Clinical impact of fluorodeoxyglucose-positron emission tomography scan/computed tomography in comparison with computed tomography on the detection of colorectal cancer recurrence

Early detection is an essential prognostic factor in colorectal cancer (CRC) recurrence. Our aim was to evaluate diagnostic performances of (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET)/computed tomography (CT) as compared with CT in the detection of CRC recurrence.Data of patients with suspected CRC recurrence and in whom both FDG-PET/CT and CT were performed were analyzed. All detected lesions were characterized according to their number, size, and localization. Positive histological or radiological follow-up was considered as the 'gold standard'. Diagnostic performances of FDG-PET/CT and CT were calculated by lesion, globally and with respect to the site of recurrence.One hundred and seventy-six true-positive lesions were identified in 71 patients. CT scan was positive in 58 (82%) patients and FDG-PET/CT in 70 (98%) patients. In per lesion analysis, the global accuracy of FDG-PET/CT in detection of lesions was of 88% (sensitivity = 95%, specificity = 54%), which was higher than that of CT (53%, sensitivity = 55%, specificity = 43%), particularly in case of lymph nodes metastases (100 vs. 35%) and locoregional lesions (100 vs. 39%) (P<0.0001). FDG-PET/CT modified the clinical management in 31 patients.FDG-PET/CT is more sensitive than CT for diagnosis of CRC recurrence and can modify the management in 40% of patients.