Logistical Issues

This pilot study aims to evaluate the feasibility of close glucose monitoring and management of patients (targeting fasting and pre-meal glucose of 4-7 mmol/L) using state-of-the-art flash glucose monitoring (FGM) technology. The glycemic intervention will be personalized based on individual blood glucose levels. Although the glycemic interventions used in this study include standard medications and methods of glucose monitoring used for patients with diabetes, this pilot study will specifically evaluate the feasibility of using these approaches in patients with GBM, appreciating their additional medical, functional and social challenges.

The purpose of this pilot study is to determine the feasibility of using close monitoring and management of glucose levels in patients undergoing radiation and chemotherapy for glioblastoma.

The glucose management will include the use of standard metformin a common treatment for patients with early type 2 diabetes that has also shown anti-tumor effects in GBM, and will be further personalized based on individual blood glucose levels. Additional anti-hyperglycemic management will be provided at the discretion of the Endocrinologist.

Close glucose monitoring will include flash glucose monitoring (FGM) with a device called an FreeStyle Libre Pro Flash Glucose Monitoring System, finger-prick glucose measures (standard approach for patients with diabetes) and weekly blood tests (our current standard for patients with GBM).

In addition to determining the feasibility of using these approaches, this pilot study will help identify the simplest and most effective approach of managing glucose levels in patients with GBM appreciating their additional medical, functional and social challenges.

Inclusion Criteria:

• Adult patients (> 18 years old) with a new histologically-confirmed diagnosis of glioblastoma who are planned to receive a 6-week course of concurrent radiation and temozolomide
• Has evidence of random glucose of at least 7.8 mmol/L or fasting blood glucose of at least 6.1 mmol/L (meeting criteria for oral diabetic medications)
• Able to provide informed consent
• Able to understand and follow instructions regarding self-administered capillary glucose measurements

Exclusion Criteria:

• Contraindication to MRI with gadolinium
• Taking anti-hyperglycemic medications at the time of study eligibility screen
• Unable to participate in neurocognitive evaluation in English

Adult patients who are newly diagnosed with glioblastoma