Ronald Jay Zagoria MD, Presenter: Grant, Covidien AG

Joseph Pettus, Abstract Co-Author: Nothing to Disclose

Morgan Rogers BS, Abstract Co-Author: Nothing to Disclose

David Werle MD, Abstract Co-Author: Nothing to Disclose

David D. Childs MD, Abstract Co-Author: Nothing to Disclose

John Richard Leyendecker MD, Abstract Co-Author: Speakers Bureau, Bracco Group Speakers Bureau, Bayer AG

Assess long-term oncologic efficacy of CT-guided radiofrequency ablation (RFA) for renal cell carcinoma (RCC)

In this IRB-approved retrospective study, the medical records, including imaging studies, for all patients with biopsy-proven RCC who underwent percutaneous RFA prior to the year 2005 were reviewed. Records were evaluated for residual or metastatic disease, and cause of death. For living patients, physical examination, and laboratory data including abdominal CT, MRI, and chest imaging studies were reviewed. We used descriptive methods to analyze patient demographics and tumor characteristics. To estimate disease-free and recurrence free survival, we employed the Kaplan Meier method.

A total of 51 RCCs in 41 patients were treated with RFA. The mean size of RCC treated was 2.6 cm (range 0.7 – 8.2 cm). Seventeen (41%) patients with 18 treated RCCs died during the follow up period at a median time of 34 (IQR: 10, 47) months. One patient (2%) in the cohort died from metastatic RCC, while the remaining 16 died from other causes unrelated to RCC. Two patients (4%) developed asymptomatic metastatic RCC, but died from other causes. Of the three patients who developed metastatic RCC, two had undergone prior resection for RCC, which may have been the source of the metastatic disease. Of the 51 treated RCCs seven (14%) had residual tumor after a single ablation session, with the median time to detection of residual viable tumor being 11 (IQR: 1,16) months. Patients with residual tumor or recurrence underwent further treatment or active surveillance.For surviving patients abdominal CT or MRI was reviewed. Median follow up for surviving patients was 61 (IQR 55, 68) months. Twenty-four patients with 33 RCCs treated with RFA survived. Of these one had a nephrectomy for 2 RCCs 5 months following RFA due to CT evidence of tumor progression. For the remaining 31 lesions, median follow up was 61 (IQR: 54, 68) months. No patients in this group of survivors had clinical evidence of metastatic RCC, one had recurrence diagnosed at 70 months.

The rate of residual RCC after RFA is 14%, but these can rertreated for cure. There is a 7% risk of metastatic disease, especially in patients with history of resected RCC. Excluding patients with prior resection of RCC, the long-term disease free rate is 95%.

The oncologic efficacy of RFA for low stage RCC is comparable to resection.

Zagoria, R, Pettus, J, Rogers, M, Werle, D, Childs, D, Leyendecker, J, Long Term Oncologic Efficacy after Percutaneous Radiofrequency Ablation for Renal Cell Carcinoma.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9015077.html