The diagnostic value of 2-¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET)/CT in the detection of colon carcinoma and adenoma was evaluated retrospectively.

Between May 2007 and June 2008, 102 patients (42 males and 60 females: age range, 28-89 years) underwent both FDG PET/CT and colonoscopy in < a 3 month interval. FDG uptake on PET/CT was divided into physiologic and pathologic uptake by a nuclear medicine specialist. Pathologic confirmation was obtained in all patients.

Forty-three patients had no abnormal findings on both FDG PET/CT and colonoscopy. One hundred five and 59 colonic lesions were detected on FDG PET/CT and colonoscopy, respectively. Eleven of 24 lesions with pathologic FDG uptake were histologically-confirmed to be malignancies. Among 18 lesions with physiologic FDG uptake, 1 carcinoma and 1 adenoma were revealed. One carcinoma, 25 adenomas, and 11 hyperplastic polyps did not reveal FDG uptake. Interpretation of pathologic FDG uptake in the colon had a sensitivity of 84.6% and 28.2%, a specificity of 90.4% and 88.1%, a positive predictive value of 45.8% and 45.8%, and a negative predictive value of 98.4% and 77.8% for carcinomas and adenomas, respectively.

FDG PET/CT is a very useful diagnostic method for the detection of colon cancer, but the sensitivity is low for adenomas, which may need further evaluation, such as a screening endoscopy.