Radiosensitizing Effects of Temozolomide Observed in vivo only in a Subset of O6-Methylguanine-DNA Methyltransferase Methylated Glioblastoma Multiforme Xenografts

Concurrent treatment with TMZ and RT provides significant survival benefit only in a subset of MGMT methylated tumors and provides superior antitumor activity relative to sequential administration of RT and TMZ.