Diaphragm thickness, mobility and respiratory muscle strength in patients with head and neck cancer receiving chemoradiation therapy: A longitudinal pilot study

Background: Head and neck cancer is the sixth most common cancer worldwide and is also associated with many pulmonary complications. Decreased cardiopulmonary function and functional capacity is one of the major treatment related side effects of chemoradiation therapy. In this study we aimed to assess and quantify the impact of treatment related side effects on the respiratory function and functional capacity of head and neck cancer patients during chemoradiation therapy.   Methods: This was a pilot longitudinal study conducted amongst 12 newly diagnosed head and neck cancer patients (stage III, IV, IVa, IVb) who were admitted to hospital care and were receiving chemoradiation therapy for seven weeks. Outcome variables assessed were diaphragmatic thickness and mobility, maximal inspiratory pressure (MIP) and maximum expiratory pressure (MEP) and functional capacity using six-minute walk test at baseline, three weeks and seven weeks of chemo radiation. Repeated measures ANOVA and Bonferroni post-hoc tests were used to identify significant differences at the three time points with a p < 0.05.  Results: Our data reported a decrease in all the variables and a significant decrease in diaphragm function during deep inspiration, respiratory pressures which indicate respiratory muscle strength and functional capacity by the end of the seventh week of chemo-radiation therapy (p <0.05).  Conclusion: We conclude that seven weeks of chemo-radiation therapy reduces the diaphragmatic thickness, mobility, respiratory muscle strength and functional capacity in head and neck cancer patients.