 - Prior chemotherapy and radiation therapy are allowed at least 4 weeks must have passed from prior chemotherapy and radiotherapy 6 weeks for nitrosoureas or mitomycin C, provided that clinically significant toxicity related to prior chemotherapy or radiotherapy has returned to baseline or National Cancer Institute NCI Common Toxicity and Adverse Events CTCAE grade 2 and are not expected to recover further. The toxicities specifically exclude alopecia. 