Dual implantation of radiation seeds and chemotherapy wafers following surgery may help treat cancerous brain tumours, according to a new study.
The finding, based on a study, led by Ronald Warnick, MD, chairman of the Mayfield Clinic and professor of neurosurgery at UC, revealed that patients treated with simultaneous implantation of radioactive seeds and chemotherapy wafers following removal of GlioBlastoma Multiforme (GBM) experienced longer survival compared with patients who had implantation of seeds or wafers alone.
Glioblastoma multiforme (GBM), also known as grade 4 astrocytoma, is the most common and aggressive type of primary brain tumor.
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 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.
"Treatment of recurrent GBM presents a major challenge to neurosurgeons and neuro-oncologists. Glioblastoma is an aggressive, highly malignant tumor with unclear boundaries. Because of its diffuse nature, surgeons are unable to remove it completely, and it regrows in the majority of patients. Our aim is to find a way to keep the infiltrating glioblastoma cells from growing into adjacent, healthy tissue," Warnick said.
Because most GBM tumours recur within two centimetres of the initial tumor margin, the researchers focused their efforts on highly localized treatment.
In the past 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 (a radioisotope of iodine) are the size of grains of rice. The seeds are left in the brain cavity permanently, and radiation is delivered for six months.
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.
Warnick said that combining radiation seeds and chemotherapy wafers was a logical next step. The combination of seeds and wafers "appears to provide longer survival" compared with studies of seeds and wafers alone, he said, and "disease progression also seems to be further delayed."
Warnick cautioned that the effectiveness of the combination therapy is not definitive, because the study did not include a control group.
The study is published in the Journal of Neurosurgery.