Jejunal Crypt Stem-cell Survival after Fractionated γ-irradiation Performed at Different Dose Rates

Summary

Jejunal crypt survival after fractionated total body irradiation of C3H mice given at dose rates between 1·2 and 0·08 Gy/min was studied and the results analysed according to the linear quadratic model. Whereas α was independent of dose rate β decreased with dose rate to approach zero at about 0·01 Gy/min.

During the period of recovery, sublethal damage from doses given at high dose rate interact with low dose rate irradiation given immediately after, and increases its effectiveness.

• fractionation
• dose rate
• sublethal damage