Low HI Number (%) High HI Number (%) P Age     0.656 <70 Years 48(65) 51(61)   70 Years or older 26(35) 32(39)   T Stage     1.000 1a-2a 73(99) 81(98)   2b 1(1) 2(2)   Gleason Score     0.829 Score <7 22(30) 26(31)   Score=7 52(70) 57(69)   PSA     0.605 <10 63(85) 73(88)   10-20 11(15) 10(12)   NCCN Risk     0.718 Low risk 27(36) 28(34)   Intermediate risk 47(64) 55(66)   Modality     0.63 RA 18(24) 23(28)   IMRT 56(76) 60(72)   Mean PTV Volume 160cc 168cc 0.304

Table 1: Patient Characteristics, Baseline patient characteristics; HI=Heterogeneity Index; NCCN= National Comprehensive Cancer Network; RA=Rapid Arc Volumetric Modulated Arc Therapy; IMRT= Intensity Modulated Radiation Therapy; PTV= Planning Target Volume