[1] Montreal Neurol Inst, Dept Biomed Engn, Montreal, PQ, Canada
[2] McGill Univ, Med Phys Unit, Montreal, PQ, Canada
[3] Jewish Gen Hosp, Dept Radiat Oncol, Montreal, PQ, Canada
[4] King Faisal Specialist Hosp & Res Ctr, Dept Biomed Phys, Riyadh, Saudi Arabia
[5] McGill Univ, Dept Oncol, Montreal, PQ, Canada
[6] Harvard Med Sch, Dana Farber Brigham & Womens Canc Ctr, Dept Radiat Oncol, Boston, MA USA