Radiation dose to the masseter and medial pterygoid muscle in relation to trismus after chemoradiotherapy for advanced head and neck cancer

• DOI: 10.1002/hed.25573
• Publication Date: 2019-01-17T05:54:58Z
• Authors: Sophie A. Kraaijenga; Olga Hamming‐Vrieze; Sonja Verheijen; Emmy Lamers; Lisette van der M...; Frans J. Hilgers; Michiel W. van de...; Wilma D. Heemsbergen
• Keywords: Trismus; Pterygoid Muscles

Abstract Background We studied the relationship between trismus (maximum interincisor opening [MIO] ≤35 mm) and dose to ipsilateral masseter muscle (iMM) medial pterygoid (iMPM). Methods Pretreatment post‐treatment measurement of MIO at 13 weeks revealed 17% cases in 83 patients treated with chemoradiation intensity‐modulated radiation therapy. Logistic regression models were fitted parameters iMM iMPM baseline (bMIO). A risk classification tree was generated obtain optimal cut‐off values groups. Results Dose levels highly correlated due proximity. Both predictive for trismus, especially mean intermediate volume parameters. Adding bMIO, significantly improved Normal Tissue Complication Probability (NTCP) models. Optimal cutoffs 58 Gy (mean iMPM), 22 iMM) 46 mm Conclusions doses, as well are clinically relevant prediction.