1. From the Departments of Radiology (T.H.K., N.G., D.D.B.B., V.P., M.J.G., N.H.), Pathology (C.F., J.S.), Surgery (H.M.T., J.G.A.), and Epidemiology and Biostatistics (J.Z., M.C.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Box 29, New York, NY 10065.