NI-58LOCATION OF GLIOBLASTOMA INTERSECTIING WHITE MATTER TRACTS PREDICT PATIENT PROGNOSIS AND RESPONSE TO BEVACIZUMAB PRIOR TO THERAPY

• Published in: Neuro-oncology (Charlottesville, Va.) Va.), 2014-11, Vol.16 (Suppl 5), p.v151-v151
• Main Authors: Mickevicius, Nikolai, Carle, Alexander, Santarriaga-Escamilla, Stephanie, Bluemel, Trevor, Connelly, Jennifer, Rand, Scott, Mueller, Wade, Schmainda, Kathleen, LaViolette, Peter
• Format: Article
• Language: English
• Subjects: Abstracts
• ISSN: 1522-8517; 1523-5866
• DOI: 10.1093/neuonc/nou264.56

INTRODUCTION: Brain tumors are known to invade healthy brain along white matter tracts. We therefore hypothesized that specific white matter tracts would be associated with poorer prognosis based on their connection to primitive brain regions necessary for essential life functions. We also hypothesized that tumors in these regions treated with bevacizumab would alter patient survival. METHODS: 109 subjects with primary GBM tumors were retrospectively included in this study. Voxel-wise survival analyses were performed to test for spatial and treatment dependence of GBM survival prognosis. An intersection analysis was first performed between an enhancing tumor mask and template-space diffusion tensor imaging (DTI) derived tractography which highlighted voxels with tumor-intersecting white matter tracts. Maps of voxels with these tracts were made for each patient. A voxel-wise Kaplan-Meier test was performed comparing the survival times of patients with and without a tumor-intersecting white matter tract in that voxel. The same analysis was implemented to compare survival of participants with and without bevacizumab. This highlighted regions where survival was effected due to anti-VEGF treatment. A Monte Carlo simulation was performed to validate the observed survival differences induced by bevacizumab considering inconsistencies in treatment regimens seen in the patient population. RESULTS: Glioblastoma patients with tumors intersecting the right anterior thalamic radiation, right inferior fronto-occipital fasciculus, bilateral corticospinal tracts, and corpus callosum have decreased survival compared to those with tumors intersecting elsewhere. Patients treated with bevacizumab and who also had tumors intersecting the corpus callosum, corticospinal tract, or the thalamic radiations were found to be at a survival advantage when compared to those who did not receive bevacizumab. CONCLUSIONS: Patient prognosis is associated with the location of tumor intersecting WM tracts. A survival advantage was found in tumors intersecting specific WM tracts treated with bevacizumab.