Variations in Rectal Volumes and Dosimetry Values Including NTCP due to Interfractional Variability When Administering 2D-Based IG-IMRT for Prostate Cancer

Table 1

The default parameter values of the LKB and RS models employed in this study for the rectum.

Parameters	LKB [3, 4]		RS [5]
𝛼/𝛽 ratio	3 Gy
𝑠	—	—	0.49
𝑚	0.14	0.13	—
𝑛	0.08	0.09	—
𝐷50	78 Gy for rectal grade ≥ 2 (RTOG)	76.9 Gy for combined grade ≥ 2 rectal toxicity (QUANTEC update)	83.1 Gy for rectal grade ≥ 2 bleeding