Personalized Risk-Adapted Therapy in Post-Pubertal Patients With Newly-Diagnosed Medulloblastoma

Medulloblastoma is a rare brain malignancy, mainly affecting children. Treatment of this rapidly growing tumor begins with maximal surgical removal plus radiation and chemotherapy. Treatment toxicity is high. Post-pubertal and pediatric medulloblastomas are biologically and prognostically different, which mandates age-adapted treatment strategies. Patients after puberty bear an intermediate to high prognostic risk. This means that a large number of these patients, are faced with death and/or disability (mainly neurocognitive). Therefore, the scientific and medical need is high. One of the genetic subgroups of medulloblastoma, the SHH-subgroup (Sonic HedgeHog- subgroup), is highly overrepresented in medulloblastoma patients after puberty. This subgroup can be treated with a targeted therapy. The investigators will therefore randomize patients and treat SHH-subgroup patients with sonidegib and a reduction of radiotherapy dose in the experimental arm of the trial. The hypothesis that this personalized risk-adapted therapy will improve outcomes in view of increased efficacy and decreased toxicity.