Role of multidetector CT and FDG-PET/CT in the diagnosis of local and distant recurrence of resected rectal cancer

PURPOSE: The aim of this study was to compare the diagnostic value of multidetector computed tomography (MDCT) and F18-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) for the detection of local and distant recurrence in patients operated on for rectal cancer. MATERIALS AND METHODS: Sixty-seven patients who underwent radical surgery for rectal cancer and were followed up with FDG-PET/CT and MDCT were included in this retrospective study. The FDG-PET/CT and MDCT findings were independently compared with histological sampling or 2 years' follow-up. RESULTS: Local recurrence occurred in 15/67 patients. MDCT diagnosed local recurrence in 15/15 cases and FDG-PET/CT in 14/15. Sensitivity and specificity were 100% and 98% for MDCT and 93% and 98% for FDG-PET/CT, respectively. Hepatic lesions were found in 17/67 patients. All hepatic metastases were detected by both techniques. Pulmonary metastases occurred in 8/67 patients: they were correctly identified in all cases by MDCT and in 6/8 by FDG-PET/CT. CONCLUSIONS: MDCT and FDG-PET/CT showed high sensitivity and specificity for the detection of local recurrence of rectal cancer. Both techniques were equally accurate for the detection of hepatic metastases. MDCT showed slightly higher sensitivity and positive predictive value in detecting pulmonary metastases compared with FDG-PET/CT.