Adjuvant Treatments for Medulloblastomas in Children

Staging Disease for Adjuvant Treatment

Postoperative treatment algorithms are affected by stratification of patients into high-risk and average-risk groups, as defined below (17).

Average risk

• Older: Age >3 years.
• Focal disease: No leptomeningeal seeding (ventricular spinal, or subarachnoid) on MRI. Negative CSF cytology (obtained > 10 days postoperatively). No extraneural metastasis (i.e., bone, lungs).
• Good resection: < 1.5 cm² of residual tumor on postoperative MRI.

High risk

• Young: Age < 3 years.
• Disease spread: Evidence of spread through CSF space or metastasis to extraneural sites.
• Significant residual disease: Residual disease > 3 cm3.

Radiation Therapy

• 2340–3600 cGy with boost: All patients who are at least 3 years of age should receive postoperative external beam radiation therapy (range, 2340–3600 cGy of craniospinal radiation) with a boost to the posterior fossa (typically to approximately 5400 cGy)  (2, 7, 21, 26).
• Reduced dose: A reduction in the dose of radiation therapy can be considered in average-risk patients.
• Younger than 3 years: Reduced-dose radiation therapy or no radiation therapy can be considered in patients less than 3 years of age.

Chemotherapy

• All patients: Chemotherapy should be given to all patients. Various regimens have been used (1).
• Myeloablative chemotherapy:  In children younger than 3 years and in patients with recurrent disease, high-dose chemotherapy with stem-cell rescue may be considered (4).