Dosimetric study of the combination of a stereotactic radiotherapy and a three-dimensional conformational radiotherapy in locally advanced bronchial cancers

The authors report a study which aims at demonstrating, with respect to a standard treatment, a possible dosimetric gain, as far as organs at risks are concerned, by treating the ganglionary mediastinal PTV (previsional target volume) by conformational irradiation and the primitive tumour previsional target volume by stereotactic irradiation by means of the CyberKnife system. Nine patients suffering from a non-small-cell lung cancer have been treated. The method allows a significant reduction of the V20 and V30 lung volumes and of the V30 heart volume. It also results in an increase of equivalent biological doses delivered to the primitive tumour PTV, and in an improvement of the mediastinal PTV coverage. Short communication