New Protocol Targets Aggressive Brain Tumors

Glioblastoma multiform is the most common and most aggressive form of brain tumors in adults. Typically, only 10% of patients live two years past their diagnosis. The treatment these patients are receiving was developed at the University of Michigan (U-M; Ann Arbor, USA). It uses a type of radiation treatment called intensity-modulated radiation therapy (IMRT). This allows clinicians to target the radiation to the most aggressive parts of the tumor and spare adjacent normal critical structures. The radiation is combined with a type of chemotherapy called temozolomide, which has been shown in previous studies to improve survival in this type of brain tumor.

The specialized radiation treatment is possible through novel imaging techniques, including magnetic resonance imaging (MRI) and positron emission tomography (PET) scans that give clinicians a clear image of the most aggressive and resistant parts of the tumor. IMRT allows individual beams of radiation to target only those cancerous areas, effectively carving out the tumor from the surrounding normal brain tissue. This allows clinicians to deliver higher doses of radiation to kill the cancer because healthy tissue will not also be damaged.

The study's findings up to now are preliminary but encouraging. Of 30 patients treated on this protocol, 20 have been followed for at least 12 months, and 16 have lived longer than 12 months. This is considerable progress for a disease that typically kills within a year. The other 10 patients are still less than one year out from their diagnosis.

"Novel imaging is a very important new tool for the treatment of high-grade gliomas. It will allow us to better define the target and to define aggressive areas of the tumor where higher radiation doses can be safely delivered, in combination with effective chemotherapies. Imaging will also allow us to assess response to treatment so that we can adjust therapies early,” stated Christina Tsien, M.D., assistant professor of radiation oncology at the U-M Medical School and lead investigator for this protocol.


Conventional imaging techniques require a patient complete seven weeks of treatment, followed by an MRI scan six weeks after completing therapy to determine if the tumor shrank. If the cancer did not respond to the treatment, a new approach may be tried. With newer imaging techniques, clinicians can determine effects as early as one week after treatment begins.

Patients in the study received six weeks of radiation therapy, five times per week. Concurrently, they received daily oral chemotherapy. "We get a certain effect with radiation and we get a certain effect with chemo. But by putting them together, we get a much larger effect,” Dr. Tsien stated.


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