International Journal of Radiation Oncology*Biology*Physics
Clinical InvestigationCandidate Dosimetric Predictors of Long-Term Swallowing Dysfunction After Oropharyngeal Intensity-Modulated Radiotherapy
Introduction
Head-and-neck cancer severely quality of life. Although aggressive radiotherapy and chemoradiotherapy regimens have improved survival outcomes for this disease (1), this success has proved costly 2, 3, 4. Intensity-modulated radiotherapy (IMRT) techniques permit protection of normal tissues adjacent to tumors (5). It has been assumed that reducing dose to the uninvolved larynx and pharyngeal axis improves posttreatment rehabilitation. However, there are limited data to support this premise or to guide radiation oncologists to avoid specific organs at risk (OARs) important to swallowing. Eisbruch et al.6, 7 have recently associated dose to the superior pharyngeal constrictors and supraglottic larynx with post–radiation (RT) aspiration. Despite such early progress, data remain sparse for post-RT swallowing outcomes past 1 year, and published series lack quantifiable measures for swallowing function.
The purpose of this study was to identify specific candidate structures and dose–volume constraints for dysphagia-sparing oropharyngeal IMRT planning. Unique features of these data include uniform disease presentation and IMRT techniques, prospective collection of longitudinal functional outcomes beyond 12 months, and use of modified barium swallow outcome measures to objectively assess swallowing function in a quantitative fashion.
Section snippets
Methods and Materials
A total of 48 patients with Stage IV head and neck squamous cell carcinoma were enrolled onto an institutional review board–approved institutional Phase II chemoradiotherapy trial (Fig. 1). Swallowing outcomes were prospectively collected as an exploratory aim of this trial. We retrospectively correlated dosimetry with these swallowing outcomes in 31 patients with tonsil or base-of-tongue primary disease after treatment had been completed.
We delivered IMRT via a step-and-shoot, multileaf
Results
The patient, tumor, and treatment characteristics of our cohort (n = 31) are presented in Table 1 and summary statistics for OAR RT doses are listed in Table 2.
Discussion
Dysphagia is a key determinant of quality of life in patients treated with radiation for advanced head-and-neck cancer 3, 4 and is potentially more important than xerostomia (17). Efforts to study post-RT dysphagia have been complicated by a diverse spectrum of head-and-neck cancer presentations and treatment regimens as well as the recent transition from conventional to IMRT techniques. Recently published data specific to IMRT have implicated high-dose treatment of pharyngeal constrictor
Acknowledgments
We acknowledge Dr. Avraham Eisbruch for his assistance with the design of our candidate dysphagia-associated OARs.
References (31)
- et al.
Head and neck cancer
Lancet
(2008) - et al.
Objective assessment of swallowing dysfunction and aspiration after radiation concurrent with chemotherapy for head-and-neck cancer
Int J Radiat Oncol Biol Phys
(2002) - et al.
Swallowing dysfunction–preventative and rehabilitation strategies in patients with head-and-neck cancers treated with surgery, radiotherapy, and chemotherapy: A critical review
Int J Radiat Oncol Biol Phys
(2003) - et al.
Determination and delineation of nodal target volumes for head-and-neck cancer based on patterns of failure in patients receiving definitive and postoperative IMRT
Int J Radiat Oncol Biol Phys
(2002) - et al.
Dysphagia and aspiration after chemoradiotherapy for head-and-neck cancer: Which anatomic structures are affected and can they be spared by IMRT?
Int J Radiat Oncol Biol Phys
(2004) - et al.
Intensity-modulated radiotherapy of head and neck cancer aiming to reduce dysphagia: Early dose-effect relationships for the swallowing structures
Int J Radiat Oncol Biol Phys
(2007) - et al.
Conformal irradiation of the prostate: Estimating long-term rectal bleeding risk using dose-volume histograms
Int J Radiat Oncol Biol Phys
(1996) - et al.
Estimation of the incidence of late bladder and rectum complications after high-dose (70–78 Gy) conformal radiotherapy for prostate cancer, using dose-volume histograms
Int J Radiat Oncol Biol Phys
(1998) - et al.
Impact of volume and location of irradiated rectum wall on rectal blood loss after radiotherapy of prostate cancer
Int J Radiat Oncol Biol Phys
(2004) - et al.
Analysis of radiation pneumonitis risk using a generalized Lyman model
Int J Radiat Oncol Biol Phys
(2008)
Dose to larynx predicts for swallowing complications after intensity-modulated radiotherapy
Int J Radiat Oncol Biol Phys
Xerostomia and its predictors following parotid-sparing irradiation of head-and-neck cancer
Int J Radiat Oncol Biol Phys
Dysphagia disorders in patients with cancer of the oropharynx are significantly affected by the radiation therapy dose to the superior and middle constrictor muscle: A dose-effect relationship
Radiother Oncol
Objective assessment of swallowing dysfunction and aspiration after radiation concurrent with chemotherapy for head-and-neck cancer
Int J Radiat Oncol Biol Phys
Aspiration rate following chemoradiation for head and neck cancer: An underreported occurrence
Radiother Oncol
Cited by (160)
Instrumental assessment of dysphagia and dysphonia in head and neck cancer and patients’ perception: Systematic review
2024, Revista de Logopedia, Foniatria y AudiologiaRadiation-induced long-term dysphagia in survivors of head and neck cancer and association with dose-volume parameters
2024, Radiotherapy and OncologyInitial Feasibility and Acute Toxicity Outcomes From a Phase 2 Trial of <sup>18</sup>F-Fluorodeoxyglucose Positron Emission Tomography Response-Based De-escalated Definitive Chemoradiotherapy for p16+ Oropharynx Cancer: A Planned Interim Analysis
2023, International Journal of Radiation Oncology Biology PhysicsImproving functional outcomes for patients with head and neck cancer
2023, The Lancet Oncology
Supported by National Cancer Institute Grant CA132281.
Conflict of interest: none.