Proton Beam Therapy for Cancer in Children and Adolescents: A Retrospective Canadian Paediatric Tumour Consortium...

Radiation therapy serves as an effective treatment modality for paediatric solid and central nervous system (CNS) tumours. Proton beam therapy (PBT) offers steeper dose gradients than conventional radiation therapy, reducing the dose to surrounding normal tissue dose. Unfortunately, PBT is unavailable in Canada and children are referred to the United States for treatment.

We describe the Canadian paediatric cancer population receiving PBT and their outcomes.

Patient demographics, treatment details, and survival outcomes were extracted for all paediatric patients from 12 of 13 provinces/territories. Eligibility criteria included: diagnosis of cancer at age ≤20 years between 2001-2021 and administration of curative-intent PBT. Temporal trends in PBT referrals were modelled using Poisson regression, and overall survival (OS) was estimated with the Kaplan-Meier method.

Of 314 eligible children (55.7% male), most patients were from Quebec (26.4%), British Columbia (24.8%), Alberta (22.6%), and Ontario (21.0%). The median age of cancer diagnosis was 7.3 years. The most patients had CNS tumours (69.4%), with medulloblastoma, craniopharyngioma, and ependymoma being the most frequently represented. Most common solid tumours included rhabdomyosarcoma, neuroblastoma, and Ewing's sarcoma. Provinces/territories usually referred patients to PBT centres close in geographical proximity. Referrals have increased at a rate of 16% per year between 2001 and 2022. For children aged <15 years, five-year OS was 85.8% and 73.1% for CNS and solid tumours, respectively.

Based on our data, there is a true need for the establishment of PBT centres in Canada for the treatment of cancers in children.