Facts on Medulloblastoma

Medulloblastoma is the most common malignant central nervous system tumour of childhood. It accounts for 15-20 percent of pediatric brain tumours. These tumours are located in the cerebellum, the part of the brain that controls balance and other complex motor functions. Within the cerebellum, medulloblastomas are most often seen in the region of the fourth ventricle/vermis, or the central part of the cerebellum, and less frequently they arise within the cerebellar hemispheres.

Surgery

- the goals of surgery are to establish a diagnosis, relieve hydrocephalus (swelling on the brain) and remove the tumor. It has been shown through national studies that outcome is correlated with the degree of removal, and therefore an attempt is made to completely remove the tumor, without compromising the child's neurologic function.

Following surgery, lumbar puncture is performed to determine the presence/absence of tumor cells in the spinal fluid, which determines the grade of disease. An MRI of the brain will also be obtained to assess the degree of surgical removal. Typically, medulloblastomas are divided into three groups: infants (children under the age of 3), standard risk (no evidence of disease outside of the posterior fossa of the brain with a complete removal of the tumor) and high risk (evidence of incomplete removal or tumor spread elsewhere in the nervous system). Further treatment is then determined upon the grade of tumor.

Radiation therapy and chemotherapy

- Radiation therapy uses high-energy rays (radiation) from a specialized machine to damage or kill cancer cells and shrink tumors. Chemotherapy is a drug treatment that works by interfering with the cancer cell's ability to grow or reproduce. Different groups of chemotherapy drugs work in different ways to fight cancer cells and shrink tumors. Often, a combination of chemotherapy drugs is used to fight a specific cancer. Certain chemotherapy drugs may be given in a specific order depending on the type of cancer it is being used to treat.

While chemotherapy can be quite effective in treating certain cancers, the agents do not differentiate normal healthy cells from cancer cells. Because of this, there can be many adverse side effects during treatment. Being able to anticipate these side effects can help the care team, parents, and child prepare, and, in some cases, prevent these symptoms from occurring, if possible. Chemotherapy is systemic treatment, meaning it is introduced to the bloodstream and travels throughout the body to kill cancer cells. Chemotherapy can be given:

as a pill to swallow

as an injection into the muscle or fat tissue

intravenously (directly to the bloodstream; also called IV)

intrathecally - chemotherapy given directly into the spinal column with a needle