Medulloblastoma

Medulloblastomas (also called embryonal tumours) are a type of brain tumour in children. They usually start in the cerebellum. Medulloblastomas are fast-growing, high-grade tumours that often spread through the cerebrospinal fluid (CSF) to other parts of the central nervous system. But they also respond well to treatment.

Medulloblastomas may be divided into different risk groups based on age, if the tumour has spread to other parts of the brain or into the cerebrospinal fluid (CSF), and if the tumour can be completely removed with surgery. The risk group helps doctors plan the most appropriate treatment.

A medulloblastoma is average risk if:

• the child is older than 3 years old
• the tumour was completely removed with surgery or only a very small amount left behind
• the tumour has not spread to other parts of the brain or into the CSF

A medulloblastoma is high risk if:

• the child is older than 3 years old
• some of the tumour is not removed with surgery
• the tumour has spread to other parts of the brain or into the CSF
• the tumour is either the large cell or anaplastic subtype of medulloblastoma

Along with risk groups, medulloblastomas can also be divided into 4 subgroups based on how the tumour cells look under a microscope and if there are certain genetic changes. Some of the subgroups have a better prognosis. Talk to the doctor for more information on the subgroup the medulloblastoma has been given and how it will be used to help plan your child's treatment.

The healthcare team will suggest treatments based on your child's needs and work with you to develop a treatment plan. Treatment for medulloblastomas depends on:

• the size and location of the tumour
• if the cancer has spread
• the child’s age, neurological condition and general health
• if the tumour is average risk or high risk

Newly diagnosed medulloblastomas are treated with surgery, radiation therapy and chemotherapy.

Recurrent medulloblastomas have come back after treatment. Treatment options include surgery, radiation therapy, chemotherapy, targeted therapy and stem cell transplant. Recurrent medulloblastoma is very hard to cure as it often keeps recurring after treatment.

Surgery is usually the first treatment used. The goal of surgery is to remove as much of the tumour as possible. Surgery is followed with radiation therapy.

Surgery may also be used to relieve a buildup of CSF (called hydrocephalus).

Find out more about surgery for childhood brain and spinal cord tumours.

Radiation therapy uses high-energy rays or particles to destroy cancer cells. Radiation therapy is usually given after surgery for children older than 3 years. Even if the tumour was completely removed, the entire brain and spinal cord are usually treated with low-dose radiation (called craniospinal radiation) because medulloblastomas often spread to these areas. A higher-dose boost of radiation is given to the area from where the tumour was removed.

For children younger than 3 years of age, doctors try to avoid giving radiation therapy because it can damage developing brain cells. Chemotherapy will be given instead to delay or avoid radiation therapy.

Find out more about radiation therapy for childhood brain and spinal cord tumours.

Chemotherapy uses drugs to destroy cancer cells. It is usually given during and after radiation therapy to treat medullablastomas. In children younger than 3 years old, chemotherapy is given to try to delay or avoid radiation therapy. Chemotherapy may also be given directly into the CSF (called intrathecal or intraventricular chemotherapy).

Chemotherapy drugs commonly used to treat medulloblastoma include:

• cisplatin
• cyclophosphamide
• vincristine
• etoposide (Vepesid)
• carboplatin
• lomustine (CeeNU, CCNU)

Chemotherapy drug combinations commonly used include:

• cisplatin, vincristine, lomustine and cyclophosphamide
• cisplatin, lomustine and vincristine
• cisplatin, cyclophosphamide and vincristine
• cyclophosphamide, etoposide, cisplatin and vincristine

High-dose chemotherapy followed by stem cell transplant may also be used to treat medulloblastoma, especially in children younger than 3 years old.

Chemotherapy drugs used to treat recurrent medulloblastoma include bevacizumab (Avastin and biosimilars) and irinotecan (Onivyde). Irinotecan may also be combined with temozolomide (Temodal).

Find out more about chemotherapy for childhood brain and spinal cord tumours.

A stem cell transplant replaces stem cells. High-dose chemotherapy followed by stem cell transplant, or rescue, may be used to treat high-risk medulloblastoma, especially in children younger than 3 years of age.

Find out more about stem cell transplant for childhood brain and spinal cord tumours.

Children with cancer may be treated in a clinical trial. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.