Effects of accelerated fractionation on radiation injury of the small intestine: a new XXXX model.

@entity35 @entity130 @entity1161
The present study assessed the influence of shortening the overall treatment time (accelerated fractionation) on radiation injury of the small intestine. A @entity35 model which allowed repeated irradiation of a localized segment of small intestine was developed. Young adult male @entity35 were orchiectomized, and a loop of the distal ileum was transposed to the left part of the scrotum. The intestinal segment was irradiated with a total dose of 56 Gy, given in 20 fractions, the total treatment time being either 26, 12, or 7 days (i.e. 1, 2, or 3 fractions per day). @entity1161 was assessed by histopathologic examination at 6 hr and at 2 weeks after the last irradiation. The surgical procedure was without complications. Shortening the overall treatment time by giving more than one radiation dose per day resulted in markedly @entity130 both at 6 hr and at 2 weeks. It is concluded that accelerated fractionation results in @entity1161 of the intestine when compared with standard fractionation. Because there may be a relationship between early and late effects in the intestine, our results also indicate that @entity1161 may result from accelerated fractionation.
