A tectal glioma is a low-grade, slow-growing brain tumor in
the tectum, the roof of the brain stem. The brain stem controls vital body
functions such as breathing, heart rate and blood pressure.
Despite their origin in a critical part of the body, tectal
gliomas have a very high cure rate and the long-term prognosis is usually
excellent. Most
children with tectal gliomas develop these brain tumors between the ages of 3
and 16. Tectal gliomas tend to develop spontaneously, which means that there is
no known environmental or genetic factor that doctors suspect could have caused
the tumor to grow.
Children with tectal gliomas are treated at Dana-Farber/Boston Children's through our Glioma Program – one of the world’s largest pediatric glioma treatment programs. Our internationally-recognized pediatric brain tumor specialists have extensive expertise in treating all types of gliomas, including tectal gliomas. Our glioma specialists – a team of neuro-oncologists, surgeons, pathologists and radiation oncologists – focus solely on the care of children diagnosed with gliomas. Our program also offers families the chance to have their child's tumor molecularly profiled (as long as a biopsy can be taken), which may help identify opportunities for targeted treatment (precision medicine).
All gliomas, including tectal gliomas, are graded using a scale
developed by The World Health Organization (WHO) according to their appearance
under a microscope and several other factors. These grades are useful to
doctors as they predict how the tumor will progress. The WHO grades are:
- grade I (benign)
- grade II (atypical)
- grade III (anaplastic, which references a lack of structure in the cell)
- grade IV (sarcomatous, the most serious kind of tumor)
Tectal gliomas are classified as grade I or grade II tumors – also known
as low-grade gliomas – and are generally not malignant.
Tectal gliomas occur spontaneously,
which means that there is no known environmental or genetic reason for your
child's condition. Scientists know that these types of tumors emerge in the
brain stem's glial cells, which make connective tissue in the brain. The exact
cause of this abnormal growth isn’t fully understood.
It’s important to understand that there’s
nothing you could have done – or avoided doing – that would have prevented your
child’s tumor from developing.
The symptoms of a tectal glioma can
be non-specific, and might mimic those of other, more common ailments. Since these tumors grow
relatively slowly, your child may see the doctor with problems that have been
occurring for many months. Or, symptoms may come on rapidly. While tectal glioma symptoms vary from child to
child, the most common include:
- Indications of increased pressure in the brain, including headache
(usually upon awakening in the morning),
vomiting and fatigue
- Abnormal eye movements
- Difficulty walking
Because many of these symptoms
can also point to other conditions, it’s important to have your child evaluated
by a qualified medical professional right away for an accurate diagnosis and
prompt initiation of treatment.
The first step in treating your child is forming an accurate
and complete diagnosis. Tectal gliomas are typically diagnosed using a combination
of imaging and biopsy. Your child’s physician may order a number of different
tests including:
- A physical exam and complete
medical history.
- A neurological exam to assess reflexes, muscle
strength, eye and mouth movement, coordination and alertness.
- Magnetic
resonance imaging, a diagnostic procedure that
produces detailed images. An MRI uses a combination of large magnets,
radiofrequencies and a computer to analyze organs and structures within
the body. For tectal gliomas, MRIs of the brain and spine are usually done.
- Computerized tomography scan (also
called a CT or CAT scan), an imaging technique that uses a combination of x-rays and computer
technology to produce cross-sectional images (often called slices), both horizontally
and vertically, of your child’s body. CT scans are more detailed than
general x-rays. For tectal gliomas, a CT scan of the brain is usually
done.
- Biopsy, a tissue sample from
the tumor taken through a needle during a simple surgical procedure.
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, we will meet with you and your family to discuss the results
and outline the best possible treatment options.
Treatment of tectal gliomas
generally focuses on relieving symptoms caused by increased pressure within the
brain and monitoring the tumor for growth or complications. Relieving cranial
pressure is usually all a patient needs for a good prognosis. Chemotherapy is
usually used as treatment for those children who require further treatment is
required. Radiation therapy is usually avoided for the majority of children
with tectal gliomas.
Our experts address
intracranial pressure by:
- Surgically inserting a device called a shunt, which drains excess fluid from your child's body.
- Performing a procedure called
a endoscopic third ventriculostomy, an
alternative to a shunt in which the surgeon creates a pathway to drain
fluid into the brain's third ventricle.
- The
oral steroid dexamethasone may also be given to relieve pressure.
As
a follow-up, your child will be followed for evidence of progressive disease
through frequent MRI scans (about every three months to start). Spinal fluid diversion has a high cure rate and is
sufficient therapy for the majority of patients.
Research is a top
priority at Dana-Farber/Boston Children's, and our physicians work continuously
to translate laboratory findings into clinical therapies and find ways to
improve survival while reducing the toxicity and long-term impact of
treatment. For instance, a 2014 study led
by Peter Manley, MD, documented the excellent
long-term survival among patients with low-grade gliomas, and the negative impact of
radiation therapy – long a mainstay of pediatric brain tumor treatment – on that
survival.
Dana-Farber/Boston Children's houses the Pediatric Low-Grade Astrocytoma (PLGA) Program, the
world's only multidisciplinary clinical and research program dedicated to
pediatric low-grade gliomas. Established in 2007 with support from the PLGA
Foundation, the program takes a multifaceted approach to finding more
effective, less toxic treatments and a cure for children battling brain tumors,
and has become the standard bearer for the research and care of pediatric brain
tumors. Our pediatric neuro-oncologists, including Mariella Filbin, MD, PhD, and Pratiti
(Mimi) Bandopadhayay, MBBS, PhD, are actively contributing to these
efforts. Our program has contributed to international research efforts that have identified genomic drivers that
contribute to growth of low-grade glioma. Specifically, we have identified
genes that are commonly mutated in low-grade glioma. These findings are guiding
clinical trials examining the activity of new drugs specifically for children
with low-grade glioma.
Clinical trialsClinical trials, or research studies
evaluating new treatment approaches, are a major offering at Dana-Farber/Boston
Children’s. For many children with rare or hard-to-treat conditions, clinical
trials provide new options.
It’s possible
that your child will be eligible to participate in one of the Glioma Program’s
current brain tumor clinical trials. 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 Pediatric Neuro-Oncology Consortium (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.
Tectal gliomas are associated
with a high cure rate. Over time, many children will demonstrate an increase in
tumor size; however, most will remain asymptomatic and not require further
treatment other than ongoing MRI scans.
However, it’s important to understand that
your child’s short-term health and long-term health can vary greatly depending
on his specific circumstances. Prompt medical attention is very important, as
is follow-up care. Follow up
care is provided by our brain tumor survivorship clinic.