GammaTile and Stupp in Newly Diagnosed GBM

At the initiation of the surgical phase maximal safe resection will be undertaken, and after 25 + 4 from surgery participants will start the concomitant phase and receive daily temozolomide (TMZ, 75mg/m2) and 20 fractions external beam radiation (EBRT). The EBRT treatment will be to the operative bed and any residual disease identified at the time of the imaging obtained for EBRT planning. The EBRT planning will utilize the GT implant dosimetry with the intent that the dose received from the GT will be accounted for during the EBRT treatment planning process. Twenty-eight days ±7 after the completion of concomitant TMZ and EBRT, participants will enter the adjuvant phase and will be treated with TMZ (150-200mg/m2) for 5 days at the start of every 28- day cycle, for 6 cycles.