IN MEMORIAM: Robert Katz (1917–2011)

Bob Katz will be well remembered for his enthusiasm and strong personality. In a scientific dispute, few indeed could match his wit or his sense of humor or survive the cutting logic of his arguments. To those who had appreciation for his science and his personality, he was truly a great scientist and a master teacher. There are many people around the world who will remember Bob Katz for what he offered them and for the way he showed them what truth in science is. The Katz Model, developed at that time for solid-state detectors and for cell cultures, relates the action of energetic ions with the radial distribution of dose due to d rays around the ion’s path and is in effect a theory of radiobiological effectiveness (RBE) (3). The model is able to yield quantitative predictions of the response of physical or biological detectors after their irradiation by energetic ions once the parameters characterizing the detector and the ion species and its energy are known. No other radiobiological model has so far been able to match these features. The model, with its fluence-based approach to radiation dosimetry, suggests changes to long-standing paradigms of radiotherapy and radiation protection. The Katz Model brought its author international recognition and respect, controversies notwithstanding. The list of U.S. and international collaborators and friends of Bob Katz is the roster of the world’s experts in microdosimetry, radiation physics, radiation protection and cancer radiotherapy – fields to which the Katz Model has contributed and will very likely contribute in the future