Atypical teratoid rhabdoid tumors (ATRT) are very rare, aggressive tumors
of the central nervous system, occurring mostly in the cerebellum (the part of
the brain that controls movement and balance) or the brain stem (the part of
the brain that controls basic body functions).
Successfully treating your child’s ATRT depends on where
the tumor is located and whether the tumor has spread.
For many tumors, we use a system of classification called “staging” to
evaluate cancers. However, there is currently no standardized classification
system for atypical teratoid rhabdoid tumors. An ATRT may be:
- localized, occurring in only
one location in the brain
- disseminated, spread to
multiple locations in the brain, spinal cord or body
Atypical teratoid rhabdoid tumors can cause a variety of symptoms in children depending on their
size and location. Keep in mind that the symptoms may resemble
other more common conditions or medical problems. It is important to consult
your child's physician if you have concerns.
ATRT symptoms can come on quickly, in a matter of days or weeks, due to the
fast-growing nature of these tumors. ATRT symptoms include:
- Headache, generally upon
awakening in the morning
- Hydrocephalus, where there is
a buildup of fluid in the brain which can result increased head size in
infants or headaches and vomiting in older children.
- Nausea and vomiting. These
symptoms are often worse in the morning and improve throughout the day
- Lethargy and fatigue
- Trouble with balance and
coordination
As a parent, you undoubtedly want
to know what may have caused your child’s tumor. It’s important to remember
that nothing you could have done or avoided doing would have prevented the
tumor from developing.
In most cases, atypical teratoid rhabdoid tumors are associated
with a specific mutation (INI1) that can occur spontaneously or be inherited.
More than 90 percent of cases of ATRT are associated with this mutation and
are not inherited. However, the cause of this abnormality is not known.
If this mutation (INI1) has been inherited, your child may be
at increased risk of developing other tumors.
The first step in treating your child's ATRT is forming an accurate
and complete diagnosis. ATRT is most commonly diagnosed from imaging studies
and biopsy. Your child's doctor will likely conduct tests including:
- A physical
exam and complete medical history. A neurological function test of
reflexes, muscle strength, eye and facial movement, coordination and
alertness.
- Magnetic resonance imaging
(MRI), a diagnostic procedure
that produces detailed images of the structures within the brain
and spine. An MRI uses a combination of large magnets, radiofrequencies
and a computer to analyze organs and structures within the body. No x-rays
or radiation are used.
- Computerized tomography scan (also called a CT or CAT scan), a diagnostic
imaging procedure that uses a combination of x-rays and computer
technology to produce cross-sectional images, often called slices, of the
body from horizontal and vertical perspectives. CT scans are more detailed
than general x-rays.
- Biopsy, a tissue
sample from the tumor during a surgical procedure.
- Lumbar puncture, (spinal tap) to remove a small sample
of cerebrospinal fluid (CSF). This can determine if any tumor cells have
spread. This procedure can safely be performed under sedation.
- Ultrasound, a diagnostic
imaging procedure that does not use x-rays, but sound waves to evaluate
organs in the body. It is good at
looking at organs in the abdomen such as the kidney. This test can usually be done without
any sedation.
- Genetic testing, to look for a specific genetic defect often associated with ATRT and
to insure that you are not at increased risk of developing other tumors.
There may be other diagnostic tests that your doctor will discuss with
you depending on your child's individual situation. 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 be able to discuss the results and
outline the best possible treatment options.
Your child's
physician will determine a specific course of ATRT treatment based on several
factors, including your child's age, overall health and medical history, the
type, location, and size of the tumor and the extent of the disease.
ATRT treatments include:
- Neurosurgery: Surgery is usually
performed first in order to remove as much of the tumor as possible.
- Radiation: High-energy waves from a
specialized machine damage or shrink tumors. Precisely targeted and dosed
radiation therapy is used to kill cancer cells left behind after surgery. Because
ATRT occurs in children under 3, reduced intensity, limited
field radiation therapy is used or radiation is avoided altogether;
children over 3 generally receive radiation therapy as standard treatment.
- Chemotherapy:Chemotherapy are drugs that interfere with
the cancer cells' ability to grow or reproduce. Chemotherapy can be
given in several different ways, but intrathecal chemotherapy is an
important part of treatment as it allows medicine to be delivered directly
to the spinal fluid and the central nervous system to treat the tumor.
- Stem cell transplant:
This allows children with aggressive ATRT to receive high doses of
chemotherapy. This treatment aims to transfuse healthy bone marrow cells
into your child after his marrow has been damaged by the intensive
chemotherapy.
There is no standard
treatment for recurrent ATRT. Children with recurrent disease are often
referred to clinical trials for the latest
experimental therapies.
Because ATRT is so rare, these tumors are difficult to study. As a result, our
researchers collaborate with other institutions around the country to improve
our current understanding of this condition and offer new treatments to
children with ATRT. Currently, researchers at Dana Farber/Boston Children’s
are working with the Children’s Hospital of Philadelphia and the Broad
Institute of MIT and Harvard to learn more about the molecular characteristics
of atypical teratoid rhabdoid tumors.
In addition, researchers in our Brain Tumor Center are collaborating with
physicians and researchers that treat other types of rhabdoid tumors in order
to study the effectiveness of current treatments and to establish new, more
standardized treatments for all types of rhabdoid tumors.
Through
clinical trials, our researchers are testing new, targeted treatments that may
help improve the survival rate for ATRT.
Most children
with a diagnosis of ATRT will be treated as part of a brain tumor clinical trial.
In addition to launching our own clinical trials, we also offer trials
available through collaborative groups such as the Children's Oncology Group
(COG) and the Pacific Neuro-oncology group (PNOC). We are also the New England
Phase I Center of the Children's Oncology Group. If your child has progressive
or recurrent tumor, she may be eligible for a number of experimental therapies
available through these groups, or from one of our independent clinical
investigators.
Clinical Trials
Participation in any clinical trial is
completely voluntary. We will take care to fully explain all elements of the
treatment plan prior to the start of the trial, and you may remove your child
from the medical study at any time.
ATRT is a very difficult tumor to cure and, unfortunately, the outcomes
remain poor. In general, older children with ATRT tend to do better than young
children. Through the studies done at Dana-Farber we have been able to improve
the cure rates from 10 percent to 50%.
After ATRT
treatment is completed we will continue to follow your child to monitor for
disease recurrence. After 2 years from
completion of therapy we also recommend that children treated for an ATRT should
visit a survivorship clinic yearly to manage disease complications, screen for recurrence and manage late
treatment side effects. A typical follow-up visit is likely to include a
physical exam, laboratory testing and imaging scans.
Through our Stop & Shop
Family Pediatric Neuro-Oncology Outcomes Clinic, children are able
to meet with their neurosurgeon, radiation oncologist, pediatric neuro-oncologist
and neurologists at the same follow-up visit. Our multidisciplinary approach
and depth of expertise will give your child on-site access to endocrinologists,
neuro-psychologists and alternative/complementary therapy specialists. School
liaison and psychosocial personnel from the pediatric brain tumor team are also
available. In addition, children
needing rehabilitation may meet with speech, physical, and occupational
therapists during and after their visit.