title: Predicting the severity and prognosis of trismus after intensity-modulated radiation therapy for oral cancer patients by magnetic resonance imaging.
abstract: To develop magnetic resonance imaging (MRI) indicators to predict trismus outcome for post-operative oral cavity cancer patients who received adjuvant intensity-modulated radiation therapy (IMRT), 22 patients with oral cancer treated with IMRT were studied over a two-year period. Signal abnormality scores (SA scores) were computed from Likert-type ratings of the abnormalities of nine masticator structures and compared with the Mann-Whitney U-test and Kruskal-Wallis one-way ANOVA test between groups. Seventeen patients (77.3%) experienced different degrees of trismus during the two-year follow-up period. The SA score correlated with the trismus grade (r = 0.52, p<0.005). Patients having progressive trismus had higher mean doses of radiation to multiple structures, including the masticator and lateral pterygoid muscles, and the parotid gland (p<0.05). In addition, this group also had higher SA-masticator muscle dose product at 6 months and SA scores at 12 months (p<0.05). At the optimum cut-off points of 0.38 for the propensity score, the sensitivity was 100% and the specificity was 93% for predicting the prognosis of the trismus patients. The SA score, as determined using MRI, can reflect the radiation injury and correlate to trismus severity. Together with the radiation dose, it could serve as a useful biomarker to predict the outcome and guide the management of trismus following radiation therapy.
authors.affiliation: Division of Medical Imaging, Department of Radiology, Far Eastern Memorial Hospital, Taipei, Taiwan; Department of Life Science, Institute of Molecular and Cellular Biology, Center for Systems Biology, National Taiwan University, Taipei, Taiwan; Medical Imaging Center, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Li-Chun
authors.initials: LC
authors.lastname: Hsieh
authors.affiliation: Center for Systems Biology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Massachusetts, United States of America.
authors.forename: John W
authors.initials: JW
authors.lastname: Chen
authors.affiliation: School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Wang
authors.affiliation: Division of Medical Imaging, Department of Radiology, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Yuk-Ming
authors.initials: YM
authors.lastname: Tsang
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Taipei, Taiwan; Department of Radiation Oncology, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Pei-Wei
authors.initials: PW
authors.lastname: Shueng
authors.affiliation: Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Li-Jen
authors.initials: LJ
authors.lastname: Liao
authors.affiliation: Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Wu-Chia
authors.initials: WC
authors.lastname: Lo
authors.affiliation: Div. Medical Oncology and Hematology, Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Yu-Chin
authors.initials: YC
authors.lastname: Lin
authors.affiliation: Department of Dentistry and Oral Surgery, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Chien-Fu
authors.initials: CF
authors.lastname: Tseng
authors.affiliation: Department of Dentistry and Oral Surgery, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Ying-Shiung
authors.initials: YS
authors.lastname: Kuo
authors.affiliation: Department of Anatomical Pathology, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Jie-Yang
authors.initials: JY
authors.lastname: Jhuang
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Hui-Ju
authors.initials: HJ
authors.lastname: Tien
authors.affiliation: Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; Medical Imaging Center, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Hsueh-Fen
authors.initials: HF
authors.lastname: Juan
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Taipei, Taiwan; Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chen-Hsi
authors.initials: CH
authors.lastname: Hsieh
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008410:Masticatory Muscles / Q000473:pathology / Q000528:radiation effects; D009062:Mouth Neoplasms / Q000532:radiotherapy*; D011379:Prognosis; D011832:Radiation Injuries / Q000209:etiology; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D014313:Trismus / Q000209:etiology*