The purpose of this study:(1) Development of a new risk classification model for childhood medulloblastoma. (2) Evaluation and improvement of existing individualized treatment protocols.

Medulloblastoma (medulloblastoma, MB) is the most common intracranial malignant tumor in children, accounting for 20% of all central nervous system tumors in children, seriously affecting the quality of life and life span of children. Based on a retrospective analysis of previous MB cases in our center, we found that the clinical prognosis of previous MB patients in our center was worse than that in foreign countries, with an overall five-year survival rate of about 65%, and nearly 30% of the patients had tumor recurrence and metastasis within 2 years after the operation, and the prognosis was poor. We analyzed the possible reasons as follows: (1) the compliance to radiotherapy and chemotherapy in children with MB in our center was poor, and some of the patients only completed radiotherapy and had poor compliance with chemotherapy; (2) due to the lack of family doctor system, the tumor of the newly diagnosed patients was huge, which seriously affected the important brain function and clinical prognosis; (3) the patients were not followed up strictly and regularly after operation to monitor tumor recurrence, which led to poor treatment effect after recurrence.

(4) the unified treatment standard has not been formed yet, and the treatment mode for patients is complex.

As the largest neurosurgery and pediatric neurosurgery center in China, the center intends to prospectively establish a high-quality homogeneous MB observation cohort in children, make use of the center's case resources and biological sample processing advantages, and carry out accurate treatment research on children's MB through regular follow-up and systematic management of the clinical cohort.

Inclusion Criteria:

• Age 0.5-18 years (except neonates).
• Pathologically confirmed medulloblastoma.
• Not having received any other relevant treatment before surgery.
• Completion of enhanced MRI of the head and spinal cord.
• Availability of tumor samples and determination of molecular typing.
• Postoperative KPS score ≥ 70.
• Voluntary enrollment in the group and the ability to receive long-term follow-up.
• The patient or the patient's family voluntarily signed the informed consent form.

Exclusion Criteria:

• Patients who have recently received other drugs or radiation therapy.
• Patients suffering from acute or chronic infectious diseases
• Patients suffering from neurological or psychiatric diseases or mental disorders that cannot be easily controlled, or poor compliance.
• Patients who cannot receive enhanced MRI scans.
• Other conditions that the investigator believes make the patient unfit to participate in this trial.

350 medulloblastoma patients aged 0.5-18 years (except newborns)