Brain Tumors

Brain Tumours

Approximately 30,000 new primary brain tumours are diagnosed each year in India. Age is also a risk factor. The incidence of brain tumours is rising steadily in India. No age group is spared from brain tumours.

The abnormal and uncontrolled growth of cells in the brain is called a brain tumour. Although such growths are popularly called brain tumours, not all brain tumours are cancerous. Cancer is a term reserved for malignant tumours. Benign tumours are non-cancerous and malignant tumours are cancerous.

Types of Brain Tumours

Primary tumours originate primarily in the brain. Secondary (metastatic) brain tumours are tumours that result from cancer that starts elsewhere in the body and then spreads to the brain.

Symptoms

• Headaches that gradually become more frequent and severe
• Unexplained nausea or vomiting
• Gradual loss of sensation or movement in an arm or a leg
• Difficulty with balance in walking or sitting
• Tremors
• Speech difficulties
• Vision problems- blurred vision, double vision or loss of peripheral vision
• Changes in hearing or smell
• Confusion in everyday matters, memory loss, personality or behaviour changes
• Seizures, especially in someone who doesn't have a history of seizures 
• Increased sleepiness, drowsiness and loss of consciousness
• Some gender-specific symptoms are also seen. Nipple discharge in non-nursing women, menstrual abnormalities, excessive body hair

Causes and Risk factors

What causes brain tumours? Despite extensive research,  the brain tumour causes are not clear. Tumours are caused by the uncontrolled and unwanted growth of cells. This is caused by a mutation in the DNA. What exactly triggers this and why at a particular location in the body, is not known. Some risk factors have been identified that may increase the risk of brain tumours - Age, radiation, exposure to certain chemicals, family history (in genetic syndromes).

Diagnosis of Brain Tumour

Neurological Examination: The physician clinically examines you for the strength of hands and legs, coordination, speech, hearing, vision and other indicators in your complaints.

Imaging: If it is suspected that the patient can have a brain tumour, the doctor may recommend a number of tests and procedures. Magnetic resonance imaging (MRI) usually with contrast, is commonly used to help diagnose brain tumours. MR Spectroscopy uses the chemical changes in the brain tumour and further corroborates the diagnosis. Other imaging tests may include computerised tomography (CT) scan and positron emission tomography (PET). PET is helpful in diagnosing the tumours in other parts of the body as well.

Angiography: It can be MR or CT based or Digital Subtraction Angiography. In this procedure, a fluorescent dye is injected into the bloodstream. The dye on reaching the brain helps the doctor in knowing the blood supply of tumours and the engulfment/proximity of large brain vessels to the tumour.

Biopsy: A tiny piece of the tumour is removed through minimally invasive surgery or stereotactic procedure and then sent for histopathological examination to determine whether it is benign or malignant. This information is critical to establish a diagnosis and prognosis and, most importantly, in guiding treatment.

It is suspected that the brain tumour may be a result of cancer that has spread from another area of the body, the doctor may recommend tests and procedures to determine where cancer originated. One example might be a CT scan of the chest to look for signs of lung cancer. PET is the gold standard to look for tumours in the whole body in a single investigation.

Treatment

Treatment for a brain tumour depends on the type, size and location of the tumour. 

Surgery: Brain surgery is a complicated procedure and requires utmost attention and care during the surgery. If the brain tumour is located in a place that makes it accessible for an operation, the neurosurgeon will operate to remove as much of the brain tumour as is safely possible. In some cases, tumours are small and easy to separate from surrounding brain tissue, which makes complete surgical removal possible. In other cases, tumours can't be separated from surrounding tissue or they're located near sensitive/eloquent areas in your brain, making surgery risky. In these situations only the part of the tumour is removed which is safe.

Neurosurgeons can perform tumour resections with the help of brain neuronavigation more precisely, perform less-invasive procedures, and help improve clinical outcomes. The neuronavigation systems enable surgeons to visualize the anatomy of a patient’s brain during surgery and precisely track the location of their surgical instruments in relation to the anatomy.

When the diagnosis of a deep-seated tumour is to be confirmed histologically, a stereotaxic biopsy is performed. It is a computer-guided procedure, which is safe and rarely causes neurological deficit. Radiotherapy & chemotherapy is started according to the obtained histological diagnosis.

Awake Craniotomy: This is done when a tumour is located in an eloquent/sensitive area. The patient is kept awake while the tumour is being excised. This avoids or minimises damage to important areas of the brain controlling speech and the power of limbs.

The advancement of medical technology with the availability of high-speed drills, microscopes, CUSA, intraoperative ultrasound and stereotactic neuronavigation has further made brain tumour surgery safe.

If a brain tumour is diagnosed, relieving symptoms remains an important part of your care and treatment. Today, most tumours can be removed safely with microsurgical techniques in a manner that maximizes tumour removal and minimizes harm to the patients. 

Even removing a portion of the brain tumour may help reduce your signs and symptoms. Surgery to remove a brain tumour carries risks such as infection, bleeding, brain swelling, seizures, memory loss, coma, weakness of hands or legs. Other risks may depend on the part of the brain where your tumour is located. For instance, surgery on a tumour near nerves that connect to your eyes may carry a risk of vision loss.

Radiation therapy

Radiation therapy uses high-energy beams, such as X-rays or proton beams to kill tumour cells. External beam radiation therapy (EBRT)  directs high energy beams at a tumour from outside the body.  Brachytherapy places radioactive sources inside or next to the tumour to kill cancer cells and shrink tumours. It uses a highly localised dose of radiation.

External beam radiation can focus just on the area of your brain where the tumour is located, or it can be applied to your entire brain (whole-brain radiation). Whole-brain radiation is most often used to treat cancer that has spread to the brain from some other part of the body. 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.

Proton therapy is a type of EBRT that uses protons rather than X rays. It is used for tumours when less radiation is needed because of the location.

Radiosurgery

Stereotactic radiosurgery is a highly precise form of radiation therapy. Multiple beams of radiation are converged and focused forms of radiation treatment to kill the tumour 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 tumour receives a very large dose of radiation to kill the tumour cells.

There are different types of technology used in radiosurgery to deliver radiation to treat brain tumours, such as Gamma Knife / Cyberknife / Linear Accelerator. Radiosurgery is usually performed on an outpatient basis and is referred to as a one-day treatment. Some large tumours may require more than one session.

Radiosurgery is sometimes advised as the primary modality of treatment in some tumours, which are deep-seated or located close to vital structures in the brain

Chemotherapy

Chemotherapy uses drugs to kill tumour cells. Chemotherapy drugs can be taken orally in pill form or injected into a vein (intravenous). A chemotherapy regimen usually consists of a specific number of cycles given over a fixed period of time. The goal is to destroy tumour cells remaining after surgery or slow down a residual tumour’s growth. Chemotherapy side effects depend on the type and dose of drugs you receive. Chemotherapy can cause weakness, nausea, vomiting and hair loss.

Targeted drug therapy

This treatment targets the tumour’s specific genes, proteins or the tissue environment that contributes to a tumour’s growth and survival. Bevacizumab and Larotrectinib are the two types of targeted therapies that are used for brain tumours.

Rehabilitation after treatment

A brain tumour and its treatment cause physical derangements as well as emotional and social problems and financial hardships. Their management requires supportive / palliative care. Since brain tumours can develop in parts of the brain that control motor skills, speech, vision and thinking, rehabilitation may be a necessary part of recovery. 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 tumour surgery. Speech therapy for speech difficulties can help if you have difficulty speaking.

Young patients may require psychological counselling as brain tumours may leave a deep impact on the daily activities of the person and their family caregivers. Emotional and spiritual support, yoga and relaxation techniques should be a part of the rehabilitation programme.  Strong willpower and a positive attitude go a long way in overcoming the psychological trauma caused by the brain tumour.

Last but not the least, a large number of brain tumours can be excised safely and the patient may lead a normal life.