Unexplained rising carcinoembryonic antigen (CEA) in the postoperative surveillance of colorectal cancer: the utility of positron emission tomography(PET)

The aim of the study was to evaluate the use of positron emission tomograph y with [F-18]-fluorodeoxyglucose (FDG-PET) ill patients with unexplained ri sing carcinoembryonic antigen (CEA) in the postoperative surveillance of co lorectal cancer. 50 consecutive patients with elevated CEA levels and a com pletely normal (n = 31) or equivocal (n = 19) conventional diagnostic work- up (CDW) were retrospectively selected. All PET images were reviewed with f ull knowledge of the CDW. The gold standard consisted of histology, or clin ical follow-up of more than 1 year. Recurrent disease was established in 56 lesions in 43 patients. On a patient-based analysis, the sensitivity of FD G-PET was 34/43 (79%), and the positive predictive value 34/38 (89%). In 14 /50 patients (28%). the FDG-PET findings led to a surgical resection with c urative intent. On a lesion-based analysis, FDG-PET detected 42/56 lesions (sensitivity: 75%), the positive predictive value was 79% (42/53). These re sults demonstrate that FDG-PET can have a clear impact on patient managemen t in patients with an unexplained elevation in CEA levels. (C) 2001 Elsevie r Science Ltd. All rights reserved.