Because most glioblastoma multiforme (GBM) tumors recur within two centimeters of the initial tumor margin, Ronald Warnick, MD, professor of neurosurgery at the University of Cincinnati (UC). and his team have focused their efforts on highly localized treatment.
Previously they studied the implantation of permanent, low-activity iodine-125 seeds following the surgical removal of the tumor. The seeds, housed in a titanium casing filled with iodine-125 are the size of grains of rice. The seeds are left in the brain cavity permanently, and radiation is delivered for six months. Other institutions have studied implantation of chemotherapy wafers, which are the size of a nickel. The wafers contain BCNU (carmustine), a standard form of chemotherapy. The wafers are placed along the surface of the brain following removal of the tumor.
Combining radiation seeds and chemotherapy wafers was a logical next step, Warnick said. The study explored the combination treatment in patients suffering from recurrent GBM. The early phase trial involved 34 patients, all of whom underwent the same treatment. No patients received a placebo. The study‘s purpose was to assess the safety and effectiveness of the highly localized, combination therapy. The median survival was 69 weeks, and nearly a quarter (eight) of the study‘s patients survived two years. In comparison, patients with recurrent GBM who undergo conventional treatment (chemotherapy) have a median survival of approximately 26 weeks.
The combination of seeds and wafers „appears to provide longer survival“ compared with studies of seeds and wafers alone, Warnick said, and „disease progression also seems to be further delayed.“ He also cautioned that the effectiveness of the combination therapy is not definitive, because the study did not include a control group.
In the most notable downside to the dual therapy, brain tissue death developed in nearly 25 percent of patients and appeared to be higher than in treatment with seeds or wafers alone. The tissue death was treated successfully with surgery or hyperbaric oxygen therapy, however, and did not affect survival.
MEDICA.de; Source: University of Cincinnati