In this research study, the investigators are using FMISO-PET and MRI scans to explore the
delivery of bevacizumab to the blood vessels in patient's with recurrent glioblastoma before
and after treatment.
Bevacizumab is approved by the U.S. Food and Drug Administration for use in patients with
recurrent glioblastoma . It works by targeting a specific protein called VEGF, which plays a
role in promoting the growth or spreading of tumor blood vessels. Since anti-VEGF agents also
affect normal blood vessels in the brain, they can inhibit the way other drugs used in
combination with bevacizumab are delivered to the tumor.
In PET scans, a radioactive substance is injected into the body. The scanning machine finds
the radioactive substance, which tends to go to cancer cells. For the PET scans in this
research study, the investigators are using an investigational radioactive substance called
FMISO. "Investigational" means that the role of FMISO-PET scans is still being studied and
that research doctors are trying to find out more about it. FMISO goes to areas with low
oxygenation so parts of the tumor that do not have enough oxygen can be seen.
In addition, a vascular MRI will be used to evaluate the changes in tumor blood flow, blood
volume, and how receptive blood vessels are. This scan will be performed at the same time of
the FMISO-PET scan.