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

To evaluate the clinical value of positron emission tomagraphy (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 I 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 coloectal 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 cancel: In addition it accurately detected distant metastases or occult secondary malignancy and may affect clinical management.