In consequence, once tumor cells are arrested and synchronized they can be targeted with a cytotoxic agent, thus maximizing cell kill fraction and minimizing normal cell killing.
From figure 3, we can see the largest cell killing rate per fraction is less than 17% (if we use 20 fractions, the cell killing rate per fraction is much smaller than 8%).
The current crop of terrorists, unlike the bombers of World War II, has no chance of conquering us or (realistically) of killing a large fraction of our population.
We want to estimate the cell killing rates per fraction.
This largest 17% is significantly smaller than other reported in literatures such as a popular 40% of cell killing rate per fraction.
If this is true; and if we use 40% constant cell killing rate per fraction, then the percentages of non-hitting cells are ranged between 23% and 34% as plotted in figure 4. It appears that tumor size of 10 cells receives largest hitting rate while the non-hitting rate varies significantly over tumor sizes.
Interleukin 2-activated killer cells (LAK) however, killed the fractions containing clonogenic cells in all 4 cases.
The pure statistical analysis supports that the so-called thyroid stunning effect can be explained by the cell-killing fraction.
The radiobiological computation using Eq. 2 and the radiosensitivities measured in thyroid cell assays confirmed the result of the statistical analysis, i.e., that the therapy to diagnostic uptake ratios can be explained by the cell-killing fraction (Table 1).
Two explanations prevail: an individual cell stunning that reduces its capability to store iodine without altering its viability, and/or a significant cell-killing fraction that reduces the number of cells in the tissue still taking up iodine.
The aim of this study is to determine whether the cell-killing fraction can quantitatively explain the uptake reductions of thyroid remnants reported after a low activity pre-therapeutic scan using either radio-iodines (131I, 123I) [6, 7].
