Abstract
Purpose : To investigate the existence of enhanced sensitivity of dermal tissue to low radiation doses in the range of 0.1 Gy to 4 Gy/fraction. Materials and methods : Top-up technique of giving higher radiation doses to skin alone from 150 kVp X-rays followed by fractionated experimental doses to total body from 137Cs were given to C3H mice. Full-depth incisions were made and the tensile strength of skin from 14 day wounds were measured as a response of dermal tissue to radiation. Results : There was no evidence of enhanced radiosensitivity to doses as low as 0.1 Gy. The data were better fitted by a nonparametric method that predicted the shape of survival curve better than an induced-repair model. Conclusions : Dermal tissue like spinal cord has a low sensitive fraction of cells, unlike jejunum, kidney or lung that showed sensitivity at these doses. Tissue kinetics play an important role in the use of low dose fractions to avoid injury to normal tissues.