1. 1Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
2. 2Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
3. 3Kaiser Permanente Washington Health Research Institute, Kaiser Permanente Washington, Seattle, Washington.
4. 4Department of Radiology, University of Washington School of Medicine, Seattle, Washington.
5. 5Department of Health Services, University of Washington School of Public Health, Seattle, Washington.
6. 6Fred Hutchinson Cancer Center, Seattle, Washington.
7. 7Departments of Medicine and Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California.
8. 8Department of Public Health Sciences, University of California, Davis, Davis, California.
9. 9Department of Surgery and University of Vermont Cancer Center, University of Vermont, Burlington, Vermont.