Diffuse Pontine Glioma
Having a tumor in the brain is always a very serious matter, and a diffuse pontine glioma – also called a brainstem glioma – is no exception. Diffuse pontine glioma is a highly aggressive and difficult to treat brain tumor and is found at the base of the brain in the pons, which controls vital body functions, such as breathing.
- Diffuse pontine glioma is a glial tumor, meaning that it arises in the glial (supportive) tissue of the lowest, stem-like part of the brain, which controls many of the body’s most vital functions.
- Diffuse pontine gliomas account for 10 to 15 percent of all childhood central nervous system tumors.
- The median age at diagnosis is 5 to 9 years old but they can occur at any age in childhood.
- These tumors occur with equal frequency in boys and girls and do not generally appear in adults.
As you read on, you’ll find detailed information about diffuse pontine gliomas.
How Dana-Farber/Boston Children's Cancer and Blood Disorders Center approaches diffuse pontine glioma
Children with diffuse pontine glioma are treated through the Glioma Program at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, an integrated pediatric hematology and oncology partnership between Dana-Farber Cancer Institute and Boston Children’s Hospital. Working together, we provide more specialists, more programs, and more clinical trials than almost any other pediatric center treating cancer and blood disorders in the world.
We understand how overwhelming a diagnosis of diffuse pontine glioma can be. Right now, you probably have a lot of questions. How dangerous is diffuse pontine glioma? What is the very best treatment? What do we do next?
We’ve tried to provide some answers to those questions here, and our expert pediatric subspecialists can explain your child’s condition fully when you meet with us.
What causes diffuse pontine glioma?
As a parent, you undoubtedly want to know what may have caused your child’s tumor. However, the cause of diffuse pontine glioma is not currently understood.
There are no known factors or conditions that make your child more or less likely to develop this type of tumor. It might be reassuring to know that there’s nothing that you could have done or avoided doing that would have prevented the tumor from developing.
What are the symptoms of a diffuse pontine glioma?
Symptoms usually develop very rapidly prior to diagnosis, reflecting the fast growth of these tumors. Most patients have less than three months and many less than three weeks of symptoms prior to diagnosis. While each child may experience symptoms of a diffuse pontine glioma differently, some of the most common include:
- rapidly developing problems controlling eye movements, facial expressions, speech, chewing and swallowing (due to problems in the cranial nerves)
- weakness in the arms and legs
- problems with walking and coordination
Keep in mind that the symptoms of a brain tumor may resemble other, more common conditions or medical problems. Always consult your child's physician for a diagnosis.
How are diffuse pontine gliomas classified?
The World Health Organization classification scheme includes 4 grades of glioma, according to how the cells look under a microscope.grade I (benign)
- grade II (fibrillary)
- grade III (anaplastic – refers to lack of structure in the cell)
- grade IV (glioblastoma multiforme – the most serious kind of tumor)
Since diffuse pontine gliomas are not generally biopsied, it can be difficult to assign a grade to one of these tumors. When biopsied, they are usually grade III or grade IV; occasionally they are grade II.
That being said, diffuse pontine gliomas usually progress like grade IV glioblastoma multiforme tumors. These are the most aggressive kind of astrocytic tumor, and they usually have the following characteristics:
- an increased number of cells
- abnormal cells and nuclei
- the cells reproduce rapidly
- the cells die quickly
- increased growth of blood vessels
These tumors are aggressive, and will invade normal brain tissue.
Frequently Asked Questions
Q: What is the expected outcome after treatment?
A: Unfortunately, the prognosis for diffuse pontine glioma tumors remains poor. Experimental chemotherapy delivered concurrent to radiation therapy is actively being investigated in the treatment of diffuse pontine gliomas.
Q: Where will my child be treated?
A: Children treated through Dana-Farber/Boston Children's Cancer and Blood Disorders Center receive outpatient care at the Jimmy Fund Clinic on the third floor of Dana Farber Cancer Institute. If your child needs to be admitted to the hospital, she will stay at Boston Children's Hospital on the ninth floor of the Berthiaume building.
Q: What services are available to help my child and my family cope?
A: We offer many services to help you, your child and your family get through this difficult time.
Q: What kind of supportive or palliative care is available for my child?
A: When necessary, our Pediatric Advanced Care Team (PACT) is available to provide supportive treatments intended to optimize the quality of life and promote healing and comfort for children with life-threatening illness. In addition, PACT can provide psychosocial support and help arrange end-of-life care when necessary.
Questions to ask your child’s doctor
After your child is diagnosed with a brain tumor, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you. Lots of parents find it helpful to jot down questions as they arise – that way, when you talk to your child’s doctors, you can be sure that all of your concerns are addressed. If your child is old enough, you may want to suggest that she write down what she wants to ask her health care provider, too. Some of the questions you may want to ask include:
- Has my child’s brain tumor spread?
- How long will my child need to be in the hospital?
- What are the possible short and long-term complications of treatment? How will they be addressed?
- What is the likelihood of cure?
- What services are available to help my child and my family cope?
The first step in treating your child is forming an accurate and complete diagnosis. Diffuse pontine glioma is most commonly diagnosed from radiologic studies such as a CT scan or more commonly MRI. The location of these tumors and their tendency to invade into normal tissue make biopsies complicated, although a biopsy may be performed if your child’s symptoms and other tests do not seem typical for the condition. Certain clinical trials require a biopsy as part of the therapy for diffuse pontine glioma.
Your child’s doctor will perform a complete medical and physical examination. In addition, your child’s physician may order some of the following tests:
- 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), both horizontally and vertically, of the body. CT scans are more detailed than general x-rays.
- magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. MRI provides greater anatomical detail than CT scan and does a better job of distinguishing between tumors, tumor-related swelling and normal tissue.
- magnetic resonance spectroscopy (MRS) - a test done along with an MRI. It can detect the presence of organic compounds within sample tissue that can identify the tissue as normal or tumor, and may also be able to tell if the tumor is a glial tumor or if it is of neuronal origin (originating in a neuron, instead of an astrocytic cell).
Surgical biopsies are not routinely performed in cases of diffuse pontine glioma because of the location of the tumor. Diffuse pontine gliomas occur in the brainstem, which controls the body’s vital functions.
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.
Treatment and care
We know how difficult a diagnosis of a pediatric brain tumor can be, both for your child and for your whole family. That’s why our physicians are focused on family-centered care: From your first visit, you’ll work with a team of professionals who are committed to supporting all of your family’s physical and psychosocial needs. We’ll work with you to create a care plan that’s best for your child.
If your child has been diagnosed with a diffuse pontine glioma, you’ll naturally be eager to know how your child’s physician will treat the tumor. Your child’s physician will determine a specific course of 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 expects the disease to progress
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.
Learn more about our pediatric Glioma Program.
What are the treatments for a diffuse pontine glioma?
If your child has been diagnosed with a diffuse pontine glioma, treatment may include:
- Radiation therapy – This is the primary therapy for newly diagnosed diffuse pontine glioma. It uses high-energy rays (radiation) from a specialized machine to damage or kill cancer cells and shrink tumors.Conventional limited-field radiation produces responses in over 90 percent of children with diffuse pontine gliomas. These responses are short-lived however, with a median duration of about 6 months. Several trials to increase the dose of radiation therapy have been performed and none has improved survival.
- Experimental chemotherapy – Chemotherapy and biologic therapy in combination with radiation therapy is actively being investigated as a treatment of this condition. Several trials evaluating new agents are either underway or have been recently completed.
In addition, there are trials evaluating whether new ways of delivering the traditional drugs might improve responses. We should know more about the results of these tests soon. Unfortunately, no currently available chemotherapy regimen has been shown to increase survival rates in this condition.
Unfortunately, complete surgical resection is not an option in the treatment of these tumors because of where the tumor is located. Diffuse pontine gliomas occur in the brainstem, which controls the body’s most vital functions. Surgery in this part of the brain can cause severe neurological damage.
How are side effects managed?
Side effects in the treatment of diffuse pontine glioma can arise from radiation and chemotherapy.
- Procedures should be performed in specialized centers where experienced specialists work in the most technologically advanced settings.
- Radiation therapy often produces inflammation, which can temporarily exacerbate symptoms and dysfunction. To control this inflammation, steroids are sometimes necessary.
- Some of the chemotherapy agents are associated with fatigue, diarrhea, constipation and headache. These side effects can be effectively managed under most circumstances.
Many specialized brain tumor treatment centers have now specialists who deliver complementary or alternative medicines. These treatments, which may help control pain and side effects of therapy include the following.
- therapeutic touch
- dietary recommendations
Talk to your child’s physician about whether complementary or alternative medicine might be a viable option.
In the event that end-of-life care is necessary, our Pediatric Advanced Care Team is available to ease symptoms and help your child maintain quality-of-life as much as possible.
What is the expected outcome after treatment for diffuse pontine glioma?
Unfortunately, the prognosis for diffuse pontine gliomas remains very poor although a small percentage of patients can survive this disease. Your child’s physician will discuss treatment options with you, including experimental clinical trials, and supportive care.
What about progressive or recurrent disease?
Clinical trials and experimental therapies are available for patients with relapsed diffuse pontine glioma. Current trials include novel medications as well as new methods for the delivery of more traditional agents.
Resources and support
We understand that you may have a lot of questions if your child is diagnosed with a diffuse pontine glioma. Will it affect my child long-term? What do we do next? We’ve tried to provide some answers to those questions here, but there are also a number of resources and support services to help you and your family through this difficult time.
Research and innovation
Clinical and basic scientists at Dana-Farber/Boston Children's are conducting numerous research studies to help clinicians better understand and treat diffuse pontine gliomas.
What is the latest research on diffuse pontine gliomas and malignant gliomas?
Dana-Farber/Boston Children's is a member of the Pediatric Oncology Therapeutic Experimental Investigators Consortium (POETIC), a collaborative clinical research group offering experimental therapies to patients with relapsed or refractory disease. It is also the New England Phase I Center of the Children's Oncology Group (COG) and the Department of Defense (DOD) Neurofibromatosis Clinical Trial Consortium.
Through these groups, a number of novel therapies are available for children with both newly diagnosed and current brain tumors. Two new protocols include a phase II trial of radiation therapy, cetuximab and irinotecan for children with newly diagnosed malignant glioma and diffuse intrinsic pontine glioma.
A second trial for newly diagnosed malignant gliomas is a Phase I gene therapy immunotherapy trial combined with radiation therapy and temozolomide. This combination is toxic to malignant glioma cells and thus stops their growth. More importantly, it can induce an immune response to malignant cells located outside of the tumor's primary site, thus targeting the infiltrative boundary of the tumor that typically results in recurrence.
We are also leading an international phase II clinical trial on the genetics of diffuse pontine glioma. Using advanced surgical techniques, a surgical biopsy of the tumor is performed on participating patients. Samples are then analyzed at the Broad Institute of Harvard and MIT in order to understand the unique molecular characteristics of each tumor. This research will allow us to tailor treatment to each individual patient and hopefully improve outcomes for children with diffuse pontine glioma.
For many children with rare or hard-to-treat conditions, clinical trials provide new options.