Genitourinary tract nuclear oncology

PET FDG studies of Wilms tumors

PURPOSE

Wilms tumor is the most common renal neoplasm in children. The diagnosis is usually suggested by anatomic imaging and established by biopsy or resection. The principal roles of functional imaging have been the search for skeletal metastases and evaluation of renal function. We hypothesized that, like many tumors, Wilms tumors could concentrate 18F-FDG and that evaluation of the metabolic activity of these neoplasms might prove clinically useful.

MATERIALS AND METHODS

Three patients with known or suspected Wilms tumors underwent positron emission tomography (PET) with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) scanning (four scans). A patient with a single Wilms tumor was studied once at the time of diagnosis. The two patients with bilateral Wilms tumors were studied during therapy.

RESULTS

Uptake of FDG was present in the Wilms tumor studied at diagnosis, and in one of the tumors in each of the patients with bilateral disease studied during therapy. In all three cases, the results of the PET scans influenced therapeutic decisions.

CONCLUSION

PET FDG scanning may be useful for the management of selected patients with Wilms tumors.

Correlative imaging of the kidney

The proliferation of imaging methods for the kidney and urinary tract, combined with advances in technology and the introduction of new techniques, has created uncertainty in selecting the most efficient method for evaluating many problems encountered in clinical medicine. The main advantage of nuclear medicine lies in demonstrating the pathophysiology involved. Recent developments in Doppler ultrasound and magnetic resonance imaging with different pulse sequences and paramagnetic contrast agents also have shown promise for imaging physiological processes. However, there is little literature to support their advantage over nuclear medicine procedures in many common clinical situations. The complementary nature of nuclear medicine studies in the imaging evaluation of hydronephrosis, renal artery stenosis, flank pain, renal mass, pyelonephritis, and the transplant kidney is reviewed.