The value of using fludeoxyglucose positron-emission tomography scan with respect to colorectal abnormalities-a cross-sectional study.

Abstract

Background\nFludeoxyglucose positron-emission tomography (FDG-PET) shows colic uptake regularly. Complementary colonoscopy is done. Aim: study the findings of colonoscopy.\n\n\nMethods\nAll consecutive scans in 5 years were studied. Focal FDG uptake in colon and/or rectum were scored as + or ++. Clinical files and endoscopy reports were studied for final diagnosis.\n\n\nResults\nFocal FDG uptake was noted in 173 out of 2,075 scans (8.4%). Focal FDG activity was judged ++ in 73 patients (42.2%) and + in 100 (57.8%). The majority of colorectal cancers scored ++. Patients with ++ activity underwent or had undergone significantly more often a colonoscopy compared with patients with + activity, 82% versus 65% (P=0.02). FDG PET/CT was false positive with respect to polyp(s) or cancer in 13 cases (22%) of ++ FGD activity and in 38 cases of + FDG (P<0.001). In 25 patients a total of 69 polyps were not FDG avid.\n\n\nConclusions\nFDG-PET scanning is a useful tool in oncology. However, false-positive and false-negative findings with respect to colonic uptake are present in a significant number of patients. If the clinical condition and the potential prognosis allows the performance of colonoscopy this procedure should be done.