There is increasing incidence of brain metastases (BM) in women with primary breast cancer (BC) due to improved efficacy of systemic therapy in controlling extra-cranial disease, and increasing use of magnetic resonance imaging (MRI) for surveillance. The conventional treatment for patients with BM has been whole brain radiotherapy. However, over the last few years, there has been a change in the philosophy in radiotherapy for limited BM, favouring the use of stereotactic radiosurgery (SRS), and avoiding or delaying whole brain radiotherapy. The aims of this...

Study population: This is a population-based cohort of women with BC who were treated with radiotherapy for BM between January 2013 and December 2016, as captured in the Victorian Radiotherapy Minimum Data Set (VRMDS). Brain radiotherapy technique was classified as SRS (including multifraction stereotactic radiotherapy) and non-SRS. The data was linked with the Victorian Cancer Registry (VCR) to capture mortality data. Outcomes: Proportion of women who were treated wtihSRS technique. Overall survival (OS) following radiotherapy for BM. Statistical analyses: Descriptive statistics was used to evaluate...

SRS utilisation A total of 336 women with primary BC who had radiotherapy for BM were included in this study, of which 27% (92/336) were treated with SRS technique (Table-1) The mean age at first course of brain radiotherapy was 59 years old (SD=12.6) A total of 533 courses of brain radiotherapy were delivered, of which 37% (195/533) were classified as SRS Two-thirds of SRS were delivered inpublic institutions (127/195), compared to one-third (68/195) in private institutions (P

This is the largest Australian population-based study evaluating the use of SRS for BM in women with primary BC, and the associated outcomes. We observed geographical variation in SRS use in women with primary BCwho received radiotherapy for BM, such that those treated in regional centres were less likely to be treated with SRS Patients who had SRS had improved OS; however, we believe that this is most likely confounded by patient selection for SRS