Spatially Limited Effects of Dose and Let Enhancement near Tissue/Gold Interfaces at Diagnostic X Ray Qualities (invited paper)

Physical and radiobiological evidence is summarised concerning significant dosimetric effects in tissue adjacent to a solid gold surface, when this interface zone is irradiated with X rays of qualities common in medical diagnosis. Physical measurements result in a more than 100-fold dose enhancement attributable to photoelectrons and Auger electrons emerging from the gold surface. The enhanced interface doses are shown to correspond with significantly diminished cell growth and cell survival as well as with enhanced oncogenic transformation and chromosome aberrations. Preliminary results of Monte Carlo based track structure calculations at the interface show electron spectra with a noticeable component of low energy electrons, so that LET effects might be expected. (author)