Quantification of tongue mobility impairment using optical tracking in patients after receiving primary surgery or chemoradiation

Abstract

Purpose Tongue mobility has shown to be a clinically interesting parameter on functional results after tongue cancer treatment which can be objectified by measuring the Range Of Motion (ROM). Reliable measurements of ROM would enable us to quantify the severity of functional impairments and use these for shared decision making in treatment choices, rehabilitation of speech and swallowing disturbances after treatment. Method Nineteen healthy participants, eighteen post-chemotherapy patients and seventeen post-surgery patients were asked to perform standardized tongue maneuvers in front of a 3D camera system, which were subsequently tracked and corrected for head and jaw motion. Indicators, such as the left-right tongue range and the deflection angle with the horizontal axis were extracted from the tongue trajectory to serve as a quantitative measure for the impaired tongue mobility. Results The range and deflection angle showed an excellent intra- and interrater reliability (ICC 0.9) The repeatability experiment showed an average standard deviation of 2.5 mm to 3.5 mm for every movement, except the upward movement. The post-surgery patient group showed a smaller tongue range and higher deflection angle overall than the healthy participants. Post-chemoradiation patients showed less difference in tongue ROM compared with healthy participants. Only a few patients showed asymmetrical movement after treatment, which could not always be explained by T-stage or the side of treatment alone. Conclusion We introduced a reliable and reproducible method for measuring the ROM and to quantify for motion impairments, that was able to show differences in tongue ROM between healthy subjects and patients after chemoradiation or surgery. Future research should focus on measuring patients with oral cancer pre- and post-treatment in combination with the collection of detailed information about the individual tongue anatomy, so that the full ROM trajectory can be used to identify changes over time and to quantify functional impairment.

Personalized biomechanical tongue models based on diffusion-weighted MRI and validated using optical tracking of range of motion

“…The difference between left and right, however, corresponded to an asymmetry in the measured ROM, specifically a deviation to the left. As explained previously (Kappert et al 2019a), this may have been caused by the order of instructions given by the investigator.…”

“…The ROM of the tongue was obtained by optical tracking of a marker on the tip of the tongue using a 3D camera. The volunteers were asked to perform four different tongue movements: left, right, down, and protrusion as described in the paper by Kappert et al ( 2019a ). The up-movement was left out since it was proven to be unreliable.…”

“…Only when the personalized models perform better than the atlas, we can conclude that personalization improves the ROM prediction. Previously, the precision of the ROM measurements, quantified by the standard deviation, was determined to a range from 2.3 to 3.2 mm (Kappert et al 2019a). We, therefore, assumed a precision of 3 mm (3.2 mm rounded off) for all ROM measurements.…”

“…By mapping the tongue of an individual to the atlas tongue, we hypothesized that the segmented fiber tracks of the atlas could be morphed back to an individual’s space and that, subsequently, from these segmented fiber tracks a personalized biomechanical model could be created. The effect of this personalization step was evaluated by comparing models with both personalized and generic muscles bundles to the predicted range of motion (ROM) of the tongue measured in vivo using 3D optical tracking (Kappert et al 2019a ).…”

Detecting and Analysing Spontaneous Oral Cancer Speech in the Wild

“…Apart from improving survival rates (mortality), research attention has shifted to improving the quality of life after surgery [2]. Oral cancer survivors can suffer from several problems affecting their quality of life: difficulty swallowing [3,4], decreased tongue mobility [5] and impaired speech intelligibility [3]. The latter is the focus of our paper.…”