Two weeks before initiation of chemoradiotherapy with temozolomide, patients undergo MRI and PET scan using FMISO. A subset of 15 patients undergo FMISO PET scans approximately 1 week before chemoradiotherapy. Blood samples are collected at baseline and periodically during study to compare image measures of tissue uptake of FMISO to blood concentrations. Tumor samples are collected from diagnostic biopsy or surgery for analysis of tumor hypoxic markers and methylguanine methyl transferase by immunohistochemical and PCR assays.