Fig. 1

Predicted survival fraction (Eq. 3) and TCP (Eq. 1) for 10⁷ and 10⁹ cells as functions of the dimensionless variable \( \widehat{\alpha}A \). Note that an activity 15 times lower than that needed to ensure a TCP between 70 and 95 % already kills about 75 % of the cells. The figure depends only on the cells number ,Nc, present in the tissue to be controlled and not on their type. The cell type only modifies the value of \( \widehat{\alpha} \), i.e., the corresponding activity A needed to control the tissue. 10⁷ and 10⁹ cells typically correspond to thyroid remnants total weight ranging from 0.02 to 2 g