The hormonal and intellectual deficits created by these therapies causes significant impairment of the survivors.In current clinical studies, the patients are divided into low-, standard- and high-risk groups:

Depending on the study, healing rates of up to 100% are achieved in the low-risk group (usually WNT-activated). The current efforts are therefore moving in the direction of reducing the intensity of the therapy and thus the negative long-term consequences while confirming the high healing rates. In the HIT-SIOP PNET 4 study, in which 340 children and adolescents of the standard-risk group between the ages of four and 21 from several European countries participated, the 5-year survival rate was between 85% and 87% depending on the randomization. Around 78% of the patients remained without relapse for 5 years and are therefore considered to be cured. After a relapse, the prognosis was very poor. Despite intensive treatment, only four of 66 patients were still alive 5 years after a relapse. A US study involved 161 patients between the ages of three and 21 with a high-risk profile. Depending on the randomization, half of the patients additionally received carboplatin daily during the radiation. The 5-year survival rate of patients with carboplatin was 82%, those without 68%. The European SIOP PNET 5 study is currently taking place and will run until April 2024, in which an attempt is made to confirm the promising results with carboplatin during irradiation in the standard risk group. Epidemiology
Medulloblastomas affect just under two people per million per year, and affect children 10 times more than adults.
The child typically becomes listless, with repeated episodes of vomiting, and a morning headache, which may lead to a misdiagnosis of gastrointestinal disease or migraine. Soon after, the child will develop a stumbling gait, truncal ataxia, frequent falls, diplopia, papilledema, and sixth cranial nerve palsy. Positional vertigo and nystagmus are also frequent, and facial sensory loss or motor weakness may be present. Decerebrate attacks appear late in the disease. Extraneural metastasis to the rest of the body is rare, and when it occurs, it is in the setting of relapse, more commonly in the era prior to routine chemotherapy. Pathogenesis
Medulloblastomas are usually found in the vicinity of the fourth ventricle, between the brainstem and the cerebellum. Tumors with similar appearance and characteristics originate in other parts of the brain, but they are not identical to medulloblastoma.Although medulloblastomas are thought to originate from immature or embryonal cells at their earliest stage of development, the cell of origin depends on the subgroup of medulloblastoma. WNT tumors originate from the lower rhombic lip of the brainstem, while SHH tumors originate from the external granular layer.Currently, medulloblastomas are thought to arise from cerebellar stem cells that have been prevented from dividing and differentiating into their normal cell types. This accounts for the histologic variants seen on biopsy. Both perivascular pseudorosette and Homer Wright pseudorosette formations are highly characteristic of medulloblastomas and are seen in up to half of cases.