Medulloblastoma is a brain tumor located in the cerebellum, the part of the brain that controls balance, coordination, and other complex motor functions. Medulloblastomas grow most often in the central part of the cerebellum and less frequently in the outer parts of the cerebellum.
The outcome for children with medulloblastoma has improved dramatically over the past several decades. Doctors historically have classified medulloblastoma as either standard or high risk based on biopsy results. In recent years, however, studies by researchers at Dana-Farber/Boston Children’s and other institutions have shown that what we call medulloblastoma could actually be several different diseases. In fact, medulloblastoma can be divided into four molecular subtypes based on specific types of gene mutations within the tumor. Each subtype has a distinct survival rate, ranging from 20 to 90 percent.
Children with medulloblastoma are treated at Dana-Farber/Boston Children's through our Medulloblastoma Treatment Program. Our pediatric brain tumor specialists provide a unique degree of specialization across many disciplines, which translates into advanced treatment options for children with medulloblastoma. We offer:
Because brain tumors in children, including medulloblastoma, behave differently than those in adults, it's important for families to seek a pediatric center with specific expertise in treating childhood brain tumors.
In
most cases, the cause of medulloblastoma is not known. In some cases,
medulloblastoma is associated with certain inherited diseases, including:
It’s
important to understand that these and other brain tumors most often occur with
no known cause. There’s nothing that you could have done or avoided doing that
would have prevented the tumor from developing.
Brain
tumors can cause a variety of symptoms in children based on their age and the location
of the tumor. Keep in mind that medulloblastoma symptoms may resemble
other more common conditions or medical problems. Always consult your child's
physician for a diagnosis.
While
your child may experience symptoms differently, common medulloblastoma symptoms include:
- Headache (generally upon
awakening in the morning)
- Nausea and vomiting
- Fatigue
- Lethargy
- Imbalance and lack of coordination
- Problems with motor skills (such
as writing)
- Neck tilt or double vision
- Changes in personality or behavior
- Seizures
Rarely,
medulloblastoma can spread into the central nervous system or the spinal canal,
and your child may experience:
- Loss of strength in the lower
extremities
- Back pain
- Bowl and bladder control issues
- Difficulty walking
The
first step in treating your child is forming an accurate and complete
diagnosis.
Your child’s physician may order a number of different tests to determine the
type and location of the tumor. In addition to a physical exam, medical
history, and neurological exam, diagnostic procedures for medulloblastoma may
include:
- Magnetic resonance imaging (MRI): This diagnostic procedure produces detailed images of structures within the
brain and spine. An MRI scan of the brain after surgery will determine how much
of the tumor was removed surgically.
- Surgical resection: After surgical
removal of the tumor, a tissue sample will be taken and analyzed to confirm
the diagnosis. While an MRI may indicate a possible medulloblastoma, only
a tissue sample can confirm the diagnosis.
- Histological diagnosis: The tissue sample obtained from surgery will be reviewed by a
neuropathologist, who looks at the tumor under the microscope to confirm whether
it has the features of medulloblastoma. We also perform a number of
molecular tests to determine the subtype of medulloblastoma. All children
undergoing resection of brain tumors at Dana-Farber/Boston Children’s are
also invited to participate in our ongoing genetic tumor profiling research
studies. These studies may help further define tumor subtypes and may
potentially guide personalized (precision) medicine.
If your child has medulloblastoma, your child’s physician also will perform a lumbar puncture, or spinal tap. However, this will be performed at a time after
the initial surgery is completed. In addition, there may be other diagnostic
tests that your doctor will discuss with you.
Successfully
treating your child’s medulloblastoma depends largely on whether the tumor can
be completely removed through surgery and whether the tumor has spread to other
parts of the brain or spinal cord. Typically, post-surgery medulloblastomas are
divided into three risk assessment groups:
- Infants (children under age 3)
- Standard risk (no evidence of disease with a complete
removal of the tumor)
- High risk (evidence of incomplete removal or tumor spread
elsewhere in the nervous system)
Medulloblastoma subtypes
Dana-Farber/Boston
Children’s clinical researchers are involved in international collaborations
that have revealed that medulloblastomas are comprised of at least four
different subtypes. Medulloblastoma subtypes include
- Wnt Medulloblastoma
- Sonic Hedgehog (SHH) Medulloblastoma
- Group 3 Medulloblastoma
- Group 4 Medulloblastoma
Each
of these subtypes has a different biological driver, and some subtypes
require more intensive treatments than others. These findings are guiding
clinical trials exploring new treatments for children with medulloblastoma.
After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we will meet with you and your family to discuss the results and outline the best treatment options.
You
and your family are key players in your child’s medical care. It’s important
that you share your observations and ideas with your child’s health care
provider and that you understand your doctor’s recommendations. If your child has been diagnosed with medulloblastoma, you probably have a lot on your
mind, so it’s often helpful to write questions down. Some of the questions you
may want to ask include:
- What does a diagnosis of medulloblastoma mean for my child?
- How will you manage my child’s symptoms?
- What are my child’s treatment options?
- How many other children with medulloblastoma does your team
treat each year?
- What are the possible short- and long-term complications of
treatment?
- What is the long-term outlook for my child?
- How likely is it that the tumor will come back?
- What services are available to help my child and my family
cope?
Coping and support
In
addition to providing medical care, at Dana-Farber/Boston Children’s, we strive
to also meet all of your family's emotional and quality-of-life needs. We know
that unfamiliar places, especially hospitals, often create anxiety and fear for
a child. We also know this isn't an easy time or task for parents, who have
their own fears and concerns about the situation. Our family support services
will help address many of your needs and concerns. Read about our patient and family support services.
Your
child's physician will determine a specific course of medulloblastoma treatment based on several factors, including:
- Your child's age, overall health, and medical history
- Type, location, and size of the
tumor
- Extent of the disease
- Your child's tolerance for
specific medications, procedures, or therapies
- How your child's doctors expect
the disease to behave
There are a number of treatments we may recommend. Some of them help to treat the
tumor while others are intended to address complications of the disease or side
effects of the treatment.
In all cases, a
multidisciplinary team is necessary to optimize care. The team may include
members from neurosurgery, neuro-oncology, neurology, radiation oncology, and
stem cell transplantation, as well as psychology/social work, nutrition,
physical and occupational therapy, and the school liaison program.
Treatment may include (alone or in combination):
Endoscopic third ventriculostomy (ETV) or ventriculo-peritoneal shunt (VP
shunt): A tumor in the brain can cause blockage of cerebral spinal fluid,
the fluid that bathes the brain and spinal cord. If this occurs, our pediatric
neurosurgeons may perform a procedure to relieve symptoms of hydrocephalus, the
build-up of fluid, which causes increased pressure within the skull.
In an endoscopic third ventriculostomy, surgeons create a small hole that allows
fluid to flow around the blockage and into the spinal column. About 90 percent
of children with symptoms of hydrocephalus will undergo this procedure.
In some cases, children may have an alternative procedure in which a tube is
installed to drain excess fluid into the abdomen (VP shunt).
Surgery may be needed to treat
hydrocephalus (fluid build-up in the skull) and to remove the tumor. Research
has shown that the more completely the tumor is removed, the better the outcome
may be. Therefore, your child's surgeon will remove as much of the tumor as
safely as possible, while avoiding neurological side effects.
Radiation therapy
uses high-energy waves from a specialized machine to damage or kill cancer
cells and shrink tumors. Your child's physician will work with pediatric
radiation oncologists to determine the optimal dose of radiation that will
effectively treat the tumor while avoiding side effects as much as possible.
Chemotherapy is a
group of drugs that interfere with the cancer cell's ability to grow. Different
groups of chemotherapy drugs work in different ways to fight cancer cells and
shrink tumors. Your child may receive chemotherapy:
- Orally, as a pill to swallow
- Intramuscularly, as an injection
into the muscle or fat tissue
- Intravenously, as a direct
injection into the bloodstream; also called IV
- Intrathecally, as a direct
injection into the spinal column through a needle
What issues might arise after surgery?
After the operation, your child may have difficulties with coordination,
weakness in his extremities, and problems with balance. These typically resolve
over a course of several weeks. Our physical and occupational therapists will
work with your child to treat these issues.
"Posterior fossa mutism" is a condition that may occur after surgery.
Within 24 hours, the child develops an inability to speak, has problems with
balance, and has difficulty with swallowing. The condition may range from mild
to severe. The cause of this condition is not entirely known, but it is unique
to this area of the brain.
In about 15 percent of the children diagnosed with medulloblastoma,
hydrocephalus may develop, requiring a procedure to drain spinal fluid. These
procedures are performed by our pediatric neurosurgeons.
The prognosis (chance
of recovery) and treatment options depend on:
- The tumor’s molecular subtype
(the specific genetic mutations within the tumor)
- The age of your child at the time
of diagnosis
- The location of the tumor
- The amount of tumor remaining
after surgery
- Whether the cancer has spread to
other parts of the central nervous system (brain and spinal
cord) or to other parts of the body such as the bones
The
outcome for children with medulloblastoma has improved dramatically over the
past several decades.
The outcomes in infants remain poor and many studies are underway to evaluate
new treatment strategies in infants. Some include aggressive chemotherapy,
including high-dose chemotherapy and stem cell transplant, and localized
radiation therapy to minimize the harmful effects of radiation therapy on the
developing brain.
Long-term follow-up
Many
children and adolescents diagnosed with medulloblastoma will survive into
adulthood. However, survivors may face physical, psychological, social, and
intellectual challenges related to their treatment and will require ongoing
assessment and specialized care.
To address the needs of this growing community of brain tumor survivors,
Dana-Farber/Boston Children’s provides brain tumor survivorship support through
the Stop & Shop Family
Pediatric Neuro-Oncology Outcomes Clinic.
As
a result of treatment, children may experience changes in intellectual and motor
function. Among several programs addressing these needs are the School Liaison and Back to School Programs,
which provide individualized services to ease children's return to school and
maximize their ability to learn.
Children
treated for a medulloblastoma should visit a survivorship clinic every year:
- To manage disease complications
- To be screened for early
recurrence of tumor
- To manage late effects of treatment
We
are conducting numerous research studies that will help clinicians better
understand and treat medulloblastoma. Recently, scientists have discovered the
molecular characteristics of medulloblastomas, identifying several subtypes,
which may be correlated with prognosis. These discoveries are now helping
researchers to develop better therapies. We
now offer and are developing further clinical trials that target these specific
subgroups.
Clinical trials
For
many children with brain tumors or other rare or hard-to-treat conditions,
clinical trials provide new options.
Contact us: If you’re not
sure which clinical trials might be right for your child, email us at clinicaltrials@danafarberbostonchildrens.org. We can help you navigate
your options.