[1] Univ Texas MD Anderson Canc Ctr, Dept Radiat Phys, Houston, TX 77030 USA
[2] Univ Texas MD Anderson Canc Ctr, Dept Radiat Oncol, Houston, TX 77030 USA
[3] Univ Texas MD Anderson Canc Ctr, UTHlth Houston Grad Sch Biomed Sci, Houston, TX 77030 USA
[4] City Hope Natl Med Ctr, Lennar Fdn Comprehens Canc Ctr, Dept Radiat Oncol, Irvine, CA USA