Who proton therapy is for

Proton therapy is used for a specific set of cancers, not all of them. Whether it is right for you depends on your diagnosis, where the cancer is, and what tissue sits nearby. This page explains how that decision is made and who makes it.

When does proton therapy make a difference?

The difference is not a luxury. When a tumour sits against the brainstem, the optic nerves, or a child’s growing spine, the limit on treatment is often how much radiation the surrounding healthy tissue can safely take. Because a proton beam stops, it can allow a full treatment dose in places where standard radiation would have to hold back. That is why Canadian provinces have paid for patients to receive it abroad: for the right case, this difference matters.

The full list of uses with the strongest evidence, and the reasons behind it, is on what proton therapy is.

Proton therapy for children

Children are still growing. Radiation reaching healthy, developing tissue can affect that growth, and it can raise the risk of a second cancer later in life. Because proton therapy can lower the total dose to the body, it is widely accepted for many childhood cancers.

Canadian provinces have funded proton therapy for children through their out-of-country programs. These routes are used and they work. If your child’s oncologist raises proton therapy, the funding route through your province is a real one. The provincial guides on this site explain how it works where you live.

Is proton therapy needed for everyone?

Proton therapy is a powerful treatment in the right place; it is not needed for every cancer. For many common cancers, standard radiation available in Canada delivers excellent results.

Prostate cancer is the clearest example. Proton therapy is used for prostate cancer, and in the largest study to compare the two, it controlled the cancer as well as standard radiation did. Whether it is the right choice for you, and whether it is funded, are decisions for your oncologist and your provincial plan. What the evidence says is explained on what proton therapy is.

Being recommended standard radiation is not a lesser option. For many cancers it is simply the treatment that fits best.

Who decides

Whether proton therapy suits your case is a medical judgment. In Canada, that judgment belongs to your treating oncologist; abroad, it belongs to the physicians at a treatment centre once they review your records.

If proton therapy is being considered, the usual step is for a radiation oncologist to compare a proton plan with a standard plan for your situation. This comparison is made by treating teams in Canada, and Princess Margaret Cancer Centre offers a free dosimetry consultation service to physicians for exactly this purpose.

Sources for this page (4)▸

1. Uses with the strongest expert support: American Society for Radiation Oncology (ASTRO), Proton Beam Therapy Model Policy. astro.org (checked 2026-07-06)
2. Benefit in children and evidence overview: Ontario Health, Health Technology Assessment, “Proton Beam Therapy for Cancer,” Ont Health Technol Assess Ser 2021;21(1):1-142. pmc.ncbi.nlm.nih.gov (checked 2026-07-06)
3. Canadian provinces fund out-of-country proton therapy for children and adults: Canadian referral experience, PubMed 34246276. pubmed.ncbi.nlm.nih.gov (checked 2026-07-06)
4. Free proton dosimetry consultation for referring physicians: University Health Network, Princess Margaret Radiation Medicine Program. uhn.ca (checked 2026-07-06)

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Every statement on this page is drawn from the sources listed below. Last updated: 15 July 2026.

This page is for general education only. It is not medical advice and it is not a decision about your care or your funding. Only your treating physician can advise you on treatment. Only your provincial or territorial health plan can decide whether it will fund treatment outside the country. protontherapy.ca is an information resource by Maple Med Global (MMG Medical Tourism Inc.), Toronto, Canada. We are not a hospital, a clinic, or a government body, and we do not provide medical care.