Flanagan F L, Dehdashti F, Ogunbiyi O A, Kodner I J, Siegel B A
Division of Nuclear Medicine, Edward Mallinckrodt Institute of Radiology, St. Louis, Missouri, USA.
Ann Surg. 1998 Mar;227(3):319-23. doi: 10.1097/00000658-199803000-00001.
To assess the potential role of positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) in patients with unexplained rising carcinoembryonic antigen (CEA) levels after the treatment of colorectal cancer.
A rising CEA level after the resection of colorectal cancer is an early indicator of tumor recurrence. However, conventional imaging techniques have limited sensitivity for detecting recurrent disease in such patients. Especially after surgical intervention, FDG-PET is rapidly gaining an important role in establishing the extent of disease in the oncology patient.
Twenty-two patients with abnormal CEA levels and normal results of conventional methods of tumor detection were studied with FDG-PET. The PET results were compared with pathologic findings (n = 9) and long-term radiologic and clinical follow-up (n = 13).
FDG-PET was abnormal in 17 of 22 patients. Tissue sampling was available in 7 of these 17 patients; all of these had recurrent disease. Definitive curative surgical intervention was performed in four patients. Subsequent dedicated imaging findings and clinical course confirmed the presence of extensive disease in 8 of the remaining 10 patients; the PET results in the other 2 patients were considered falsely positive. FDG-PET was negative in 5 of 22 patients. No disease was found by tissue sampling (n = 2) and clinical follow-up (n = 3). Overall, the positive-predictive value for PET was 89%, (15 of 17) and the negative-predictive value was 100% (5 of 5).
When conventional examinations are normal, FDG-PET is a valuable imaging tool in patients who have a rising CEA level after colorectal surgery.
评估采用2-[18F]氟-2-脱氧-D-葡萄糖（FDG）的正电子发射断层扫描（PET）在结直肠癌治疗后癌胚抗原（CEA）水平不明原因升高患者中的潜在作用。
结直肠癌切除术后CEA水平升高是肿瘤复发的早期指标。然而，传统成像技术在检测此类患者的复发疾病方面敏感性有限。特别是在手术干预后，FDG-PET在确定肿瘤患者的疾病范围方面正迅速发挥重要作用。
对22例CEA水平异常且传统肿瘤检测方法结果正常的患者进行了FDG-PET研究。将PET结果与病理结果（n = 9）以及长期影像学和临床随访结果（n = 13）进行比较。
22例患者中有17例FDG-PET结果异常。这17例患者中有7例进行了组织取样；所有这些患者均患有复发性疾病。4例患者接受了确定性根治性手术干预。随后的专门影像学检查结果和临床病程证实，其余10例患者中有8例存在广泛病变；另外2例患者的PET结果被认为是假阳性。22例患者中有5例FDG-PET结果为阴性。通过组织取样（n = 2）和临床随访（n = 3）均未发现疾病。总体而言，PET的阳性预测值为89%（17例中的15例），阴性预测值为100%（5例中的5例）。
当传统检查结果正常时，FDG-PET对于结直肠癌手术后CEA水平升高的患者是一种有价值的成像工具。
