Less well known parameters of in vitro radiosensitivity.

In addition to well known parameters used for measuring in vitro cellular radiosensitivity (mean lethal dose, extrapolation number, quasithreshold dose), there are other, less well known measures that may be more important. The authors recently surveyed the literature and found that mean activation dose (D) has been neglected in the analyses. Among 70 articles published in the radiation oncology and biology literature that used cell survival curves or parameters to measure radiosensitivity, only two used the values of D in their analysis. By recalculating D from published survival curves, different conclusions may be drawn. The authors see a definite need for more prospective application of D and surviving fraction at 2 Gy.