Phosphorus 32 in Treating Patients With Glioblastoma Multiforme

OBJECTIVES: * Determine the dosimetry toxicity of interstitial colloidal phosphorus P32 (C P32) in patients with recurrent or poor prognosis grade 4 astrocytoma. * Determine the maximum tolerated dose of C P32 administered directly into the tumor of these patients. * Determine the maximum tolerated fractionated dose of interstitial C P32 in these patients. * Determine the therapeutic response rate to the acceptable single and fractionated doses of C P32 in these patients. OUTLINE: This is a dose-escalation study. Patients receive interstitial colloidal phosphorus P32 (C P32) on day 0. Courses repeat every 4-6 weeks in the absence of disease progression or unacceptable toxicity. Cohorts of 3 patients receive escalating doses of C P32 until the maximum tolerated dose (MTD) is determined. The MTD is defined the dose at which 2 of 3 patients experience dose-limiting toxicity. Patients are followed at 1, 2, 4, 6, 9, 15, and 24 weeks. PROJECTED ACCRUAL: A minimum of 12 patients will be accrued for this study.