About Proton Therapy

Radiation therapy can be categorized into particle therapy and X-ray therapy, with proton therapy falling under particle therapy along with heavy ion therapy. Proton therapy utilizes accelerated hydrogen nuclei (protons) to deliver high-energy proton beams, while heavy ion therapy primarily uses accelerated carbon nuclei to produce high-energy heavy ion beams.
In principle, proton therapy tends to require a smaller installation area, making it relatively easier to implement.
Boron Neutron Capture Therapy (BNCT) is a treatment method that utilizes the reaction between neutrons generated from a nuclear reactor and boron, which has a sensitizing effect. This therapy selectively destroys tumor cells while sparing normal tissues.

In comparison to the commonly used X-ray therapy in radiation treatments, proton therapy offers precise delivery of radiation to cancer tissues. This precision enables maximum energy deposition in the tumor while minimizing damage to surrounding healthy tissues and organs. As a result, the occurrence of side effects from the treatment is significantly reduced.

Proton beams exhibit a unique characteristic known as the Bragg Peak, where they enter the body with a low dose from the surface and come to a “stop” at a specific depth. Just before reaching this stopping point, the radiation dose reaches its maximum intensity. This distinctive property allows for precise targeting of the radiation dose.
By precisely adjusting the position of the Bragg Peak based on the size and depth of the tumor, it becomes possible to minimize damage to normal cells and concentrate the radiation dose effectively on the affected area, limiting its impact to the intended site.

Proton therapy is applicable for treating cancers in various parts of the body. Currently, it is commonly used for head and neck, lung, hepatobiliary, prostate, and esophageal cancers.

Over the past decade, the number of treatments has significantly increased, and as of now, the cumulative treatment cases have surpassed 300,000 in 2022. (Source: Particle Therapy Co-Operative Group)

As of May 2023, there are 108 operational proton therapy facilities worldwide. The number of treatment facilities is hardly sufficient, given the increasing demand for treatment. And there is a pressing need to address the unequal distribution of treatment facilities.

Conventional proton therapy systems use a rotating gantry structure, about 10 meters in diameter, to irradiate proton beams from various directions around the patient. This large size, approximately 12 meters in height, and high initial cost have hindered widespread adoption.