The role of stereotactic body radiation therapy (SBRT) in the treatment of oligometastatic disease in the elderly

Objective: To report about clinical outcome of stereotactic body radiation therapy (SBRT) in the treatment of oligometastatic disease in elderly patients. Methods: Patients with 1-4 inoperable metastases were treated with SBRT. Dose prescription ranged from 40 to 75Gy in 3-8 fractions. SBRT was delivered using the volumetric modulated arc therapy technique with flattening filter-free photon beams. The primary end points were in-field local control (LC) and toxicity. Secondary end points were overall survival (OS) and disease-specific survival (DSS). Results: 82 patients with 111 total metastases were treated. Median age was 79 years. 64 patients (78%) had a single lesion; the remaining patients had 2-4 lesions. 16 (14.4%) lesions were localized in the abdomen, 50 (45.0%) in the liver and 45 (40.5%) in the lungs. Local response was observed for 87 lesions (78.4%) while local progression was observed in 24 lesions (21.6%). Actuarial 1-year LC was 86.8%63.3%. Actuarial 1-year OS was 93.6%62.7%. 2-year findings were 76.3%64.4% and 72.0%65.6%, respectively. Actuarial 1- and 2-year DSS results were 97.5%62.0% and 81.6%64.9%, respectively. Treatment-related Grade 2-3 toxicity was observed in five patients (4.2%); Grade 1 toxicity in seven patients (5.9%) and no toxicity was observed in 85.4% of the cases. Conclusion: SBRT is a safe and effective therapeutic option for the treatment of oligometastatic disease in the elderly with acceptable rates of LC and low treatmentrelated toxicity. Advances in knowledge: The use of SBRT for oligometastatic disease in the elderly can be considered as a valuable approach, particularly for patients with fragile status or refusing other approaches.