Threshold dose effect in FXG gels: real or apparent?

摘要

The results from this present study show that chemical impurities are not responsible for the threshold dose effect. The threshold dose is an apparent effect, that is, an artifact of the spectroscopic measurement of multiple Fe(III)_(i):XO_(j) species formed at varying dose levels and it can be avoided by selecting an optimal wavelength that is sensitive to detecting only the species of interest. By resolving the threshold dose issue, it will be possible to precisely and accurately verify doses in 3D over a wide range of dose gradients produced by modern radiotherapy machines (i.e. IMRT).