Background: Trismus is a complication post-radiotherapy for head and neck cancer (HNC), which causes pain, eating limitations and reduced quality-of-life. However, little is known about the condition long-term or how trismus fluctuates within an irradiated population.
Aim/objective: To prospectively map trismus prevalence in irradiated HNC patients up to 5-years following treatment completion including describing intra-group fluctuation of maximum interincisal opening (MIO).
Materials and methods: 211 patients receiving curatively intended radiotherapy for HNC were included in this prospective study. Patients were followed pre-radiotherapy (baseline), 3-, 6-, 12-, 24-, 36- and 60-months post-radiotherapy completion using MIO.
Results: Mean MIO at baseline, 12-months and 5-years following radiotherapy were 51.5 mm, 41.7 mm and 41.3 mm respectively. A total of 28% (n = 36) fulfilled the trismus criterion at 5-years post-radiotherapy. Eighty percent of patients (n = 24) with trismus at 5 years post-radiotherapy also suffered from trismus at 12 months post-radiotherapy, whilst 88-92% of all patients reported reduced MIO at any given timepoint compared to baseline. 15% of patients never exceeded an MIO of >35 mm at any time-point.
Conclusion: Trismus is a prevalent long-term complication of HNC and its treatment, which does not appear to heal spontaneously. The majority of fluctuations in MIO occur during the first 12 months post-radiotherapy completion.
Keywords: Radiotherapy; head and neck neoplasm; trismus.