Proton beam therapy for reirradiation in pediatric cancer

Abstract

Proton beam therapy (PBT) has a dosimetric advantage over X-ray radiation therapy, which allows for equivalent target volume coverage with reduced dose delivered to normal tissues and provides opportunities for acute and late morbidity risk reduction in pediatric cancer patients. PBT has been covered by the national health insurance for localized solid malignancies in patients under the age of 20 since April 2016 in Japan, and the number of patients subjected to PBT for pediatric cancer has been increasing at each institution. Reirradiation for patients with local or regional recurrences may retard tumor progression, palliate symptoms, and in some cases, even cure or provide long-term disease control, which can positively impact the overall health status and quality of life. Although data on the cumulative tolerance dose of critical organs and safety of reirradiation for pediatric patients are currently limited, there are some reports demonstrating the efficacy and safety of PBT for the reirradiation of recurrent central nervous system tumors. In the future, prospective clinical trials are required to evaluate the usefulness of proton beam reirradiation as a treatment option for pediatric cancer recurrence.