Purpose
To describe the safety and efficacy of image-guided radiofrequency ablation (RFA) of solid renal tumors
Material and methods
Between May 2000 and July 2005, 177 tumors in 137 patients have been treated with image guided percutaneous or intraoperative RFA. Since December 2003, biopsies were performed, when technically possible, on all tumors immediately prior to ablation. Tumor location was classified as exophytic, intraparenchymal or central. Initial technical success was defined as an ablation that produced a volume of tissue showing no enhancement on CT or MRI that encompassed the original tumor. Local tumor progression was defined as any tumor that showed visible intralesional enhancement or serial increase in size when compared to the immediate post ablation CT or MRI study.
Results
Treated tumors ranged in size from 0.3 - 6.5 cm, (mean, 2.2 cm  0.9 cm ). One hundred two of 177 tumors (58%) were exophytic, 67 (38%) were intraparenchymal and 8 (5%) were central. One hundred twenty eight of 137 patients (93%) were treated percutaneously alone, 7 (6%) were treated intraoperatively alone and 2 (1%) were treated by both methods. Immediate post ablation CT or MR was available in 129 patients with 167 tumors. Two of 167 treated tumors (1%) showed residual enhancement in 2 of 129 patients (2%) resulting in a technical success rate of 98%. Contrast enhanced CT or MRI follow-up imaging was available in 114 patients with 150 tumors with a range of 2-57 months (mean, 15 months). Local tumor recurrence was identified in 6 of 150 tumors (4%) in 6 of 114 patients (5%) resulting in a local tumor control rate of 95%. Major complications were seen in 7 of 137 patients (5%) including 4 proximal ureteral injuries with secondary urinary obstruction, one AV fistula successfully treated with embolization, one significant self-limiting perirenal hematoma, and one patient with pyelonephritis requiring hospitalization for antibiotics.
Conclusion
RFA of renal tumors is a safe and effective minimally invasive alternative treatment option for renal tumors in select patients