Abstract 3754: A prospective imaging biomarker trial for early identification of GBM patients resistant to first line therapy

Abstract

Abstract We assessed whether quantification of therapeutic-associated tumor cellularity and hemodynamic alterations may help in the early assessment of treatment resistance in patients with high grade glioma. Patients with high grade glioma (n=45) received concurrent chemoradiation. Apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) maps were acquired prior to chemoradiation and at week 3 during treatment on a prospective IRB-approved study. Clinical and conventional MR parameters, including average baseline ADC and rCBV and radiological response, were evaluated as prognostic indicators of one-year survival. Parametric response map (PRM), an innovative, voxel-by-voxel method of image analysis, was also performed. Of 45 patients, median survival was found to be 14.9 months with 44% of patients living shorter than one year (median survival of 6.6 months). Baseline ADC was the only single model not found to be predictive of survival at one year, whereas in a multivariate analysis PRMADC+ and PRMrCBV- had a stronger correlation to survival than baseline rCBV. Overall, a composite model of PRMADC+ and PRMrCBV- was found to have the strongest correlation with one-year survival. This study demonstrates the potential of a composite parametric model sensitive to both tumor cellularity and hemodynamic alterations following first line therapy for providing an early assessment of patient resistant to chemoradiation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3754.