Pediatric Proton Therapy in Ontario: Current Status and Future Directions

Purpose/Aim

Proton therapy is widely used worldwide for treating pediatric cancers because of its significant clinical benefits, yet Canada remains the only G7 country without a proton therapy centre. This abstract explores why proton therapy is particularly beneficial for pediatric patients by reviewing supporting literature, examines Ontario’s current out-of-country referral process for accessing treatment abroad, and discusses progress toward establishing Canada’s first proton therapy centre.

Methods/Process

Ontario Health has recommended proton therapy for pediatric cases based on strong clinical evidence. In 2022, the provincial government provided a $5 million planning grant as part of a $17.1 million investment to start design and feasibility work for Canada’s first hospital-based proton therapy centre at University Health Network (UHN) in Toronto. The plan includes up to five treatment suites and could serve about 1,500 pediatric and adult patients each year. Economic modeling suggests that having a domestic program would improve access, reduce delays, and save costs compared to sending patients to the U.S.

Results or Benefits/Challenges

Children undergoing cancer treatment are highly vulnerable to long-term side effects and secondary cancers, making precision in radiation delivery critical. Proton therapy addresses this need by offering superior dose conformity and reducing radiation exposure to healthy tissues compared to conventional photon therapy. Evidence from systematic reviews and meta-analyses shows proton therapy helps preserve neurocognitive function and lowers endocrine toxicity. For example, children treated with protons for brain tumors tend to maintain higher IQ and memory scores over time, while those treated with photons often show declines. Endocrine issues such as hypothyroidism and sex hormone deficiency are also reported far less often after proton craniospinal irradiation than after photon therapy. These findings highlight why access to proton therapy is so important for pediatric patients. In Ontario, patients eligible for proton therapy can access this specialized treatment by traveling to the United States. While treatment costs are covered through out-of-country programs, families must pay for travel, accommodations, and meals, which can create a significant financial burden. In some cases, these costs—along with social factors such as caregiving responsibilities or inability to take time off work—make it impossible for families to travel, resulting in patients receiving photon therapy in local treatment centers instead. Building a Canadian proton therapy centre is essential to eliminate these barriers, and although it requires significant upfront investment, it would ultimately reduce long‑term costs for the province.

Conclusions/Impact

Ontario Health’s advisory committee has endorsed publicly funded proton therapy for pediatric and select adult cancers. Establishing a Canadian proton therapy centre will significantly reduce reliance on out-of-country care, improve equitable access, and align Canadian oncology practice with international standards. Most importantly, it will enhance quality of care and minimize treatment-related toxicity for pediatric patients, ensuring timely access to this advanced therapy for those who need it most.