[1] Brigham & Womens Hosp, Dept Radiat Oncol, Dana Farber Canc Inst, Boston, MA 02115 USA
[2] Brigham & Womens Hosp, Dept Biostat Sci, Dana Farber Canc Inst, Boston, MA 02115 USA
[3] Brigham & Womens Hosp, Dept Adult Oncol, Dana Farber Canc Inst, Boston, MA 02115 USA
[4] Massachusetts Gen Hosp, Dept Radiat Oncol, Boston, MA 02114 USA