT was identical to that by PET-CT in 31(53.5%) cases, but changed in the other 27(46.5%) cases when 18F-FDG PET data was added. The accuracy was 75. 9% in detecting metastatic lymph nodes in the radiation target volume defined by PET-CT, while it was much lower by CT alone (48. 3%) with a statistically significant difference between two methods (P<0.05). Conclusion 18F-FDG PET-CT is more accurate than CT alone in assessment of mediastinal lymph nodes for NSCLC patients. It may be recommended as a method in defining the radiation target volume.