In order to facilitate the display and evaluation of data acquired while irradiating a body, e.g. a patient undergoing radiation therapy, a dosimetry system has a plurality of sensors for disposition on, in or near the body to be irradiated and connected to a sensor reading instrument which is interfaced with a display system, for example a personal computer, which is arranged to display, in use, one or more representations, for example drawings or photographs, of the body to be irradiated, along with the positions and the dose data for those specific locations where the dosimeter sensors were placed.