Annually, more than 350,000 children in the world are affected by pediatric cancer. Radiation has improved outcomes dramatically, but the damage caused to healthy tissue can affect the long-term health of a child. While clinicians and radiation specialists design treatments using the most up-to-date information available, there hasn’t been a single guiding source of data to make evidence-based decisions that are specific for children. Now, a volunteer international research collaboration is working toward providing evidence-based guidelines for radiation therapy dosing for children. Results from this effort will help in minimizing side effects while continuing to provide effective radiation therapy.