Agata Gawryszuk1, Hendrik P Bijl2, Monique Holwerda3, Gyorgy B Halmos4, Jan Wedman4, Max J H Witjes5, Anton M van der Vliet6, Bart Dorgelo6, Johannes A Langendijk2. 1. Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, The Netherlands. Electronic address: a.gawryszuk@umcg.nl. 2. Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, The Netherlands. 3. Department of Otolaryngology, Speech Language Pathology, University of Groningen, University Medical Center Groningen, The Netherlands. 4. Department of Otolaryngology, Head and Neck Surgery, University of Groningen, University Medical Center Groningen, The Netherlands. 5. Department of Oral and Maxillofacial Surgery, University of Groningen, University Medical Center Groningen, The Netherlands. 6. Department of Radiology, University of Groningen, University Medical Center Groningen, The Netherlands.
Abstract
BACKGROUND AND PURPOSE: When optimising radiotherapy treatments today, the pharyngeal constrictor muscles and the larynx are usually regarded as the swallowing organs at risk (SWOARs). The purpose of this study was to identify and describe additional, previously undefined groups of muscles (functional units) involved in crucial components of swallowing (hyolaryngeal elevation (HLE), tongue base retraction (TBR) and tongue motion), and to emphasise their relevance in radiation-induced dysphagia. MATERIAL AND METHODS: Based on available literature on human anatomy and swallowing physiology, the functional units of muscles involved in HLE, TBR and tongue motion have been identified and described. RESULTS AND CONCLUSION: Functional swallowing units (FSUs) were defined as groups of swallowing muscles sharing their function, that are in close proximity to each other. Seven FSUs involved in HLE, TBR and tongue motion were identified: floor of mouth, thyrohyoid muscles, posterior digastric/stylohyoid muscles complex, longitudinal pharyngeal muscles, hyoglossus/styloglossus muscles complex, genioglossus muscles, intrinsic tongue muscles. The swallowing physiology and anatomy of the FSUs described in this paper will lead to a greater understanding of radiation-induced dysphagia mechanisms and, consequently, to an improvement in the development of swallowing sparing strategies. This article (PART 1) serves as the theoretical foundation for a subsequent article (PART 2), which provides detailed delineation guidelines for FSUs.
BACKGROUND AND PURPOSE: When optimising radiotherapy treatments today, the pharyngeal constrictor muscles and the larynx are usually regarded as the swallowing organs at risk (SWOARs). The purpose of this study was to identify and describe additional, previously undefined groups of muscles (functional units) involved in crucial components of swallowing (hyolaryngeal elevation (HLE), tongue base retraction (TBR) and tongue motion), and to emphasise their relevance in radiation-induced dysphagia. MATERIAL AND METHODS: Based on available literature on human anatomy and swallowing physiology, the functional units of muscles involved in HLE, TBR and tongue motion have been identified and described. RESULTS AND CONCLUSION: Functional swallowing units (FSUs) were defined as groups of swallowing muscles sharing their function, that are in close proximity to each other. Seven FSUs involved in HLE, TBR and tongue motion were identified: floor of mouth, thyrohyoid muscles, posterior digastric/stylohyoid muscles complex, longitudinal pharyngeal muscles, hyoglossus/styloglossus muscles complex, genioglossus muscles, intrinsic tongue muscles. The swallowing physiology and anatomy of the FSUs described in this paper will lead to a greater understanding of radiation-induced dysphagia mechanisms and, consequently, to an improvement in the development of swallowing sparing strategies. This article (PART 1) serves as the theoretical foundation for a subsequent article (PART 2), which provides detailed delineation guidelines for FSUs.
Authors: Yimin Li; Shyam Rao; Wen Chen; Soheila F Azghadi; Ky Nam Bao Nguyen; Angel Moran; Brittni M Usera; Brandon A Dyer; Lu Shang; Quan Chen; Yi Rong Journal: Technol Cancer Res Treat Date: 2022 Jan-Dec