Treatments

Surgery is usually done to

• Take a tumour tissue sample to find out pathology and establish diagnosis
• Total removal if possible with minimal affecting of surrounding tissues.
• Reduce size of tumour before chemotherapy and/ or radiation.
• Relieve symptoms due to pressure effects of the tumour viz. seizures

Common types of brain tumours

Different types of cells make up the brain and central nervous system and tumours can arise from any of these cell groups.  The commonest types seen are

• Astrocytomas – arising in the largest part of the brain, the cerebrum, are infiltrating and cause seizures.
• Meningiomas – the most common primary brain tumours in adults arising in the meninges, the lining of the brain. They are usually benign and grow slowly.
• Oligodendrogliomas – arising in the cells that form the protective covering of the nerves, grow slowly and don’t spread to nearby tissue.

Brain tumours are usually benign, their borders are well defined and they do not infiltrate the brain tissue, and hence easy to enucleate.  However, they can recur after surgery. These tumours can also damage the surrounding brain cells and cause disabilities, or be life threatening if arising in a sensitive part of the brain.

Primary cancerous tumours spread to other parts of the brain and spinal cord only and not to other parts of the body.

Brain tumour grading

Grading of the tumour is on the basis of how normal or abnormal the cells look, and on how fast the tumour is going to grow and spread.

• Grade 1 – cells look nearly normal, grow slowly, and long-term survival is likely
• Grade 2 – cells look slightly abnormal, grow slowly, but may spread to nearby tissue, chance of recurrence and maybe a bit more life-threatening
• Grade 3 – cells look abnormal, are actively growing into nearby brain tissue and will recur
• Grade 4 – cells look most abnormal and grow and spread rapidly

Very rarely, a benign tumour can turn cancerous, and a lower-grade tumour may recur as a higher grade tumour.

Symptoms of brain tumours

Symptoms of brain tumours are based on the type of tumour, and its location as different areas of the brain control different functions of the body, and the related symptoms.

Some tumours have no symptoms until they are quite large and then cause a serious, rapid decline in health. Other tumours may have symptoms that develop slowly.  The most common symptoms are

• Headache
• Seizures
• Changes in speech or hearing
• Changes in vision
• Balance problems
• Problems with walking
• Numbness or tingling in the arms or legs
• Problems with memory
• Personality changes
• Inability to concentrate
• Weakness in one part of the body

It should also not be assumed that manifesting any of these symptoms means the cause is a brain tumour.

Diagnosing a brain tumour

The different ways of diagnosing a brain tumour and assessing its type is by the following methods:

• Doctor’s assessment of history, symptoms, and signs (thorough physical and neurological examination)
• Tests such as CT scan, MRI to for detailed imaging of the brain
• Angiogram or an MRA helps highlights the blood vessels in the brain to look for abnormalities
• Biopsy of the tumour tissue either through surgery or needle biopsy

Treatment of brain tumours

Treatment depends on the type and grade of the cancer, its location, size, age of patient and the general health status. Each of the following treatment modalities can be administered individually or in combination based on the requirements.

• Surgery
• Chemotherapy
• Radiation
• Gamma Knife therapy – for deep seated tumours where a form of highly focussed radiation is administered.

During the treatment, surrounding brain tissue can be damaged and hence counselling of patients for side effects and the adjuvant treatment for the same should be discussed.  It is also important to consider and plan physical rehabilitation for any possible sequelae. This rehab will involve a physical therapist, speech therapist and an occupational therapist.

The common surgeries performed for brain tumours are

• Biopsy – Surgical removal of a small tumour tissue
• Craniotomy – Opening the skull bone and removing as much of the tumour as possible, and the skull bone piece is placed back
• Craniectomy – Very similar to a craniotomy, but the skull bone piece is not replaced
• Debulking – The size of the tumour is reduced
• Partial Removal – Only a part of the tumour is removed due to risk of neurological damage.
• Complete Removal – The tumour is totally removed
• Shunt – Insertion of a drainage tube to move excess fluid from the brain to another part of the body
• Ommaya Reservoir – Insertion of a small container under the scalp which is attached to a tube that delivers chemotherapy treatment to the brain and the surrounding cerebrospinal fluid (CSF)
• Skull Base Surgery – This is a specialized technique used to remove a tumour in that area.
• Transphenoidal Surgery – This is an operative procedure for the rare pituitary tumours and craniopharyngeomas.
• Stereotactic surgery – Is a minimally invasive form of surgical intervention that makes use of a 3 dimensional coordinate system to locate deep seated small tumours after which other procedures like ablation, biopsy, lesion, injection, stimulation, implantation, radiosurgery (SRS), etc can be performed.  Plain X-ray images (radiographic mammography), computed tomography, and magnetic resonance imaging are used to guide the procedure.

Chemotherapy for brain tumours

Chemotherapy is the use of anti-cancer drugs orally or through a vein to allow the drug to reach cancer cells throughout the body.  For general information on cancer chemotherapy, click here. Chemotherapy is generally used to treat faster growing brain tumors viz. medulloblastoma and lymphoma, and these respond well to chemotherapy.  Sometimes, the drugs are given directly into the cerebrospinal fluid space (CSF) either directly around the brain or though the spinal column for which a ventricular access catheter is inserted through a small hole in the skull.  (see the Surgery brain tumours section).  Chemotherapy is used individually or in combination with surgery and/or radiation therapy.

Some of the chemo drugs used to treat brain tumours include Carboplatin, Carmustine (BCNU), Cisplatin, Cyclophosphamide, Etoposide, Irinotecan, Lomustine (CCNU), Methotrexate, Procarbazine, Temozolomide and Vincristine.  Carmustine dissolvable wafers are sometimes placed directly on to the site from where the tumour has been removed and this concentrates the drug at the tumour site, reducing the chances of systemic side effects.

Side effects of chemotherapy

Rapidly multiplying normal cells are also affected by chemotherapy drugs and the damage to these cells add to the side effects of the chemo drugs.  Possible side effects depend on the drugs and the number of cycles administered and include

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Diarrhea
• Increased chance of infections (from having too few white blood cells)
• Easy bruising or bleeding (from having too few blood platelets)
• Extreme tiredness

Usually these stop soon after treatment is completed, but specifically, drugs like cisplatin and carboplatin can cause kidney damage and hearing loss.

Radiation for brain tumours

Detailed information on Radiation therapy is given in Radiation Oncology.

Gamma Knife surgery for brain tumours
Gamma Knife/ Stereotactic Radiosurgery/ Cyber Knife is not an actual surgical procedure in the true sense of the word as there is no surgical incision made.  Specialized medical equipment is used to deliver several small beams of radiation on a tumour with a great level of accuracy. Small multiple beams are made to converge on a certain point on the tumour or area for treatment, and together create a strong dose of radiation to kill/alter tumour cells.

Reasons for Gamma Knife Surgery

This is an alternative to conventional brain surgery for some specific conditions such as brain tumours, arteriovenous malformations (AVM – abnormal blood vessels in the brain), trigeminal neuralgia, some specific forms of epilepsy, etc.  It is used especially when the tumour or AVM is hard to reach/visualize and when a less invasive method of treatment is preferred by the treating doctors and the patient.

Description of the Procedure

Before the Procedure

• The doctor will explain the procedure to the patient/family and offer the opportunity to ask any questions about the procedure.
• The patient will be asked to sign a consent form that gives permission to do the surgery. The patient/family must read the form carefully and ask questions if something is not clear.
• The patient should fast for about eight hours before the procedure, generally after midnight.
• The patient will usually be asked to wear a hospital gown.  Jewellery, eye-glasses, contact lens, make-up, nail polish, dentures, wigs, etc. should be removed.
• Based on medical condition of the patient, the doctor may request other specific preparation.
• Patients may be given mild sedatives if required, in order to help them relax.

During the Procedure

• An intravenous (IV) line may be started in the arm or hand of the patient to inject dye into the blood vessel so that circulation of blood in the brain can be viewed properly.
• A frame will be attached to the patient’s head. The patient will be given local anaesthesia at four point on the head and the frame is attached to the head with four pins at these points.
• Hair is usually not shaved for this procedure
• Imaging of the tumour or AVM are done using CT scanning or MRI or both.
• After imaging, the doctors plan the radiation dosage to be given, the target areas, etc.  During this time the patient can relax but should not remove the frame.
• Once the procedure is planned in detail, the patient will lie on a bed that slides into the machine and the head frame is securely attached inside the machine
• The actual radiation procedure takes about one to four hours depending on the condition that is being treated.
• The patient will usually not feel any vibration or sound while inside the machine.  The patient can talk to the doctors through a microphone.

After the Procedure

After the procedure, the head frame is removed.  There may be slight pain at the sites where the pins are inserted.  Some patients experience headache and nausea after the procedure and these are treated with medications.  The patient can eat and drink normally after the procedure. Although the procedure per se is an outpatient procedure, the whole process of scanning and treatment usually takes up the entire day.  Some patients are advised to stay overnight for observation.

Risks / Complications

As with any procedure, complications can occur. But since this procedure does not involve anaesthesia and incisions, complications / side effects are far less compared to conventional neurosurgery.  Some of the early complications that can occur include:

• Fatigue
• Swelling in the brain at the site of treatment
• Scalp irritation
• Hair loss

These effect are usually temporary although some patients do experience long term side effects.

Outlook

Unlike conventional surgery, the results of treatment can be seen over a period of time.  They are not immediate. It usually depends on the condition being treated. In case of benign tumours of the brain, Gamma knife radiosurgery prevents the tumour from growing any further.  The tumour may shrink in size over a period of time ranging anywhere from 6 months to 24 months. Regular reviews and scans will show the effect of the treatment.

In malignant tumours, the tumours usually shrink rapidly within a few months.  Follow-up visits should be meticulously adhered to in order to monitor the progress of the recovery.

In epilepsy, it may take 18 to 24 months for the seizures to resolve.  But it must be noted that not all types of epilepsy can be treated with Gamma knife radiosurgery.

In Arterio Venous Malformations, Gamma knife radiosurgery is used to gradually close off the feeder vessels and can take about 2 years.

In Trigeminal Neuralgia, this procedure creates a scar that blocks the pain signals from passing along the trigeminal nerve with substantial pain relief achieved after several months.