To evaluate the use of computed tomography-guided, resistance-based, percutaneous radiofrequency ablation of renal malignancies using conscious sedation.

Twenty-three patients with a mean age of 74 years underwent 27 PRFA treatments, using only conscious sedation, for enhancing renal masses, with a mean renal mass of 2.69 cm. All patients had multiple medical comorbidities that precluded standard operative management. Patients were followed up postoperatively at 3-month intervals with renal function studies and enhanced imaging. Successful ablation was defined as a lack of enhancement or resolution of the renal mass.

Of the 23 patients, 16 (80%) had successful ablation with a single treatment, 4 had initial failure, and 3 were lost to follow-up. Of the 4 patients with initial failure, 2 underwent reablation successfully, 1 patient elected watchful waiting, and 1 patient died of metastatic renal cell carcinoma. The overall cancer-free survival rate was 90% (18 of 20 patients) at a mean follow-up of 24 months. The exclusion of 2 patients who underwent four sessions for renal masses greater than 4 cm improved the survival rate to 94% (17 of 18). No statistically significant difference was found between the preoperative and postoperative serum creatinine levels (P = 0.46), even in the patients with a preoperative creatinine level greater than 1.5 (P = 0.51). Our only complication was a single perinephric hematoma that resolved spontaneously.

We have demonstrated promising oncologic results for computed tomography-guided percutaneous radiofrequency ablation of tumors in select patients with small renal masses. The procedure was well tolerated under conscious sedation. None of the patients demonstrated significant changes in renal function.