Evaluation of FDG uptake by renal malignancies (primary tumor or metastases) using a coincidence detection gamma camera.
The aim of this study was to evaluate the usefulness of FDG scanning using an ordinary gamma camera equipped with coincidence detection (CDET) for 2 renal cancer indications: characterization and staging of renal masses before nephrectomy and search for recurrence after nephrectomy.


METHODS
Between September 1997 and June 1998, a whole-body scan and at least 1 tomoscintigram were obtained on 23 occasions in 22 patients (fasting for at least 6 h) using a Prism XP 2000 CDET gamma camera; scanning was begun 45 min after intravenous injection of 150-250 MBq FDG.


RESULTS
Postoperative histologic evidence was obtained from 13 of 16 patients who underwent FDG using a CDET gamma camera before renal surgery; 4 renal masses did not accumulate FDG (3 true-negatives, 1 false-negative), whereas 9 renal tumors accumulated FDG (8 true-positives, 1 false-positive). In the other 3 patients, only 1 extrarenal site of FDG uptake was checked and confirmed on histologic examination: a bone metastasis from renal cell carcinoma in 2 cases and lymph node metastasis from a squamous cell carcinoma (3 true-positives). The primary local and regional staging of the malignant renal tumors was accurate in the 9 patients who underwent nephrectomy (8 true-negatives, 1 true-positive). The primary distant staging was positive in 1 case (focus in the chest corresponding to a probable true-positive on follow-up). In the 7 examinations performed because of suspected recurrence of renal cell carcinoma several months after nephrectomy, metastases were visualized by FDG in 4 patients, confirmed by biopsy in 2 patients, and confirmed by conventional imaging or follow-up (or both) in 2 patients. The other 3 patients had negative FDG scans, corresponding to probable true-negative results on follow-up.


CONCLUSIONS
FDG using a CDET gamma camera can be used effectively for the staging and restaging of renal tumors and might be useful for characterization of the primary renal tumor in doubtful cases.
Montravers
F
F
Services de Médecine Nucléaire, Hôpital Tenon, Paris, France.
Grahek
D
D
Kerrou
K
K
Younsi
N
N
Doublet
J D
JD
Gattegno
B
B
Rossert
J
J
Costa de Beauregard
M A
MA
Thibault
P
P
Talbot
J N
JN
D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D015902:Gamma Cameras; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D009367:Neoplasm Staging; D009392:Nephrectomy; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18