Abstract Background: We studied the relationship between trismus (maximum interincisor opening [MIO] ≤35 mm) and the dose to the ipsilateral masseter muscle (iMM) and ipsilateral medial pterygoid muscle (iMPM). Methods: Pretreatment and post-treatment measurement of MIO at 13 weeks revealed 17% of trismus cases in 83 patients treated with chemoradiation and intensity-modulated radiation therapy. Logistic regression models were fitted with dose parameters of the iMM and iMPM and baseline MIO (bMIO). A risk classification tree was generated to obtain optimal cut-off values and risk groups. Results: Dose levels of iMM and iMPM were highly correlated due to proximity. Both iMPM and iMM dose parameters were predictive for trismus, especially mean dose and intermediate dose volume parameters. Adding bMIO, significantly improved Normal Tissue Complication Probability (NTCP) models. Optimal cutoffs were 58 Gy (mean dose iMPM), 22 Gy (mean dose iMM) and 46 mm (bMIO). Conclusions: Both iMPM and iMM doses, as well as bMIO, are clinically relevant parameters for trismus prediction.
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Objective: Chemoradiotherapy (CRT) for head and neck cancer (HNC) is associated with high toxicity that adversely affects physical functioning, body composition, fatigue, quality of life and treatment outcomes. Exercise interventions during treatment might counteract these negative effects. We therefore assessed the feasibility of an exercise programme for HNC patients during CRT. Methods: Forty patients were offered a tailored 10-week endurance and resistance training with supervised and home-based sessions. Feasibility endpoints were (1) adherence (main outcome): ≥60% attendance; (2) recruitment: ≥30%; (3) retention rate: ≥85% and (4) compliance rate: ≥60%. Physical performance, muscle strength, body composition, quality of life and fatigue were assessed pre- and post-intervention. Results: Overall adherence was 54%. The recruitment rate was 36%, and the retention rate was 65%. Compliance to the supervised intervention protocol was 66%. Statistically significant decreases were found in mean grip strength, fat-free mass and clinically relevant deteriorations on several domains of quality of life, and fatigue subscales were found. Conclusion: We conclude that this exercise programme for HNC patients during CRT in its current form is feasible for only a minority of patients. We suggest adaptations to improve adherence and retention rates for a definitive multicentre trial. Trial registration: This study is registered at the Netherlands Trial Register (NTR7305), 6 June 2018, retrospectively registered.
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