 The main objective of this study is to achieve cross-cultural and psychometric validation of the Xerostomia Inventory initially developed in English language into French Language. This will be achieved in two stages: First, cross-cultural validation, and a second, psychometric validation The cross-cultural validation will be performed according to the methodology of the Institute for Work and Health, according to the recommended six phases. In a second step, the psychometric validation will be done using longitudinal study. Indeed, an observational, longitudinal, and prospective study will be set up. Analysis of the results will help define the feasibility and acceptability of the tool, its validity content validity, perceived validity, construct validity, concurrent validity, and discriminant validity, its reliability internal consistency and reproducibility over time. Longitudinal follow-up of patients is expected to also assess the predictive validity and responsiveness. 