Childhood Brain and Spine Tumours: Comprehensive Health Information

Childhood Brain and Spine Tumours: A Comprehensive Guide

General Information

Brain and spine tumours are the second most common forms of cancer in children, following leukaemia. Each year, brain tumours affect many children in India, accounting for 20% of all childhood cancers.

The brain is responsible for vital aspects of daily life, including thought, emotion, speech, vision, hearing, and movement. Messages are relayed throughout the body via the spinal cord and cranial nerves, forming the central nervous system (CNS). Tumours can develop in the spinal cord and cranial nerves as well as the brain itself.

The brain is protected by the hard, bony skull, and the spinal cord is protected by the vertebrae. Both are surrounded by a liquid called cerebrospinal fluid (CSF).

The brain is divided into four main parts:

Basal ganglia

Located deep within the brain, these structures are involved in muscle movement.

Brain stem

Situated at the base of the brain, this vital area contains nerve fibres that transmit messages between the cerebrum and the rest of the body, and it controls essential functions like breathing and heartbeat.

Cerebellum

Found at the back of the brain, this part helps control and coordinate movements such as walking and swallowing.

Cerebrum

The largest, outermost part of the brain, consisting of two hemispheres. It governs emotions, reasoning, language, movement, and the senses (sight, hearing, smell, and touch), as well as the perception of pain.

Types of Childhood Brain Tumours

The brain and spinal cord are complex structures composed of various tissues and cells, leading to many types of tumours, which can be either benign (non-cancerous) or malignant (cancerous). These different types require specific treatments and have varying prognoses.

Even benign brain tumours can cause significant problems. Although they typically grow slower than malignant tumours, their growth may damage or press against normal brain tissue or the spine.

Childhood brain and spinal cord tumours often differ from those found in adults in terms of location, the type of cell in which they originate, treatment methods, and overall outlook. Brain tumours are classified by their cell type, which determines their growth pattern and necessary treatment. The most commonly found brain tumours in children include:

Medulloblastoma

The most common malignant brain tumour in children.

Astrocytoma

These form in the cerebrum from cells called astrocytes. They are generally slow-growing, though higher-grade tumours can spread more quickly. They can be difficult to remove surgically because they mix with normal brain tissue. Glioblastoma is the highest-grade and fastest-growing astrocytoma.

Diffuse intrinsic pontine glioma (DIPG)

A dangerous tumour with a typically poor prognosis, growing in the pons, a vital area within the brain stem.

Ependymomas

Developing in the brain lining, usually in the posterior fossa or along the spinal cord. They begin in the cells that line the ventricles or the central canal of the spine. While they rarely spread outside the CNS, they can block CSF, leading to hydrocephalus.

Primitive neuroectodermal tumours (PNET)

Aggressive tumours that can develop anywhere but are typically found in the frontal, temporal, or parietal lobes. Pineoblastomas are a type of PNET that develops in the pineal gland and can be challenging to treat.

Craniopharyngiomas

Slow-growing tumours that start above the pituitary gland. They may compress the pituitary gland and hypothalamus, leading to hormone problems. Located near the optic nerves, they can cause vision issues and may be difficult to remove without damaging sight.

Mixed Glial and Neuronal Tumours

These have components of both glial and neuronal cells and generally have a favourable prognosis.

  • Pleomorphic xanthoastrocytoma (PXA) and dysembryoplastic neuroepithelial tumours (DNETs) are often benign and mostly cured by surgery alone.
  • Ganglioglioma is a tumour with both mature neurons and glial cells, often cured by surgery alone or combined with radiation therapy.

Choroid Plexus Tumours

Rare tumours that start in the choroid plexus within the brain's ventricles. Most are benign and can be removed with surgery.

Other Tumours Near the Brain

Meningiomas

These tumours originate in the meninges, the tissue surrounding the outer part of the brain and spine. They are nearly always benign and usually cured by surgery, though additional treatment may be needed if they are close to vital structures.

Chordomas

Starting in the bone at the base of the skull or the lower end of the spine, they can injure the nervous system by applying pressure. They seldom spread to other parts of the body.

Germ Cell Tumours

Rare tumours developing from germ cells, typically found in children, most often in the pineal gland or above the pituitary gland.

Brain Metastases

Cancers that have spread to the brain from other parts of the body. They are treated differently from primary brain cancers.

Childhood Brain Tumour Risk Factors

While no definitive causes for childhood brain tumours have been established, certain factors may increase a child's risk, including:

  • Radiation Exposure: Especially if a child was treated with radiation to the brain for conditions like leukaemia. This late effect is usually observed 10 to 15 years after treatment.

Rare Inherited Genetic Conditions

Such as:

  • Tuberous sclerosis
  • Neurofibromatosis types 1 and 2
  • Von Hippel-Lindau disease
  • Li-Fraumeni syndrome

Other Familial Diseases

Including Turcot syndrome, Rubinstein-Taybi syndrome, and Gorlin syndrome (basal cell nevus syndrome).

Genetic counselling may be appropriate for families with a history of brain cancer.

Symptoms

Childhood brain tumours frequently lead to changes in a child's hearing, memory, learning, sight, smell, or emotional state. Because these changes are often noticed early, childhood brain tumours are frequently diagnosed before they have spread widely.

Symptoms vary depending on the tumour's location and are different for every child. Signs of a possible brain tumour can include:

  • Frequent nausea and vomiting
  • Seizures
  • Headache, typically worse in the morning
  • Delayed growth and developmental milestones (e.g., walking, talking)
  • Blurred vision
  • Difficulty speaking or swallowing
  • Changes in mood or behaviour
  • Problems with coordination and balance
  • Weakness or tingling in the arms or legs
  • Swelling around an eye
  • Weakness of facial muscles
  • Abnormal eye movement
  • Abnormal head tilt to one side
  • Increase in head size (in infants)
  • Pain in the back, arms, or legs
  • Changes in bowel or urinary habits

It is important to remember that these symptoms are often caused by conditions less serious than a brain tumour. However, any persistent symptoms should be discussed with a doctor as they may signal other health issues.

Diagnosis

An early and accurate diagnosis significantly improves the chances of successful treatment for a childhood brain tumour.

The specialized medical team at SSCHRC possesses the expertise vital for targeting brain tumours in children, utilising advanced and accurate equipment to pinpoint the tumour's exact extent and location.

Diagnostic Tests

If a child presents with symptoms suggesting a brain tumour, the doctor will conduct a careful examination and inquire about the child's and family's medical history. A neurological exam may also be performed to assess reflexes, muscle strength, vision, and other functions of the brain and spine. If any abnormalities are noted, the child may be referred to a neurologist or neurosurgeon.

One or more diagnostic tests may be used to confirm a brain tumour, check for spread, and monitor the effectiveness of treatment:

Imaging Tests

These may include:

  • CT or CAT (computed axial tomography) scans
  • MRI (magnetic resonance imaging) scans
  • PET (positron emission tomography) scans
  • X-rays
  • Angiogram to examine blood vessels
  • Bone scan

Biopsy

If imaging tests identify a possible tumour area, a biopsy is almost always required for a definitive diagnosis. The doctor removes a small tissue sample for microscopic examination. Biopsy methods include:

  • Surgical Biopsy: Performed during a craniotomy (an operation to open the skull), where all or part of the tumour is removed.
  • Stereotactic (Needle) Biopsy: A CT scan is used to precisely guide a hollow needle into a hard-to-reach tumour to remove a small tissue sample.

Other Diagnostic Procedures

  • Bone marrow aspiration and biopsy
  • Lumbar Puncture (Spinal Tap): A small amount of CSF is withdrawn with a needle and examined under a microscope.
  • Blood and Urine Tests

Treatment

Upon a diagnosis of a brain tumour, the doctor will discuss the optimal treatment options, which are determined by the tumour's location and type, as well as the child's overall health.

One or more of the following therapies may be recommended to treat the cancer or help alleviate symptoms:

Surgery

Surgery is typically the initial treatment for brain tumours in children. If complete removal is not possible, the surgeon will remove as much of the tumour as possible without causing damage to surrounding areas.

Surgery can also help to:

  • Reduce the overall size of the tumour.
  • Relieve symptoms such as headaches and nausea.
  • Place a shunt to drain excess cerebrospinal fluid (CSF), which can cause symptoms like headaches and blurred vision.

The most common surgical procedure is a craniotomy, which involves opening the skull. While some tumours can be removed with minimal damage, many are located in areas that make removal difficult or impossible without affecting crucial parts of the brain.

SSCHRC utilises advanced equipment, such as functional MRI (fMRI), to help map the brain area and improve surgical accuracy. Many childhood brain tumours are successfully treated with surgery alone. If additional treatment is needed, surgery can help by reducing the tumour size before radiation or chemotherapy.

Brainsuite® iMRI: For tumours in challenging locations, SSCHRC neurosurgeons can use this innovative open MRI system, allowing them to view the tumour during surgery. This maximizes tumour removal while preserving healthy brain tissue.

Radiation Therapy

Radiation therapy may be used to halt or slow the growth of childhood brain tumours that cannot be removed through surgery. It is generally not used for children under three years of age. Radiation therapy may be used:

  • As the main treatment if surgery is unfeasible.
  • After surgery to destroy any remaining tumour cells.
  • To help relieve symptoms.

New techniques and the skill of SSCHRC doctors allow for precise targeting of brain tumours, delivering the maximum necessary radiation dose while minimizing damage to healthy cells.

SSCHRC employs advanced radiation methods, including:

  • Gamma Knife radiosurgery: Delivers a focused dose of radiation to the tumour from multiple angles, often used for hard-to-reach tumours or if the child is not healthy enough for surgery.
  • Focused radiation therapy: Targeted directly at the tumour and the immediate surrounding area.
  • Whole-brain radiation therapy: May be required if a child has two or more brain tumours.
  • Intensity-modulated radiotherapy (IMRT): Shapes the radiation beam precisely to the tumour, reducing exposure to the rest of the brain.

Chemotherapy

SSCHRC provides the most current and advanced chemotherapy options. Chemotherapy is often used for fast-growing tumours, frequently alongside radiation and surgery. In children under the age of three, it may sometimes be used instead of radiation therapy. Chemotherapy's effectiveness for brain cancer can be limited by the blood-brain barrier, which acts as a protective shield against many chemotherapy drugs.

Targeted Therapies

Targeted therapy drugs work by focusing on the specific genetic changes that drive the cancer. SSCHRC is a leader in discovering these agents, and many of its clinical trials for brain tumours focus on determining the best drug for each patient based on the molecular profile of their tumour.

Medications to Decrease Symptoms

Certain medications, such as anti-seizure drugs, hormones, and corticosteroids, may be prescribed to help children with brain tumours manage and relieve their symptoms.

Sri Shankara Cancer Hospital Footer Shankara Cancer Hospital & Research Center