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9 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Medulloblastoma is the most common malignant childhood brain tumour, arising in the cerebellum. Surgery, radiation to the whole brain and spine, and chemotherapy cure about 70%, at a heavy cost to thinking and growth; treatment is now being tailored to four molecular subgroups so that the low-risk children get less.
Medulloblastoma is an embryonal tumour of the posterior fossa with four consensus molecular subgroups (WNT, SHH, Group 3, Group 4) that differ in age, genetics, metastatic tendency and survival: WNT (~10%, CTNNB1 mutations, >95% survival), SHH (~30%, PTCH1/SUFU/SMO, TP53-mutant subset with shorter survival; infants and adults), Group 3 (~25%, MYC amplification, worst prognosis) and Group 4 (~35%, most common, intermediate). WHO 2021 integrates histology and molecular group.
Standard therapy is maximal safe resection, craniospinal irradiation (CSI; 23.4 Gy for average risk, 36 Gy for high risk) with posterior fossa/tumour bed boost, and adjuvant cisplatin-based chemotherapy (cisplatin, vincristine, cyclophosphamide, lomustine). Infants under 3 receive radiation-sparing intensive chemotherapy (with high-dose chemotherapy/autologous rescue or intraventricular methotrexate) because CSI causes lasting harm to the developing brain. Risk-adapted trials (SJMB12, ACNS1422, SIOP PNET5) are reducing CSI dose for WNT tumours and testing SMO inhibitors for SHH tumours in skeletally mature patients. Proton therapy reduces exit dose to cochlea, heart and thyroid. Relapse is rarely curable outside infants; MRI-based surveillance, cfDNA in CSF, and survivorship (neurocognition, endocrine, hearing, second cancers, cerebellar mutism) dominate follow-up.
| Setting | Approach | Guideline |
|---|---|---|
| Average risk (≥3 years, M0, <1.5 cm² residual, no MYC amp) | Resection, CSI 23.4 Gy with boost to 54 Gy (proton where available), then cisplatin/vincristine/cyclophosphamide or lomustine-based chemotherapy (ACNS0331); WNT tumours receive reduced CSI in trials. | not mapped |
| High risk (metastatic, residual, anaplastic, MYC) | CSI 36 Gy ± concurrent carboplatin (ACNS0332 for Group 3), then multi-agent chemotherapy; high-dose chemotherapy with stem-cell rescue in some protocols. | not mapped |
| Infants (<3 years) | Radiation-avoiding intensive chemotherapy (Head Start, HIT-SKK with intraventricular methotrexate); desmoplastic/SHH infants do well, Group 3 infants poorly. | not mapped |
| Relapsed | Re-irradiation, temozolomide-irinotecan ± bevacizumab, SMO inhibitor (vismodegib/sonidegib) for SHH in post-pubertal patients, clinical trials; cure is rare. | not mapped |