ABSTRACT
During the last twenty years, important new insights have been gained into the
principles of dose fractionation in radiotherapy. The linear-quadratic (LQ) approach
(see Section 7.13) provides a new understanding of why fractionation works and how it
may be optimised; this approach has now become the standard method of calculation in
modern radiotherapy departments, and it will be described in detail below. The practical
basis of fractionation was established many years ago, well before the introduction of the
LQ approach, through the skill, observation, and wisdom of radiotherapists in France,
Austria, and other countries. These historical aspects have been well described by Thames
and Hendry (1987), Bentzen (2002) and Fowler (2006).
