[1] Northeastern Univ, Dept Phys, Boston, MA 02115 USA
[2] Brigham & Womens Hosp, Dana Farber Canc Inst, 75 Francis St, Boston, MA 02115 USA
[3] Harvard Med Sch, Dept Radiat Oncol, Boston, MA 02115 USA
[4] NHTherAguix, Lyon, France
[5] Univ Claude Bernard, Lyon, France
[6] Univ Massachusetts, Dept Phys & Appl Phys, Lowell, MA USA
[7] Univ Lyon, Univ Lyon1, CNRS, Inst Lumiere Matiere,UMR 5306, Villeurbanne, France