Childhood Brain tumors

Mrs. Rupali A. Patil.

Childhood brain tumors are a diverse group of diseases characterized by the abnormal growth of tissue contained within the skull. Brain tumors can be benign (without cancer cells) or malignant (contains cancer cells).

The brain controls vital functions such as memory and learning, the senses (hearing, sight, smell, taste, and touch), and emotion.

It also controls other parts of the body, including muscles, organs, and blood vessels. Other than leukemia and lymphoma, brain tumors are the most common type of cancer that occurs in children.

The articles in this section refer only to tumors that originate in the brain (primary brain tumors). Metastatic brain tumors, which are secondary tumors formed by cancer cells that begin in other parts of the body and spread to the brain, are not included. Brain tumors can occur in both children and adults; however, treatment may be different for adults than for children.

Incidence and Prevalence ¹

In the United States, the annual incidence of brain cancer generally is 15-20 cases per 100,000 people. Brain cancer is the leading cause of cancer-related death in patients younger than age 35.

Primary brain tumors account for 50% of intracranial tumors and secondary brain cancer accounts for the remaining cases. Approximately 17,000 people in the United States are diagnosed with primary cancer each year and nearly 13,000 die of the disease. The annual incidence of primary brain cancer in children is about 3 per 100,000.

Secondary brain cancer occurs in 20-30% of patients with metastatic disease and incidence increases with age. In the United States, about 100,000 cases of secondary brain cancer are diagnosed each year.

Causes and Risk Factors ^1,3

Primary brain tumors include any tumor that starts in the brain. Tumors may be confined to a small area, invasive (spread to nearby areas), benign (not cancerous), or malignant (cancerous). Tumors can directly destroy brain cells. They can also indirectly damage cells by producing inflammation, compressing other parts of the brain as the tumor grows, causing swelling in the brain, and increasing pressure within the skull. Exposure to some types of radiation, head injuries, and hormone replacement therapy may be risk factors, as well as many others. The risk of using cell phones is hotly debated.

Genetic mutations and deletions of tumor suppressor genes (i.e., genes that suppress the development of malignant cells) increase the risk for some types of brain cancer. Inherited diseases that are associated with brain tumors include the following:

• Multiple endocrine neoplasia type 1 (pituitary adenoma)
• Neurofibromatosis type 2 (brain and spinal cord tumors)
• Retinoblastoma (malignant retinal glioma)
• Tuberous sclerosis (primary brain tumors)
• Von Hippel-Lindau disease (retinal tumor, CNS tumors)
• Li-Fraumeni syndrome, and
• Turcot's syndrome

Patients with a history of melanoma, lung, breast, colon, or kidney cancer are at risk for secondary brain cancer. Exposure to vinyl chloride is an environmental risk factor for brain cancer. Vinyl chloride is a carcinogen, that is, a cancer-causing substance.

Classification of Brain Tumors ²

This classification is based on the World Health Organization (WHO) classification of nervous system tumors. The WHO approach incorporates and interrelates morphology, cytogenetics, molecular genetics, and immunologic markers in an attempt to construct a cellular classification that is universally applicable and prognostically valid.

Earlier attempts to develop a TNM-based classification were dropped. The WHO grading of CNS tumors establishes a malignancy scale based on histologic features of the tumor. The histologic grades are as follows:

WHO grade I includes lesions with low proliferative potential, a frequently discrete nature, and the possibility of cure following surgical resection alone.

WHO grade II includes lesions that are generally infiltrating and low in mitotic activity but recur. Some tumor types tend to progress to higher grades of malignancy.

WHO grade III includes lesions with histologic evidence of malignancy, generally in the form of mitotic activity, clearly expressed infiltrative capabilities, and anaplasia.

WHO grade IV includes lesions that are mitotically active, necrosis-prone, and generally associated with a rapid preoperative and postoperative evolution of disease.

Symptoms ² 

The specific symptoms depend on the tumor's size, location, degree of invasion, and related swelling. Headaches, seizures, weakness in one part of the body, and changes in the person's mental functions are most common.

Headache - a persistent headache that is new for the person, worse on awakening, Vomiting - possibly accompanied by nausea; more severe in the morning, Personality and behavior changes, Emotional instability, rapid emotional changes, Loss of memory, impaired judgment, Seizures that are new for the person, Reduced alertness, Double vision, decreased vision, Hearing loss, Decreased sensation of a body area, Weakness of a body area, Speech difficulties, Decreased coordination, clumsiness, falls, Fever (sometimes), Weakness, lethargy, General ill feeling, Positive Babinski's reflex, Decerebrate posture, Decorticate posture

Additional symptoms that may be associated with primary brain tumors:

Tongue problems, Swallowing difficulty, Impaired sense of smell, Obesity, Uncontrollable movement, Dysfunctional movement, Absent menstruation, Hiccups, Hand tremor, Facial paralysis, Eye abnormalities - pupils different sizes, uncontrollable movements, eyelid drooping, Confusion, Breathing, absent temporarily, Unusual or strange behavior.

Complications ¹

• Obstructed flow of cerebrospinal fluid from the third ventricle may cause sudden death.
• Cerebral hernia is a progressive, fatal condition in which the brain is forced through an opening in the skull.
• Hemorrhagic stroke produces sudden loss of vision and/or speech, unconsciousness, and paralysis.

Types ²

There are many types of brain tumors that occur in children. Treatment and chance of recovery (prognosis) depend on the type of tumor, its location within the brain, the extent to which it has spread, and child’s age and general health.

1. Central Nervous System Germ Cell Tumor

Germ cell tumors arise from the sex cells found in the brain. There are different types of germ cell tumors, including germinomas, embryonal cell carcinomas, choriocarcinomas, and teratomas. These tumors usually occur in the center of the brain, and can spread to other parts of the brain and spinal cord.

2. Childhood Brain Stem Glioma

Childhood brain stem glioma is a disease in which benign (noncancer) or malignant (cancer) cells form in the tissues of the brain stem. The brain stem is the part of the brain connected to the spinal cord. It is located in the lowest part of the brain, just above the back of the neck. The brain stem is the part of the brain that controls breathing, heart rate, and nerves and muscles used in seeing, hearing, walking, talking, and eating.

Although cancer is rare in children, brain tumors are the most common type of childhood cancer other than leukemia or lymphoma.

The symptoms of childhood brain stem glioma vary and often depend on the child's age and where the tumor is located.

These symptoms may be caused by a brain stem glioma or other conditions.

• Loss of balance and difficulty walking.
• Vision and hearing problems.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Unusual sleepiness or change in energy level.
• Tests that examine the brain are used to detect (find) childhood brain stem glioma.

Childhood brain stem glioma is diagnosed and removed in surgery.

If the tumor has not spread widely within the brain stem, a biopsy may be done by removing part of the skull and using a needle to remove a sample of the brain tissue. If cancer cells are found, as much tumor as safely possible during the same surgery will be removed.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) depends on:

• The type of brain stem
• Where it is located and if it has spread within the brain stem.
• Whether or not the child has an underlying condition called neurofibromatosis type 1.
• Whether the glioma has just been diagnosed or has recurred (come back).
• Treatment options depend on the type and location of the glioma.

3. Childhood Cerebellar Astrocytoma

Childhood cerebellar astrocytoma is a disease in which benign (noncancer) or malignant (cancer) cells form in the tissues of the brain. Astrocytomas are tumors that develop from brain cells called astrocytes. Cerebellar astrocytomas start in the cerebellum, which is located at the lower back of the brain. The cerebellum is the part of the brain that controls movement, balance, and posture.

About 15-25% of all childhood brain tumors are cerebellar astrocytomas. Although cancer is rare in children, brain tumors are the most common type of childhood cancer other than leukemia and lymphoma.

The symptoms of childhood cerebellar astrocytoma vary and often depend on the child’s age and where the tumor is located.

These symptoms may be caused by an astrocytoma or other conditions. A doctor should be consulted if any of the following problems occur:

• Loss of balance, difficulty walking, worsening handwriting, or slow speech.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.
• Unexplained weight loss or weight gain.
• Tests that examine the brain and spinal cord are used to detect (find) childhood cerebellar astrocytoma.

Childhood cerebellar astrocytoma is diagnosed and removed in surgery.

If a brain tumor is suspected, a biopsy is done by removing part of the skull and using a needle to remove a sample of the brain tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as safely possible during the same surgery.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) depends on:

• The type of astrocytoma.
• Whether cancer cells remain after surgery.

Treatment options depend on:

• Whether cancer cells remain after surgery or have spread to other parts of the brain.
• The location of the tumor.
• The child's age.

4.Childhood Cerebral Astrocytoma

Cerebral astrocytoma is a type of malignant glioma. Childhood cerebral astrocytoma is a disease in which benign (noncancer) or malignant (cancer) cells form in the tissues of the brain.

Astrocytomas are tumors that start in brain cells called astrocytes. Cerebral astrocytomas form in the area of the brain called the cerebrum. The cerebrum, which is at the top of the head, is the largest part of the brain. The cerebrum controls thinking, learning, problem-solving, speech, emotions, reading, writing, and voluntary movement.

Although cancer is rare in children, brain tumors are the most common type of childhood cancer other than leukemia and lymphoma.

The symptoms of childhood cerebral astrocytoma vary and often depend on the child’s age, where the tumor is located, and the size of the tumor.

These symptoms may be caused by an astrocytoma or other conditions. A doctor should be consulted if any of the following problems occur:

• Weakness or change in feeling on one side of the body.
• Seizures.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.

Tests that examine the brain are used to detect (find) childhood cerebral astrocytoma.

Childhood cerebral astrocytoma is diagnosed and removed in surgery.

If a brain tumor is suspected, a brain biopsy is done by removing part of the skull and using a needle to remove a sample of the tumor tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as safely possible during the same surgery.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) depends on:

• Cancer cells remaining after surgery.
• The type of astrocytoma.
• The location of the tumor.

Treatment options depend on:

• Whether cancer cells remain after surgery.
• The location of the tumor.
• The child's age.

5. Childhood Medulloblastoma

Childhood medulloblastoma (tumor) usually forms in the cerebellum, which is at the lower back of the brain. The cerebellum is the part of the brain that controls movement, balance, and posture. Childhood medulloblastoma may also be called primitive neuroectodermal tumor (PNET).

About 1 out of 5 childhood brain tumors are medulloblastomas. Although cancer is rare in children, brain tumors are the most common type of childhood cancer other than leukemia and lymphoma.

The signs of childhood medulloblastoma vary and often depend on the child’s age and where the tumor is located.

These symptoms may be caused by a medulloblastoma or other conditions. A doctor should be consulted if any of the following problems occur:

• Loss of balance, difficulty walking, worsening handwriting, or slow speech.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.
• Unexplained weight loss or weight gain.

Childhood medulloblastoma is diagnosed and removed in surgery.

If a brain tumor is suspected, a biopsy is done by removing part of the skull and using a needle to remove a sample of the tumor tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as possible during the same surgery.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on:

• The age of the child when the tumor is found.
• The location of the tumor.
• The amount of tumor remaining after surgery.
• Whether the cancer has spread to other parts of the central nervous system (brain and spinal cord), or to other parts of the body, such as the bones.

6.Childhood Medulloblastoma

Childhood medulloblastoma (tumor) usually forms in the cerebellum, which is at the lower back of the brain. The cerebellum is the part of the brain that controls movement, balance, and posture. Childhood medulloblastoma may also be called primitive neuroectodermal tumor (PNET).

About 1 out of 5 childhood brain tumors are medulloblastomas. Although cancer is rare in children, brain tumors are the most common type of childhood cancer other than leukemia and lymphoma.

The signs of childhood medulloblastoma vary and often depend on the child’s age and where the tumor is located.

These symptoms may be caused by a medulloblastoma or other conditions. A doctor should be consulted if any of the following problems occur:

• Loss of balance, difficulty walking, worsening handwriting, or slow speech.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.
• Unexplained weight loss or weight gain.

Childhood medulloblastoma is diagnosed and removed in surgery.

If a brain tumor is suspected, a biopsy is done by removing part of the skull and using a needle to remove a sample of the tumor tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as possible during the same surgery.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on:

• The age of the child when the tumor is found.
• The location of the tumor.
• The amount of tumor remaining after surgery.
• Whether the cancer has spread to other parts of the central nervous system (brain and spinal cord), or to other parts of the body, such as the bones.

7. Childhood Pineoblastoma

Childhood pineoblastoma are tumors in which malignant (cancer) cells form in the tissues of the brain. Pineoblastoma form in or near the pineal gland. The pineal gland is a tiny organ in the brain that produces melatonin, a substance that helps control our sleeping and waking cycle.

The symptoms of pineoblastoma vary and often depend on the child’s age, where the tumor is located, and the size of the tumor.

These symptoms may be caused by a pineoblastoma, or by other conditions. A doctor should be consulted if any of the following problems occur:

• Weakness or change in sensation on one side of the body.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Seizures.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.
• Unexplained weight loss or weight gain.

Childhood pineoblastoma are diagnosed and removed in surgery.

If a brain tumor is suspected, a biopsy is done by removing part of the skull and using a needle to remove a sample of brain tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as safely possible during the same surgery.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) depends on:

• Size and spread of the tumor before surgery.
• Cancer cells remaining after surgery.

Treatment options depend on:

• The age of the child when the tumor is found.
• The location of the tumor.
• The amount of tumor remaining after surgery.
• Whether the cancer has spread to other parts of the central nervous system, such as the meninges (membranes covering the brain) and spinal cord.
• Whether the cancer has spread to other parts of the body, such as the bone or lung.

8. Childhood Supratentorial Primitive Neuroectodermal Tumors

Childhood supratentorial primitive neuroectodermal tumors are tumors in which malignant (cancer) cells form in the tissues of the brain. Childhood supratentorial primitive neuroectodermal tumors start in the cerebrum. The cerebrum, which is at the top of the head, is the largest part of the brain.

The cerebrum controls thinking, learning, problem solving, speech, emotions, reading, writing, and voluntary movement. Childhood supratentorial primitive neuroectodermal tumors are also called cerebral neuroblastomas or cerebral medulloblastomas.

The symptoms of childhood supratentorial primitive neuroectodermal tumors vary and often depend on the child's age, where the tumor is located, and the size of the tumor. These symptoms may be caused by a supratentorial primitive neuroectodermal tumor, a pineoblastoma, or by other conditions. A doctor should be consulted if any of the following problems occur:

• Weakness or change in sensation on one side of the body.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Seizures.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.
• Unexplained weight loss or weight gain.

Tests that examine the brain and spinal cord are used to detect (find) childhood supratentorial primitive neuroectodermal tumors.

Childhood supratentorial primitive neuroectodermal tumors are diagnosed and removed in surgery.

If a brain tumor is suspected, a biopsy is done by removing part of the skull and using a needle to remove a sample of brain tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as safely possible during the same surgery.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) depends on:

• Size and spread of the tumor before surgery.
• Cancer cells remaining after surgery.

Treatment options depend on:

• The age of the child when the tumor is found.
• The location of the tumor.
• The amount of tumor remaining after surgery.
• Whether the cancer has spread to other parts of the central nervous system, such as the meninges (membranes covering the brain) and spinal cord.
• Whether the cancer has spread to other parts of the body, such as the bone or lung.

9. Infratentorial Ependymoma

Ependymal tumors are tumors that begin in the ependyma, the cells that line the hollow cavities within the brain (called ventricles) which are filled with cerebrospinal fluid).

The growth of ependymal tumors can obstruct the flow of the cerebrospinal fluid through the brain and spinal cord. Infratentorial ependymomas begin in the lower part of the brain. These tumors may spread via the cerebrospinal fluid to other areas of the brain and spinal cord. read via the cerebrospinal fluid to other areas of the brain and spinal cord.

10. Spinal Cord Tumors

Spinal cord tumors are rare benign or cancerous tumors in the spinal cord (the bundles of nerves that carry messages between the brain and the body).

The diagnosis of spinal cord tumors depends on how the tumor looks under a microscope and its location. Spinal cord tumors compress the spinal cord and the surrounding nerves causing symptoms such as pain or numbness in the back, arms, or legs, decreased muscle strength, and in some cases, loss of bowel or bladder control.

X-rays of the brain and the entire spine are done at the time of diagnosis to determine extent of disease.

11. Supratentorial Ependymoma

Ependymal tumors are tumors that begin in the ependyma, the cells that line the hollow cavities within the brain (called ventricles) which are filled with cerebrospinal fluid.

The growth of ependymal tumors can obstruct the flow of the cerebrospinal fluid through the brain. Supratentorial ependymomas begin in the upper part of the brain.

These tumors may spread to other areas of the brain and spinal cord, depending on their grade.

12. Childhood Visual Pathway and Hypothalamic Glioma

Childhood visual pathway glioma is a type of brain tumor in which cancer (malignant) cells begin to grow in the tissues of the brain.

Gliomas are a type of astrocytoma, tumors that start in brain cells called astrocytes. A visual pathway glioma occurs along the nerve that sends messages from the eye to the brain (the optic nerve). Visual pathway gliomas are visual pathway tumors. They may grow rapidly or slowly, depending on the grade of the tumor.

Brain Tumor Diagnosis ^2,4

Physical exam -

The doctor checks general signs of health.

Neurologic exam -

The doctor checks for alertness, muscle strength, coordination, reflexes, and response to pain. The doctor also examines the eyes to look for swelling caused by a tumor pressing on the nerve that connects the eye and brain.

CT scan -

An x-ray machine linked to a computer takes a series of detailed pictures of the head. The patient may receive an injection of a special dye so the brain shows up clearly in the pictures. The pictures can show tumors in the brain. A computerized tomography (CT) scan uses an X-ray and a complex computer to take cross-sectional pictures of your child. These pictures allow doctors to see the structures inside the body at different levels. A CT scan can be done on any body part. The length of your child’s CT scan depends on many things. A routine scan may take anywhere from 5 to 30 minutes, depending on the part of the body being scanned, the size of your child, and the amount of cooperation your child can give.

Magnetic resonance imaging (MRI)-

A powerful magnet linked to a computer makes detailed pictures of areas inside the body. These pictures are viewed on a monitor and can also be printed. Sometimes a special dye is injected to help show differences in the tissues of the brain. The pictures can show a tumor or other problem in the brain.

Functional magnetic resonance imaging (fMRI):

This is another type of magnetic resonance imaging (MRI) scan. It is a newer procedure that measures tiny changes in the brain. The general areas in the brain where functions such as memory, speech, and sensations are controlled are slightly different in every person. Also, injuries or diseases such as brain tumors can also cause the functions to move slightly to different parts of the brain. This information is important for planning surgery, radiation therapy, or other treatments.

Electrophysiological tests: Electrophysiological tests use special equipment to measure the patterns and locations of electrical activity in the brain. Electroencephalograms (EEG) and magnetoencephalograms (MEG) are two types of electrophysiological tests.

Electroencephalogram (EEG)

An electroencephalogram is a test that looks at the patterns of electrical activity in the brain. During the test these patterns of electricity are recorded as wavy lines on a computer or on paper. The doctor uses these wavy lines to find out what your child’s problem is. This test usually takes about 1 hour and does not hurt.

Magnetoencephalogram (MEG)

A magnetoencehalogram measures magnetic fields in the brain. These magnetic fields are caused by the electrical activity of nerve cells in the brain. An MEG is used to map brain function near a tumour or the site of epileptic seizure, or during recovery after brain injury.

Other tests:

Angiogram -

Dye injected into the bloodstream flows into the blood vessels in the brain to make them show up on an x-ray. If a tumor is present, the doctor may be able to see it on the x-ray.

Skull x-ray -

Some types of brain tumors cause calcium deposits in the brain or changes in the bones of the skull. With an x-ray, the doctor can check for these changes.

X-rays :

X-rays are not often used to diagnose brain tumours. However, they may provide useful information in certain cases. Certain tumours may cause one or more of the following changes:

Ø changes in the bones of the skull

Ø wearing away of bone from increased intracranial pressure

Ø increased skull size in infants

A myelogram is an X-ray of the spine. This test may be done when the doctor suspects a tumour in the spinal cord.

• Spinal tap - The doctor may remove a sample of cerebrospinal fluid (the fluid that fills the spaces in and around the brain and spinal cord). This procedure is performed with local anesthesia. The doctor uses a long, thin needle to remove fluid from the spinal column. A spinal tap takes about 30 minutes. The patient must lie flat for several hours afterward to keep from getting a headache. A laboratory checks the fluid for cancer cells or other signs of problems.
• Myelogram - This is an x-ray of the spine. A spinal tap is performed to inject a special dye into the cerebrospinal fluid. The patient is tilted to allow the dye to mix with the fluid. This test helps the doctor detect a tumor in the spinal cord.

Biopsy -

The removal of tissue to look for tumor cells is called a biopsy. A pathologist looks at the cells under a microscope to check for abnormal cells. A biopsy can show cancer, tissue changes that may lead to cancer, and other conditions. A biopsy is the only sure way to diagnose a brain tumor. A biopsy is a type of surgery. It is the best way to get an accurate diagnosis, because sometimes brain scans do not give enough information about the type of tumour.

During the biopsy, the neurosurgeon removes a small sample of brain tumour tissue. The neurosurgeon then gives the tumour sample to a pathologist. After studying the tissue, the pathologist will know what type of tumour it is, and whether it is cancer. In some cases, the surgeon will remain in the operating room while the tissue is being studied. This is called an intra-operative biopsy. Once she knows the type of tumour, she will then make a decision. She may choose to remove the rest of the tumour right away. The other option is to end the operation, because radiation or chemotherapy would be better treatments.

Surgeons can obtain tissue to look for tumor cells in three ways:

1. Needle biopsy - The surgeon makes a small incision in the scalp and drills a small hole into the skull. This is called a burr hole. The doctor passes a needle through the burr hole and removes a sample of tissue from the brain tumor.
2. Stereotactic biopsy - An imaging device, such as CT or MRI, guides the needle through the burr hole to the location of the tumor. The surgeon withdraws a sample of tissue with the needle.
3. Biopsy at the same time as treatment - Sometimes the surgeon takes a tissue sample when the patient has surgery to remove the tumor.

Sometimes a biopsy is not possible. If the tumor is in the brain stem or certain other areas, the surgeon may not be able to remove tissue from the tumor without damaging normal brain tissue. The doctor uses MRI, CT, or other imaging tests instead.

Blood work

Blood work is necessary for all children with brain tumors undergoing treatment. Blood is needed to monitor and prevent side effects or adjust treatment modalities. A specific blood investigation is used to help diagnose and monitor a type of brain tumor called a germ cell tumor. Some of these tumors secrete proteins that can be measured in the blood. These proteins are called alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG).

Lumbar puncture

A lumbar puncture is used to get a sample of cerebrospinal fluid (CSF). The CSF is studied to see if tumour cells have spread to the CSF. A lumbar puncture is also used to inject a dye before a myelogram. Your child will need to lie down for an hour or so after the lumbar puncture and will be monitored by a nurse. Other names for a lumbar puncture include spinal tap, spinal puncture, thecal puncture, and rachiocentesis.

Bone marrow aspiration and biopsy

A bone marrow aspiration and biopsy is used to study bone marrow. This is the tissue in the center of the bones, where blood cells are made. Bone marrow aspiration may be used to diagnose leukaemia and other cancers as well as many other disorders such as anaemia. Bone marrow aspiration is also used to remove bone marrow for a bone marrow transplantation, or to see how effective a bone marrow transplant has been.

Treatment ^1,2,5

Like most cancer, childhood brain tumor is best treated when it is found (diagnosed) early. If child has symptoms, a computed tomographic (CT) scan, a magnetic resonance imaging (MRI) scan, may also be done.

An anticancer "smart bomb" that delivers a lethal dose of drugs directly to tumors is developed.This tiny agent, called a "nanocell," enables precision targeting of the tumor while leaving adjacent healthy tissue unharmed. ⁵

Treatment for childhood brain tumor depends on the type and grade of the tumor, its location within the brain, and your child’s age and overall health.

Often, surgery is required to see whether there is a brain tumor and to tell what type of tumor it is. Sometimes biopsy may be done.

There are many types of brain tumors in children and the chance of recovery (prognosis) depends on the type of tumor, where it is located within the brain, and your child's age and general health.

There are treatments for all children with visual pathway gliomas. Three kinds of treatment are used:

1. Surgery (taking out the cancer in an operation).
2. Radiation therapy (using high-dose x-rays to kill cancer cells).
3. Chemotherapy (using drugs to kill cancer cells).

Experienced doctors working together can often give the best treatment for children with visual pathway glioma. Your child's treatment will often be coordinated by a pediatric oncologist, a doctor who specializes in cancer in children. The pediatric oncologist may refer you to other doctors, such as a pediatric neurosurgeon (a specialist in childhood brain surgery), a pediatric neurologist, a psychologist, a radiation oncologist, and other doctors who specialize in the type of treatment your child requires.

1. Surgery

Surgery is one treatment for visual pathway glioma. Surgery is the treatment of choice for accessible primary brain tumors, when the patient is in good health. The goal of surgery is to remove as much of the tumor as possible without damaging nearby normal brain tissue. Depending on where the cancer is and the type of cancer, child's doctor may remove as much of the tumor as possible. If the tumor cannot be totally removed, radiation therapy and chemotherapy may also be given. If the cancer is in a place where it cannot be removed, surgery may be limited to a biopsy of the cancer.

Removal is often complicated by the nature of the tumor (e.g., invasive, highly vascularized) and by its location. Partial removal (debulking) of the tumor can improve quality of life by alleviating symptoms and sometimes improve the effectiveness of radiation therapy or chemotherapy.

Before surgery, some important tests are performed. Patients over the age of 40 usually undergo an electrocardiogram (ECG or EKG) and a chest x-ray. Other tests are used to detect the presence of uncontrolled hypertension, diabetes, active coronary ischemia, or the presence of circulating anticoagulant (substance that inhibits normal blood clotting) in the blood. If any of these conditions are present, it may not be advisable to undergo craniotomy.

2. Radiation therapy

Uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation therapy for childhood brain tumors usually comes from a machine outside the body (external radiation therapy). The use of radiation put into the brain through thin plastic tubes (internal radiation therapy) is under study. For some types of brain tumors, clinical trials are evaluating radiation therapy given in several small doses per day (hyperfractionated radiation therapy). Radiation therapy can affect growth and brain development, so clinical trials are testing ways to decrease or delay radiation therapy, especially for younger children.

Radiation is used when the entire primary tumor cannot be surgically removed. Most malignant brain tumors are treated with external-beam radiation even if the entire primary tumor is surgically removed, because hidden tumor cells often remain in brain tissue. The survival rate for patients with malignant tumors (e.g., anaplastic astrocytoma, glioblastoma multiforme) more than doubles with radiation therapy, and it can prolong life for patients with low-grade gliomas as well.

Radiation therapists use several different approaches to treat primary brain tumors, but external-beam radiation is the most common. Local radiation therapy techniques, including external focal, brachytherapy, and stereotactic radiosurgery, may be administered to selected patients.

There are various other radiation techniques, some of which are being used on an experimental basis. An assortment of technologies, as well as the use of medications and other compounds, can make tumor cells more sensitive to radiation.

a. External-beam radiation

External-beam radiation, the traditional form of radiation therapy, delivers radiation from outside the body. Therapy usually begins a couple of weeks after surgery and is typically repeated at regular intervals for several weeks. Hyperfractionation is a modified form of external-beam radiation that involves applying less intense but more frequent doses of radiation. Some benign tumors are treated with external-beam radiation to prevent recurrence, even if the entire primary tumor has been surgically removed. They also may be treated with radiation at the time of recurrence.

b. Stereotactic radiosurgery

Stereotactic radiosurgery delivers radiation to the tumor in a single dose and does not involve surgery, as the term may imply. In this procedure, a head frame supporting a CT or MRI scanner may be attached to the skull. With the aid of computer imaging, the radiologist is able to pinpoint the exact location of the tumor and aim the beam of radiation directly at it. Newer stereotactic techniques do not involve the use of the head frame. Often the radiation is delivered from several different directions, hitting the tumor at various angles.

The advantage of using localized radiation is that the surrounding, healthy tissue is left undestroyed. It often is used in addition to external-beam radiation, especially in cases of malignant gliomas and mestastases that are in deep or sensitive areas of the brain. Some tumors, however, cannot be treated with the intense local radiation of radiosurgery. For example, tumors near the optic nerves are better treated with several small doses because the optic nerves are especially sensitive to radiation. Stereotactic radiotherapy involves applying many small doses of radiation, using the same imaging techniques used in stereotactic radiosurgery.

3. Chemotherapy

Uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in a vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells throughout the body. Chemotherapy is being studied to delay the use of radiation therapy in some patients. Clinical trials are studying different chemotherapy drugs for visual pathway gliomas.

4.Craniotomy:

Craniotomy is the treatment of choice and the goal is to remove as much of the tumor as possible. The procedure is performed under general anesthesia and involves opening the skull (cranium).

The neurosurgeon makes an incision into the scalp and several holes (called burr holes) are made in the skull. A bone saw is used to join the holes together to create a flap of bone.

The bone flap is then removed to expose the brain and remove as much of the tumor as possible. After the tumor has been partially or completely resected, the bone flap is replaced and secured using fine wire. Recovery from the procedure may take as long as 8 weeks.

Complications of craniotomy include bleeding (hemorrhage), swelling (edema), increased intracranial pressure (IICP), infection, and brain tissue damage.

5. Laser microsurgery :

In laser microsurgery, MRI is used to pinpoint the location of the tumor and a laser is used to destroy the tumor. This procedure may be used after craniotomy to remove remaining tumor tissue.

6. Brain-mapping

Is performed under local anesthesia and sedation. Electrodes stimulate nerves in the brain, measure responses, and allow communication with the patient. The surgeon removes as much of the tumor as possible without damaging vital areas of the brain, such as those that control motor function and speech.

Postoperative care includes drug therapy with corticosteroids, histamine inhibitors (block stomach acid), and antiepileptics. Corticosteroids (dexamethasone and Decadron®) help reduce swelling and can relieve various postoperative neurological effects. An MRI scan, with and without contrast, is often obtained to determine the extent of residual disease following surgery. Sometimes, a plan for rehabilitation is needed.

7. Brachytherapy :

Brachytherapy involves implanting capsules containing radioactive substances into the tumor to deliver localized radiation. It is frequently applied to treat recurrent disease in an area previously treated by external-beam radiation. Advantages of this type of radiation therapy include sparing vital structures close to the tumor and a shorter length of treatment (i.e., hours to days instead of weeks).

Radiation follow-up

Because loss of pituitary function can be a long-term side effect of radiation therapy, an endocrine evaluation is an important part of follow-up care for patients who have received radiation. Neuropsychological testing may also be done to evaluate whether a patient has incurred diminished intellectual activity resulting from brain tumor radiation.

References :

1. www.oncologychannel.com
2. www.myDNA.com
3. www.MedlinePlus.com
4. www.aboutkidshealth.ca
5. www.MedicineNet.com

About Authors:

Mrs. Rupali A. Patil

*Author for Correspondance
Lecturer, Dept of Pharmacology, MAEER’s Maharashtra Institute of Pharmacy,
Pune – 411 038. Email : ruupalipatil@rediffmail.com
Ritesh Soni
Student, MAEER’s Maharashtra Institute of Pharmacy, Pune – 411 038