High Light and Low Light Dose PDT in Glioma

RATIONALE: Photodynamic therapy uses a drug, such as porfimer sodium, that becomes active when it is exposed to a certain kind of light. When the drug is active, tumor cells are killed. Giving photodynamic therapy after surgery may kill any remaining tumor cells. PURPOSE: This randomized clinical trial is studying two different light doses of photodynamic therapy using porfimer sodium to compare how well they work in treating patients who are undergoing surgery for recurrent malignant astrocytoma.