Proton Therapy for Pediatric Malignancies

Abstract

In 2005–2011, the 5-year overall survival rate for children diagnosed with cancer reached 83.4%. While an increasing number of children are cured, two-thirds of childhood cancer survivors will develop chronic health conditions and 20% will die from toxicities or secondary malignancies as a result of their curative treatment. Decreasing the late effects of treatment while maintaining high tumor control rates are fundamental to improving survivorship. The primary advantage of proton therapy in pediatric cancer lies in the potential to reduce the late toxicities of radiation therapy. Efforts to quantify the therapeutic value of proton therapy relative to photon radiation are underway but require systematic tracking of disease control and adverse events. The economic value of proton therapy may be justified if the costs of managing acute symptoms, hormone deficiencies, normal-tissue complications, loss of productivity and achievement, and secondary cancers are considered in long-term survivors. As proton therapy matures, however, it is important to recognize that, unlike recent technological advancements in photon radiation delivery, proton therapy involves an inherently different radiobiology and clinicians should monitor unexpected toxicities. The purpose of this chapter is to review the rationale for proton therapy in pediatric malignancies and to objectively critique the existing evidence for proton therapy in this population.