J Korean Soc Ther Radiol.  1986 Dec;4(2):89-98.

Dose-Response Curves of Mouse Jejunal Crypt Cells by Multifrationated Irrdiation

• Hong SE
• Ahn CY

Abstract

Using as assay for jejunal crypt stem cell survival, dose-response curves for the reproductive capacity of crypt stem cells mouse jejunum exposed to multifractionated gamma-ray irradiation(single, 2, 3, 4, 5, 6, 7, 8, 10,12, and 16 fractions) were analyzed and single-dose survival curve of these cells was constructed. The following conclusion were drawn: 1) Survival curves for higher numbers of dose fractions were displaced to higher dose, and characterized by increasingly shallower slopes. 2) The single-dose survival curve had broad shoulder, Dq=460 cGy, remaining near-exponential over initial dose range 0 to 300 cGy, with initial slope 1Do=474 cGy 3) At fractionated dose in the range of 180 to 450 cGy, the average recovered dose per fraction interval was approximately 50% of the dose per fraction. 4) The value of a/b ratio by using of linear regression analysis for the reciprocal dose plots was 8.3Gy which lied in the range of 6-14Gy for early-reacting tissues. 5) The linear-quadratic model for dose-response formula offers valid approximations for all doses to be used in radiotherapy, only two parameters to be determined, and considerable convenience in practical applications.

Keyword

Radiation; Fractionation; jejunal crypt

MeSH Terms

Animals
Jejunum
Linear Models
Mice*
Radiotherapy
Shoulder
Stem Cells