Varkarakis IM et al. (2005) Percutaneous radio frequency ablation of renal masses: results at a 2-year mean followup. J Urol 174: 456–460

The emerging technique of percutaneous CT-guided RADIOFREQUENCY ABLATION (RFA) is a minimally invasive alternative to surgical tumor resection. Varkarakis and colleagues at the Johns Hopkins Medical Institutions have recently published their experience of RFA for the treatment of small renal tumors, with a mean follow-up of 27.5 months.

This retrospective analysis reviewed 46 patients with renal masses (56 tumors) who had undergone percutaneous CT-guided RFA between September 2000 and September 2003. Patients were followed up with CT or MRI at 3, 6, and 12 months, and then at 6–9-monthly intervals. Ablation was considered successful if follow-up imaging revealed no evidence of tumor growth or contrast enhancement.

Local tumor control was achieved in 94.6% of tumors. The success rate was significantly higher for tumors <3 cm in diameter than for those ≥3 cm (100% and 78.5%, respectively; P <0.05). There were three treatment failures, at 24, 25, and 31 months, respectively, all of which occurred in patients with tumors ≥3 cm. Non-centralized tumors (those located >5 mm from the renal sinus) were associated with higher success rates than centralized masses (P <0.05). The authors concluded that RFA can achieve outstanding local control of small renal masses, particularly in tumors <3 cm in diameter. However, they caution that a treatment failure as late as 31 months demonstrates the importance of long-term follow-up in future trials of this therapy.