An audit of initial experience of stereotactic body radiotherapy for extracranial oligometastases.

Abstract

e23333 Background: To retrospectively review the toxicity and early outcome data from patients who have received stereotactic body radiotherapy (SBRT) for extracranial oligometastases in our institution. Methods: Eligible patients had ≤3 extracranial metastases and performance status ≤2. Prior systemic therapy and radical treatment of oligometastastic relapse with any standard treatment modality was permitted. Follow-up consisted of clinical examination, and radiological assessments. RECIST criteria was used for defining progression events. Toxicity was evaluated using CTCAE v5.0. Local control, progression-free survival (PFS) and freedom from widespread distant metastasis were calculated. Results: Between August 2023 and April 2025, 22 patients with 43 metastases received SBRT (range 1–3 per patient). Most common sites were lymph nodes(19), liver(14) ad spine(10). The median follow-up was 12.5 months (range 0–20.4). The median PFS was 12.5 months (1 year PFS 57%); 1 year local control 96%. At 1 year, 76% of patients were free from widespread distant metastases. No ≥ grade 3 acute or late toxicity was observed. Conclusions: SBRT for extracranial oligometastases demonstrated excellent early local control with minimal toxicity. These findings warrant confirmation with longer follow-up and randomized controlled trials to determine the impact on survival outcomes when added to standard care.