The first Rs of radiotherapy: or standing on the shoulders of giants

The name of the Australian-born professor, Rodney H. Withers, is highly acknowledged among radiation biologists, radiation oncologists, medical physicists and other professionals. The list of his contributions towards knowledge enhancement and better understanding of the biological basis for radiotherapy is a long one. However, there are certain landmarks of Dr. Withers’ research that are worth emphasizing, as they have marked several paths along the development of radiotherapy: the four Rs of radiotherapy, the accelerated tumour growth during treatment, the time-factor in radiotherapy, altered fractionation schemes and their corresponding isoeffect curves, normal tissue tolerance and organ architecture—just to name a few. This paper is a tribute to the work of Rodney Withers, which, far from being exhaustive, marks some of his greatest contributions to radiotherapy.