CTNI-01. EFFECT OF PRE-OPERATIVE STEREOTACTIC RADIOSURGERY ON BRAIN METASTASIS: ANALYSIS OF DNA AND RNA GENOMIC PROFILES FROM PHASE-II CLINICAL TRIAL NCT03398694

Abstract BACKGROUND With improved systemic therapy that has limited impact on the intracranial compartment, incidence of brain metastasis (BM) from solid cancers is rising. Treatment varies based presentation, however, for patients with < 4 symptomatic BMs current clinical practice involves surgical resection followed by stereotactic radiosurgery (SRS) to cavity. Post-operative SRS associated increased risk leptomeningeal disease (LMD) and local recurrence. We hypothesize pre-operative will decrease LMD as well recurrence, increase patient’s OS delivering a lethal dose radiation tumor cells before they are disturbed resection. In Phase II trial (NCT03398694) we treating 1-4 while collecting DNA RNA sequencing data core peripheral edges resected examine genomic effects tumor. METHODS Post-SRS specimens were divided into two groups: ‘center’ ‘periphery’ respect center treatment periphery within 50% isodose line. Previously untreated used control. RESULTS/CONCLUSIONS Our initial analyses show pre-treatment results in significant changes at levels throughout when compared non-radiated tumors. matched samples damage levels, measured high mutation load, similar indicating no evidence fall off effect damage. However, differing locations expression profiles between present, which may indicate unequal repair processes Furthermore, global differed significantly different primary signaling importance cancer location determining viable therapeutic targets.