18F-FDG PET/CT显像在不明原发癌中的诊断价值

目的探讨18F-FDG PET/CT在不明原发癌(CUP)患者中的临床作用。方法选择2018年3月~2019年8月经临床诊断为CUP的121例患者，其中男性79例、女性42例，年龄30~86岁(63±12岁)，回顾性分析其全身18F-FDG PET/CT显像结果。本研究的最终诊断均通过病理证实或临床随访证实。结果18F-FDG PET/CT显像成功在121例患者中检出原发性肿瘤59例(49%)。18F-FDG PET/CT显像检测出最常见的原发肿瘤是肺癌(n=31)。1例患者在18F-FDG PET/CT显像中发现两种原发性肿瘤(前列腺癌和结肠癌)，肺活检显示此患者为前列腺癌，结肠癌被认为是同步的第二原发肿瘤。11例18F-FDG PET/CT显像结果为假阳性。51例患者在18F-FDG PET/CT显像中未能检测到任何原发肿瘤病灶，其中有11例患者在临床随访中检测到原发肿瘤病灶，因此认为假阴性。18F-FDG PET/CT检测原发性肿瘤的敏感性、特异性和准确性分别为84%、78%和82%。结论全身18F-FDG PET/CT显像是检测CUP病灶原发肿瘤的可靠方法。除了发现原发性肿瘤外，还可帮助确定疾病的程度，并有助于患者的临床管理。 

Diagnostic value of 18F-FDG PET/CT in patients with carcinoma of unknown primary

Objective To investigate the diagnosis value of 18F-FDG PET/CT in patients with carcinoma of unknown primary(CUP). Methods A total of 121 patients(79 males,42 females, age range 30-86 years) with a diagnosis of CUP who underwent whole body 18F-FDG PET/CT imaging were included in this retrospective study from March 2018 to August 2019. The final diagnoses were confirmed either histopathologically or by clinical follow-up. Results The 18F-FDG-PET/CT successfully detected the primary tumor in 59 out of 121(49%) patients. The most common primary tumor as detected by 18F-FDG PET/CT was lung cancer(n=31). In a patient, two primary tumors(colon and prostate) were detected on PET/CT imaging. Lung biopsy revealed prostate cancer in this patient and the colon cancer was accepted as a synchronous second primary tumor. 18F-FDG PET/CT findings were false-positive in 11 patients. 18F-FDG PET/CT could not detect any primary lesion in 51 patients, whose conventional work-up detected a primary tumor in 11 and thus considered as false-negative. The sensitivity, specificity rate and accuracy of 18F-FDG PET/CT in detection of primary tumor were identified as 84%, 78% and 82%, respectively. Conclusion 18F-FDG PET/CT of total body is an effective method for detecting the primary tumor in patients with CUP. In addition to detect the primary tumor, it can help determine disease extent and contribute to patient management.