Imaging and Tissue Biomarkers in Patients with Newly Diagnosed Glioblastoma Multiforme (GBM)

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Investigator: Sarah Nelson, PhD
Sponsor: NIH National Cancer Institute

Location(s): United States

Description

The objective of this project is to integrate metabolic and physiologic MR imaging data into the clinical management of patients with newly diagnosed glioblastoma multiforme (GBM) who are being treated with combined radiation, chemo and antiangiogenic therapy. Our current studies have provided strong evidence that Magnetic Resonance Spectroscopic Imaging (MRSI), Perfusion Weighted imaging (PWI) and Diffusion Weighted Imaging (DWI) produce information concerning the biological behavior of such lesions that is likely to be valuable for clinical decision making. We propose to explore the impact of these imaging methods with respect to quantifying changes in imaging parameters and assessing therapeutic response in patients treated with concurrent Enzastaurin, Temozolomide and Radiation Therapy (ETRT), a therapeutic strategy that combines cytotoxic and antiangiogenic approaches. The first area that is of interest is to validate the biological interpretation of selected imaging variables presumed to be representative surrogates for tumor extent, heterogeneity, and therapeutic responsiveness, as well as prognostic significance with respect to survival. The second area of interest is in evaluating imaging characteristics prior to ETRT and their short and longer term changes that occur as a result of ETRT in order to quantify and assess treatment response. Previous studies have not utilized state of the art metabolic and physiologic imaging methods to select patients, to identify microscopic disease and heterogeneity or to evaluate response to therapy. We believe that it is critical to determine whether this approach is feasible and to obtain evidence that would help in deciding how to best integrate such information into future clinical trials. Specific Aim 1 will provide direct correlation between specific in vivo imaging and tissue characteristics by immunohistochemical and ex vivo NMR spectroscopy of image guided surgical samples from patients with newly diagnosed GBM. This will establish the link between in vivo and ex vivo MR parameters and biological behavior as defined by molecular morphology. Specific Aim 2 will analyze the characteristics of GBM in patients who are participating in an institutional Phase II clinical trial of ETRT. It will examine the relationship between pre-ETRT MR parameters and subsequent imaging changes at multiple time points up to 6 months after completion of RT. While the focus of this proposal is on one specific clinical trial, the knowledge that will be gained has broad implications for selecting and designing many other types of antiangiogenic and molecularly targeted therapies and is likely to enhance the non-invasive imaging based interpretation of treatment response, change the definition of tumor burden in patients with GBM as well as improve patient selection for future clinical trials.