A Study of Bicalutamide With Brain Re-irradiation to Treat Recurrent/Progressive High Grade Glioma

Inclusion Criteria: * Histopathologically proven diagnosis of relapsed/refractory high-grade glioma (HGG) including glioblastoma or variants (gliosarcoma, giant cell glioblastoma etc), World Health Organization (WHO) grade IV, or anaplastic astrocytoma, or anaplastic oligodendroglioma, WHO grade III. Participants will be eligible if the original histology was lower-grade glioma and a subsequent diagnosis of HGG (secondary HGG) is made. * Participants who did not have surgery for their HGG within 5 weeks prior to enrollment must have shown unequivocal radiographic evidence for tumor progression by contrast-enhanced magnetic resonance imaging (MRI) scan (or CT scan for participants with non-compatible devices). Imaging completed prior to enrollment will be acceptable for eligibility purposes if completed within 4 weeks prior to enrollment. If imaging was not completed within 4 weeks prior to enrollment then imaging must be completed within 14 days after enrollment and prior to the start of RT. Participants unable to undergo magnetic resonance (MR) imaging because of non-compatible devices can be enrolled provided CT scans are obtained and are of sufficient quality. Participants without non-compatible devices may not use CT scans performed to meet this requirement. * Participants must have passed an interval of 6 months or greater between completion of prior radiotherapy and enrollment. If participants have not passed an interval of at least 6 months, they may still be eligib…