1 Departments of Pediatrics and Radiation Oncology, University of Rochester, Rochester, New York. Electronic address: louis_constine@urmc.rochester.edu.
2 Department of Radiation Oncology, University of Southern California and Children's Hospital of Los Angeles, Los Angeles, CA.
3 Department of Radiation Oncology and Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC.
4 Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY.
5 Department of Epidemiology and Public Health, University of Maryland, Baltimore, MD.