The controversial linear no-Threshold model

Estimating the risk of cancer induction by low-dose radiation (e.g., diagnostic) remains one of the most contentious issues in modern science and has engendered often-strident debate (1,2), particularly with respect to the linear no-Threshold (LNT) dose-response model. As John Boice, Jr., president of the National Council on Radiation Protection and Measurements (NCRP), has aptly stated (3), "LNT is not TNT, but differences in opinions sometimes appear explosive!" A critical assessment of the LNT model and a consideration of alternative dose-response models are presented in the article by Siegel, Pennington, and Sacks in this issue of The Journal of Nuclear Medicine (3). The article highlights the uncertainty associated with the LNT model and LNT model-based risk factors.