From: Modeling of α/β for late rectal toxicity from a randomized phase II study: conventional versus hypofractionated scheme for localized prostate cancer
A
B
Clinical incidence
14.0%
12.3%
NTCP (prior to optimization)
TD50 = 80 Gy, α/β = 3 Gy
10 ± 3%
6 ± 2%
NTCP (after optimization)
TD50 = 76 Gy, α/β = 2.3 Gy
15 ± 5%
12 ± 4%