Hemangiopericytoma

Every new classification depends on its prognostic power and on the type of treatment given. With the rapid evolution of diagnostic methods and the advance in new treatments, there is much less reliable information available on how patients with newly defined brain tumour entities should be treated and what to expect from the current treatments. The goal is to determine whether the new 2021 WHO classification, based on cIMPACT-NOW recommendations, results in more homogeneous patient groups than the old 2016 classification. Furthermore, it will help derive provisional guidelines on how patients with these newly defined tumour entities are best treated. These recommendations will be based on the experience of EORTC investigators with chosen treatments and their experience as reported in this data collection report.