Value of 18F-fluoro-2-deoxyglucose positron emission tomography in the evaluation of recurrent colorectal cancer.

To evaluate the clinical value of positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) in recurrent colorectal cancer, the records of 33 patients who underwent 34 FDG-PET scans were reviewed and compared with computed tomography (CT) and carcinoembryonic antigen (CEA). The final diagnosis was based on operative, histopathological findings or clinical follow-up > 1 year. FDG-PET detected all 15 patients with recurrent diseases (9 local recurrences, 4 lymphatic metastases, 2 hepatic metastases and 8 pulmonary metastases) and 1 primary lung cancer. However, there were 3 false positive cases. The overall sensitivity and specificity of FDG-PET were 100% and 83%, respectively. The sensitivity and specificity of CEA were 33% and 86%, respectively, for detecting recurrent colorectal cancer. Abdominal CT had a sensitivity and specificity of 78% and 61% for detecting local recurrence and detected one lymphatic and one hepatic metastasis. In conclusion, the FDG-PET was more accurate than CT and CEA for the detection of recurrent colorectal cancer. In addition, it accurately detected distant metastases or occult secondary malignancy and may affect clinical management.