1. From the Departments of Radiology (S.K.K.), Population Health (S.K.K., R.S.B.), Urology (W.C.H.), and Medicine (R.S.B.), NYU School of Medicine, 550 First Ave, New York, NY 10016; Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (E.B.E.); and Institute for Technology Assessment and Department of Radiology, Massachusetts General Hospital, Boston, Mass (P.V.P.).