The application of simultaneous PET/MRI in preclinical cancer research, focusing on the study of novel cancer immunotherapies.
Kim Brewer, PhD, Assistant Professor – Department of Diagnostic Radiology, Dalhousie University,
Our research program is investigating the application of simultaneous PET/MRI in preclinical cancer research, focusing on the study of novel cancer immunotherapies. PET/MRI allows for advanced localization of both primary tumors and metastases, particularly in more complex models that are difficult to monitor without imaging, such as ovarian cancer and glioblastoma. Some of our specific ongoing research includes:
1. Evaluating combination immunotherapy in ovarian cancer – Our goal is to better understand the effects of individual immunotherapies and how these effects change in response to combination. We are using quantitative MRI cell tracking to monitor the migration and recruitment of cytotoxic T cells and dendritic cells to tumors and lymph nodes while also using [F18]FDG PET to monitor metabolic changes.
2. Developing novel PET probes for multi-parametric imaging of cancer immunotherapies – Simultaneous PET/MRI offers valuable opportunities for using novel PET probes specific to immune cells in combination with MRI specific probes and complementary MRI contrast mechanisms, particularly apoptosis as measured by a caspase-sensitive Gadolinium probe. We are working on evaluating novel [89Zr] probes that are specific to activated T cells to evaluate how different immunotherapies can affect the recruitment and migration of these cells.
3. Developing novel PET/MRI radiomic biomarkers for glioblastoma – To maximize the effect of immunotherapies, it is crucial that we develop better imaging biomarkers, both for early diagnosis and therapeutic efficacy. Simultaneous PET/MRI allows for the acquisition of several different types of image contrast and molecular indications (depending on probes used). The rapidly expanding field of radiomics seeks to move past the use of simple image analysis by incorporating larger, more comprehensive parameters encoded within images. We are developing novel radiomic biomarkers for immunotherapies and glioblastoma, one of the deadliest and hardest to treat cancers. These biomarkers as based on traditional forms of image contrast (T1, T2, DCE, [18F]FDG), as well as cutting edge techniques such as magnetic resonance fingerprinting and novel PET probes (such as a [89Zr] B cell probe).