This article summarizes the results obtained from several studies conducted by the author, concerning the calculation of doses received at moving radiation fields generated by photon-emitting radiation sources. An attempt is made to provide a methodology for the aforementioned calculation, in those cases where simple geometries are involved, using what is described as the "duality principle" and the concept known as "equivalent static system" (EES), so as to be able to draw upon the wealth of data available in reference material relating to static systems.