Experiences in US-guided percutaneous radiofrequency ablation of 44 renal tumors in 31 patients:: Analysis of predictors for complications and technical success

Purpose: Preliminary clinical studies have shown the feasibility, safety, and efficacy of radiofrequency thermal ablation (RFA) of renal tumors, but only a few have analyzed the prognostic factors for technical success and there are no long-term results. Our objective was to statistically evaluate our mid-term results of percutaneous US-guided RFA in order to define predictors for complications and technical success. Methods: We selected for treatment 44 tumors in 31 patients (24 with renal cell carcinoma, 7 with hereditary tumors, 15 with a solitary kidney), up to 5 cm in diameter. Results: Eight adverse events occurred; 3 (6.8%) were major complications, successfully treated with interventional radiology procedures in 2 cases. Exophytic extension of the tumor was protective against complications (p = 0.040). Technical success was obtained in 38 lesions after one RFA session and in 39 (89%) after one more session, when possible. At the end of treatment, central extension was the only negative predictor for technical success (p = 0.007), while neither size > 3 cm (p = 0.091) nor other prognostic factors were statistically significant. Conclusion: US-guided percutaneous RFA can be proposed for non-central renal tumors up to 5 cm, also in patients without surgical contraindications, thanks to a low incidence of complications and a high success rate. Randomized controlled trials versus surgery are now needed to investigate long-term comparative results.