Dysphagia is a common and severe toxicity after oncological treatment of head and neck cancer (HNC). The study aim was to investigate relationships between patient-reported dysphagia and clinically measured swallowing function in HNC after modern curative radiotherapy with or without chemotherapy to identify possible alarm symptoms for clinically manifest dysphagia. Patients with tumors of the tonsil, base of tongue, hypopharynx, and larynx treated in 2007–2015 were assessed for dysphagia post-treatment by telephone interview and videofluoroscopy (VFS). A study-specific categorized symptom score was used to determine patient-reported dysphagia (DESdC = presence of Drinking, Eating, Swallowing difficulties, and Coughing when eating/drinking (any combination); scores between 0 and 4 with 0 = no symptom); the penetration–aspiration scale (PAS) to determine swallowing function by VFS. Swallowing difficulties were defined as DESdC ≥ 1 and PAS ≥ 2. Relationships between clinically relevant cut-offs for DESdC and PAS were determined by Pearson’s correlation coefficient (Pr). Swallowing difficulties according to DESdC were reported by 89% of the patients and according to PAS by 60% at a median of 7 months post-treatment. Averaged correlations between DESdC score 1/2/3/4 and PAS were 0.16/0.10/0.27/0.18. Almost one in two patients with DESdC score ≥3 had severe swallowing difficulties according to PAS. Correlations between individual DESdC:s were highest for swallowing and eating (Pr = 0.53) and lowest for swallowing and coughing (Pr = 0.11). Our data suggest that if a patient reports having swallowing difficulties, it is likely that he or she also has eating difficulties but not necessarily coughing problems when eating/drinking. However, if all these three symptoms are reported, it is likely that the patient will present with moderate or severe impaired swallowing function according to PAS and thus should be referred for further evaluation and treatment.

Mouth-opening distances in patients with HNC post-RT can be understood in terms of associated patient-reported outcomes on trismus-related difficulties. Our data suggest that a reduction in MIO can be expected as patients communicate their mouth-opening status to interfere with private/social life, a clinical warning signal for emerging or worsening trismus as patients are being followed after RT.

HighlightsMajority of DARS investigated for radiation-induced late dysphagia in HNC.Epiglottis (E) and submandibular glands (SG) have previously not been reported as critical for dysphagia.Reduced epiglottic inversion may explain the importance of E dose.Interplay between xerostomia and dysphagia may explain the importance of SG dose.Potential DVH thresholds to reduce dysphagia: E V60 = 60% and contralateral SG V60 = 17%