Background: The HIT network was established in 2000 to create a population-based structure aiming to improve survival rates and reduce late effects for children with central nervous system (CNS) tumors by conducting comprehensive clinical trials.

Methods: The HIT network currently consists of 10 coordinating trial centers mandated by the German Society for Pediatric Oncology and Hematology (GPOH) to conduct clinical trials and research projects, and to provide counseling to local centers for individual patients. The network is complemented by 11 reference centers (neuropathology, tumor biology, neuroradiology, pediatric neurosurgery, cerebrospinal fluid [CSF], assessments, radiotherapy, genetics), biostatistical support, and currently 72 local treatment sites.

Results: Numbers of children and adolescents with newly diagnosed CNS tumors registered to trials and registries increased from approximately 500 to more than 600 per year, corresponding to >95% of affected HIT-eligible children and adolescents in Germany. Clinical counseling and upfront reference assessments ensure homogeneous clinical standards and avoid inadequate treatment of individual patients. Since 2007, the established reference services have been partially re-funded by German health insurances.

Discussion: The HIT network provides a unique structure for population-based state-of-the-art diagnostic assessments, treatment recommendations and counseling. It increases the "a priori" accuracy of stratification parameters, and the timely inclusion into clinical trials and tumor-specific registries. Favorable outcomes are achieved within the trials and registry landscape, for example, through consistent reference assessments, reducing the gap to real world data. Resulting data facilitate representative, unbiased high-quality research projects across all CNS tumor entities. Interdisciplinary cooperation and competitive scientific output are enhanced.