Metabolic imaging in non-small-cell lung cancer radiotherapy

Metabolic imaging by positrons emission tomography (PET) offers new perspectives in the field of non-small-cell lung cancer radiation therapy. First, it can be used to refine the way nodal and primary tumour target volumes are selected and delineated, in better agreement with the underlying tumour reality. In addition, the non-invasive spatiotemporal mapping of the tumour biology and the organs at risk function might be further used to steer radiation dose distribution. Delivering higher dose to low responsive tumour area, in a way that better preserves the normal tissue function, should thus reconcile the tumour radiobiological imperatives (maximising tumour local control) with dose related to the treatment safety (minimising late toxicity). By predicting response early in the course of radiation therapy, PET may also participate to better select patients who are believed to benefit most from treatment intensification. Altogether, these technological advances open avenues to in-depth modify the way the treatment plan is designed and the dose is delivered, in better accordance with the radiobiology of individual solid cancers and normal tissues.