The Role of Stereotactic Body Radiotherapy in Geriatric Patients With Oligometastatic Cancer: A Geriatric Oncology...

To evaluate the efficacy, safety, and prognostic factors of stereotactic body radiotherapy (SBRT) in older patients (≥65 years) with oligometastatic disease (OMD).

In this single-center retrospective cohort study, 137 patients aged ≥65 years received SBRT to 196 metastatic lesions between March 2019 and November 2024. OMD was defined as ≤8 metastatic lesions and classified into de novo, repeat, or according to ESTRO-EORTC criteria. Outcomes of interest included overall survival (OS), progression-free survival (PFS), and local control (LC). Prognostic factors were analyzed with Kaplan-Meier estimates and Cox regression, and toxicities were graded using standard criteria.

The median age was 74 years. Prostate cancer was the most common primary tumor (43.1%), and most patients had an ECOG performance status of 0-1. The median overall survival (OS) was 47 months. Concurrent or peritreatment systemic therapy correlated with improved OS and PFS in univariate analysis (p < 0.001) but lost significance in multivariable models. Prostate cancer was linked with significantly longer OS and PFS. Patients with lung metastases had improved OS compared with those with metastases at other sites (p = 0.038). The 1- and 2-year local control (LC) rates were 93% and 88%, respectively. Adrenal metastases were associated with lower LC (p = 0.003). No grade 4 toxicity was observed. Rates of grade 2-3 acute and late toxicities were 8.7% and 6.6%, respectively, and were predominantly pulmonary.

SBRT is a safe and effective modality for older OMD patients, particularly in indolent primaries such as prostate cancer. High LC with low toxicity supports the integration of SBRT into geriatric oncology practice. Site- and histology-specific differences (e.g., adrenal vs lung) highlight the need for individualized strategies. Prospective trials incorporating Comprehensive geriatric assessment(CGA) are warranted.