Treatment for childhood brain tumors is based on the type of tumor, the tumor location, age of the child and other factors. Because of the unique challenges of treating the brain and CNS, the healthcare team developing and implementing the treatment plan often includes several specialists:
- Pediatric neurosurgeon: a doctor who specializes in surgery to the brain and nervous system
- Pediatric neuro-oncologist: a doctor who specializes in treating brain tumors with chemotherapy
- Radiation therapist: a doctor who specializes in treating brain tumors with radiation therapy
- Pediatric neurologist: a doctor who treats brain and nervous system diseases in children
- Endocrinologist: a doctor who treats diseases in glands that secrete hormones
The healthcare team will develop an individualized treatment plan for each patient. More often than not, treatment will include multiple forms of therapy.
Almost all children will undergo a surgical biopsy. At that time the surgeon will remove as much of the tumor as can be done safely. Some children may not have surgery because it is too dangerous and/or there has not been a benefit shown for such patients. Examples of these patients are:
- Children with diffuse tumors in the brain stem (the upper part of the back of the neck)
- Children with tumors in the pituitary, pineal or thalamic areas (in the deep center of the brain) may undergo biopsy only
Most children recover very well from surgery, and many gradually regain any neurological function lost because of the tumor. Occasionally, a child will have additional brain damage caused by unexpected bleeding or pressure on the brain during surgery, but these children frequently recover as well.
Depending on the specific brain tumor and age of the child, there are a number of treatments that may be given after surgery.
Some children will require the placement of a shunt to drain away excess cerebrospinal fluid caused by tumor blockage. A shunt is a small plastic tube coming from one of the normal cavities (ventricles) in the brain through a small hole in the skull. The fluid then drains either temporarily into a small plastic receptacle outside the skull or permanently through a longer tube directed underneath the skin into the abdominal cavity. The neurosurgeon decides whether only a temporary drainage over a week or so will be needed, or whether a permanent tube under the skin will be necessary. Many children with brain tumors have permanent shunts placed. These are hardly visible after treatment and may remain in place unnoticeably for years. It is best to discuss the reasons for a shunt and the outlook for the future with the neurosurgeon.
Almost all patients undergoing neurosurgery will be given dexamethasone (Decadron). Dexamethasone is a strong steroid medication that reduces swelling of the brain, which is common after surgery. Dexamethasone is started at an initial dose and then slowly tapered over 1-2 weeks following surgery. The steroid is usually given with an acid blocker to prevent stomach irritation or ulcers and can be associated with increased appetite (and occasionally other side effects) when given for more than a few days.
Patients undergoing surgical resection in the upper part of the brain may also be placed on anti-seizure medications following surgery.
Most patients with brain tumors will be treated with radiation therapy over a period of approximately 6 weeks following recovery from surgery. Very young children and those with low-grade tumors may have radiation therapy delayed or significantly reduced. Radiation therapy may be omitted entirely if chemotherapy alone is judged to be effective. Radiation is given on weekdays and only takes a few minutes, provided that the child can lie still with the head supported by a custom-made ‘cast.’ Young children and those who have difficulty lying still usually require anesthesia. Sometimes radiation therapy is given twice each day to try to maximize its effect.
The chemotherapy protocols for children with brain tumors are similar to those used for other cancers, and are tailored to both the tumor type and age of the child. In young children (less than 3 years of age), chemotherapy may be given to postpone radiation that can be damaging to developing brains. Sometimes chemotherapy is given weekly during the radiation treatments to enhance the effect of the radiation.
There are some experimental protocols evaluating chemotherapy given directly into the brain fluid via a reservoir in the skull. This reservoir is placed like a shunt with a tube that runs into the ventricles.
Specific Types of Brain Tumors and Treatment
Many of the different types of brain tumors have unique treatment regimens that researchers have shown to be the most effective for that specific type of cancer. Below are some descriptions of the different types of treatment protocols for different tumor types.
Chemotherapy: Children with medulloblastoma, pineoblastoma and PNET are treated similarly, usually with about one year of multi-agent chemotherapy.
Radiation: Children usually receive radiation to the whole brain and spinal cord. This is done to reduce the risk of later metastasis (spread of the cancer). Children less than 3 years of age may receive chemotherapy first with delayed and/or reduced radiation in order to lessen the effects of radiation on intelligence.
Future trends: Newer protocols will incorporate biological information about the tumors to adjust therapy. For tumors that are cured with current therapy, there will be an attempt to cautiously reduce therapy so that long-term side effects can be lessened.
Low-grade tumors that cannot be removed safely through surgery (unresectable) are usually located deep in the brain or along the optic pathway (along the nerves to the eyes). These children usually receive chemotherapy on an outpatient basis for at least 12 months. Increasingly, physicians are choosing to postpone radiation therapy, sometimes indefinitely, if chemotherapy prevents the tumor from growing. New therapies are being developed to target the molecular changes that are known to occur in these tumors. These therapies are generally available in clinical trials.
These are aggressive cancers that are difficult to treat. As a result, doctors take an aggressive approach to treatment. Most children tolerate therapy better than adults, but fewer than 1 out of 5 children with these tumors become long-term survivors. Treatment includes:
- Surgery: Removal of as much of the tumor as can be done safely.
- Radiation: High doses of radiation to the tumor to shrink it for later surgery, or to destroy the remaining cancer cells.
- Chemotherapy: Chemotherapy to destroy any remaining cancer cells; this therapy may involve experimental drugs.
Diffuse Intrinsic Pontine Glioma
These high-grade gliomas grow amidst the nerves coming down the upper spine. It is an extremely difficult tumor to cure.
- Surgery: Because of their location, these tumors usually cannot be removed by surgery.
- Radiation: Radiation therapy is given to the upper neck.
- Chemotherapy: This tumor often requires experimental chemotherapy.
Surgery: Surgical removal of most of the tumor is key to a good prognosis (chance of recovery) if the cancer has not spread.
Radiation: Children receive radiation therapy to the site of the tumor after the tumor has been removed.
Chemotherapy: New protocols that are being developed are adding chemotherapy to try to improve survival if there is residual disease and/or if the child is very young.
Patients with pure germinomas have excellent survival with radiation alone. New research studies are exploring ways to reduce the long-term risks associated with radiation to the whole brain and spine.
Non-germinoma tumors are more malignant and require more intensive chemotherapy plus increasedradiation to achieve probable long-term cure. Because these children often have hormone deficits related to tumor location, they may require life-long hormone replacement therapy.
Surgery: most children will have surgery to remove as much tumor as possible without further damaging the spinal nerves.
For children with low-grade tumors, surgery is followed by frequent MRIs to monitor the tumor site. Some patients may receive outpatient chemotherapy similar to that used for low-grade astrocytomas.
For children with high-grade tumors, chemotherapy and radiation to the tumor will follow surgery.
Choroid Plexus Tumors, including papillomas and carcinomas, usually occur in infants and are treated primarily with surgical resection and occasionally chemotherapy. Craniopharyngiomas are treated by surgical resection and radiation therapy based on the location of the tumor and involvement of the surrounding tissues. Sarcomas of various types that usually arise from soft tissues in the body, including muscle, sometimes occur in the brain. These sarcomas are treated with maximal surgery, local radiation and chemotherapy appropriate for body sarcomas.