This section refers to children less than three years old:
As the side effects of RT can be very severe in children less than 3 years old chemotherapy is routinely given to delay the age at which they start RT or to completely avoid RT.
The treatment of children between 3 - 5 years remains controversial in terms of RT toxicity. Some centers give low dose craniospinal RT plus chemotherapy (long term toxicity of this approach is really unknown) and some centers delay the start of RT still further to age 5.
There continues to be a push towards intensive chemotherapy regimens alone, especially for those under the age of 5 years as the morbidity of whole brain RT in this age group is particularly devastating.
North American (Headstart I – III protocols; COG 99703), UK and the German (HIT’91 and HIT’2000 protocols) have used a few cycles of intensive induction chemotherapy followed by myeloablative chemotherapy and autologous stem cell transplantation.
The early results of both the HIT’91 and Headstart I and II Protocols have been fairly promising, especially in the non-metastatic medulloblastoma group.
There also appears to be a sub-group within the non-metastatic medulloblastomas, namely those with desmoplastic histology, which appear to show even better response to chemotherapy, with up to an 80% 3 yr EFS.
The Headstart II Protocol used the intensive combination of cisplatin, vincristine, etoposide, cyclophosphamide and G-CSF as its induction cycles. Peripheral stem cells were collected after one of the early induction cycles to be used as a rescue for the myeloablative last cycle. This last consolidative cycle used thiotepa, carboplatin, and etoposide followed by re-infusion of the stem cells previously collected. Headstart II also added high-dose methotrexate to the higher risk tumors in their group, namely those with disseminated disease. This subgroup showed an excellent tumor response rate to the methotrexate with a 50% 5 year event free survival therefore the addition of high-dose methotrexate for all medulloblastomas is being investigated in
The Headstart-III trial used the addition of high dose methotrexate for all medulloblastomas and improved outcomes for young children with medulloblastoma not receiving radiation therapy.
The French experience - using less intensive chemotherapy lead to a 25% EFS however patients could be salvaged with combined bulsuphan thiotepa and posterior fossa RT.
Young Children with Medulloblastoma May Be Able to Avoid Post-Surgery Radiotherapy at the National Cancer Institute