Given the poor prognosis of high risk GBM, the interest of IMRT techniques for sparing healthy tissue, the replication dependent efficacy of PARPi, and the increased PARP expression in GBM as compared to non-neoplastic brain tissue, a combination of PARP inhibitors with radiotherapy and chemotherapy in newly diagnosed unresectable or partially resected GBM represents a promising way to improve care for these patients. The gene discussed is PARP1; the disease is glioblastoma.