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.