 RATIONALE: Biological therapies, such as lymphokine-activated killer cells, may stimulate the immune system in different ways and stop tumor cells from growing. Drugs used in chemotherapy, such as Gliadel wafer, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. It is not yet known whether lymphokine-activated killer cells are more effective than Gliadel wafer in treating patients with glioblastoma multiforme. 