Objective To evaluate the clinical value of 18F-FDG PET/CT for detecting tumor on physical examination people with unexplained elevated serum carcinoembryonic antigen (CEA). Methods A total of 100 physical examination people with unexplained elevated serum levels of CEA in our hospital from June 2010 to December 2014 were involved in the study. All the people were detected with 18F-FDG PET/CT. The pathology, clinical follow ups and conventional medical imaging results were combined to evaluate the value of 18F-FDG PET/CT in diagnosing tumor. The doubling time (DT) of CEA was calculated in the patients who were received more than twice of serum CEA detection. The relationships between serum CEA levels, CEA DT and 18F-FDG PET/CT imaging were analyzed. The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of serum CEA. Results Twenty-seven patients were confirmed with malignant tumor, and the rest of 73 cases were excluded. The 18F-FDG PET/CT reported one false positive and one false negative respectively. The sensitivity, specificity, accuracy, positive and negative predictive values of 18F-FDG PET/CT in diagnosing malignant tumors were 96.3%, 98.6%, 98.0%, 96.3% and 98.6% respectively. The median serum CEA levels were significantly higher in the positive 18F-FDG PET/CT patients than those in the negative patients (Z=5.796, P<0.05). The prevalence of 18F-FDG PET/CT positive patients was higher with an increase in absolute CEA levels (χ2=37.823, P<0.05). The median DT of serum CEA levels was shorter in the positive 18F-FDG PET/CT patients than that in the negative patients (Z=4.301,P<0.05). The positive rates of 18F-FDG PET/CT in patients with 0 d180 d and DT<0 d (χ2=17.472 and 17.325, both P<0.05). There was no significant difference in the positive rate of 18F-FDG PET/CT between patients with DT>180 d and patients with DT<0 d (χ2=0.255,P>0.05). The area under the curve (AUC) of serum CEA was 0.894, the optimal diagnostic cutoff value was 14.24μg/L. Conclusion 18F-FDG PET/CT is a useful image modality for detecting malignant tumors in patients with unexplained elevated serum CEA, especially for patients with CEA≥14.24μg/L and increase progressively.%目的：探讨18氟-氟代脱氧葡萄糖（18F-FDG）PET/CT在体检人群血清癌胚抗原（CEA）水平不明原因升高时诊断肿瘤的临床价值。方法选取2010年6月—2014年12月我院健康体检时发现血清CEA不明原因升高并行18F-FDG PET/CT检查的体检者100例。结合病理学检查、临床随访和其他影像学检查结果，评价18F-FDG PET/CT对恶性肿瘤的诊断价值。对于接受＞2次血清CEA测定的患者，计算CEA倍增时间（DT）；分析血清CEA水平及其DT与18F-FDG PET/CT显像的关系。利用受试者工作特征（ROC）曲线分析血清CEA诊断恶性肿瘤的效能。结果100例患者中有27例最终确诊为恶性肿瘤，73例排除恶性肿瘤。18F-FDG PET/CT诊断假阳性和假阴性各1例，其诊断敏感度、特异度、准确度、阳性预测值和阴性预测值分别为96.3%、98.6%、98.0%、96.3%和98.6%。18F-FDG PET/CT显像阳性者血清CEA水平明显高于显像阴性者（Z=5.796，P＜0.05）；且随着CEA水平的升高，显像阳性率有升高的趋势（χ2=37.823，P＜0.05）。18F-FDG PET/CT显像阳性患者血清CEA DT明显短于显像阴性患者（Z=4.301，P＜0.05）；DT 为0~180 d 的患者显像阳性率明显高于 DT＞180 d 及 DT＜0 d 的患者（χ2分别为17.472、17.325，均P＜0.05）；DT＞180 d与DT＜0 d的患者18F-FDG PET/CT显像阳性率差异无统计学意义（χ2=0.255，P＞0.05）。血清CEA诊断恶性肿瘤的ROC曲线下面积（AUC）为0.894，当诊断界值为14.24μg/L时诊断效能最佳。结论18F-FDG PET/CT显像对于血清CEA不明原因升高者是否罹患肿瘤具有较高的诊断价值，尤其对于血清CEA≥14.24μg/L或呈进行性升高的患者，行18F-FDG PET/CT探查恶性肿瘤的价值更大。
展开▼
