X-ray induced thyroid adenocarcinoma.

A comparison is made of the x-ray induced thyroid adenocarcinoma in the rat by the in-vitro, in-vivo method of Clifton et al. with previous data of Doniach on in-vivo irradiation in whole animals. The Clifton data consists of only one point at 500 rad. I have assumed that the probability of transformation per viable cell from 0 to 500 rad is proportioned to dose and that at higher doses, it is proportional to dose squared. The fraction of rats developing adenocarcinoma agrees with the data of Doniach at 500 and 1100 rads. The rest of the data is filled in by calculation.