Trismus in patients with oropharyngeal cancer: relationship with dose in structures of mastication apparatus.
BACKGROUND
Our aim was to assess the correlation between the radiation therapy (RT) dose to the mastication apparatus and trismus of oropharyngeal cancer patients.


METHODS
Eighty-one patients treated with RT were analyzed. The masseter, pterygoid, and temporalis muscles and the coronoid and condyl were delineated on axial CT slices. The mean dose in these structures was correlated with outcome of quality of life questionnaires.


RESULTS
Fifty-six (88%) patients responded; 16% of the patients scored grade 3/4 on the Head & Neck 35 "opening mouth" question. A significant correlation was observed between dose in masseter and pterygoid muscles and trismus (p= .02).


CONCLUSIONS
Patients treated with brachytherapy received a lower dose in masticatory muscles. A steep dose-effect relationship between mean dose in masseter muscle and pterygoid muscles and the probability of having trismus complaints was observed; with every additional 10 Gy to the pterygoid muscle, an increase of the probability of trismus of 24% was observed.
Teguh
David N
DN
Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
Levendag
Peter C
PC
Voet
Peter
P
van der Est
Henri
H
Noever
Inge
I
de Kruijf
Willy
W
van Rooij
Peter
P
Schmitz
Paul I M
PI
Heijmen
Ben J
BJ
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000532:radiotherapy*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000528:radiation effects*; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D011626:Pterygoid Muscles / Q000528:radiation effects*; D011788:Quality of Life; D011878:Radiotherapy / Q000009:adverse effects / Q000379:methods; D011879:Radiotherapy Dosage; D011795:Surveys and Questionnaires; D014313:Trismus / Q000145:classification / Q000209:etiology*