Significance of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography for the postoperative surveillance of advanced renal cell carcinoma.

OBJECTIVES: To evaluate the role of (18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) for the surveillance of patients with renal cell carcinoma (RCC) who have a high risk of local recurrence or distant metastasis, by comparing the results with those of conventional imaging methods.

PATIENTS AND METHODS: Sixty-three patients with RCC had conventional imaging studies and FDG PET/CT during the follow-up after surgical treatment. Their pathological stages were T2 in 28 patients, T3a in 14, T3b in 19 and T4 in two; lymph-node or distant metastases were present in 12 patients. Suspicious recurrent or metastatic lesions were confirmed by histopathology or by clinical follow-up. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of conventional surveillance methods and FDG PET/CT were analysed. The difference in the accuracy of FDG PET/CT by nuclear grade and histological subtype of tumours was also assessed.

RESULTS: The FDG PET/CT accurately classified the presence of a recurrence or metastasis in 56 (89%) patients. FDG PET/CT had an 89.5% sensitivity, 83.3% specificity, 77.3% positive predictive value, 92.6% negative predictive value, and 85.7% accuracy in detecting recurrence or metastasis, which was not significantly different from the results with conventional methods. Moreover, the accuracy of the FDG PET/CT by nuclear grade and histological subtypes was not significantly different.

CONCLUSION: For the surveillance of high-risk RCC, FDG PET/CT had results that were as good as conventional methods and were not influenced by the nuclear grades of cancer cells. In addition, it was possible to examine all organ systems in one procedure, and there was no need for contrast agents, that can damage renal function. Therefore, FDG PET/CT might replace conventional methods.