OP09STEREOTACTIC RADIOSURGERY FOR BRAIN METASTASES AT THE CHRISTIE AT SALFORD ROYAL HOSPITAL: OUR TWO-YEAR EXPERIENCE

INTRODUCTION: Stereotactic radiosurgery (SRS) for brain metastases (BMs) commenced at The Christie at Salford in Dec 11 using the Novalis TxTM and BrainLab ExacTrac® system. We report our first 2 years' data. METHOD: Patients meeting NHS commissioning criteria were referred via MDT for assessment and if suitable consent. We used the BrainLab mask, CT and MRI. Gross tumour volumes (GTVs) were grown by 2mm if 4cm3 to a planning target volume. The dose to the 80% isodose was 21Gy/1 fraction(#), 18Gy/1# and 25.5Gy/3# alternate days for PTVs 13cm3 respectively and 30Gy/5# on alternate days to the 90% isodose in critical locations or where organ at risk constraints were exceeded. Follow up was 3-monthly with MRI and clinic review. Radiological response was classified as complete, unequivocal, enlargement consistent with treatment, enlargement suspicious of progression or unequivocal progression. RESULTS: Between Dec 11-Jan 14, 89 patients were consented, 51% female. Median age was 61 years (range 16-81). Primaries included lung (34%), breast (22%) and melanoma (15%), which was controlled in 67%; 42% had no extracranial metastases. A total of 170 BMs were treated (1 a retreat); per course a median of 2 (1-5) BMs were treated with median total GTV 4.87cm3 (0.05-29.9cm3). Prescribed dose was 21Gy/1# in 101 BMs, 18Gy/1# in 43, 25.5Gy/3# in 10 and 30Gy/5# in 16. One year survival from first SRS was: overall 48% (95% CI 34%-60%), lung 39% (18%-59%), breast 89% (62%-97%) and melanoma 44% (10%-75%). CONCLUSION: Overall survival results are encouraging and suggest appropriate patient selection. More detailed analysis including toxicity and time to intracranial progression will be presented.