Immunosuppresion:
- There is minimal repair after damage to normal lymphoctes, represented by minimal shoulder on cell survival curve
- Effective D0 about 3.8 Gy, the fractionated dose required by a given regimen to reduce the cell population to 37% on straight line portion of survival curve ( Shank, B Int J Radiat Oncol Biol Phys 9: 1613, 1983)
Leukemic cells:
- Direct toxicity - also likely have minimal cell repair capacity, most fit the linear quadratic (LQ) model of cell survival (Lehnert et al. Int J Radiat Biol 49: 423, 1986) (Shank et al Radiother Oncol 27: 30, 1993)