Efficacy of Radiofrequency Ablation in the Treatment of Small Functional Adrenal Neoplasms

Purpose: To evaluate the use of radiofrequency (RF) ablation as a primary treatment for symptomatic primary functional adrenal neoplasms and determine the efficacy of treatment with use of clinical and biochemical follow-up. Materials and Methods: After obtaining institutional review board approval, the authors retrospectively evaluated images and medical records from 13 consecutive patients with symptomatic functional adrenal neoplasms (<3.2 cm in diameter) who underwent RF ablation during a 7-year period. There were six men and seven women with a mean age of 54.1 years (range, 42-71 years). Cross-sectional images, findings from clinical examination, and adrenal biochemical markers were available for all patients. Ten of the 13 patients (77%) had an aldosteronoma and one patient each had a cortisol-secreting tumor, testosterone-secreting tumor, and pheochromocytoma. RF ablation was performed by two radiologists using an internally cooled electrode and a pulsed technique according to manufacturer's specifications. Clinical and laboratory follow-up was performed for all patients. Three patients underwent imaging follow-up for other reasons. Results: All patients demonstrated resolution of abnormal biochemical markers after ablation (mean biochemical follow-up, 21.2 months). In addition, all patients experienced resolution of clinical symptoms or syndromes, including hypertension and hypokalemia (in patients with aldosteronoma), Cushing syndrome (in the patient with cortisol-secreting tumor), virilizing symptoms (in the patient with testosterone-secreting tumor), and hypertension (in the patient with pheochromocytoma). For the patients with aldosteronoma, improvements in hypertension management were noted. The mean blood pressure before ablation was 149/90 mm Hg with a mean (+/- standard deviation) of 3.1 +/- 0.6 blood pressure medications, and this decreased to 122/77 mm Hg at a mean of 2.8 months after ablation with 1.3 6 0.9 medications (P < .001) and 124/75 mm Hg at a mean of 41.4 months. There were two minor complications: one small pneumothorax and one limited hemothorax, neither of which required overnight admission. There were two episodes of transient self-remitting procedural hypertension-one in a patient with aldosteronoma and one in the patient with a cortisol-secreting tumor; however, none of these patients required further therapy during overnight observation. Conclusion: RF ablation may be an effective, minimally invasive method for treating small functional primary adrenal tumors. (C) RSNA, 2010