Introduction CT PET scan with fluorine-18 (F-18) fluorodeoxyglucose (FDG), is a increasingly common investigation in the evaluation and management of several malignant and non-malignant conditions. ^(1–3). The usefulness of this technique in diagnosing incidental gastrointestinal lesions in literature is scanty. The purpose of this study was to assess the usefulness of PET scan in detecting incidental significant gastrointestinal disease.

Methods 696 PET scans were undertaken in Doncaster and Bassetlaw NHS Trust from 2009 to 2012. The principal indications were malignancy (lung 57%, GI tract 16%, head and neck 7%, haematological 4%, breast 2%) and nonmalignant 11%, unknown indication 3%. Of these, 44 cases (males 61%, median age 70) of incidental increased focal FDG uptake in gastrointestinal tract were detected. All patients underwent endoscopic procedure (Gastroscopy 10, Flexible sigmoidoscopy 10 and colonoscopy 24).

Results 21 of 44 (48%) had polyps (malignant n = 3, tubulovillous adenoma n = 11, hyperplastic n = 6, not retrieved n = 1). Other pathologies included vascular lesions, inflammation, and diverticular disease. 11 patients had a false positive PET scan. The overall correlation between PET scanning and Endoscopic findings were found to be 75%.

Conclusion PET scan is a valuable tool in localising incidental gastrointestinal pathology and a positive incidental finding merits further follow up endoscopy. The technique detected 6% new gastrointestinal lesions of which nearly half were polyps and two-thirds of these were malignant or adenomatous.

References 1 Wong PS, Lau WF, Worth LJ, Thursky KA, Drummond E, Slavin MA, Hicks RJ. Clinically important detection of infection as an ‘incidental’ finding during cancer staging using FDG-PET/CT. Int Med J 2012;42(2):(176–83)

2 Gambhir SS, Czernin J, Schwimmer J, Silverman DH, Coleman RE, Phelps ME. A tabulated summary of the FDG PET literature. J Nucl Med. 2001;42(suppl): 1S–93S

3 I Takayoshi, et al. Detection of unexpected additional primary malignancies with PET/CT. J Nucl Med. 2005;46(5):752–757

Disclosure of Interest None Declared.