response of the skin of swine to increasing multiple exposures of X-ray (250 KVP)

The evolution, the time course, and the dose dependence of the moist reaction occurring in the skin of swine following increasing exposures given in two equal increments at intervals of 6 hours and 24 hours, and in five increments at daily intervals have been quantified. The time of the first appearance of the moist reaction was variable, occurring between 15 and 22 days following irradiation. The irradiated field was maximally involved with a moist reaction between 22 and 23 days, and the moist reaction was maximally healed between 29 and 33 days. The greatest variation in the parameters of the moist reaction was noted when the total exposure was given in two equal increments at a 24-hour interval. The exposure at which 50% of the fields were not healed by 49 days following irradiation was 2437 R following single exposures; 2794 R following two exposures given at an interval of 6 hours; 3360 R following two exposures given at an interval of 24 hours; and 4761 R following five exposures given at an interval of 24 hours.