1. From the Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, TX; NYU School of Medicine, New York, NY; Department of Radiological Sciences, Thoracic Imaging and Intervention, and Diagnostic Radiology Education, David Geffen School of Medicine at UCLA, Los Angeles, CA; Department of Radiation Oncology, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX.