Anyone experiencing neurological symptoms should see their health care provider for a complete checkup, including a neurological exam. A primary care doctor who suspects a brain tumor will likely refer the patient for brain scans. As with other brain tumors, imaging studies are the key component in diagnosing a medulloblastoma.
Magnetic resonance imaging (MRI) and computerized tomography (CT) scans produce detailed images of the brain and spine and allow doctors to detect the presence of a tumor. They are much more detailed than X-rays. Both of these tests are noninvasive, but they do require time in a scanner to produce tiny slices of images that are then combined into three-dimensional pictures. Sometimes the child will need a special contrast agent in advance to increase the visibility of any abnormality found, and some young children may need to be sedated to keep them still enough to ensure a high-quality image. MRI scans are also important tools in determining the relationship of the tumor to the adjacent structures. Sometimes a medulloblastoma or other PNET can be diagnosed by ultrasound before a child is born.
Medulloblastomas can be diagnosed based on imaging alone and do not require a biopsy.
Treatment Options
At the Weill Cornell Pediatric Brain and Spine Center, a multidisciplinary team of specialists will evaluate the individual patient to develop a recommendation for the best course of treatment. The treatment plan may include:
Surgery to remove as much of the tumor as possible and remove any blockage in the flow of cerebrospinal fluid (CSF) that may be causing hydrocephalus; this is the initial and critical part of the treatment (see Surgery for Medulloblastomas).
Radiation therapy to target any cancer cells that remain after surgery or to attack a tumor that recurs. Because of the potential for the tumor to spread, the radiation therapy is usually given to the brain and spine, with a more concentrated dose (a boost) at the tumor site itself. Radiation therapy treatments are usually given daily for five weeks. Since radiation therapy can have cognitive and other side effects on young children, it is generally not recommended for those younger than age three. In rare cases, a child can be treated with surgery and chemotherapy first, with radiation delayed until he or she is older.
Chemotherapy, which is included in most treatment plans to stop the growth and spread of cancer cells and also to allow for smaller radiation doses. Chemotherapy can be given in pill form and as an IV drip. The chemotherapy goes on for several months and usually does not require hospitalization.
The type of treatment a patient may be offered depends on a number of things, including how much of the tumor was removed during surgery, the age of the patient, and whether or not the tumor has spread. To check for metastasis (tumor spread), the neurosurgeon will order an MRI of the spine and a lumbar puncture (spinal tap) at some time during the treatment.
Recent scientific advances allow doctors to use the genetic and molecular features of each individual tumor to help determine the best (and least risky) form of treatment. Patients diagnosed with a medulloblastoma should be referred to a major medical center with specialists experienced in treating brain tumors in children and young adults. When treated using the latest techniques and therapies, a medulloblastoma has a good chance of being eradicated, especially if found and treated before it has spread very far. Cure rates in the best circumstances reach 70 to 80 percent.
Reviewed by: Mark Souweidane, MD
Last reviewed/last updated: April 2022
