Reducing posttreatment dysphagia: Support for the relationship between radiation dose to the pharyngeal constrictors and swallowing outcomes

Functional swallowing outcomes related to radiation exposure to dysphagia and aspiration-related structures in patients with head and neck cancer undergoing definitive and postoperative intensity-modulated radiotherapy

BACKGROUND

The relationship between swallowing outcomes and radiotherapy dose to dysphagia and aspiration-related structures (DARS) may be different following definitive versus postoperative radiotherapy (PORT) for mucosal head and neck cancer (HNC) and has not been well-studied.

METHOD

Patient- and clinician-reported swallowing measures were prospectively collected at six time points from baseline to 24 months postradiotherapy HNC. Radiotherapy plans were retrospectively analyzed to assess dose delivered to DARS. The association between swallowing outcomes and participant demographics, tumor characteristics, and radiotherapy dose in definitive and postoperative treatment cohorts was assessed.

RESULTS

Ninety-three participants who received radiotherapy for HNC were included in the analysis (n = 49 definitive radiotherapy for laryngeal/pharyngeal primary tumors and n = 44 postoperative PORT for predominantly oral cavity/salivary gland tumors). Participants undergoing PORT had lower doses to DARS than those undergoing definitive RT. High dose to the pharyngeal constrictors and base of tongue for definitive RT and the esophageal inlet, supraglottic larynx and cervical esophagus for the PORT group were associated with worse swallowing function.

CONCLUSION

Radiation dose to DARS is associated with post-treatment swallowing outcomes. These dose/outcome relationships may vary between the definitive and postoperative settings.

Identifying organs at risk for radiation-induced late dysphagia in head and neck cancer patients

Background and purpose

Dysphagia is a common, severe and dose-limiting toxicity after oncological treatment of head and neck cancer (HNC). This study aims to investigate relationships between radiation doses to structures involved in normal swallowing and patient-reported as well as clinically measured swallowing function in HNC patients after curative (chemo-) radiation therapy (RT) with focus on late effects.

Materials and methods

Patients (n = 90) with HNC curatively treated with RT ± chemotherapy in 2007-2015 were assessed for dysphagia post-treatment by telephone interview and videofluoroscopy (VFS). A study-specific symptom score was used to determine patient-reported dysphagia. The Penetration-Aspiration Scale (PAS) was applied to determine swallowing function by VFS (PAS ≥ 4/ ≥ 6 = moderate/severe dysphagia). Thirteen anatomical structures involved in normal swallowing were individually delineated on the patients' original planning CT scans and associated dose-volume histograms (DVHs) retrieved. Relationships between structure doses and late toxicity were investigated through univariable and multivariable logistic regression analysis (UVA/MVA) accounting for effects by relevant clinical factors.

Results

Median assessment time was 7 months post-RT (range: 5-34 months). Mean dose to the contralateral parotid gland and supraglottic larynx as well as maximum dose to the contralateral anterior digastric muscle predicted patient-reported dysphagia (AUC = 0.64-0.67). Mean dose to the pharyngeal constrictor muscle, the larynx, the supraglottic larynx and the epiglottis, as well as maximum dose to the contralateral submandibular gland predicted moderate and severe dysphagia by VFS (AUC = 0.71-0.80).

Conclusion

The patients in this cohort were consecutively identified pre-treatment, and were structurally approached and assessed for dysphagia after treatment at a specific time point. In addition to established dysphagia organs-at-risk (OARs), our data suggest that epiglottic and submandibular gland doses are important for swallowing function post-RT. Keeping DVH thresholds below V60 = 60% and V60 = 17%, respectively, may increase chances to reduce occurrence of severe late dysphagia. The results need to be externally validated in future studies.

Dysphagia-optimised Intensity-modulated Radiotherapy Techniques in Pharyngeal Cancers: Is Anyone Going to Swallow it?

Dysphagia after primary chemoradiotherapy or radiation alone in pharyngeal cancers can have a devastating impact on a patient's physical, social and emotional state. Establishing and validating efficient dysphagia-optimised radiotherapy techniques is, therefore, of paramount importance in an era where health-related quality of life measures are increasingly influential determinants of curative management strategies, particularly as the incidence of good prognosis, human papillomavirus-driven pharyngeal cancer in younger patients continues to rise. The preferential sparing achievable with intensity-modulated radiotherapy (IMRT) of key swallowing structures implicated in post-radiation dysfunction, such as the pharyngeal constrictor muscles (PCM), has generated significant research into toxicity-mitigating strategies. The lack of randomised evidence, however, means that there remains uncertainty about the true clinical benefits of the dosimetric gains offered by technological advances in radiotherapy. As a result, we feel that IMRT techniques that spare PCM cannot be incorporated into routine practice. In this review, we discuss the swallowing structures responsible for functional impairment, analyse the studies that have explored the dose-response relationship between these critical structures and late dysphagia, and consider the merits of reported dysphagia-optimised IMRT (Do-IMRT) approaches, thus far. Finally, we discuss the dysphagia/aspiration-related structures (DARS) study (ISRCTN 25458988), which is the first phase III randomised controlled trial designed to investigate the impact of swallow-sparing strategies on improving long-term function. To maximise patient benefits, improvements in radiation delivery will need to integrate with novel treatment paradigms and comprehensive rehabilitation strategies to eventually provide a patient-centric, personalised treatment plan.

Treatment de-intensification strategies for head and neck cancer

Increasingly, squamous cell carcinoma of the oropharynx (OPSCC) is attributable to transformation resulting from high-risk human papillomavirus (HPV) infection. Such cancers are significantly more responsive to treatment than traditional tobacco- and alcohol-associated squamous cell cancers of the head and neck. Conventional management with definitive chemoradiation, surgery and adjuvant radiation, or radiation given with altered fractionation schemes, while effective, incurs long-term morbidity that escalates with treatment intensity and significantly impairs quality of life. Recent trials have suggested that less intensive treatment regimens may achieve similar efficacy with decreased toxicity. In this article, we review the primary strategies used for de-escalation of treatment, which include the reduction of radiation dose, substitution and/or elimination of concurrent radiosensitising chemotherapy, and the use of minimally invasive surgery. We discuss the rationale behind these approaches and the preliminary data demonstrating the success of de-escalation, as well as potential considerations raised by treatment de-intensification in HPV-associated OPSCC.

The clinical research of the endoscopic sequential treatment for patients with intermediate-advanced esophageal cancer: a randomized clinical trial

We tried to find an ideal therapeutic regimen for patients with advanced esophageal cancer. Totally 240 patients with advanced esophageal cancer were randomly divided into experimental group (endoscopic sequential treatment, 126 cases) and control group (traditional treatment, 114 cases) with a 2-year follow-up period. The experimental group was randomly divided into three subgroups: group A: local chemotherapeutic drug injection with ordinary metal stent implantation; group B: local chemotherapeutic drug injection with iodine-125 particle implantation; and group C: radiofrequency (RF) therapy with ordinary metal stent group. The control group was also randomly divided into three subgroups: group D: local chemotherapeutic drug injection group; group E: RF therapy group; and group F: common metal stent implantation group. The survival rate, survival quality, adverse reactions, and complications were compared among these groups. A significant improvement of curative effect was found in the experimental group. Group A and B had higher survival rate and survival quality, and lower esophagotracheal fistula incidence and metastasis rate, compared with group C. There was no significant difference in survival rate between group A and group B, while the quality of life was higher in group B than in group A. While patients in group B had lower esophagotracheal fistula incidence and metastasis rate comparing with group A. Local chemotherapeutic drug injection combined with iodine-125 particle stent might be an effective sequential treatment to improve the life quality of advanced esophageal cancer patients.

What is the best treatment for patients with human papillomavirus-positive and -negative oropharyngeal cancer?

The discovery that the human papilloma virus (HPV) is associated with a high and increasing percentage of oropharyngeal squamous cell carcinomas (SCCs) is among the most significant advances in the field of head and neck oncology. HPV-positive oropharyngeal cancer (HPVOPC) has clinical, etiologic, pathologic, and molecular features that distinguish it from HPV-negative disease. Increasingly, HPVOPC is being diagnosed in clinical practice because of the easy availability of p16 immunohistochemistry, a surrogate marker of HPV. The superior prognosis of HPVOPC has led to a reexamination of treatment approaches, and clinical trials are currently investigating strategies to deintensify treatment to reduce acute and late toxicity while preserving efficacy. This is of particular interest in low-risk patients. Unfortunately, patients with HPV-negative tumors still have high rates of locoregional failure and more efficacious treatments are required. This review of oropharyngeal SCC focuses on current and investigational treatment strategies in patients with both HPV-positive and HPV-negative oropharyngeal SCC.