1. Department of Radiation Oncology Allegheny Health Network Cancer Institute Pittsburgh Pennsylvania USA
2. Department of Biostatistics University of Nebraska Medical Center Omaha Nebraska USA
3. Department of Radiation Oncology Hospital of the University of Pennsylvania Philadelphia Pennsylvania USA
4. Department of Therapeutic Radiology Yale University School of Medicine New Haven Connecticut USA
5. Department of Radiation Oncology City of Hope National Medical Center Duarte California USA
6. Department of Radiation Oncology University of Texas M.D. Anderson Cancer Center Houston Texas USA
7. Department of Radiation Oncology Norris Cotton Cancer Center @ Dartmouth University Lebanon New Hampshire USA