[Conservative therapy by percutaneous radiofrequency ablation of renal cell carcinomas--therapeutic experiments of four patients with seven renal tumors--].

We report 7 renal cell carcinomas in 4 patients treated by percutaneous image-guided radiofrequency ablation (RFA). The mean age of the patients was 59 years (male: 2, female: 2). All 4 were imperative cases. Two patients (5 tumor) had hereditary multiple renal cell carcinomas with von Hippel-Lindau (VHL) disease. The other two patients had sporadic renal cell carcinomas. RFA was performed guided by computed tomography under conscious sedation with local anesthetics. The mean size of the treated tumors was 4.5 (1.8-8.1) cm. Impedance-regulated RF energy from a generator at 94 (45-130) watts was applied at 11 (8-14) min intervals. The average procedure time was 91 (45-165) minutes. The maximum tissue temperature reached 82 (56-91) degrees C immediately after ablation. Three of the 7 lesions (42.9 %) were locally well controlled during the mean follow-up period of 6.3 (4-9) months. The two patients with VHL disease developed visceral metastasis after There were no major complications. Minor complications encountered included flank pain, nausea, perinephritic hematoma and fever. Although percutaneous image-guided RFA showed limited success in large or central renal tumors, the therapy against small exophytic renal tumors would be well tolerable and successful.