What is a brain tumour?

A brain tumour is an abnormal growth of cells which divide uncontrollably. Some brain tumours grow quickly, invading and damaging healthy brain tissue, while others grow more slowly. 

Brain tumours are graded following how fast they grow, and how likely they are to grow back after a patient undergoes treatment. Grade 1 and grade 2 tumours are called ‘low grade’. Low-grade tumours grow slowly and are unlikely to grow back after treatment. These are benign (non-cancerous) tumours. Grade 3 and grade 4 brain tumours are called ‘high-grade’. High-grade tumours grow faster and are more likely to return after treatment and spread to other areas of the body. These are malignant (cancerous) tumours.

Brain tumours can develop in people of any age, including children, although they are more common in older adults.

Brain tumour symptoms vary depending on which part(s) of the brain are affected by the tumour. Common symptoms include: headaches, seizures, nausea, drowsiness, mental or behavioural changes, such as memory problems or changes in personality, progressive weakness or paralysis on one side of the body, and vision or speech problems. Some people do not have any symptoms, and symptoms may develop slowly over time.

Brain tumours require urgent medical attention because they can be life-threatening. This is because brain tumours can put extra pressure on healthy parts of the brain. Due to the serious nature of brain tumours, it is important to understand as much as we can about the possible treatment options available. A recent treatment for brain tumours is ‘proton therapy’, which is effective and varies slightly from traditional forms of radiotherapy.

To learn more about brain tumours and how they can affect you, see here.

Traditional treatments for brain tumours

If you are diagnosed with a brain tumour, your treatment options will depend on various individual factors.¹

• Type of tumour
• Location of the tumour
• Size and spread of the tumour
• Overall health

The most common treatment options available for brain tumours include the following:

• Surgery: this is a very common option, and in many cases, surgery is the only treatment required for the brain tumour. This is unlikely to be a viable option for tumours near the brainstem, as the risk of surgical complications increases for these kinds of tumours
• Radiation therapy: radiation therapies work by using X-rays or other forms of energy to slow down the growth of tumours and destroy them. Radiation therapy is a very common practice for treating tumours and is sometimes done to shrink the tumour before surgery. Proton therapy is a specific kind of radiation therapy which uses proton particles to target brain tumours with higher precision
• Chemotherapy: chemotherapy drugs are medications designed to kill the cancer cells. Chemotherapy also damages healthy brain tissue, which is why it is infamous for its unpleasant side effects. Chemotherapy can be given intravenously (into a vein), as a pill, or as a cream. Chemotherapy can make other treatments, like surgery or radiation therapy, more effective
• Targeted drug therapy: these medications are more precise than those used in standard chemotherapy, selectively damaging tumour cells, so side effects are less common and milder
• Tumour treating fields: this involves using a device to send electrical pulses over the brain to impede the growth and spread of tumour cells.

Depending on your circumstances, you may undergo several treatment options, potentially simultaneously. To read more about the treatment options available for treating brain tumours, as well as how they work, see here.

What is proton therapy?

A proton is a positively charged particle found inside of atoms. During proton therapy, also known as proton beam therapy, a machine called a cyclotron is used to fire protons at a tumour to damage it. The protons are obtained from hydrogen atoms and accelerated inside the cyclotron. A magnet is then used to direct the beam of protons at the tumour from different angles.

Proton therapy is particularly effective because the high-energy beam of proton particles is designed to travel specific distances into the brain tumour before stopping. This enables high precision in directly attacking certain parts of the brain tumour, and minimising any damage to neighbouring, healthy brain tissue. The therapy specifically damages the DNA of the tumour, preventing the tumour from dividing and spreading even further throughout the brain. Eventually, this can lead to the brain tumour shrinking.

Proton therapy can treat both benign and cancerous tumours in the brain. Proton therapy can also be used to treat tumours in various parts of the body, not just the brain.

Depending on your circumstances and the nature of your cancer, you may be recommended to have proton therapy by itself or in conjunction with other treatments like surgery or chemotherapy.

To learn more about proton therapy, and how you can prepare for proton therapy, see here.

How is proton therapy different from conventional radiotherapy?

Proton therapy is a type of radiotherapy that uses proton particles instead of photons (light particles) that are used in conventional radiotherapy.

During conventional radiotherapy, radiation affects all tissues it crosses, including any tissue behind the brain tumour. Proton therapy administers high radiation to the tumour, with minimal radiation reaching adjacent tissues. This is because proton therapy is more precise, as the protons do not travel as far as photons do, and can be stopped more easily.

The protons release a burst of energy when they stop, which damages the brain tumour. During conventional radiotherapy, compared to proton therapy, a higher dose is delivered to healthy brain tissue while the radiation is travelling to its target.

There is currently a lack of high-quality research comparing the efficacy of proton therapy against conventional radiotherapy.² However, scientists are increasingly interested in the advantages of proton therapy as related to the reduction in side effects.

Advantages of proton therapy for brain tumours

Proton therapy presents several advantages in reducing brain tumours, for instance:

• High precision
• Proton therapy is a good alternative treatment for brain tumours which would be difficult to access through surgical means
• Proton therapy can help to combat brain tumours which are irregularly shaped, as these tumours are difficult to target with traditional radiotherapy
• Proton therapy is a good option for children because it reduces the exposure of healthy brain tissue to radiation. Less exposure to radiation is good because radiation can increase the risk of developing neurological problems
• Usually painless - you can resume normal daily activities after the session²

To learn more about the benefits of proton therapy, see here.

Limitations of proton therapy for brain tumours

• Proton therapy is not appropriate for those who have had a titanium mesh or other materials placed in the skull during cranioplasty surgery. This is because some types of skull implants can interfere with the efficacy of proton therapy
• If you pay for healthcare, proton therapy is more expensive than other radiation treatments due to the high cost of equipment
• Typical side effects are still experienced, such as fatigue, headaches, nausea, hair loss and others, depending again on where the brain tumour is located. However, these side effects are considered less severe than in conventional radiotherapy

To learn more about the limitations of proton therapy, see here.

Summary

• A brain tumour is an abnormal growth of cells in the brain which can, in some cases, be fatal.
• Proton therapy is a kind of radiotherapy which can treat brain tumours by preventing the tumour from growing.
• Proton therapy involves firing proton particles precisely at the tumour cells, whereas conventional radiotherapy uses photons.
• Proton therapy damages the DNA of tumour cells, preventing the tumour from replicating and spreading.
• Proton therapy minimises any damage to healthy brain tissue due to the high levels of precision, whereas typical radiotherapy is less precise.
• Your treatment plan may involve proton therapy combined with other treatments.
• Proton therapy is preferential to traditional forms of radiotherapy because there are fewer side effects, and the side effects are less severe.
• Proton therapy is more expensive than other treatments for brain tumours, including standard radiotherapy, due to the high cost of equipment.