ESTRO 2024 - Abstract Book

S1252

Clinical - Head & neck

ESTRO 2024

Figure 2. Dose-response relationship for radiation-induced trismus using the bilateral masseter mean absorbed dose. The data have been stratified into seven bins to visualize the correspondence between the observed data and the resulting model fit. The horizontal bars show the range of mean doses within each bin, and the vertical bars show the 95% binomial confidence interval (CI) of the observed probability in each bin. Dose-response parameter values and their 95% CIs are also given.

Conclusion:

Modern RT (VMAT) without masseter-sparing intent resulted in more than 80% reduction in the occurrence of radiation-induced trismus among HNC patients in comparison to HNC patients treated with older techniques (3DCRT/IMRT). Using high-qualitative prospectively collected objective data for almost 250 HNC patients, this study could identify a well-defined dose-response relationship between masseter dose and trismus that can be used during treatment planning to help avoid trismus in future patients being treated with RT for HNC.

Keywords: trismus, dose-response, masseter muscles

1118

Mini-Oral

Unilateral treatment of lateralised oral cavity and pharynx squamous cell carcinomas

Jesper Grau Eriksen 1,2 , Hanne Primdahl 2 , Christian Nicolaj Andreassen 2 , Kasper Toustrup 2 , Anne Ivalu Sander Holm 2,3