- Recovery from Prior Therapy Patients must have recovered from the acute toxic effects of all prior chemotherapy, immunotherapy, or radiotherapy, prior to entering this study and must be without significant systemic illness (e.g. infection unresponsive to treatment after 7 days). Such that they are healthy enough to safely undergo tumor biopsy and Ommaya reservoir placement. Patients must not have received any systemic therapy for recurrent disease within 3 weeks (6 weeks if a nitrosourea), or irradiation within 8 weeks prior to treatment on this study.