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.
Weston
Brian R
BR
Department of Gastroenterology, Hepatology and Nutrition, Unit 1466, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030-1402, USA.
Iyer
Revathy B
RB
Qiao
Wei
W
Lee
Jeffrey H
JH
Bresalier
Robert S
RS
Ross
William A
WA
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