Dose Escalated MRSI Guided Radiation Therapy in Glioblastoma

This phase II study will investigate efficacy and safety of volumetric 3D MRSI-directed treatment for newly diagnosed GBM patients. This study will enroll 48 patients in order to obtain at least 40 patients receiving RT and temozolomide. Depending on the size and number of HTVs, a patient will receive either simultaneous integrated boost (SIB) with IMRT (Group 1) or SRS boost followed by IMRT 1 week later (Group 2). Duration of enrollment will be 2 years and minimum follow-up will be 2 years. The duration of treatment and follow-up will occur as follows: * Six weeks of RT with concurrent Temozolomide treatment; * 3D MRSI at week 3 and at the end of RT; * 28 day break; * Adjuvant treatment with Temozolomide administered daily on days 1-5 of each cycle, for up to 12 cycles (one cycle = 28 days) which will include standard gadolinium enhanced MRI and 3D MRSI prior to cycle 1, 5, 9, and post cycle 12 of adjuvant Temozolomide; * Active follow-up at least every three months for one year after the end of adjuvant Temozolomide treatment; * After one year follow-up for survival will occur every three months for one year.