摘要目的 探讨18F-FDG PET-CT显像在原发灶不明转移性肿瘤中的应用价值.方法 应用PET-CT技术,对67例原发灶不明转移性肿瘤患者行显像检查,将结果与病理学检查或临床结果对照,并比较原发灶与转移灶标准摄取值(SUV)的相关性和差异.结果 67例患者中,18F-FDG PET-CT发现可疑原发灶39例,经病理或临床诊断证实36例,检出率为53.7%(36/67).新检出远处转移灶13个,淋巴结转移灶17个.原发灶SUV(6.3103±3.1162)与转移灶SUV(10.4586±5.6337)有相关性(r=0.738,P=0.000);原发灶SUV较转移灶SUV低,且差异有统计学意义(t=3.470,P=0.001).结论 18F-FIX;PET-ET对寻找转移性肿瘤的原发灶有重要价值,为寻找转移性肿瘤的原发灶提供了一种新的检查手段.临床上可充分利用功能显像的优势,进一步研究恶性肿瘤的生物学特性.

abstractsObjective To evaluate the value of 18F-FDG PET-CT in detecting the primary tumor in patients with metastatic cancers of unknown primary origin. Methods Sixty-seven patients with metastatic cancers of unknown primary origin after extensive conventional diagnostic work-up were enrolled into this study, 18F-FDG PET-CT scans were performed at approximately 60 minutes after the intravenous injection of 7.4 MBq 18F-FDG/kg, then delayed imaging scans was done at approximately 180 minutes for detecting the primary focus. The standardized uptake value (SUV)≥2.5 on standard PET/CT imaging was considered as positive. Ten percent increase of retention index (RI) was also regarded as positive. The correlation between 18F-FDG PET-CT results and histopathological and clinical findings were analyzed, and the SUV of detected primary focus and that of metastatic cancers were compared. Results Of the 67 patients, the primary tumors were identified in 39 (53.7%) by 18F-FDG PET-CT, and 36 of them were confirmed by pathology or follow-up. Thirteen distant metastases and seventeen lymphatic metastases were newly discovered by whole body 18F-FDG PET-CT imaging. The SUV of metastatic tumors was significantly lower than that of primary tumors (t=3.470, P=0.001) and closely correlated with that of the primary tumors (r=0.738, P=0.000). Conclusion 18F-FDG PET-CT is not only valuable in identifying the unknown primary tumor in patients with metastatic carcinoma, but can also be used to reveal the biological characteristics of the tumors by functional imaging.