Glioma

What is glioma

Glioma is a general term used to describe any tumor that arises from the supportive (“nerve glue”) tissue of the brain and the spinal cord. This tissue, called “glia” or “neuroglia” helps to keep the neurons in place and functioning well.

There are three types of normal glial cells that can produce tumors. An astrocyte will produce astrocytomas (including glioblastomas), an oligodendrocyte will produce oligodendrogliomas, and ependymomas come from ependymal cells. Tumors that display a mixture of these different cells are called mixed gliomas.

Tumors such as “optic nerve glioma” and “brain stem glioma” are named for their locations, not the tissue type from which they originate.

Types of glioma include:

Astrocytomas, including astrocytoma, anaplastic astrocytoma and glioblastoma
Ependymomas, including anaplastic ependymoma, myxopapillary ependymoma and subependymoma
Oligodendrogliomas, including oligodendroglioma, anaplastic oligodendroglioma and anaplastic oligoastrocytoma

Gliomas can affect your brain function and be life-threatening depending on their location and rate of growth.

Gliomas are one of the most common types of primary brain tumors. About half of all brain and spinal cord tumors in children are gliomas.

The type of glioma you have helps determine your treatment and your prognosis. In general, glioma treatment options include surgery, radiation therapy, chemotherapy, targeted therapy and experimental clinical trials.

Neuroglia

Neuroglia or glia make up about half the volume of the CNS (central nervous system= brain+spinal cord). There are 6 types of neuroglia—4 in the CNS and 2 in the PNS (peripheral nervous system). Their name derives from the idea of early histologists that they were the “glue” that held nervous tissue together. Scientists now know that neuroglia are not merely passive bystanders but rather actively participate in the activities of nervous tissue. Generally, neuroglia are smaller than neurons, and they are 5 to 25 times more numerous. In contrast to neurons, glial cells do not generate or propagate action potentials, and they can multiply and divide in the mature nervous system. In cases of injury or disease, neuroglia multiply to fill in the spaces formerly occupied by neurons. Brain tumors derived from glia, called gliomas, tend to be highly malignant and to grow rapidly. Of the six types of neuroglia, four—astrocytes, oligodendrocytes, microglia, and ependymal cells—are found only in the CNS. The remaining two types—Schwann cells and satellite cells—are present in the PNS (peripheral nervous system).

Neuroglia of the CNS (central nervous system= brain+spinal cord) can be classified on the basis of size, cytoplasmic processes, and intracellular organization into four types (Figure 1):

Astrocytes,
Oligodendrocytes,
Microglial cells, and
Ependymal cells.

Figure 1. Glia cells (Neuroglia) of the CNS

Astrocytes

Star-shaped astrocytes (“star cells”) are the most abundant glial cells of the CNS (Figure 1). Astrocytes have many radiating processes with bulbous ends. Some of these bulbs cling to neurons (including the axon terminals), whereas others cling to capillaries. The functions of astrocytes are numerous and not fully understood. Known functions include (1) regulating neurotransmitter levels by increasing the rate of neurotransmitter uptake in regions of high neuronal activity; (2) signaling increased blood flow through capillaries in active regions of the brain; (3) controlling the ionic environment around neurons; (4) astrocytes contain microfilaments that give them considerable strength, which enables them to support neurons; (5) astrocytes may also play a role in learning and memory by influencing the formation of neural synapses; (6) in the embryo, astrocytes secrete chemicals that appear to regulate the growth, migration, and interconnection among neurons in the brain.

Astrocytes also help synapses form in developing neural tissue, produce molecules necessary for neural growth (brain-derived trophic factor, BDTF), and propagate calcium signals that may beinvolved with memory. No longer are these cells considered passive supportive cells for neurons; rather, they appear to have an active role in neural activity. Understanding the activities of these abundant glial cells is an area of ongoing research.

Microglial Cells

Microglial cells, the smallest and least abundant neuroglia of the CNS, have elongated cell bodies and cell processes with many pointed projections, like a thorny bush (Figure 1). They are phagocytes, the macrophages of the CNS. They migrate to, and then engulf, invading microorganisms and injured or dead neurons. Unlike other neuroglial cells, microglial cells do not originate in nervous tissue; like the other macrophages of the body, they are derived from blood cells called monocytes. The monocytes that become microglial cells migrate to the CNS during the embryonic and fetal periods.

Ependymal Cells

The CNS originates in the embryo as a hollow neural tube and retains a central cavity throughout life. Ependymal cells form a simple epithelium that lines the central cavity of the spinal cord and brain (Figure 1). Here these cells provide a fairly permeable layer between the cerebrospinal fluid (CSF) that fills this cavity and the tissue fluid that bathes the cells of the CNS. Ependymal cells bear cilia that help circulate the cerebrospinal fluid. Functionally, ependymal cells produce, possibly monitor, and assist in the circulation of cerebrospinal fluid. They also form the blood–cerebrospinal fluid barrier.

Oligodendrocytes

Oligodendrocytes (“few-branch cells”) (Figure 1) have fewer branches than astrocytes, as their name implies. These resemble astrocytes but are smaller and contain fewer processes. They line up in small groups and wrap their cell processes around the thicker axons in the CNS, producing insulating coverings called myelin sheaths. Processes of oligodendrocytes are responsible for forming and maintaining the myelin sheath around CNS axons. The myelin sheath is a multilayered lipid and protein covering around some axons that insulates them and increases the speed of nerve impulse conduction. Such axons are said to be myelinated.

Glioma tumor types and location

The location of the tumor depends on the type of cells from which it originates.

Three types of normal glial cells can produce tumors—astrocytes, oligodendrocytes, and ependymal cells. Tumors that display a mixture of these cells are called mixed gliomas.

Unspecified gliomas

Unspecified glioma means that the cells are glioma cells. But your doctor cannot tell exactly the tumor grade or sometimes the type of cell it started from. Sometimes this can be because it was only safe to take a small biopsy and this may not give the full picture.

Your doctors will use scans and information about your symptoms to decide:

how your tumor is likely to behave
what the best treatment is

Astrocytoma

Astrocytomas are the most common type of glioma in both adults and children. Astrocytomas are tumors that arise from astrocytes—star-shaped cells that make up the “glue-like” or supportive tissue of the brain. Astrocytes are the cells of the brain that support the nerve cells (neurones).

Astrocytomas can be low grade (slow growing) or high grade (fast growing), or grades on a scale from I to IV based on how normal or abnormal the cells look. Grade 4 (IV) tumors look the most abnormal under the microscope and are more fast growing. There are low-grade astrocytomas and high-grade astrocytomas. Low-grade astrocytomas are usually localized and grow slowly. High-grade astrocytomas grow at a rapid pace and require a different course of treatment. Most astrocytoma tumors in children are low grade. In adults, the majority are high grade.

The most common types of brain tumor in adults are:

grade 3 astrocytoma – also called anaplastic astrocytoma
grade 4 astrocytoma – also called glioblastoma multiforme (GBM)

These are malignant (high grade) brain gliomas. They are generally fast growing and can sometimes spread to other parts of the brain.

Some astrocytomas are very localized (focal). This means it is easy to see the border between the tumor and normal brain tissue on a scan or during an operation. Focal astrocytomas are often diagnosed in children and are not common in adults.

Other astrocytomas are called diffuse. These do not have a clear boundary between the tumor and normal brain tissue.

Astrocytomas includes juvenile pilocytic astrocytoma, low grade astrocytoma, anaplastic astrocytoma, or glioblastoma.

Most astrocytomas can spread widely throughout the brain and blend with the normal brain tissue, which can make them very hard to remove by surgery. Sometimes they spread along the cerebrospinal fluid (CSF) pathways. It is very rare for them to spread outside of the brain or spinal cord.

Astrocytoma Cause

Like many tumor types, the exact cause of astrocytoma is not known.

Descriptions of the various grades of astrocytoma tumors:

Pilocytic Astrocytoma (also called Juvenile Pilocytic Astrocytoma)—These grade I astrocytomas typically stay in the area where they started and do not spread. They are considered the “most benign” (noncancerous) of all the astrocytomas. They account for nearly 1 out of 5 brain tumors in children. Two other, less well known grade I astrocytomas are cerebellar astrocytoma and desmoplastic infantile astrocytoma.
Diffuse Astrocytoma (also called Low-Grade or Astrocytoma Grade II) Types: Fibrillary, Gemistocytic, Protoplasmic Astrocytoma—These grade II astrocytomas tend to invade surrounding tissue and grow at a relatively slow pace. The important characteristic of growing into nearby tissues, which makes them hard to remove with surgery. Though these tumors are thought of as low grade, they tend to become more aggressive and fast growing over time.
Anaplastic Astrocytoma—An anaplastic astrocytoma is a grade III tumor. These rare tumors require more aggressive treatment than benign pilocytic astrocytoma.
Astrocytoma Grade IV (also called Glioblastoma, previously named “Glioblastoma Multiforme,” “Grade IV Glioblastoma,” and “GBM”)— There are two types of astrocytoma grade IV—primary, or de novo, and secondary. Primary tumors are very aggressive and the most common form of astrocytoma grade IV. The secondary tumors are those which originate as a lower-grade tumor and evolve into a grade IV tumor. Glioblastoma can occur at any age, but tends to occur more often in older adults. It can cause worsening headaches, nausea, vomiting and seizures. Glioblastoma can be very difficult to treat and a cure is often not possible. Treatments may slow progression of the cancer and reduce signs and symptoms.
Subependymal Giant Cell Astrocytoma—Subependymal giant cell astrocytomas are ventricular tumors associated with an inherited condition called tuberous sclerosis.

Astrocytoma Location

Astrocytomas can appear in various parts of the brain and nervous system, including the cerebellum, the cerebrum, the central areas of the brain, the brainstem, and the spinal cord.

Astrocytoma Description

Pilocytic Astrocytomas generally form sacs of fluid (cysts), or may be enclosed within a cyst. Although they are usually slow-growing, these tumors can become very large.
Diffuse Astrocytomas tend to contain microcysts and mucous-like fluid. They are grouped by the appearance and behavior of the cells for which they are named.
Anaplastic Astrocytomas tend to have tentacle-like projections that grow into surrounding tissue, making them difficult to completely remove during surgery.
Astrocytoma Grade IV (Glioblastoma) may contain cystic material, calcium deposits, blood vessels, and/or a mixed grade of cells.

Astrocytoma Symptoms

Headaches, seizures, memory loss, and changes in behavior are the most common early symptoms of astrocytoma. Other symptoms may occur depending on the size and location of the tumor.

Astrocytoma Incidence

Pilocytic astrocytomas are typically seen in children and young adults. The other types tend to occur in males more often than females, and most often in people age 45 and over.

Astrocytoma Treatment

Treatment options depend on the type, size, and location of the tumor, if and how far it has spread, previous treatment received, and the patient’s overall health. Treatment methods for the various types of astrocytomas are briefly explained below.

Pilocytic Astrocytoma: These tumors are often removed by surgery alone. In adults and older children, radiation may follow surgery if the tumor cannot be completely removed. Or, the patient may be watched carefully for signs that the tumor has returned.
Diffuse Astrocytoma: If the tumor is accessible and can be completely removed, the only additional care required is follow-up scans. In adults and older children, radiation may be suggested in addition to surgery. Radiation may also be used to treat an unremovable low-grade astrocytoma. The role of chemotherapy in treating these tumors is being investigated.
Anaplastic Astrocytoma: The first step in treatment of anaplastic astrocytoma is surgery. Radiation is then used to treat the remaining tumor. Chemotherapy may be recommended immediately after radiation or when and if the tumor recurs.
Astrocytoma Grade IV (Glioblastoma): The first treatment step is surgery to remove as much tumor as possible. Surgery is almost always followed by radiation. Chemotherapy is often given at the same time as radiation and may be used to delay radiation in young children.

Tumor re-growth can be treated with additional surgery, another form of radiation, a different chemotherapy drug (or combination of drugs), or any number of new approaches to treatment currently in development. These new therapies are offered in organized research studies called clinical trials.

Oligodendroglioma

Oligodendrogliomas come from oligodendrocytes, one of the types of cells that make up the supportive, or glial, tissue of the brain. They can be low-grade (grade II) or high-grade (grade III, or anaplastic).

About 3-4% of primary brain tumors are oligodendrogliomas, representing about 10-15% of the gliomas. Only 6% of these tumors are found in infants and children. Most oligodendrogliomas occur in adults ages 50-60, and are found in men more often than women.

Oligodendrogliomas are generally soft, grayish-pink tumors. They often contain mineral deposits (called calcifications), areas of hemorrhage, and/or cysts. Under the microscope, these tumor cells appear to have “short arms,” or a fried-egg shape.

Sometimes oligodendrogliomas are mixed with other cell types. These tumors may be graded using an “A to D” system, which is based on microscopic features of the individual tumor cells. The grade indicates how quickly the tumor cells reproduce and how aggressive the tumor is.

Oligodendrogliomas can be found anywhere within the cerebral hemisphere of the brain, although the frontal and temporal lobes are the most common locations.

Oligodendrogliomas tend to grow slowly, but like astrocytomas, most of them can grow into nearby brain tissue and can’t be removed completely by surgery. Oligodendrogliomas rarely spread along the CSF pathways and even less frequently spread outside the brain or spinal cord. Only about 1% of brain tumors in children are oligodendrogliomas. As with astrocytomas, they can become more aggressive over time.

Oligodendrogliomas cause

Like many tumor types, the exact cause of oligodendroglioma is not known. However, scientists have identified chromosomal abnormalities which may play a role in the development of these tumors.

Oligodendrogliomas symptoms

Because of their generally slow growth, oligodendrogliomas are often present for years before they are diagnosed. The most common symptoms are seizures, headaches, and personality changes. Other symptoms vary by location and size of the tumor.
Tumors of the frontal lobe may cause weakness on one side of the body, personality or behavior changes, and difficulty with short-term memory. Temporal lobe tumors are usually “silent,” causing few symptoms other than perhaps seizures or language problems.

Oligodendrogliomas treatment

Your treatment depends on whether your oligodendroglioma is a slow growing type (low grade or grade 2). Or a faster growing type (grade 3 or an anaplastic tumor).

If the tumor is accessible, standard treatment for oligodendroglioma is surgical removal of as much of the tumor tissue as possible. Biopsy is typically performed on tumors that are not accessible to confirm the diagnosis and determine the grade of tumor. Recurrent low-grade oligodendrogliomas can be treated with surgery, radiation therapy (if not given initially), and chemotherapy.

Grade II Oligodendrogliomas: Close follow-up with regular MRI scans is recommended following the successful removal of low-grade oligodendrogliomas. If some of the tumor remains (also called “residual” tumor), radiation treatment is recommended following surgery. The best timing for radiation therapy (ie, immediately or when the tumor appears to be growing again), is currently being studied in clinical trials.
Grade III Oligodendrogliomas: Anaplastic oligodendroglioma is typically treated with a combination of radiation therapy and chemotherapy. Recurrent anaplastic oligodendroglioma may be treated with surgery and/or chemotherapy.

Ependymoma

Ependymomas arise from the ependymal cells that line the ventricles of the brain and the center of the spinal cord.

Ependymomas are relatively rare tumors in adults, accounting for 2-3% of primary brain tumors. However, they are the sixth most common brain tumor in children. About 5% of brain tumors in children are ependymomas. About 30% of pediatric ependymomas are diagnosed in children younger than 3 years of age.

The various types of ependymomas appear in different locations within the brain and spinal column. Subependymomas usually appear near a ventricle. Myxopapillary ependymomas tend to occur in the lower part of the spinal column. Ependymomas are usually located along, within, or next to the ventricular system. Anaplastic ependymomas are most commonly found in the brain in adults and in the lower back part of the skull (posterior fossa) in children. They are rarely found in the spinal cord.

These brain tumors can grow in the brain, or in the spinal cord. They can spread into the fluid that surrounds the brain. So sometimes ependymomas spread into other areas of the lining of the brain and spinal cord.

In children, ependymomas most often occur in the cerebellum. They might develop in the cerebrum, or less commonly in the spinal cord.

Ependymomas can range from fairly low-grade (slow growing) tumors to higher grade ones, which are called anaplastic ependymomas.

Ependymomas are divided into four major types:

Subependymomas (grade I): Typically slow-growing tumors.
Myxopapillary ependymomas (grade I): Typically slow-growing tumors.
Ependymomas (grade II): The most common of the ependymal tumors. This type can be further divided into the following subtypes, including cellular ependymomas, papillary ependymomas, clear cell ependymomas, and tancytic ependymomas.
Anaplastic ependymomas (grade III): Typically faster-growing tumors.

Ependymomas are soft, grayish, or red tumors which may contain cysts or mineral calcifications.

Ependymomas cause

Like many tumor types, the exact cause of ependymomas is not known.

Ependymomas symptoms

Ependymomas may spread along the CSF pathways but do not spread outside the brain or spinal cord. These tumors can block the flow of CSF out of the ventricles, causing the ventricles to become very large – a condition called hydrocephalus.

Symptoms of an ependymoma are related to the location and size of the tumor. In babies, increased head size may be one of the first symptoms. Irritability, sleeplessness, and vomiting may develop as the tumor grows. In older children and adults, nausea, vomiting, and headache are the most common symptoms.

Ependymomas treatment

Unlike astrocytomas and oligodendrogliomas, ependymomas usually do not grow into normal brain tissue. As a result, some (but not all) ependymomas can be removed and cured by surgery. But because they can spread along ependymal surfaces and CSF pathways, treating them can sometimes be difficult.

The first step of ependymoma treatment is to remove as much of the tumor as possible. Radiation is usually recommended for older children and adults following surgery, in some cases even if the tumor was completely removed.

You are more likely to have radiotherapy to the whole brain and spinal cord if the fluid around the brain (cerebrospinal fluid) has cancer cells. You might have radiotherapy to the area of the tumour (and not the spinal cord) if there are no cancer cells in the cerebrospinal fluid.

Children under 3 usually have chemotherapy instead of radiotherapy after surgery. Cancer specialists don’t like to treat children under 3 with radiotherapy. Their young age makes them more likely to develop side effects. They use chemotherapy to keep a young child’s tumour under control. Children usually have chemotherapy every 8 weeks for about a year.

The role of chemotherapy in treating newly diagnosed ependymomas is not clear. However, it may be used to treat tumors that have grown back after radiation therapy, or to delay radiation in infants and very young children.

Mixed Glioma (also called Oligoastrocytoma)

These tumors usually contain a high proportion of more than one type of cell, most often astrocytes and oligodendrocytes. Occasionally, ependymal cells are also found. The behavior of a mixed glioma appears to depend on the grade of the tumor. It is less clear whether their behavior is based on that of the most abundant cell type.

The initial symptoms, including headache and nausea, usually are the result of increased pressure inside the brain. Vision problems, as well as changes in behavior and personality, are also fairly common in mixed glioma patients.

Treatment is typically based on the fastest-growing component of the tumor.

Optic Glioma

These tumors may involve any part of the optic pathway, and they have the potential to spread along these pathways. Most of these tumors occur in children under the age of 10. Grade I pilocytic astrocytoma and grade II fibrillary astrocytoma are the most common tumors affecting these structures. Higher-grade tumors may also arise in this location. Twenty percent of children with neurofibromatosis type 1 (NF-1) will develop an optic glioma. These gliomas are typically grade I, pilocytic astrocytomas. Children with optic glioma are usually screened for neurofibromatosis type 1 (NF-1) for this reason. Adults with neurofibromatosis type 1 (NF-1) typically do not develop optic gliomas.

These tumors may cause few or no symptoms. Their placement along the optic nerve, however, can cause vision loss (depending on the location of the tumor) or strabismus (“crossed eyes”). Hormonal disturbance might also occur, causing developmental delay(s), early puberty, and other symptoms.

These tumors are rarely fatal, but they may cause vision loss and injury to nearby brain tissue.

Brain stem gliomas

This term refers to the location of the tumor, rather than the type of cell it starts in. A small number of brain stem gliomas occur as a tumor with very distinct edges (called a focal brain stem glioma). More often, brain stem gliomas grow diffusely throughout the brain stem, rather than growing as a focal tumor. These tumors often start in the pons, where they are called diffuse intrinsic pontine gliomas.

About 10% to 20% of brain tumors in children are brain stem gliomas. Nearly all of these tumors are some type of astrocytoma.

Gliomatosis Cerebri

This is an uncommon brain tumor that features widespread glial tumor cells in the brain. This tumor is different from other gliomas because it is scattered and widespread, typically involving two or more lobes of the brain. It could be considered a “widespread low-grade glioma” because it does not have the malignant features seen in high-grade tumors.

Symptoms are often nonspecific and can include personality and behavioral changes, memory disturbance, increased intracranial pressure with headache and sometimes seizures.

The widespread nature of gliomatosis cerebri causes enlargement of any part of the brain it involves. This may include the cerebral hemispheres, or less often, the cerebellum or brain stem.

Glioma causes

Like most primary brain tumors, the exact cause of gliomas is not known. But there are some factors that may increase your risk of a brain tumor.

Risk factors for glioma

Risk factors include:

Your age. Your risk of a brain tumor increases as you age. Gliomas are most common in adults between 60 and 80 years old. However, a brain tumor can occur at any age. Certain types of gliomas, such as ependymomas and pilocytic astrocytomas, are more common in children and young adults.
Exposure to radiation. People who have been exposed to a type of radiation called ionizing radiation have an increased risk of brain tumor. Examples of ionizing radiation include radiation therapy used to treat cancer and radiation exposure caused by atomic bombs. More-common forms of radiation, such as electromagnetic fields from power lines and radiofrequency radiation from cellphones and microwave ovens, have not been shown to increase the risk of glioma.
Family history of glioma. It’s rare for glioma to run in families. But having a family history of glioma can double the risk of developing it. Some genes have been weakly associated with glioma, but more study is needed to confirm the link between these genetic variations and brain tumors.

Glioma symptoms

The symptoms of glioma vary by tumor type as well as the tumor’s size, location and rate of growth.

Common signs and symptoms of gliomas include:

Headache
Nausea or vomiting
Confusion or a decline in brain function
Memory loss
Personality changes or irritability
Difficulty with balance
Urinary incontinence
Vision problems, such as blurred vision, double vision or loss of peripheral vision
Speech difficulties
Seizures, especially in someone without a history of seizures

Glioma diagnosis

If your primary care doctor suspects you have a brain tumor, you may be referred to a specialist who is trained in treating brain and nervous system disorders (neurologist). Your doctor may recommend a number of tests and procedures, including:

A neurological exam. During a neurological exam, your doctor may check your vision, hearing, balance, coordination, strength and reflexes. Problems in one or more of these areas may provide clues about the part of your brain that could be affected by a brain tumor.
Imaging tests. Magnetic resonance imaging (MRI) is often used to help diagnose brain tumors. In some cases, a dye (contrast material) may be injected through a vein in your arm during your MRI study to help show differences in brain tissue. A number of specialized MRI scan components — including functional MRI, perfusion MRI and magnetic resonance spectroscopy — may help your doctor evaluate the tumor and plan treatment. Other imaging tests may include computerized tomography (CT) scan and positron emission tomography (PET).
Tests to find cancer in other parts of your body. To rule out other types of brain tumors that may have spread from other parts of the body, your doctor may recommend tests and procedures to determine where the cancer originated. Gliomas originate within the brain and are not the result of cancer that has spread (metastasized) from elsewhere.
Collecting and testing a sample of abnormal tissue (biopsy). Depending on the location of the glioma, a biopsy may be performed with a needle before treatment or as part of an operation to remove the brain tumor.A stereotactic needle biopsy may be done for gliomas in hard-to-reach areas or very sensitive areas within your brain that might be damaged by a more extensive operation. During a stereotactic needle biopsy, your neurosurgeon drills a small hole into your skull. A thin needle is then inserted through the hole. Tissue is removed through the needle, which is frequently guided by CT or MRI scanning.The biopsy sample is then analyzed under a microscope to determine if it’s cancerous or benign.
A biopsy is the only way to definitively diagnose a brain tumor and give a prognosis to guide treatment decisions. Based on this information, a pathologist can determine the grade or stage of a brain tumor.
Tumors are divided into four grades with grade I tumors having the slowest growing, most benign cells and grade IV tumors having the most abnormal and aggressive cancer cells.

Glioma treatment

Treatment for glioma depends on the type, size, grade and location of the tumor, as well as your age, overall health and preferences.

In addition to actions to remove the tumor itself, treatment for glioma may also require using drugs to reduce the signs and symptoms of your tumor.

Your doctor may prescribe steroids to reduce swelling and relieve pressure on affected areas of the brain. Anti-epileptic drugs may be used to control seizures.

Surgery

Surgery to remove as much of the tumor as possible is usually the first step in treating most types of gliomas.

In some cases, gliomas are small and easy to separate from surrounding healthy brain tissue, which makes complete surgical removal possible. In other cases, tumors can’t be separated from surrounding tissue, or they’re located near sensitive areas in your brain and make surgery risky. In these situations your doctor removes as much of the tumor as is safe.

Even removing a portion of the tumor may help reduce your signs and symptoms.

In some cases, neuropathologists may analyze tissue samples removed by a surgeon and report the results while surgery is underway. This information helps the surgeon decide how much tissue to remove.

A variety of surgical technologies and techniques may be used to assist the neurosurgeon in protecting as much healthy brain tissue as possible while removing the tumor, including computer–assisted brain surgery, awake brain surgery and intraoperative MRI. For example, during awake brain surgery, you may be asked to move a limb or tell a story during surgery to ensure the areas of the brain controlling those functions are not damaged.

Surgery to remove a glioma carries risks, such as infection and bleeding. Other risks may depend on the part of your brain in which your tumor is located. For instance, surgery on a tumor near nerves that connect to your eyes may carry a risk of vision loss.

Radiation therapy

Radiation therapy usually follows surgery in treatment of glioma, especially high-grade gliomas. Radiation uses high-energy beams, such as X-rays or protons, to kill tumor cells.

Radiation therapy for glioma comes from a machine outside your body (external beam radiation).

There are several types of external beam radiation currently used and under study for the treatment of glioma. The type of glioma you have, its grade and other prognostic factors are considered in determining the timing and type of radiation therapy you may receive.

Radiation therapy options include using computers to target the brain tumor (intensity-modulated radiation therapy), using protons rather than X-rays as the source of radiation (proton beam therapy) and stereotactic radiation therapy (radiosurgery).

Stereotactic radiosurgery is not surgery in the traditional sense. Instead, radiosurgery uses multiple beams of radiation to give a highly focused form of radiation treatment to kill the tumor cells in a very small area. Each beam of radiation isn’t particularly powerful, but the point where all the beams meet — at the brain tumor — receives a very large dose of radiation to kill the tumor cells.

There are different types of technology used in radiosurgery to deliver radiation to treat brain tumors, such as a Gamma Knife or linear accelerator (LINAC).

Side effects of radiation therapy depend on the type and dose of radiation you receive. Common side effects during or immediately following radiation include fatigue, headaches and scalp irritation.

Chemotherapy

Chemotherapy uses drugs to kill tumor cells. Chemotherapy drugs can be taken in pill form (orally) or injected into a vein (intravenously).

Chemotherapy is usually used in combination with radiation therapy to treat gliomas.

The chemotherapy drug used most often to treat gliomas is temozolomide (Temodar), which is taken as a pill.

Side effects of chemotherapy depend on the type and dose of drugs you receive. Common side effects include nausea and vomiting, headache, hair loss, fever, and weakness. Some side effects may be managed with medication.

Targeted drug therapy

Targeted drug treatments focus on specific abnormalities present within cancer cells. By blocking these abnormalities, targeted drug treatments can cause cancer cells to die.

One targeted drug therapy used to treat a type of brain cancer called glioblastoma is bevacizumab (Avastin). This drug, given through a vein (intravenously), stops the formation of new blood vessels, cutting off blood supply to a tumor and killing the tumor cells.

Low grade glioma treatment options

Monitoring

You might not need treatment straight away for a very slow growing low grade tumor. You have regular MRI scans to monitor your tumor. This is called watchful waiting.

About half (50%) of people with low grade tumors will need surgery within 2 to 3 years of monitoring.

Surgery

Your surgeon will remove as much of the tumor as possible. This is called debulking. Even when some tumor is left behind, slow growing tumors may take years to cause symptoms again.

You may be asked to swallow a capsule called Gliolan before surgery. This contains a florescent dye. It shows up the border of the tumor and allows the surgeon to remove more of the tumor safely.

Radiotherapy

You might have radiotherapy after surgery. Your doctor is likely to recommend this if you:

are over 40
have a lot tumor left behind
have symptoms such as weakness in one area of your body

Chemotherapy

Your doctor might recommend chemotherapy (instead of radiotherapy) after surgery if you have a gene change (mutation) called 1p19q.

High grade glioma treatment options

Surgery

Your surgeon will remove as much of the tumor as possible. This is called debulking.

Radiotherapy

You might have radiotherapy after surgery. It will not cure your tumor, but aims to control your tumor for as long as possible. You might have one treatment a day, from Monday to Friday for a few weeks.

A long course of radiotherapy might not be suitable if you are not very fit. So your doctor might offer you a shorter course over 2 weeks and you may have treatment every day, or every other day.

Chemotherapy

You might have temozolamide (chemotherapy tablets) after surgery if you are faily fit and well. You have this for several months.

You might have temozolamide alongside a course of radiotherapy after your operation.

Your surgeon might use carmustine (chemotherapy) implants if more than 90% of your tumor is removed. Your surgeon places the implants in the area of your tumor during your operation. This treatment is only available in specialist centers and may not be suitable for everyone.

If your tumor starts to grow again

You might have one, or a combination of the following treatments:

further surgery
carmustine wafers
radiotherapy
chemotherapy

Brain stem glioma treatment options

Glioma in the brain stem are very rare. It might sometimes be possible to take a biopsy from the tumor but the tumor cannot be removed. The brain stem is too delicate an area to operate on.

The most common treatment is radiotherapy. It will not cure your cancer, but it might slow its growth and control your symptoms.

Follow up

You will have regular check ups once you finish your treatment. Your doctor will examine you and ask about your general health.

This is your chance to ask questions and to tell your doctor if anything is worrying you.

How often you have check ups depends on your individual situation.

Rehabilitation after treatment

Because brain tumors can develop in parts of the brain that control motor skills, speech, vision and thinking, rehabilitation may be a necessary part of recovery. Your doctor may refer you to services that can help, such as:

Physical therapy can help you regain lost motor skills or muscle strength
Occupational therapy can help you get back to your normal daily activities, including work, after a brain tumor or other illness
Speech therapy with specialists in speech difficulties (speech pathologists) can help if you have difficulty speaking
Tutoring for school-age children can help kids cope with changes in their memory and thinking after a brain tumor

Coping and support

Coping with a diagnosis of cancer can be difficult, overwhelming and frightening. It can be especially difficult if you have a rare and aggressive cancer. Being well informed about your cancer and its treatment can make it easier to make decisions and cope with what happens.

Coping with the shock, fear and sadness that come with a cancer diagnosis can take time. You may feel overwhelmed just when you need to make crucial decisions. With time, each person finds a way of coping and coming to terms with the diagnosis.

You can take steps to cope with the shock and grief that may come after your diagnosis. Consider trying to:

Find out enough about the cancer to make decisions about your care. Ask your doctor for the specifics about your cancer, such as its type and stage. And ask for recommended sources of information where you can learn more about your treatment options. The National Cancer Institute ¹ and the American Cancer Society ² are good places to start.
Learn enough about gliomas to make decisions about your care. Ask your doctor about your specific type of brain tumor, including your treatment options and, if you like, your prognosis. As you learn more about brain tumors, you may become more confident in making treatment decisions.
Stay connected to friends and family. Your friends and family can provide a crucial support network for you during your cancer treatment. As you begin telling people about your cancer diagnosis, you’ll likely get offers for help. Think ahead about things you may like help with, whether it’s having someone to talk to if you’re feeling low or getting help preparing meals.
Find someone to talk to. You might have a close friend or family member who’s a good listener. Or talk to a counselor, medical social worker, or pastoral or religious counselor.
Consider joining a support group for people with cancer. You may find strength and encouragement in being with people who are facing the same challenges you are. Ask your doctor, nurse or social worker about groups in your area. Or try online message boards, such as those available through the American Cancer Society ².
Ask your doctor about support groups in your area. Or check your phone book, library or a cancer organization, such as the National Cancer Institute ¹ or the American Cancer Society ².