What is Proton Therapy

What is Proton Therapy?

Proton therapy is a modality of radiation treatment that targets cancer cells using positively charged subatomic particles called protons. Due to the unique physical properties of protons, tumours can be targeted more precisely compared to the x-rays used in conventional radiotherapy. This results in less damage to nearby healthy tissues and organs, hence less treatment-related side effects.

How is proton therapy different from conventional radiotherapy?

Conventional radiotherapy delivers x-rays (also referred to as photons), to the tumour. Photons are electromagnetic waves and carries no charge which allows it to penetrate the body from one end to another. The photon beam loses energy gradually as it travels along inside the patient, resulting in some radiation dose in tissue beyond the tumour. This may cause damage to nearby healthy tissues and thus cause side effects.

Proton therapy delivers a beam of positively charged particles (called protons) that have a lower entrance dose and stop at a limited depth. This physical property of protons results in a significantly lower dose distal to the intended target. This makes it less damaging to nearby healthy tissues. Proton therapy has been shown to produce fewer side effects when compared to conventional radiotherapy.

What are the main benefits of proton therapy?

There are two main advantages of protons over conventional therapy. Firstly, reduced radiation exposure to nearby healthy tissues and organs reduces treatment-related side effects. Secondly, in certain situations, we may be able to deliver a higher dose with protons compared to x-rays. This is known as dose escalation and has the potential for better tumour control.