DIPG, or diffuse intrinsic pontine glioma, is a type of brain tumor that mainly affects children and develops in an area of the brainstem called the pons.
DIPG is usually diagnosed in children between the ages of 5 and 7 years and accounts for 10-15% of all brain tumors in children.
The survival rate of DIPG is low.
- The five-year survival rate, that is, how many people will be alive five years after diagnosis, is about 2%
- Fewer than 10% of children survive two years from diagnosis
- The median survival ranges from 8 to 11 months
There are some factors that may indicate patients will survive longer than 2 years, including:
- The patient is younger than 3 or older than 10 years of age
- There are fewer symptoms present at diagnosis
- Having smaller tumors on MRI at diagnosis, with less evidence of extension beyond the pons
- Having an HIST1H3B mutation
What Are Symptoms of DIPG?
Subtle symptoms of DIPG (diffuse intrinsic pontine glioma) may start to appear up to six months prior to diagnosis, but they typically start to become evident about one month before diagnosis.
DIPGs cause pressure on the cranial nerves in an area of the brainstem called the pons. Buildup of fluid in the cavities of the brain (hydrocephalus) may also occur. Parents may notice symptoms such as:
- Odd eye movements
- Slurred speech
- Difficulty chewing and swallowing
- Trouble maintaining balance
- Drooping of one part of their child’s face
- Weakness in the arms and legs
- Persistent headaches (especially in the morning)
- Double vision
- Difficulty controlling facial expressions
- Difficulty speaking
- Difficulty urinating
- Difficulty walking
DIPGs are aggressive and grow quickly, so symptoms usually worsen very fast.
What Causes DIPG?
The cause of DIPG (diffuse intrinsic pontine glioma) is unknown. It is believed that DIPG occurs when something goes wrong during the process of cell reproduction but the reason for this occurring is not understood.
There is no evidence DIPG is caused by environmental factors (such as exposure to chemicals or radiation), inherited genetic variations, or infectious agents.
How Is DIPG Diagnosed?
DIPG (diffuse intrinsic pontine glioma) is diagnosed with a physical examination and patient history. If a brain tumor is suspected, tests include:
- Magnetic resonance imaging (MRI) scan (preferred diagnostic tool)
- Computed tomography (CT)
- Whether biopsies should be routinely done is controversial
- Biopsy material can provide important information that may help define a prognosis or help direct the type of treatment
What Is the Treatment for DIPG?
The standard course of treatment for DIPG (diffuse intrinsic pontine glioma) includes:
- First-line treatment
- Radiation therapy
- Provided soon after the steroid regimen
There are no chemotherapy drugs known to have an impact on survival for patients who have DIPG.
In most cases, after about six to 12 months, the DIPG tumor begins to grow again and once this occurs, no further treatment has been shown to improve survival. When children have neurologic symptoms, they may be given steroids again.