Programming of radiotherapy in the treatment of non-small-cell lung cancer--a way to advance care

Abstract

Radical radiotherapy, the mainstay of treatment for early inoperable non-small-cell lung cancer, is most commonly given in daily fractions, Monday to Friday, to a total dose of 60-70 Gy over 6-8 weeks. Since the 1980s, novel fractionation schedules have been explored with the aim of improving local tumour control and survival without increasing late morbidity. There have been two main approaches. In hyperfractionated radiotherapy the dose per fraction is reduced and the total dose increased to give improved tumour control without increased late morbidity. Hyperfractionation schedules, with more than one fraction per day have been successfully evaluated, but so far significant benefit has not been achieved when compared with conventional radiotherapy plus chemotherapy. In accelerated radiotherapy the overall duration of radiotherapy is reduced to overcome repopulation of tumour cells during the course of treatment. In all the different regimens of accelerated radiotherapy a common feature is giving two or more fractions on some or all treatment days and, in some cases, a lower dose per fraction is also incorporated. CHART (continuous hyperfractionated accelerated radiotherapy) is the most novel and accelerated schedule tested, and a randomised controlled trial showed a significant survival advantage from CHART compared with conventional radiotherapy. Changes in the fractionation of radiotherapy must be combined with other approaches such as neoadjuvant and concomitant chemotherapy, hypoxic-cell modifiers, and conformal radiotherapy, so that care of patients with non-small-cell lung cancer can be further advanced.