A Brain Tumour is defined as an abnormal growth of brain cells (neural or connective cells). Brain Tumours may be malignant (cancerous) or benign (non-cancerous). The suspicion of a brain tumour may arise from headaches, abnormal behaviour or a variety of other symptoms. The symptoms would need to be investigated with a series of tests. Generally, the malignant or benign nature of a tumour can be decided on the basis of imaging.
Benign brain tumours: These are often extra-axial in location. A benign brain tumour is a cluster of cells that grows relatively slow in the brain. Benign brain tumours are usuallly localised and they don't spread to other sites in the body. These tumors do not reccur once they are safely removed during the surgery.
Malignant brain tumours: Malignant brain tumours can be slow or fast-growing and is usually life threatening due to their ability to invade and destroy surrounding normal brain tissue. There are two types of malignant brain tumours, primary and metastatic. Primary brain tumours originate from cells in the brain and there are many types. The most common type of malignant primary brain tumour is glioblastoma multiforme (grade IV astrocytoma), which makes up approximately 20% of all primary brain tumours. Metastatic brain tumours are cancers that have spread from other areas of the body to the brain. These tumours are the most common, occurring as much as four times more frequently than primary brain tumours. Cancers that commonly spread to the brain include breast and lung cancers.
The symptoms of brain tumours vary widely depending on the type and location of the tumour. However, some of the most common symptoms are headaches, associated with vomiting or nausea. These are often caused by increased intracranial pressure. Besides increase in intracranial pressure, tumours encroach on and/or compress the surrounding brain tissue. This would be responsible for the additional symptoms noted by patients, which include drowsiness, seizures and problems with sleep.
Brain tumor may occur amongst children aswell. Behavioural changes or rapid decline in the child's progress may be probable symptoms of brain tumour.
Other Symptoms of Brain Tumor may include the following:
Impaired vision, judgment, speech and sense of smell
Behavioural, Emotional and Cognitive changes
Inability to write
Lack of recognition
Vision loss in one or both eyes
Difficulty in swallowing
Drowsiness and headaches, especially in the morning
Muscle weakness on one side of the face or body
Increased Intracranial Pressure (ICP)
Uncoordinated muscle movements
Problems walking (Ataxia)
The causes of brain tumours are largely unknown; however the risk of brain tumour is higher among people who have suffered from, or have had exposure to:
Genetic cell mutations
If the brain tumor is caused due to above factors, it is called primary brain tumors. Apart from the above causes, brain tumours may also be a result from other cancers (metastatis). These tumors are called secondary brain tumours.
Neurological examination: This helps us establish the Increased Intracranial Pressure, and the focal deficit which would help us determine the probable site of tumour.
Magnetic Resonance Imaging (MRI): MRI is perhaps the most valuable scan used to diagnose brain tumours because it provides an accurate anatomical location of the tumour, including proximity to important areas (DTI and functional MRI) and probable pathology of the tumour (with the help of spectroscopy / perfusion studies).
Computed Tomography (CT): A CT scan may be advantageous in detecting lesions with calcification or blood in the lesion.
Benign brain tumours: Surgery is the most common treatment for benign tumours. Of course, at times, due to mere location of the tumour, the surgeon may not be able to excise the tumour completely, and then additional radiotherapy or radiosurgery may have to be considered as adjuvant therapy.
Malignant brain tumours: The prognosis depends on the grade of the malignant tumour, generally grade 1 or pilocytic tumours behave like a benign one, and the patient could be cured of the disease. However, they do need long-term follow up. The grade 2-4 lesion generally recurs. The tumour-free period depends on the grade of tumour, and also the response of the lesion to radiation and chemotherapy. In the present era with immune histology, tumour marker, modern radiotherapy techniques and newer, less toxic chemotherapy, the outcome of the treatment for the disease has improved.
Brain tumours are typically treated with surgery, radiation therapy, chemotherapy, or combination of any of these three modalities. Surgery is the primary treatment for brain tumours, where the tumor can be removed without causing severe damage.
The goals of surgical treatment for brain tumours are multiple and may include one or more of the following:
Confirm diagnosis by obtaining tissue that is examined under a microscope
Remove all or as much of the tumour as possible
Reduce symptoms and improve quality of life by relieving intracranial pressure caused by the tumour
Provide access for implantation of internal chemotherapy or radiation
A stereotactic/navigation guided biopsy is used to access the tumour in deep seated areas where surgery is hazardous. This technique utilises a computer and a three-dimensional scan to direct the placement of the needle. Radiation Therapy (RT) may be used alone or in combination with surgery and/or chemotherapy in the treatment of primary or metastatic brain tumours. External Beam RT is the conventional technique for administering radiation therapy for brain tumours. The CyberKnife is a frameless robotic radiosurgery system used for treating benign tumours, malignant tumours and other medical conditions.
The CyberKnife system is a method of delivering radiotherapy, with the intention of targeting treatment more accurately than standard radiotherapy. This system improves on other radiosurgery techniques, enabling doctors to achieve a high level of accuracy in a non-invasive manner and allows patients to be treated on an outpatient basis. The CyberKnife system can pinpoint a tumours’ exact location in real time using X-ray images taken during the brain tumor treatment that refer to the unique bony structures of a patient's head. It has a strong record of proven clinical effectiveness. It is used either on a stand-alone basis or in combination with other brain tumor treatments, such as chemotherapy, surgery or whole brain radiation therapy.
Treating brain tumours with chemotherapy is more complicated than treating tumours elsewhere in the body because of a natural defence system called the blood-brain barrier that protects the brain from foreign substances. Furthermore, not all brain tumours are sensitive to or respond to chemotherapy, even if the drug does penetrate the blood brain barrier. Actively dividing cells are the most vulnerable to chemotherapy. Most tumour cells and some normal cells fall into that category and hence CyberKnife is the most recommended treatment for brain tumors.