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

BACKGROUND AND AIMS: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: FDG-PET/CT is more sensitive than CT for diagnosis of CRC recurrence and can modify the management in 40% of patients.