1. From the Division of Interventional Radiology, Department of Radiology, MedStar Georgetown University Hospital, 3800 Reservoir Rd NW, CCC Bldg, Rm CG225, Washington, DC 20007 (N.N.); Georgetown University School of Medicine, Washington, DC (N.N.); Lombardi Comprehensive Cancer Center, Washington, DC (N.N.); and Division of Vascular and Interventional Radiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Md (C.G.).