Pediatric Brain Tumors: Diagnosis & Treatment at Memorial Sloan-Kettering

Memorial Sloan-Kettering Cancer Center’s experts on the Pediatric Brain Tumor team diagnose and treat children, adolescents, and young adults who have any form of brain tumor. We tailor our innovative treatments for each patient, based on the characteristics of your child and of his or her disease.

Symptoms from tumors that grow in the brain vary widely, depending upon the tumor’s location and size. Tumors at the base of the brain often cause headaches, vomiting, and behavioral changes because they block the normal passage of cerebrospinal fluids, causing the pressure within the head to rise. Tumors near the surface of the brain may cause seizures. Tumors arising at the brain stem often cause weakness in the structures of the head and neck.

Establishing the proper diagnosis is the crucial first step to ensure that your child receives the most appropriate treatment at Memorial Sloan-Kettering. Once a child exhibits symptoms that may be caused by a brain tumor, imaging tests such as CT or MRI scans are performed. These tests help doctors see the extent of the tumor and plan for either the removal of the tumor or a biopsy. Doing this allows the doctors to know exactly what type of tumor they are treating.

Developing a Treatment Plan

Once a diagnosis has been made, doctors will then decide on a treatment plan. Possible plans include:

1. Close observation using physical examination and imaging, which requires no immediate therapy.
2. Surgery, in which the tumor is physically removed during a procedure in the operating room.
3. Radiation therapy, which uses high-energy particles or waves, such as x-rays, to destroy or damage cancer cells.
4. Chemotherapy, which uses drugs to treat the tumor.
5. A combination of any of the above.

These plans may range from observation (no need for immediate therapy at all) to a combination of surgery (in which the tumor is physically removed during a surgical procedure), radiation therapy (which uses high-energy particles or waves, such as x-rays, to destroy or damage cancer cells), and chemotherapy (which uses drugs to treat the tumor). Your child's chance of recovery depends on a number of factors, including tumor type and location, and amount of tumor spread, or metastasis. It is important to note that there are treatments available for every type of brain tumor.

Tumors that form in the tissues and cells of a child's brain are called primary brain tumors. In some cases, tumors that have originated in other parts of the body spread to the brain, but this is rare in children. The following is a list of some of the most common types of primary brain tumors found in children.

Tumor Types

Astrocytomas (also known as gliomas)

Accounting for almost half of all childhood brain tumors, astrocytomas are tumors that arise in brain cells called astrocytes, star shaped cells in the central nervous system that support neurons and help remove debris. Astrocytomas can be further divided into the following types:

• Low-grade astrocytomas, which include Grade 1 (juvenile pilocytic astrocytomas) and Grade 2 (diffuse astrocytomas) astrocytomas. They may be cured with surgery alone if they can be completely removed. If not, observation only may be considered. If additional treatment is required, radiation therapy is usually used for the older children and chemotherapy is used for the younger children.

• High-grade astrocytomas include Grade 3 (anaplastic astrocytomas) and Grade 4 (glioblastoma multiforme) astrocytomas. They are highly malignant tumors that have a much more guarded prognosis. Surgery, radiation therapy, and chemotherapy are usually recommended.

Also, diffuse pontine gliomas (a type of brain stem glioma) are highly malignant astrocytomas that occur in a very delicate part of the brain. Surgery cannot be done safely, and patients are usually treated with radiation therapy and may be candidates for new investigational treatments. Prognosis is very guarded.

Ependymomas

Ependymomas develop within the ependymal cells lining the brain's ventricles (a series of fluid filled cavities in the brain) and are treated with surgical resection and often with radiation therapy. Ependymomas, unlike astrocytomas, typically do not spread into normal, surrounding brain tissue. Children who have ependymomas that cannot be completely surgically removed are often also treated with chemotherapy. Though there are no treatments unique to ependymomas, radiation therapy is an extremely important part of the typical treatment plan, often including the use of intensity modulated radiation therapy (IMRT), a targeted treatment that delivers high-doses of radiation to tumor cells while sparing surrounding healthy tissue.

Medulloblastomas and PNETs

Representing approximately 20 percent of childhood brain tumors, medulloblastomas are tumors that, doctors think, arise from undeveloped stem cells in the portion of the brain that controls voluntary movement, known as the cerebellum. They are highly malignant, but with appropriate treatment many children can be cured. Medulloblastomas usually are accompanied by headaches and vomiting, particularly first thing in the morning. Sometimes the child will show behavioral changes and deterioration of their school performance. The diagnosis is suspected using CT or MRI scans and confirmed by a pathology examination after the tumor's surgical removal. Treatment for medulloblastomas usually includes surgery, radiation therapy (except in the very young), and chemotherapy.

Primitive neuroectodermal tumors (PNET) are another form of rapidly growing tumor that are known as pineoblastomas when they occur in the pineal gland (a pea-sized gland at the center of the brain), or as supratentorial PNETs when occurring in the cerebral hemispheres. The diagnosis is suspected via CT or MRI scan and confirmed by pathology after the tumor's surgical removal. PNETs can prove less responsive to therapies, but treatments are available.

Germ Cell Tumors

Germ cell tumors, as the name suggests, arise from germ cells, which during normal development of the embryo form into either egg or sperm cells. In the case of germ cell tumors located in the brain, the embryonic germ cells have mistakenly traveled to the brain, where they develop into tumors. Occurring most frequently in children, germ cell tumors comprise several different types of tumors (including germinomas, endodermal sinus tumors, and choriocarcinomas). Though their symptoms depend on the tumor location, germ cell tumors in the pineal region usually are accompanied by headaches and vomiting, particularly first thing in the morning. Tumors in the suprasellar region (near the pituitary gland) usually are accompanied by hormonal abnormalities, particularly increased urination and thirst. Sometimes the child will show behavioral changes and deterioration of their school performance. Most of them are malignant tumors but can often be cured with current treatments that may include surgery, radiation therapy, and chemotherapy.

Rare Tumors

From time to time, pathologists make a diagnosis of a particular type of central nervous system tumors that very few doctors have heard of or feel comfortable treating. Working with partners around the hospital and colleagues around the world, our team of doctors regularly treats the rarest of cases. Examples of these tumors include: atypical teratoid/rhabdoid tumor (AT/RT), choroid plexus carcinoma, dysembryoplastic neuroepithelial tumors, and craniopharyngiomas.

Young Children and Brain Tumors

Young children (those less than three years old) with brain tumors are considered a special treatment group. Regardless of the type of tumor, we often try to avoid radiation therapy due to the risk of causing learning and memory problems in this age group. Chemotherapy is more frequently recommended.

Innovative Treatments

Caitlin’s Story At risk of losing her sight, Caitlin received extensive treatment at Memorial Sloan-Kettering for a tumor behind her left eye. Learn more »

In addition to participating in national trials through the Children's Oncology Group, the Memorial Sloan-Kettering childhood brain tumor group also offers many treatment protocols unique to Memorial Sloan-Kettering. For pediatric patients with brain tumors, institutional studies currently include protocols using:

• A procedure that uses high-dose chemotherapy with autologous stem cell rescue for appropriate patients with recurrent brain tumors (including medulloblastoma, PNET, and germ cell tumors).
• For patients with recurrent tumors that have spread along the surface of the brain and/or spinal cord (a condition known as leptomeningeal disease), they may be eligible for a protocol using a substance known as an intrathecal monoclonal antibody (in this case called 3F8), which is attached to a radioactive form of iodine. The idea is to deliver targeted radiation to the tumor cells, while the normal surrounding structures, which are not targeted, receive very little radiation.
• A radiation oncology treatment called IMRT (intensity modulated radiation therapy) that more tightly focuses the radiation on the tumor, paired with immunotherapy is being used for most of our patients to reduce the side effects related to radiation therapy, such as cognitive changes, hearing loss, and/or hormonal changes. By reducing the dose of radiation to normal brain tissue, we expect that the risk of these side effects will be reduced. In addition, our doctors have expertise in various forms of radiosurgery — in this process, which uses precise (stereotactic) positioning, computer guidance using MRI scans, and other modern technology, the radiation oncologist can deliver high-dose radiation treatments to tumors anywhere in the brain.
• Also available are sophisticated new radiology services such as PET scanning (a highly sensitive technology that picks up the metabolic signal of actively growing cancer cells in the body) and functional MRI scanning (a diagnostic test that indicates areas of increased brain function activity corresponding to specific tasks the patient is asked to perform, allowing the surgery to be planned to avoid these areas). We also use MR Spectroscopy, a non-invasive diagnostic test that identifies the chemical composition of tumors and can aid in diagnosis and prognosis.
• Our team is also currently working with partners in laboratories and pharmaceutical industries to test a group of medications known as “targeted agents.” These medications, rather than working like standard chemotherapy drugs, target molecular pathways that are known to be disturbed in cancer cells. These treatments are very early on in development, and always changing.