FDG PET characterization of renal masses: preliminary experience.
OBJECTIVE
This study was undertaken to evaluate the potential efficacy of fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) to detect renal tumours and to characterize indeterminate renal cysts.


METHODS
Twenty-six PET scans were performed in 21 patients (14 PET scans in 10 patients with malignant renal tumours and 12 PET scans in 11 patients with Bosniak type 3 indeterminate renal cysts). Pathological proof was obtained in 18 of 21 patients (10 with solid neoplasms, eight with indeterminate cysts). Imaging was performed 1 h after injection of 5-10 mCi of FDG with IV administration of Lasix (10 mg) 20 mins after injection. Two consecutive 9.7-cm image segments were scanned to cover the entire renal areas.


RESULTS
PET accurately depicted solid neoplasms as areas of increased uptake in nine of 10 patients. Bilateral renal cell carcinomas were missed in one diabetic patient. All but one indeterminate renal cysts were correctly classified as benign (photopenic areas), but an indeterminate cyst with a 4-mm papillary neoplasm was wrongly classified as benign. There were no false positive PET interpretations. The mean tumour-to-kidney ratio was 3.0 for malignant lesions.


CONCLUSIONS
We conclude that FDG PET scanning shows promise in the evaluation of indeterminate renal cysts. A positive PET scan in the appropriate clinical setting obviates the need for cyst aspiration. A negative PET scan in conjunction with a negative cyst aspiration offers confirmatory evidence of benignity. Our preliminary results are encouraging and further work is ongoing.
Goldberg
M A
MA
Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, USA.
Mayo-Smith
W W
WW
Papanicolaou
N
N
Fischman
A J
AJ
Lee
M J
MJ
D000328:Adult; D000368:Aged; D003847:Deoxyglucose / Q000031:analogs & derivatives; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000000981:diagnostic imaging*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose