Temporal patterns of patient-reported trismus and associated mouth-opening distances in radiotherapy for head and neck cancer: A prospective cohort study.

Abstract

To identify temporal patterns of patient-reported trismus during the first year post-radiotherapy, and to study their associations with maximal interincisal opening distances (MIOs). Single institution case series. University hospital ENT clinic. One hundred and ninety-six subjects who received radiotherapy (RT) for head and neck cancer (HNC) with or without chemotherapy in 2007-2012 to a total dose of 64.6/68Gy in 38/34 fractions, respectively. All subjects were prospectively assessed for mouth-opening ability (Gothenburg Trismus Questionnaire (GTQ), European Organization for Research and Treatment of Cancer quality of life Questionnaire (EORTC QLQ-H&N35), and MIO) pre-RT and at 3, 6 and 12months after RT. Correlations between temporally robust GTQ symptoms and MIO as given by Pearson's correlation coefficients (Pr ); temporally robust GTQ-symptom domains as given by factor analysis; rates of trismus with respect to baseline by risk ratios (RRs). Four temporally robust domains were identified: Eating (3-7 symptoms), Jaw (3-7), Pain (2-5) and Quality of Life (QoL, 2-5), and included 2-3 persistent symptoms across all post-RT assessments. The median RR for a moderate/severe (>2/>3) cut-off was the highest for Jaw (3.7/3.6) and QoL (3.2/2.9). The median Pr between temporally robust symptoms and MIO post-radiotherapy was 0.25-0.35/0.34-0.43/0.24-0.31/0.34-0.50 for Eating/Jaw/Pain/QoL, respectively. 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.