Introduction Many colorectal lesions with focal 18F-FDG uptake discovered incidentally on 18F-FDG PET/CT are neoplastic and often malignant, with a positive predictive value of 87%. Several large studies of focal 18F-FDG bowel uptake report a very low incidence of pathologic uptake within the small bowel (SB). This is not surprising as both benign and malignant small bowel neoplasms (SBN) are relatively uncommon. Subsequently, there is paucity of data on the PET/CT findings of SB lesions. CT detects approximately 73% of SBN. The actual incidence of...

Methods We conducted computerized text search for the word duodenum appearing anywhere within the PET/CT report on all patients undergoing FDG- PET/CT at the University of Rochester Medical Center from January 1, 2009 - July 30, 2012. Three expert radiologists reviewed those cases and classified cases with duodenal uptake as focal, multifocal, segmental, or diffuse. Results were correlated with histopathology, other imaging studies, and clinical follow up. Exclusion criteria included: Use of the word duodenum unassociated with FDG uptake Extra-duodenal tumors invading the duodenum Duplicated...

Results A total of 8725 PET/CT Scans were performed from January 1, 2009 - July 30, 2012. Only 94 of 8725 PET/CT reports contained the word duodenum in 83 patients 41 Females: age range 20.8-86 years 42 Males: Age range 20.5-89.4 years 26 of these 83 patients (28%) had duodenal FDG uptake 52 patients were excluded for the following reasons 41 for the word duodenum unassociated with FDG uptake 11 extra-duodenal tumors invading the duodenum 4 patients had no FDG uptake (3 lipomas,1 duodenal diverticulum)...

Conclusions Focal or multifocal duodenal FDG uptake is highly predictive of an underlying malignancy with a positive predictive value of 90% Diffuse and segmental uptake is commonly related to a nonspecific physiologic process and/or inflammation Further studies with larger sample sizes are needed to determine the incidence and significance of various patterns of duodenal FDG uptake in oncology patients referred for PET/CT imaging for evaluation of other unrelated malignancies Summary Small bowel tumors including the duodenum are rare, accounting for only 1-5% of all GI...

References Kamel EM, Thumshirn M, Truninger K, et al. Significance of incidental 18F-FDG accumulations in the gastrointestinal tract in PET/CT: correlation with endoscopic and histopathologic results. J Nucl Med 2004; 45:1804-1810. Israel O, Yefremov N, Bar-Shalom R, et al. PET/CT detection of unexpected gastrointestinal foci of 18F-FDG uptake: incidence, localization patterns, and clinical significance. J Nucl Med 2005; 46:758-762. Gutman F, Alberini JL, Wartski M, et al. Incidental colonic focal lesions detected by FDG PET/CT. AJR 2005;185: 495-500. Kostakoglu L, Hardoff R, Mirtcheva R, Goldsmith...

Savita Puri, MD, MPH Associate Professor University of Rochester Medical Center Department of Imaging Sciences 601 Elmwood Avenue, Box 648 Rochester, NY 14642 Phone: 585 275 6359 Fax: 585 276 1881