Dose equivalents of tumour repopulation during radiotherapy: the potentialfor confusion

When employing linear quadratic equations to calculate compensation for cha nges in overall treatment time, a potential confusion exists regarding use of the parameter commonly described as the dose equivalent of tumour repopu lation. The more correct term for this factor is the biologically effective dose equivalent of tumour repopulation. The distinction between the two co ncepts is discussed and the potential errors arising from their confusion a re illustrated by means of an example.