From the Departments of Otolaryngology (J.R.L., J.L.R., S.H.C., S.Y.N., S.Y.K.), Nuclear Medicine (J.S.K.), Radiology (J.H.L., J.H.B.), and Pathology (K.J.C.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Republic of Korea; and Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea (S.Y.K.).
Radiology. 2015 Mar;274(3):764-71. doi: 10.1148/radiol.14141073. Epub 2014 Nov 17.
To assess diagnostic accuracy of fluorine 18 ((18)F) fluorodeoxyglucose (FDG) combined positron emission tomography (PET) and computed tomography (CT) in the detection of occult primary tumors and determination of optimal care in patients with cervical metastasis of an unknown primary tumor (CUP) compared with contrast material-enhanced CT alone or combined contrast-enhanced CT and magnetic resonance (MR) imaging (CT/MR imaging).
Institutional review board approval and written informed consent were obtained. In total, 56 patients with initially undetected tumors after endoscopic or physical examination were prospectively assessed with (18)F FDG PET/CT and contrast-enhanced CT or contrast-enhanced CT/MR imaging. The contrast-enhanced CT/MR images were read in combination. Results of guided biopsy with general anesthesia served as the reference standard. Diagnostic values of (18)F FDG PET/CT, contrast-enhanced CT, and contrast-enhanced CT/MR imaging were compared with the McNemar test.
Primary tumors were detected at 32 sites in 31 (55%) of 56 patients. There were 26 tumors in the palatine tonsil, two in the hypopharynx, two in the base of the tongue, and two in the nasopharynx. PET/CT depicted 22 (69%) of 32 primary tumors, but it failed to depict primary tumors in 10 (31%) of 32 cases. Overall, sensitivity of PET/CT (69%) in detection of primary tumors was higher than that of contrast-enhanced CT (16%) (P < .001) or contrast-enhanced CT/MR imaging (41%) (P = .039), while specificity of these methods did not differ (88%, 76%, and 59% for PET/CT, contrast-enhanced CT, and contrast-enhanced CT/MR imaging, respectively; P > .4). Diagnostic performance (area under the receiver operating characteristics curve [AUC] = 0.759) of PET/CT in tumor detection was significantly better than that of contrast-enhanced CT alone (AUC = 0.531) (P = .001) or contrast-enhanced CT/MR imaging (AUC = 0.537) (P = .036). PET/CT depicted primary tumors in eight (50%) of 16 cases of false-negative CT/MR imaging findings, one distant metastatic case, and two cases of synchronous cancer.
(18)F FDG PET/CT is more sensitive in detection of primary tumors than is contrast-enhanced CT or contrast-enhanced CT/MR imaging in patients with CUP; therefore, it may lead to improved therapeutic planning in these patients.
评估氟 18（18）氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）和计算机断层扫描（CT）联合与单独增强 CT 或增强 CT 联合磁共振（MR）成像（CT/MR 成像）在检测隐匿性原发肿瘤和确定颈转移未知原发性肿瘤（CUP）患者最佳治疗方案方面的诊断准确性。
获得机构审查委员会批准和书面知情同意。共前瞻性评估了 56 例经内镜或体检后最初未发现肿瘤的患者，采用 18F FDG PET/CT 和增强 CT 或增强 CT/MR 成像。结合阅读增强 CT/MR 图像。全麻引导活检的结果作为参考标准。采用 McNemar 检验比较 18F FDG PET/CT、增强 CT 和增强 CT/MR 成像的诊断价值。
在 56 例患者中，32 个部位发现了原发性肿瘤。其中 26 例位于扁桃体，2 例位于下咽，2 例位于舌底，2 例位于鼻咽。PET/CT 显示 32 个原发性肿瘤中的 22 个（69%），但未能显示 32 个病例中的 10 个原发性肿瘤。总体而言，PET/CT 检测原发性肿瘤的敏感性（69%）高于增强 CT（16%）（P<.001）或增强 CT/MR 成像（41%）（P=.039），而这些方法的特异性无差异（PET/CT 为 88%，增强 CT 为 76%，增强 CT/MR 成像为 59%；P>.4）。PET/CT 在肿瘤检测中的诊断性能（受试者工作特征曲线下面积[AUC] = 0.759）明显优于单独增强 CT（AUC = 0.531）（P =.001）或增强 CT/MR 成像（AUC = 0.537）（P =.036）。PET/CT 在 16 例 CT/MR 成像假阴性结果、1 例远处转移病例和 2 例同时性癌症病例中显示了原发性肿瘤。
在 CUP 患者中，18F FDG PET/CT 检测原发性肿瘤的敏感性高于增强 CT 或增强 CT/MR 成像，因此可能导致这些患者的治疗计划得到改善。
