Oligometastatic cancer in elderly patients: the "blitzkrieg" radiotherapy approach : SBRT in oligometastatic elderly patients.

Abstract

To retrospectively evaluate the outcome of stereotactic body radiation therapy (SBRT) in the treatment of elderly patients affected by isolated body metastasis from different primitive tumors. 70 patients with isolated body metastasis were treated. Median age at diagnosis was 75years (IQR 69-80). The most common SBRT fractionation scheme was 5 × 7Gy (total dose 35Gy). The primary endpoints were Local Control (LC) and Toxicity. Secondary endpoints were Overall Survival (OS) and Disease-Specific Survival (DSS). Response to radiotherapy was assessed according to RECIST criteria v1.1. Toxicity was registered according to Common Terminology Criteria for Adverse Events (CTCAE) v 4.0. We performed survival analysis with the Kaplan-Meier method. The correlation between time actuarial incidence and clinical parameters was studied. Median follow-up was 26.5months. 44 patients (62.8%) were alive at the time of analysis, while 22 (31.4%) died because of the disease. Local control at 2 and 3years was 87%. The 2-year OS and DSS were 84 and 71%, respectively, while the 3-year values were 57 and 62%. PFS at 2 and 3years was 41 and 25%, respectively. On univariate analysis, KPS ≥ 90 is statistically correlated with improved OS and DSS (p < 0.05). Acute toxicity of grade ≥ 2 occurred in 4 (5.7%) patients, while late toxicity ≥ 2 was recorded in 6 (8.6%) patients. Ablative Radiotherapy represents a safe, effective, and minimally invasive treatment modality for elderly oligometastatic patients who are judged unfit for systemic therapy.