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High Risk Disease

Risk Category



<3 years (generally treated with initial intensive chemotherapy alone - see infant medullo)

>3 years with:


  • Overt metastatic disease based on CSF cytology or neuro-imaging


  • Gross residual disease (more than 1.5 cm2 after surgery)



It is generally recommended that children with metastatic disease should be given full dose craniospinal radiation therapy (36 Gy to the craniospinal axis in 180 cGy fractions) plus intensive chemotherapy and boosts to spinal deposits to a total of 45 Gy and a boost to the posterior fossa to a total of 55.8 Gy in 180 cGy fraction size or 54 Gy in 180 cGy fraction size.

If the child is between 3 and 5 years old, this treatment plan is sometimes modified because of the risks of serious neurocognitive delay after moderately high craniospinal RT.  Intensive chemotherapy may be given and attempts made to reduce the amount of radiotherapy used.

Chemotherapy such as vincristine and carboplatin may be given, (concurrent with radiation therapy in older children as the carboplatin acts as a radiosensitizer).

Following concurrent therapy adjuvant post-RT chemotherapy has been shown to give a survival advantage. Agents used include cyclophosphamide, cisplatin, nitrosurea and vincristine.

This combined approach with standard 36 Gy to the craniospinal axis in high risk medulloblastoma (M+ and not GTR) plus boost to 54 Gy to the posterior fossa and bulky metastatic disease has increased the three year event free survival to 70%.

Carboplatin during RT may however significantly increase long term morbidity by sensitizing normal brain to radiation as well as the tumor.


COG-ACNS0332: This is a COG phase III trial for children older than 3 years with high risk medulloblastoma or supratentorial PNET.  The trial is evaluating the efficacy of adding carboplatin to radiation therapy with vincristine, followed by maintenance chemotherapy with conventional adjuvant chemotherapy and isotretinoin.


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