Quality assurance of thoracic radiotherapy in EORTC 08941: a randomised trial of surgery versus thoracic radiotherapy in patients with stage IIIA non-small-cell lung cancer (NSCLC) after response to induction chemotherapy.

The aim of this study was to investigate the improvement of quality of radiotherapy and compliance to the protocol amendment of EORTC study 08941. The radiotherapy-specific data were analysed from 154 patients with stage IIIA-N2 Non-Small-Cell Lung Cancer who were actually irradiated after response to 3 cycles of platinum-based induction chemotherapy. The parameters of quality, assessed in 93 patients before and in 61 after protocol amendment, included: time interval between last chemotherapy course and start of thoracic radiotherapy, the use of a 3-D planning CT, dose and fractionation scheme to the primary tumour, the involved and uninvolved mediastinum, duration of radiotherapy and toxicity. A significant improvement of all quality parameters was noted, except for the overall treatment time, which decreased slightly. Protocol amendment resulted in an improvement of the quality and the compliance of most observed parameters, at the cost of some increase in overall treatment time. The latter reflects logistical problems rather than poor compliance.