*Rutgers Cancer Institute of New Jersey, New Brunswick, NJ

†Department of Radiation Oncology, Henry Ford Cancer Institute, Detroit

**Department of Radiation Oncology, University of Michigan, Ann Arbor, MI

‡Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT

§Department of Radiation Oncology, Virginia Commonwealth University Health System, Massey Cancer Center, Richmond, VA

∥Allegheney Health Network

¶Department of Radiation Oncology, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh

‡‡Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA

#Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA

††Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada

§§Department of Radiation Oncology, Duke University Medical Center, Durham, NC

∥∥Department of Radiation Oncology, Massachusetts General Hospital

##Department of Radiation Oncology, Brigham and Women’s Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA

¶¶Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX

✠Deceased.

Y.W.: responsible for statistical analyses.

The authors declare no conflicts of interest.

Correspondence: Lara Hathout, MD, Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901-1914. E-mail: [email protected].