The first use of stereotactic ablative body radiotherapy (SABR) in extracranial non-lung oligometastatic disease: a single centre

Abstract

Background to the audit: There is evidence that the use of SABR is associated with improved patient outcomes.1 This audit evaluates the first use of SABR through the NHS Commissioning through Evaluation (CtE) programme in patients with extra-cranial, non-lung oligometastatic disease. Standard: The Kings Health Partnership National CtE Report V1.6,2 and the National Cancer Institute (NCI) toxicity grading criteria V5.0.3 Indicator: To evaluate local control (LC) and overall survival (OS) at 12 months, freedom from systemic anti-cancer therapy (SACT) interval and grade 3/4 toxicity. Target: To compare with the National CtE data outcomes (LC 86.8% and OS 92.3% at 12 months).2 Methodology: A retrospective review of all patients treated with SABR between April 2017eSeptember 2019. The inclusion criteria were up to three lesions, each 6c m in size, World Health Organization (WHO) performance status of 2. Results of first audit round: A total of 54 patients were treated and 11 patients had SABR to >1 site. Prescribed doses ranged from 30e60 Gray (Gy) in 3e8 fractions. The median follow up was 12 months. The LC at one year was 94.4% (51/54). The OS rate at one year was 88.8%. In 63% (34/54), there was no evidence of progressive disease during the follow-up period. Of the 37% (20/54) who did have progression, 15% (3/20) had local progression whereas 85% (17/20) had distant progression. The median freedom from SACT interval was 5.9 months (range five dayse17 months). There were no G3/4 toxicity. First action plan: This real-world data reflects the efficacy and safety for SABR in oligometastatic disease. SABR can delay systemic therapy and offer longer treatment free intervals. Updated data with an expanded cohort and assessment of tumour-specific factors will be presented.