Imaging-Guided Radiofrequency Ablation of Cystic Renal Neoplasms

OBJECTIVE. The purpose of this article is to determine whether percutaneous radiofrequency ablation (RFA) is effective and safe for the treatment of cystic renal neoplasms. MATERIALS AND METHODS. This is a retrospective review of imaging-guided RFA of Bosniak III and IV cysts from one institution. Thirty-eight subjects (19 men and 19 women; mean age, 71 years; age range, 46-95 years) underwent RFA of 40 cystic neoplasms (Bosniak III, n = 25; Bosniak IV, n = 15). Percutaneous biopsy was performed in 90% (36/40) of lesions. For patients with imaging follow-up of at least 1 year (n = 21), the mean duration of surveillance was 2.8 years (range, 1-6.5 years). The electronic medical record was reviewed for complications related to the procedure. Estimated glomerular filtration rate (GFR) was measured before RFA and at the last follow-up visit more than 6 months after the RFA session. RESULTS. According to percutaneous biopsy, 61.1% (22/36) of lesions were malignant, and 38.9% (14/36) of biopsies were inconclusive. There was no local tumor progression, and no subjects developed metastatic disease. One subject developed a new solid renal mass during the course of follow-up. Minor complications occurred in 5.3% (2/38) of ablations and included dysuria and mild hydronephrosis related to a blood clot in the ureter. There was one major complication (2.6%), a case of flash pulmonary edema. On average, estimated GFR decreased by 2.5 mL/min/1.73 m(2). CONCLUSION. Imaging-guided RFA is an effective and safe treatment of Bosniak III and IV cystic renal neoplasms with outcomes comparable to those of surgical therapies.