What you need to know about proton therapy

Cancer treatment has come a long way over the years, with advancements in medical technology improving treatment outcomes and making more survivors. As a leading cancer centre committed to providing the latest in oncology care for patients, the National Cancer Centre Singapore (NCCS) now offers proton therapy at the Goh Cheng Liang Proton Therapy Centre.

1. What is proton therapy?

Proton therapy is a type of radiation treatment that uses protons to irradiate or kill cancer cells. While conventional x-ray radiation therapy is the gold standard for treating most solid cancers, proton therapy delivers a highly focused dose of radiation directly to the tumour site, making it suitable to treat some cancers of the brain, head and neck, bone and soft tissue and certain childhood cancers. This is possible because of the unique properties of protons which allow them to deposit most of their energy at a specific depth, ensuring that the maximum radiation dose is delivered to the tumour, while minimising the exposure of healthy tissues to radiation.

Proton therapy deliver a highly focused dose of radiation directly to the tumour site

2. When would proton therapy be recommended rather than conventional radiation therapy?

There are several reasons why proton therapy may be recommended for certain cancers. It can deliver radiation precisely to the tumour site, while minimising damage to healthy tissues. This is important for patients with tumours that are located close to vital organs or intricate structures within the body, or paediatric patients whose bodies are still developing. Because of proton therapy’s ability to directly target tumours there are potentially less risk of short- and long-term side effects.

3. Why is proton therapy not recommended to treat all cancers?

While proton therapy has benefits, such as precise targeting of tumours and reduced damage to healthy tissues, more clinical evidence is needed to indicate that it is better than traditional radiotherapy, which is currently the gold standard treatment to treat most cancers. As the medical community continues to gather data and conduct studies, long term results of proton therapy will guide appropriate use of the technology.

Another consideration is cost. Conventional radiation therapy is most cost-effective radiation treatment option. Proton therapy facilities are complex and expensive to build and operate, which makes proton therapy more costly compared to traditional radiation therapy.

4. Who is best suited to undergo proton therapy?

Identifying the appropriate patients who will benefit the most from proton therapy is very important to ensure the best possible treatment outcomes. Proton therapy can be used to treat some cancers and benign tumours, in adults and children. These include brain, spinal cord, gastrointestinal, head and neck, and prostate tumours, sarcoma as well as advanced cancers. Proton therapy may be used as the only treatment or may be used in conjunction with other treatments, such as surgery and chemotherapy.

Before a patient undergoes radiation therapy, they are reviewed by a team of radiation oncologists to ensure the most appropriate type of radiation treatment is recommended. Proton therapy at the Goh Cheng Liang Proton Therapy Centre at NCCS is administered in line with MOH-approved indications, which you can find here, that outlines specific medical conditions for which proton therapy is deemed effective and beneficial.

5. What should a patient undergoing proton therapy expect?

During proton treatment, the patient is positioned on a high precision robotic couch. Treatment rooms are equipped with imaging systems to precisely position the patient for accurate beam delivery. The gantry system delivers proton beams by rotating a nozzle around the patient, enabling treatment beams to be delivered from any angle to target tumours with pin-point accuracy, to a spot size as small as 2 mm across.

During proton treatment, the patient is positioned on a high precision robotic couch

Depending on the complexity, each treatment lasts 15 to 30 minutes, this includes preparation time in the treatment room. The actual proton therapy treatment lasts less than two minutes each time. Depending on the type of cancer and location in the body, the overall duration of proton therapy treatment varies from 3 to 8 weeks, with an average number of 30 sessions/fractions.

6. How can I get referred for proton therapy?

General practitioners (GPs) often serve as the first point of contact for patients seeking medical advice. When appropriate, GPs can refer patients to NCCS for consultation with oncologists for assessment and advice.

For more information on how to make referrals, visit the Goh Cheng Liang Proton Therapy Centre website here.