Diagnostic role of [F-18]-FDG positron emission tomography in restaging renal cell carcinoma.
OBJECTIVE
To retrospectively assess the diagnostic utility of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in restaging renal cell carcinoma.


METHODS
We performed whole-body PET scans (45 minutes after intravenous injection of 10 - 15 mCi FDG) for restaging 25 patients (18 male, 7 female, 42 - 81 years old) with known or suspected metastatic renal cell carcinoma. Prior treatments included immunotherapy (n = 1), nephrectomy (n = 16), nephrectomy followed by chemotherapy (n = 3), by radiation therapy (n = 1), and by combined chemoradiation therapy (n = 4). Contrast-enhanced chest, abdomen and pelvis CT studies were available for all patients. Diagnostic validation was by histological sampling (n = 2) and clinical and imaging follow-up for up to 1 year (n = 23).


RESULTS
PET was concordant with the findings of CT in 18 patients (3 TN, 15 TP). PET was discordant with CT in 7 patients (28% of total). PET was falsely negative in 6 of these patients and did not demonstrate hypermetabolism in pulmonary (n = 4), mediastinal (n = 2), adrenal (n = 1) and lytic osseous (n = 2) metastatic lesions. PET was falsely positive in the remaining 1 patient in the discordant group with lumbar facet arthropathy. The diagnostic performance of PET in detection of recurrent and metastatic renal cell carcinoma revealed a sensitivity of 71%, specificity of 75%, accuracy of 72%, negative predictive value of 33% and positive predictive value of 94%.


CONCLUSIONS
FDG PET demonstrates modest accuracy in the diagnostic imaging evaluation of patients with suspected or known metastatic renal cell carcinoma. A negative study may not exclude disease while a positive study is suspicious for malignancy.
Jadvar
H
H
Department of Radiology, PET Imaging Science Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA. jadvar@usc.edu
Kherbache
H M
HM
Pinski
J K
JK
Conti
P S
PS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18