[1] Cent Res Inst Elect Power Ind, Nucl Technol Res Lab, Radiat Safety Res Ctr, 2-17-1 Iwado Kita, Komae, Tokyo 2078517, Japan
[2] Univ Eastern Finland, Kuopio, Finland
[3] STUK Radiat & Nucl Safety Author, Helsinki, Finland
[4] Harvard Med Sch, Massachusetts Gen Hosp, Dept Radiat Oncol, Boston, MA USA
[5] Natl Council Radiat Protect & Measurements, Bethesda, MD USA
[6] Vanderbilt Univ, Sch Med, Dept Med, Nashville, TN 37212 USA
[7] Vanderbilt Univ, Sch Med, Vanderbilt Ingram Canc Ctr, Nashville, TN 37212 USA