Outcome of Chemotherapy for Medulloblastomas in Children

Standard-Risk Medulloblastoma

• 80–90% PFS rate: The treatment of standard-risk medulloblastomas in children over 3 years of age with combined radiation and chemotherapy has resulted in a 5-year PFS rate of 80–90%.

High-Risk Medulloblastoma

• 30–60% overall survival rate: The use of a combination of radiation and chemotherapy following surgery has resulted in a 5-year overall survival rate that varies between 30 and 60% depending on the extent of disease.
• Radiation therapy: 3600 cGy craniospinal radiation plus a boost to the primary site and any metastases is administered.
• Chemotherapy: Radiation is followed by maintenance chemotherapy with cisplatin, lomustine, vincristine, and cyclophosphamide.
• 80% EFS rate with carboplatin as radiosensitizer: The addition of daily carboplatin as a radiosensitizer Monday through Friday appears to have improved survival substantially, with the 3-year EFS rate reported as 80% (29). This treatment protocol is not as well tolerated, however. Consequently, the COG now has a high risk protocol ACNS 0331 randomizing between the use of carboplatin or not during the radiation and the use of a biological agent (52).
• 74% PFS rate with Strother protocol: The more intense post-radiation submyeloablative chemotherapy proposed by Strother and colleagues also has an improved 2-year PFS rate of 74% (41).

Cognitive Outcome and Radiation

Increasing age below which radiation avoided: Radiation to the developing brain should be carefully considered, particularly when treating children under 6 years of age. The author’s center and some others have adopted a primary intensive chemotherapy approach for children younger than 6 years, with the plan to salvage with radiation at the time of relapse if it is required.