INTRAGO-Intraoperative Radiotherapy for Glioblastoma - a Phase I/II Study

Glioblastoma multiforme (GBM) is a disease with an extremely poor prognosis. Despite surgery and radiochemotherapy, the tumors are likely to grow back very quickly. Intraoperative radiotherapy (IORT) may improve local control rates while sparing healthy tissue (Giordano et al. 2014). IORT takes place before cranioplasty directly after gross (or subtotal) tumor resection. Several past studies on IORT for GBM conducted in Japan and Spain have yielded encouraging results (Sakai et al. 1989; Matsutani et al. 1994; Fujiwara et al. 1995; Ortiz de Urbina et al. 1995). However, the full potential of the procedure is to date largely unexplored as most previous studies used forward-scattering (electron-based) irradiation techniques, which frequently led to inadequately covered target volumes. With the advent of the spherically irradiation devices such as the Intrabeam® system (Carl Zeiss Meditec AG, Oberkochen, Germany), even complex cavities can be adequately covered with irradiation during IORT. However, there is no data on the maximum tolerated dose of IORT with low-energy X-rays as generated by this system. The INTRAGO I/II study aims to find out which dose of a single shot of radiation, delivered intraoperatively direct after surgery, is tolerable for patients with GBM. A secondary goal of the study is to find out whether the procedure may improve survival rates.