[Treatment of renal tumors with radiofrequency: preliminary results]

To study the feasibility and the innocuity of the treatment by radiofrequency of small renal tumours.

From June 2000 to September 2001, 10 renal tumours in 6 patients were treated by radiofrequency. The mean age of the patients was 57 years. The mean tumour diameter was 20 mm. Indications for partial surgery were 3 solitary kidneys, one patient with chronic renal failure, one patient with Von Hippel Lindau disease and one patient in whom several angiomyolipomas were discovered in the right kidney. 4 patients were treated via a lumbar incision and 2 were treated percutaneously (one with ultrasound guidance and the other with computed tomography guidance). Patients were reviewed by imaging (CT and/or MRI) with injection of contrast agent to demonstrate complete devascularization of the tumour.

Treatment lasted an average of 180 minutes. The intraoperative complication rate was 16%. The mean hospital stay was 9 days (4 days for the percutaneous route). Nine tumours (5 patients) were devascularized after a single session. One patient (treated via the percutaneous route under ultrasound guidance) showed persistence of tumour tissue (identified by CT). A second session, performed 4 months later, allowed complete devascularization of the tumour. The mean follow-up is 13 months.

This study demonstrates the feasibility and safety in terms of renal function of radiofrequency treatment of small renal tumours. However further studies are necessary to precisely define the radiological criteria of tumour necrosis and to evaluate the long-term results of this method (outcome of necrotic tumour tissue, metastatic risk, cancer recurrence along the needle track in the case of a percutaneous approach). This treatment must be reserved for selected patients.