Aim The aims of the present study were: (i) to evaluate the focal incidental colorectal uptake of 18F-fluorodeoxyglucose ([18F]FDG) and to correlate it with colonoscopy and histological findings; (ii) to evaluate the relationship between the presence/absence of neoplastic disease and clinical data and the anatomical site of [18F]FDG uptake; and (iii) to compare our results with those reported for incidental colorectal uptake of [18F]FDG in the literature and those obtained from various screening programmes for colorectal cancer. Method The database of 6000 patients referred for [18F]FDG positron emission tomography/computed tomography (PET-CT) to our centre was retrospectively reviewed for incidental colorectal uptake of [18F]FDG. Patients with focal uptake were selected and the aetiology of PET findings was verified with a subsequent colonoscopy and histopathological analysis when available. Results Incidental colorectal uptake of [18F]FDG was seen in 144 (2.4%) patients, of whom 64 (1.1%) had focal uptake; 48 out of these 64 patients underwent colonoscopy, which showed malignant tumours in 12 (25%), premalignant lesions in 19 (40%), non-neoplastic lesions in six (12%) and lesions not confirmed by colonoscopy in 11 (23%). Our data agreed with previously published data. Statistical analysis did not show any significant relationship between the presence/absence of neoplastic disease and patient sex or age, type of primary disease and anatomical site of [18F]FDG uptake. Comparing our data with various screening programmes, a significant difference was found only with series in which colonoscopy was performed in patients at high risk for colorectal cancer. Conclusion Focal incidental colorectal uptake of [18F]FDG is observed in about 1% of PET/CT studies and carries a high risk of neoplastic disease. A PET-CT report should suggest colonoscopy when abnormal findings are reported.
Treglia, G., Calcagni, M. L., Rufini, V., Leccisotti, L., De Gaetano, A. M., Giordano, A., Clinical significance of incidental focal colorectal (18)F-fluorodeoxyglucose uptake: our experience and a review of the literature., <<COLORECTAL DISEASE>>, 2012; 2012 (14): 174-180. [doi:10.1111/j.1463-1318.2011.02588.x] [http://hdl.handle.net/10807/93670]