Late Effects of Radiation Therapy in Pediatric Cancer Survivors

The overall survival rates of many pediatric cancers continue to improve with each decade due to new advances in therapy. As this trend continues, the focus and importance of minimizing acute and long-term toxicity associated with treatment is paramount. While significant research regarding many of the late responses of normal tissues associated with radiation exposure has been established, future endeavors must be directed toward the identification of therapy related factors including radiation total dose, dose rate, exposure, and target treatment volumes. Awareness of short and long-term health risks of these patients is important and careful follow-up of long-term survivors is essential. In this report, we review some selected late adverse effects including the development of secondary malignancies, cardiotoxicity, physiological changes to glandular tissue, hormonal and reproductive changes to germ cells, and neurocognitive changes. Furthermore, we compared the differences regarding late effects of normal tissues associated with the use of proton versus photon radiotherapy, a topic that has received a great deal of attention in pediatric cancer and is increasing in utilization in the United States and world-wide.