Residual and Recurrent Disease Following Renal Energy Ablative Therapy: A Multi-Institutional Study

Purpose: In this study we detail the incidence and pattern of residual and recurrent disease after radio frequency ablation or cryoablation of a renal mass and, using this information, determine reasonable minimum recommendations for when to perform surveillance imaging during year 1 after treatment. To our knowledge no evidence based guidelines exist for determining how or when followup abdominal imaging should be performed after renal energy ablative therapy. Materials and Methods: We reviewed treatment and followup information of patients who underwent radio frequency ablation or cryoablation for a renal mass at 7 institutions. Postoperative monitoring was performed using a variety of surveillance schedules. Results: Of 616 patients 63 were found to have residual or recurrent disease after primary radio frequency ablation (13.4%) or cryoablation (3.9%) for a median of 8.7% in 7 institutions. Most incomplete treatments (70%) were detected within the first 3 months. After salvage ablative therapy was rendered, therapy failed in only 4.2%. At a mean followup of 2 years patients with residual or recurrent disease had an overall survival rate of 82.5% and a 2-year metastasis-free survival rate of 97.4% for those with localized, unilateral renal tumors. Conclusions: In most cases initial treatment failure was detected within the first 3 months after treatment. Our findings support a minimum of 3 to 4 imaging studies in year 1 after ablative therapy, and at months 1, 3, 6 (optional) and 12.