Ability of integrated positron emission and computed tomography to detect significant colonic pathology: the experience of a tertiary cancer center.
BACKGROUND
The ability of integrated positron emission tomography and computed axial tomography (PET-CT) to detect colonic pathology is not fully defined. The purpose of this study was to assess the ability of PET-CT to detect colonic pathology and to determine the significance of ((18)F)2-fluoro-2-deoxyglucose ((18)F-FDG) activity noted incidentally in the colon on PET-CT.


METHODS
Records for all patients who underwent PET-CT and colonoscopy at our institution were reviewed. Patients with history of colonic malignancy or colon surgery were excluded.


RESULTS
Fifty-eight patients had incidental colonic (18)F-FDG activity on PET (Group A) and 272 had none (Group B). In Group A, 65% of patients had pathologic findings detected on colonoscopy that corresponded to the site of PET activity. Standardized uptake value (SUV) readings were not helpful in distinguishing true-positives from false-positives. In Group B, 11.8% of patients were found to have significant colonic findings. Lesions not detected by PET-CT included 4 colon cancers, 7 advanced adenomas, and 10 patients with colonic lymphoma. Overall, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET-CT for detecting significant pathology were 53%, 93%, 65%, 89%, and 85%, respectively. For detecting colon cancer and adenomas 10 mm or more, the sensitivity, specificity, PPV, NPV, and accuracy of PET-CT were 72%, 90%, 45%, 96%, and 88%, respectively.


CONCLUSIONS
Incidental colonic activity detected by PET-CT warrants further evaluation with colonoscopy. However, negative PET-CT does not rule out significant colonic pathology including colon cancer, advanced adenomas, or lymphoma.
Department of Gastroenterology, Hepatology and Nutrition, Unit 1466, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030-1402, USA.
Brian R
BR
Weston
Revathy B
RB
Iyer
Wei
W
Qiao
Jeffrey H
JH
Lee
Robert S
RS
Bresalier
William A
WA
Ross
D000236:Adenoma / Q000175:diagnosis; D003106:Colon / Q000000981:diagnostic imaging*; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003113:Colonoscopy; D003847:Deoxyglucose; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008223:Lymphoma / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D003847:Deoxyglucose