Theoretical analysis of simultaneous mixed irradiation with multiple types of radiation.
A survival model Eq.1 was presented for cells irradiated simultaneously with multiple types of radiation using the extended Zaider-Rossi model, which is model for mixed irradiation with two types of radiation. [equation : see text] Eq.1. Where q(t)=2t0/t-2(t0/t)2 ¿1-exp(-t0/t)¿ Eq.2. Eq.1 was proved by mathematical induction using the concept that mixed irradiation with n types of radiation is considered as mixed irradiation with two types of radiation regarding n-1 types as one type of radiation. The model is not limited by the dose rate of radiation, because its effect is corrected by reduction factor Eq.2. The problem of the model is that Eq.2 was led assuming repair function to be exponential given by Eq.3. tau(t)=exp(-t/t0) Eq.3. However, the repair function is usually expressed by biphasic Eq.4 rather than monophasic Eq.3. tau(t)=Aexp(-t/01)+(1-A)exp(-t/t02) Eq.4. It is, therefore, important to keep in mind that Eq. 4 should be used instead of Eq.3.
Suzuki
S
S
Tokyo Metropolitan Institute of Gerontology, Japan.
Miura
Y
Y
D002468:Cell Physiological Phenomena / Q000528:radiation effects*; D002470:Cell Survival; D004307:Dose-Response Relationship, Radiation; D008433:Mathematics; D008962:Models, Theoretical; D011829:Radiation Dosage; D011853:Radiobiology