INNV-32. LASER INTERSTITIAL THERMAL THERAPY FOLLOWED BY CONSOLIDATION STEREOTACTIC RADIOSURGERY (LITT-CSRS) IN PATIENTS WITH NEWLY DIAGNOSED BRAIN METASTASIS

Abstract INTRODUCTION The efficacy and safety of laser interstitial thermal therapy followed by consolidation radiosurgery (LITT-cSRS) was previously studied in brain metastasis that recurs locally after initial radiosurgery (BMRS). Here, we characterize the clinical outcome of LITT-cSRS in patients with newly diagnosed brain metastasis. METHODS Between 2017 and 2023, ten consecutive cancer patients with newly diagnosed brain mass of unclear etiology who underwent stereotactic needle biopsy (SNB) and LITT in the same setting followed by consolidation SRS (cSRS) with > 6 months follow-up were identified retrospectively. Clinical and imaging outcomes were collected. RESULTS The histology of the BM were: breast cancer (n=3), melanoma (n=3), non-cell cell lung cancer (n=3), colon (n=1). There were no wound or procedural complications. All patients were discharged home, with a median one-day hospital stay (range: 1-2 days). All patients were off corticosteroid therapy by the one-month follow-up. cSRS were carried out 12-27 days (median of 19 days) after SNB+LITT. There were no subsequent emergency room presentation, 30-day or 90-day re-admission. The Karnofsky Performance Score (KPS) remains stable or improved at the 3 months-follow-up. With a median follow-up of 416 days (13.8 mo; range: 199-1,096 days), there was one local recurrence at 384 days (12.8 mo) post-LITT-cSRS. Of note, this is the only patient who underwent incomplete ablation with LITT and the location of the recurrence corresponded to the residual tumor that was not treated with LITT. With exception of this patient with local recurrence, all patients showed decreased FLAIR volume surrounding the LITT-cSRS treated BMRS by the six-month follow-up. CONCLUSIONS To our awareness, this case series represent the first to describe LITT-cSRS in the setting of newly diagnosed BM. The results presented here provide pilot data to support the safety and efficacy of LITT-cSRS and lay the foundation for future studies.