Minimally Invasive Stereotactical Radio-ablation of Adrenal Metastases as an Alternative to Surgery

PURPOSE: The purpose of this study was to study the clinical outcome for patients with metastases of the adrenal gland treated with stereotactic body radiation therapy. MATERIALS AND METHODS: Forty-six patients were studied retrospectively. The dose prescription was 40 Gy in four fractions. Dosimetric analysis was performed using the dose volume histograms while clinical outcome was assessed using actuarial analysis with determination of the overall survival (OS) and local control (LC) rates. RESULTS: The planning objectives were met for all patients. With a median follow-up period of 7.6 months, at the last follow-up 42 patients (91.3%) were alive and four had died because of distant progression. The actuarial mean OS was 28.5±1.6 months, the median was not reached. One-year and 2-year OS were 87.6±6.1%. None of the risk factors was significant in univariate analysis. Actuarial mean LC was 14.6±1.8 months (95% confidence interval [CI], 11.0 to 18.2) and median LC was 14.5±2.0 months (95% CI, 10.5 to 18.5). One-year and 2-year LC were 65.5±11.9% and 40.7±15.8%, respectively. A mild profile of toxicity was observed in the cohort of patients. Forty patients (86.9%) showed no complication (grade 0); two patients reported asthenia, six patients (13.1%) reported either pain, nausea, or vomiting. Of these six patients, five patients (10.9%) were scored as grade 1 toxicity while one patient (2.2%) was scored as grade 2. CONCLUSION: Stereotactic body radiation therapy treatment provided an adequate clinical response in the management of adrenal gland metastases.