PreOperative Brain Irradiation in Glioblastoma

PreOperative Brain Irradiation in Glioblastoma (POBIG) is a phase I study that will test the safety and feasibility of a single fraction of preoperative radiotherapy in patients with a new radiological diagnosis of glioblastoma (GBM). After the single fraction of radiotherapy, patients will receive standard treatment. The standard treatment consists of resection of the tumor followed by (chemo)radiation (i.e. radiotherapy +/- daily temozolomide (75mg/m2) for 6 weeks (60Gy/30fr) or for 3 weeks (40Gy/15fr)).

Glioblastoma is the most common primary malignant brain tumour in adults. Its outcomes are poor due to local disease progression in most patients. Current treatment includes surgery followed by chemotherapy and radiotherapy 4-6 weeks after surgery. In this time interval, some tumour cells do not receive any treatment. Furthermore, studies show that around half of all glioblastoma patients experience rapid early progression (REP) i.e. growth of the tumour in the time interval between surgery and postoperative chemotherapy/radiotherapy. REP is associated with a shorter survival and there are currently no effective treatments or preventative measures to address it. Radiotherapy delivered earlier before the operation could prevent REP and improve patient outcome. In this phase I study - PreOperative Brain Irradiation in Glioblastoma (POBIG), we will test the safety and feasibility of giving a single dose (fraction) of radiotherapy before surgery in patients with a new radiological diagnosis of glioblastoma. This study will be a dose escalation study to determine the maximum tolerated dose of preoperative radiotherapy and maximum volume of tumour that can be safely irradiated preoperatively. We hypothesise that preoperative radiotherapy will reduce the rate of REP and improve patient outcome.