Clinical Role of F-18 Fluorodeoxyglucose Positron Emission Tomography for Diagnosis and Staging of Renal Tumors

Lee, Su Whan; Jo, Moon Ki; Lee, Hyun Moo

Abstract

PURPOSE: The role of [18F]fluorodeoxyglucose-positron emission tomography (FDG-PET) in renal cell carcinoma remains to be clearly defined. The sensitivity, specificity and accuracy of FDG-PET to detect renal cell carcinomas and a distant metastatic disease were compared with other established imaging modalities, including computerized tomography (CT), chest PA and bone scan.
MATERIALS AND METHODS
FDG-PET and conventional imaging techniques, including CT, chest PA and bone scan, were performed in 43 patients with primary renal tumors and/or metastatic diseases. Radical nephrectomy and metastatectomy were then performed. The results of FDG-PET were compared with the conventional imaging techniques and postoperative histopathological diagnoses.
RESULTS
The postoperative histopathological diagnoses of the 43 patients were renal cell carcinomas in 41 and benign renal tumors in 2. The results of FDG-PET were true positive, equivocal and false negative in 26, 8 and 9 of the 41 patients with renal cell carcinomas, respectively. The results of the CT were true positive in all patients. The results of FDG-PET were true negative in 2 patients, but those of CT were false positive in 2 patients with benign renal leiomyoma and angiomyolipoma. Therefore, FDG-PET was less sensitive, but more specific and accurate, than CT for the evaluation of primary renal tumors. CT was false positive for retroperitoneal lymph node metastasis and at the ascending colon in each of 1 patient, but FDG-PET was true negative. FDG-PET detected unsuspected pulmonary metastatic diseases that were not detected on chest PA in 4 patients. FDG-PET was more sensitive, specific and accurate than CT in the evaluation of metastasis.
CONCLUSIONS
FDG-PET was complementary to conventional imaging in the initial staging of renal cell carcinomas, but superior in evaluating the metastasis.