Contribution of 18F-fluorodeoxyglucose positron emission tomography in the detection and evaluation of peritoneal metastasis in colorectal cancer

Accurate detection of peritoneal metastasis in colorectal cancer remains a diagnostic challenge. The accuracy of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis of peritoneal recurrence was evaluated, FDG-PET was conducted in 18 patients previously treated for colorectal cancer and suspected recurrence with clinical symptoms, computed tomography (CT), and tumor markers. Final Diagnosis was obtained by histological evaluation (n=14) or clinical follow-up (n=4). FDG-PET sensitivity was 88%, and accuracy in detecting peritoneal recurrence was 78%. For CT scans, sensitivity was 38% and accuracy 44% Six patients were suspected to have peritoneal recurrence based on FDG-PET and 5 were identified pathologically with peritoneal metastasis. Lesions smaller than 30 mm were not detected by CT. FDG-PET detected 15 mm lesions. In conclusion, FDG-PET is an accurate, noninvasive way to detect peritoneal recurrence in colorectal cancer and would play an important role in clinical management. (author)