To prospectively investigate changes in objective deglutition scores and to correlate them with MDADI scores in patients (pts) affected by naso and oropharynx cancer after definitive radiochemotherapy using SWOARs-sparing IMRT (Clinical Trial ID NCT03448341) Pts underwent objective evaluation by means of Fiberoptic Endoscopic Evaluation of Swallowing (FEES) and Videofluoroscopy (VFS) together with subjective evaluation by means of MDADI questionnaire at baseline and at 6 and 12 months after treatment. Pts were categorized in two groups based on baseline MDADI-C value: MDADI-C≥80 and MDADI-C<80. The amount of pharyngeal residue (PR) and the occurrence of penetration and/or aspiration (P/A) were considered as surrogate of dysphagia. Specifically, PR was categorized as 0: absence; 1: mild; 2: moderate; 3: severe and dichotomized as 0-1 vs 2-3. Between August 2015 and November 2021 we enrolled 75 pts of whom 40 (53%) were MDADI-C >80 and 35 (47%) were MDADI-C<80 at baseline. Among MDADI-C≥ 80 pts group the mean baseline PR-score at FEES was 0,42 rising to 1,36 at 6 months (p=0,001) and stabilizing to 1,15 at 12 months (p= 0,21); indeed, the mean baseline PR-score at VFS was 0,55 rising to 1 at 6 months (p=0,069) and slightly dropping to 0,7 at 12 months (p=0,069). Among MDADI-C <80 pts group the mean baseline PR-score at FEES was 0,56 rising to 1,07 at 6 months (p=0,012) and stabilizing to 1,07 at 12 months (p=0,99); indeed the mean baseline PR-score at VFS was 0,67 rising to 1,19 at 6 months (p=0,04) and dropping to 0,78 at 12 months (p=0,04). No correlation was found between baseline dichotomized MDADI-C group and PR-score both at FEES and VFS at the 3 different time intervals. Indeed, a statistical significant correlation was found between PR-score and P/A at VFS at 12 months after treatment (p<0,001). Our results suggest objective deglutition benefit of dose optimization to SWOARs by means of mean low objective scores after treatment both in MDADI-C ≥ 80 and MDADI-C<80 pts group. This means that subjective referred dysphagia is likely not to be associated to a major functional deglutition impairment in our daily clinical practice. [ABSTRACT FROM AUTHOR]