E.E. Rutherford¹, D. Breen¹, J. Cast², C.J. Smart¹, M.C. Hayes¹; ¹Southampton/GB, ²Hull/GB

Purpose
The incidence and 5 year survival rate for renal cell carcinoma is increasing, largely due to the incidental detection of lesions at cross sectional imaging studies performed for other symptomatology. Radical and partial nephrectomy are associated with a not insignificant morbidity and mortality and as many patients are elderly with comorbidity, a minimally invasive treatment for renal tumours is clearly a valuable therapeutic option. We present our experience of percutaneous radiofrequency ablation (RFA) in the treatment of 100 renal tumours and to assess the complications and oncological efficacy of the procedure over a 6 year period.

Material and methods
RFA was performed on 100 renal tumours in 95 patients (64 male, 31 female) with a mean tumour size of 32mm. The mean patient age was 71.8 years (range 36 – 89). The ablations were carried our under ultrasound (US)(n=41) or computed tomography (CT) (n=59) guidance. Imaging follow-up was by contrast-enhanced CT within 10 days and then at 6 monthly intervals.

Results
Seventy-seven tumours were completely treated at a single sitting. Twelve of the remaining lesions were completely treated at a second sitting and a clinical decision was made not to re-treat in 8 patients. One re-treatment was abandoned due to complicating pneumothorax and the decision was made not to perform a third treatment in 2 patients with small residual crescents of tumour enhancement. The overall technical success rate was therefore 89 out of 100 tumours (89%). Twelve patients have died from unrelated pathologies during follow up. A further death due to disseminated metastases occurred in a patient with von Hippel-Lindau disease and multiple renal cell carcinomas. Follow-up of surviving patients ranged from 1 to 76 months (mean 18 months). Five patients had complications: self-limiting haematuria, duodenal thermal injury, pneumothorax, calyceal injury and ureteric stricture. No local recurrences have occurred.

Conclusion
Our experience of 100 cases over a 6 year period suggests that RFA is a safe and effective, minimally invasive method of treating small renal tumours.