Ravasco showed in his study that the impact on the nutritional state of a nutritional care by dietary advices was more important as the prescription of oral nutritional supplements but based on a short period (the dietary intervention covered only the duration of the radiotherapy). But what would happen after the end of treatments? The investigators emit the hypothesis that a post-therapeutic systematic and regular dietary support has a positive impact on the prevention of the undernutrition among the patients affected by a first cancer of the upper aerodigestive tract whom therapeutic sequence involves a radiotherapy.