Radiation dose to the floor of mouth muscles predicts swallowing complications following chemoradiation in oropharyngeal squamous cell carcinoma.
OBJECTIVE
While radiation dose to the larynx and pharyngeal constrictors has been the focus of swallowing complications, the suprahyoid muscles, or floor of mouth (FoM) muscles, are critical for hyoid and laryngeal elevation and effective bolus diversion, preventing penetration and aspiration. We hypothesize that radiation dose to these muscles may be important in the development of dysphagia.


METHODS
We studied 46 patients with OPSCC treated with CRT and who underwent baseline swallowing evaluations and post-treatment videofluoroscopic swallowing studies (VFSS) from 2007 to 2010. Patients with abnormal penetration aspiration scores (PAS>2) served as the study population and patients with normal PAS scores (≤ 2) served as the control cohort. Three suprahyoid muscles and two extrinsic tongue muscles were individually delineated and collectively referred to as the FoM muscles. Radiation dose-volume relationships for these muscles were calculated. Univariate logistic regression analysis was used to determine parameters of significance between patients with normal or abnormal PAS scores. A multivariate regression analysis was subsequently performed to isolate the most statistically critical structures associated with abnormal PAS.


RESULTS
Univariate analysis resulted in significance/borderline significance of multiple structures associated with abnormal PAS following irradiation. However, when a multivariate model was applied, only the mean dose to the floor of mouth and minimum dose to the geniohyoid were associated with post-radiation abnormal PAS.


CONCLUSIONS
The dose and volume delivered to the collective FoM muscles may be associated with an increased risk of laryngeal penetration/aspiration to a greater degree than previously recognized organs at risk.
Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA. Electronic address: rkumar16@jhmi.edu.
Rachit
R
Kumar
Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Sara
S
Madanikia
Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Heather
H
Starmer
Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Wuyang
W
Yang
Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Emi
E
Murano
Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Sara
S
Alcorn
Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Todd
T
McNutt
Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Yi
Y
Le
Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA; Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA. Electronic address: hquon2@jhmi.edu.
Harry
H
Quon
D000328:Adult; D000368:Aged; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000503:physiopathology* / Q000532:radiotherapy; D002415:Cats; D003131:Combined Modality Therapy; D003679:Deglutition / Q000187:drug effects* / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008297:Male; D009132:Muscles / Q000503:physiopathology / Q000528:radiation effects*; D009959:Oropharyngeal Neoplasms / Q000188:drug therapy / Q000503:physiopathology* / Q000532:radiotherapy; D011879:Radiotherapy Dosage
Aspiration; Dysphagia; Floor of mouth; Oropharyngeal cancer; Penetration; Radiation; Suprahyoid muscles