Dysphagia - Results from multivariable predictive modelling on aspiration from a subset of the ARTSCAN trial

Radiation-induced long-term dysphagia in survivors of head and neck cancer and association with dose-volume parameters

BACKGROUND

Although dysphagia is a common side effect after radiotherapy (RT) of head and neck cancer (HNC), data on long-term dysphagia is scarce. We aimed to 1) compare radiation dose parameters in HNC survivors with and without dysphagia, 2) investigate factors associated with long-term dysphagia and its possible impact on health-related quality of life (HRQoL), and 3) investigate how our data agree with existing NTCP models.

METHODS

This cross-sectional study conducted in 2018-2020, included HNC survivors treated in 2007-2013. Participants attended a one-day examination in hospital and filled in patient questionnaires. Dysphagia was measured with the EORTC QLQ-H&N35 swallowing scale. Toxicity was scored with CTCAE v.4. We contoured swallowing organs at risk (SWOAR) on RT plans, calculated dose-volume histograms (DVHs), performed logistic regression analyses and tested our data in established NTCP models.

RESULTS

Of the 239 participants, 75 (31%) reported dysphagia. Compared to survivors without dysphagia, this group had reduced HRQoL and the DVHs for infrahyoid SWOAR were significantly shifted to the right. Long-term dysphagia was associated with age (OR 1.07, 95% CI 1.03-1.10), female sex (OR 2.75, 95% CI 1.45-5.21), and mean dose to middle pharyngeal constrictor muscle (MD-MPCM) (OR 1.06, 95% CI 1.03-1.09). NTCP models overall underestimated the risk of long-term dysphagia.

CONCLUSIONS

Long-term dysphagia was associated with higher age, being female, and high MD-MPCM. Doses to distally located SWOAR seemed to be risk factors. Existing NTCP models do not sufficiently predict long-term dysphagia. Further efforts are needed to reduce the prevalence and consequences of this late effect.

Acute effects of radiation treatment to submental muscles on burrowing and swallowing behaviors in a rat model

Swallowing impairments are a major complication of radiation treatment for oropharyngeal cancers, influencing oral intake and quality of life. The timing and functional consequences of radiation treatment on the swallowing process is not clearly understood. A rodent radiation injury model was used to investigate the onset of oral and pharyngeal dysfunctions in deglutition related to radiation treatment. This study tested the hypothesis that (Wall et al., 2013) alterations in normal biting, licking, and swallowing performance would be measurable following 64Gy of fractionated radiation to the submental muscles; and (Kotz et al., 2004) radiation will affect the animal’s general well-being as measured via burrowing activity. Seven rats received radiation using a clinical linear accelerator given in 8 fractions of 8Gy and another seven animals received sham anesthesia only treatment. Swallowing bolus transit/size was assessed via videofluoroscopy, tongue movement during drinking was measured via an electrical lick sensor, and biting was analyzed from acoustic recordings of a vermicelli pasta test. Burrowing activity was measured by the amount of gravel substrate displaced within a container. Measurements were taken at baseline, during treatment (1–4 weeks), and after completion of treatment (weeks 5 & 6). Decreases in licking frequency and increases in inter-lick interval were observed 5- and 6-weeks post-treatment. Significant decreases in burrowing performance, swallowing frequency, and inter-swallow interval were observed starting the last week of treatment and continuing up to 2-weeks after completion. Results suggest that tongue dysfunction is one of the first treatment related feeding problems to present immediately after the completion of radiation to the submental muscles.

Evaluation of Objective and Subjective Swallowing Outcomes in Patients with Dysphagia Treated for Head and Neck Cancer

We evaluated objective and subjective swallowing function outcomes in patients with dysphagia treated for head and neck cancer (HNC) and identified risk factors for poor swallowing outcomes. Patients undergoing videofluoroscopic swallowing studies (VFSS) between January 2016 and March 2021 were divided into four groups according to primary tumor sites; post-treatment dysphagia was assessed. The penetration–aspiration scale (PAS) and bolus residue scale (BRS) were used to objectively assess swallowing function through VFSS. The Functional Oral Intake Scale (FOIS) was used for subjective analyses of swallowing statuses. To account for potential confounding, important covariates were adjusted for in logistic regression models. Oropharyngeal tumors were significantly more likely to have poor PAS and BRS scores than oral cavity tumors, and the patients with nasopharyngeal tumors were significantly less likely to have poor FOIS scores. Old age, having multiple HNCs, and a history of radiotherapy were associated with an increased odds of poor PAS scores (for all types of swallows), poor BRS scores (for semiliquid and solid swallows), and poor FOIS scores, respectively. This indicates using only subjective assessments may not allow for accurate evaluations of swallowing function in patients treated for HNC. Using both objective and subjective assessments may allow for comprehensive evaluations.

Patient-Reported Outcomes-Guided Adaptive Radiation Therapy for Head and Neck Cancer

Purpose

To identify which patient-reported outcomes (PROs) may be most improved through adaptive radiation therapy (ART) with the goal of reducing toxicity incidence among head and neck cancer patients.

Methods

One hundred fifty-five head and neck cancer patients receiving radical VMAT (chemo)radiotherapy (66-70 Gy in 30-35 fractions) completed the MD Anderson Symptom Inventory, MD Anderson Dysphagia Inventory (MDADI), and Xerostomia Questionnaire while attending routine follow-up clinics between June-October 2019. Hierarchical clustering characterized symptom endorsement. Conventional statistical approaches indicated associations between dose and commonly reported symptoms. These associations, and the potential benefit of interfractional dose corrections, were further explored via logistic regression.

Results

Radiotherapy-related symptoms were commonly reported (dry mouth, difficulty swallowing/chewing). Clustering identified three patient subgroups reporting: none/mild symptoms for most items (60.6% of patients); moderate/severe symptoms affecting some aspects of general well-being (32.9%); and moderate/severe symptom reporting for most items (6.5%). Clusters of PRO items broadly consisted of acute toxicities, general well-being, and head and neck-specific symptoms (xerostomia, dysphagia). Dose-PRO relationships were strongest between delivered pharyngeal constrictor Dmean and patient-reported dysphagia, with MDADI composite scores (mean ± SD) of 25.7 ± 18.9 for patients with Dmean <50 Gy vs. 32.4 ± 17.1 with Dmean ≥50 Gy. Based on logistic regression models, during-treatment dose corrections back to planned values may confer ≥5% decrease in the absolute risk of self-reported physical dysphagia symptoms ≥1 year post-treatment in 1.2% of patients, with a ≥5% decrease in relative risk in 23.3% of patients.

Conclusions

Patient-reported dysphagia symptoms are strongly associated with delivered dose to the pharyngeal constrictor. Dysphagia-focused ART may provide the greatest toxicity benefit to head and neck cancer patients, and represent a potential new direction for ART, given that the existing ART literature has focused almost exclusively on xerostomia reduction.

Comparisons of normal tissue complication probability models derived from planned and delivered dose for head and neck cancer patients

BACKGROUND AND PURPOSE

Normal tissue complication probability (NTCP) models are typically derived from the planned dose distribution, which can deviate from the delivered dose due to anatomical day-to-day variations. The aim of this study was to compare NTCP models derived from the planned and the delivered dose for head and neck cancer (HNC) patients.

MATERIAL AND METHOD

322 HNC patients who received radiotherapy with daily CBCT guidance were included in this retrospective study. The delivered dose was estimated by deformably accumulating dose from daily CBCT to planning anatomy. We used a Lyman-Kutcher-Burman NTCP model, to relate the equivalent uniform dose (EUD) of organs at risk (OAR) with oral mucositis, xerostomia and dysphagia respectively. We compared the model parameters and performances.

RESULTS

The median differences between planned and delivered EUD to the OARs were significantly larger for patients with toxicity than without for acute dysphagia (≥G2 and ≥G3) and late dysphagia (≥G3) (p < 0.05). Those differences resulted in small differences in steepness and agreement to the data between delivered- and planned-fitted NTCP curves, and the differences were not significant. The differences in AUC were less than 0.01.

CONCLUSION

Differences between delivered and planned dose did not lead to significant differences in NTCP curves. The additional clinical relevance of NTCP models using accumulated dose for oral mucositis, xerostomia and dysphagia in HNC radiotherapy is likely to be limited.

Relationship between videofluoroscopic and subjective (physician- and patient- rated) assessment of late swallowing dysfunction after (chemo) radiation: Results of a prospective observational study

BACKGROUND AND PURPOSE

Primary (chemo)radiation (CHRT) for HNC may lead to late dysphagia. The purpose of this study was to assess the pattern of swallowing disorders based on prospectively collected objective videofluoroscopic (VF) assessment and to assess the correlations between VF findings and subjective (physician- and patient-rated) swallowing measures.

MATERIAL AND METHODS

189 consecutive HNC patients receiving (CH)RT were included. Swallowing evaluation at baseline and 6 months after treatment (T6) encompassed: CTCAE v.4.0 scores (aspiration/dysphagia), PROMs: SWAL QOL/ EORTC QLQ-H&N35 (swallowing domain) questionnaires and VF evaluation: Penetration Aspiration Scale, semi-quantitative swallowing pathophysiology evaluation, temporal measures and oral/pharyngeal residue quantification. Aspiration specific PROMs (aPROMs) were selected. Correlations between late penetration/aspiration (PA_T6) and: clinical factors, CTCAE and aPROMs were assessed using uni- and multivariable analysis.

RESULTS

Prevalence of PA increased from 20% at baseline to 43% after treatment (p < 0.001). The most relevant baseline predictors for PA_T6 were: PA_T0, age, disease stage III-IV, bilateral RT and baseline aPROM 'Choking when drinking' (AUC: 0.84). In general aPROMs correlated better with VF-based PA than CTCAE scores. The most of physiological swallowing components significantly correlated and predictive for PA (i.e. Laryngeal Vestibular Closure, Laryngeal Elevation and Pharyngeal Contraction) were prone to radiation damage.

CONCLUSION

The risk of RT-induced PA is substantial. Presented prediction models for late penetration/aspiration may support patient selection for baseline and follow-up VF examination. Furthermore, all aspiration related OARs involved in aforementioned swallowing components should be addressed in swallowing sparing strategies. The dose to these structures as well as baseline PROMs should be included in future NTCP models for aspiration.

Death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy for head and neck cancer

BACKGROUND AND PURPOSE

The incidence of hypopharyngeal and supraglottic cancer (HSC) is high in Japan. This study aimed to retrospectively identify risk factors for death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy (RT) for HSC.

MATERIALS AND METHODS

Overall, 391 patients who began definitive RT for HSC between 2006 and 2014 were identified from the Osaka International Cancer Institute electronic database. Among 391 patients, 33 had a history of surgery for esophageal cancer (EC) and 19 received simultaneous RT for synchronous EC. The cause of death was divided into 3 main categories: "cancer under study," "other malignancy," and "unrelated to cancer." Cox proportional hazard model was used to estimate the hazard ratio (HR).

RESULTS

The median follow-up for survivors was 8 (range 3.6-14.1) years. At the last follow-up, 202 patients died. Death from "cancer under study," "other malignancy," and "unrelated to cancer" occurred in 92 (45.5%), 55 (27.2%), and 55 (27.2%) patients, respectively. Twelve patients died from aspiration pneumonia. In multivariate analysis for death unrelated to cancer and death from aspiration pneumonia, history of surgery for EC (HR: 3.87, p < 0.001; HR: 6.84, p = 0.007, respectively) and simultaneous RT for synchronous EC (HR: 3.74, p = 0.006; HR: 16.37, p < 0.001, respectively) were significant risk factors.

CONCLUSION

The laryngeal preservation approach by RT for HSC patients with a history of surgery for EC and simultaneous RT for synchronous EC should be used with caution.

Individualized prediction of late-onset dysphagia in head and neck cancer survivors

BACKGROUND

Limited data exist regarding which head and head and neck cancer (HNC) survivors will suffer from long-term dysphagia.

METHODS

From a population-based cohort of 1901 Utah residents with HNC and ≥3 years follow-up, we determined hazard ratio for dysphagia, aspiration pneumonia, or gastrostomy associated with various risk factors. We tested prediction models with combinations of factors and then assessed discrimination of our final model.

RESULTS

Cancer site in the hypopharynx, advanced tumor classification, chemoradiation, preexisting dysphagia, stroke, dementia, esophagitis, esophageal spasm, esophageal stricture, gastroesophageal reflux, thrush, or chronic obstructive pulmonary disease were associated with increased risk of long-term dysphagia. Our final prediction tool gives personalized risk calculation for diagnosis of dysphagia, aspiration pneumonia, or gastrostomy tube placement at 5, 10, and 15 years after HNC based on 18 factors.

CONCLUSION

We developed a clinically useful risk prediction tool to identify HNC survivors most at risk for dysphagia.

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.

Modeling Dose Response for Late Dysphagia in Patients With Head and Neck Cancer in the Modern Era of Definitive Chemoradiation

PURPOSE

To develop personalized multivariate dose-response models for late dysphagia in patients with head and neck cancer treated in the modern era of combined chemotherapy with intensity-modulated radiation therapy.

PATIENTS AND METHODS

The analysis included 424 patients (oropharyngeal cancer [n = 295] and nasopharyngeal, hypopharyngeal, or laryngeal cancer [n = 129]) who received definitive chemoradiation between January 2004 and April 2009. The superior, middle, and inferior pharyngeal constrictor muscles were contoured. We calculated generalized equivalent uniform dose (gEUD) for each and the total constrictor muscle volume, with the volume effect parameter a varying from log10 a = -1 to +1 in steps of 0.1. We used the National Cancer Institute Common Toxicity Criteria for Adverse Events (version 3.0) to grade late dysphagia and logistic regression to evaluate the correlation of gEUD( a) with grade 2 or higher (≥ G2) and grade 3 or higher (≥ G3) late dysphagia at each value of a.

RESULTS

Median follow-up was 33.3 months (range, 6 to 69 months). There were 41 cases (10%) of ≥ G2 dysphagia and 22 cases (5%) of ≥ G3 dysphagia. Mean doses to the total constrictor ranged from 30.1 to 85.7 Gy (median, 61.2 Gy). The predicted rate of ≥ G2 dysphagia increased by approximately 3.4% per Gy at the mean dose, for which the probability of ≥ G2 dysphagia is 50%. The threshold mean total constrictor doses that limited rates of ≥ G2 and ≥ G3 dysphagia to < 5% were < 58 Gy and < 61 Gy, respectively. Other significant factors in the multivariate predictive model included disease site, mean dose to total constrictor muscle, and patient age.

CONCLUSION

Incidences of both ≥ G2 and ≥ G3 dysphagia were dependent on the mean radiation dose to the total constrictor muscle volume, disease site, and patient age. Limiting the total volume of constrictor muscle to < 58 Gy could keep the predicted rate of ≥ G2 dysphagia to < 5%.

Chronic radiation-associated dysphagia in oropharyngeal cancer survivors: Towards age-adjusted dose constraints for deglutitive muscles

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Age at treatment for OPSCC is a strong predictor of chronic radiation associated dysphagia (RAD).

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For swallowing regions of interest (ROIs), dose to ROI and age impact patients’ risk of chronic RAD.

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For patients at high risk for RAD more intense prophylactic swallowing therapies may be warranted.

Objectives

We sought to model chronic radiation-associated dysphagia (RAD) in patients given intensity-modulated radiation therapy (IMRT) for oropharyngeal squamous cell cancer (OPSCC) as a function of age and dose to non-target swallowing muscles.

Methods

We reviewed 300 patients with T1-T4 N0-3 M0 OPSCC given definitive IMRT with concurrent chemotherapy. Chronic RAD was defined as aspiration or stricture on videoflouroscopy/endoscopy, gastrostomy tube, or aspiration pneumonia at ≥12 months after IMRT. Doses to autosegmented regions of interest (ROIs; inferior, middle and superior constrictors, anterior and posterior digastrics, mylo/geniohyoid complex, intrinsic tongue, and gengioglossus) were obtained from DICOM-RT plans and dose-volume histograms. The probability of chronic RAD as a function of mean ROI dose, stratified by age (<50, 50–59, 60–69, or ≥70 years), was estimated with logistic probability models and subsequent unsupervised nonlinear curves.

Results

Chronic RAD was observed in 34 patients (11%). Age was a significant correlate of chronic RAD, both independently and with dose for all muscle groups examined. Distinct muscle-specific dose–response profiles were observed as a function of age (e.g., 5% of patients in their 50 s [but 20% of those 70 + ] who received 60 Gy to the superior constrictor had chronic RAD). This effect was stable across all observed muscle ROIs, with a false discovery rate-corrected p < 0.05, for all dose/muscle/age models, suggesting that including age as a covariate improves modeling of chronic RAD.

Conclusions

Age at treatment moderates the probability of chronic RAD after chemo-IMRT for OPSCC, with aging muscles showing lower dose thresholds. Uniform dose constraints may not predict toxicity in older patients.

Rates of Dysphagia-Related Diagnoses in Long-Term Survivors of Head and Neck Cancers

OBJECTIVE

To estimate long-term prevalence of new dysphagia-related diagnoses in a large cohort of head and neck cancer survivors.

STUDY DESIGN

Retrospective cohort.

SETTING

Population based.

SUBJECTS AND METHODS

In total, 1901 adults diagnosed with head and neck cancer between 1997 and 2012 with at least 3 years of follow-up were compared with 7796 controls matched for age, sex, and birth state. Prevalence of new dysphagia-related diagnoses and procedures and hazard ratio compared to controls were evaluated in patients 2 to 5 years and 5 years and beyond after diagnosis. Risk factors for the development of these diagnoses were analyzed.

RESULTS

Prevalence of new diagnosis and hazard ratio compared to controls remained elevated for all diagnoses throughout the time periods investigated. The rate of aspiration pneumonia was 3.13% at 2 to 5 years, increasing to 6.75% at 5 or more years, with hazard ratios of 9.53 (95% confidence interval [CI], 5.08-17.87) and 12.57 (7.17-22.04), respectively. Rate of gastrostomy tube placement increased from 2.82% to 3.32% with hazard ratio remaining elevated from 51.51 (13.45-197.33) to 35.2 (7.81-158.72) over the same time period. The rate of any dysphagia-related diagnosis or procedure increased from 14.9% to 26% with hazard ratio remaining elevated from 3.32 (2.50-4.42) to 2.12 (1.63-2.75). Treatment with radiation therapy and age older than 65 years were associated with increased hazard ratio for dysphagia-related diagnoses.

CONCLUSION

Our data suggest that new dysphagia-related diagnoses continue to occur at clinically meaningful levels in long-term head and neck cancer survivors beyond 5 years after diagnosis.

Revisiting the dose constraints for head and neck OARs in the current era of IMRT

Head and neck cancer poses a particular challenge in radiation therapy, whilst being an effective treatment modality it requires very high doses of radiation to provide effective therapy. This is further complicated by the fact that the head and neck region contains a large number of radiosensitive tissues, often resulting in patients experiencing debilitating normal tissue complications. In the era of intensity-modulated radiation therapy (IMRT) treatments can be delivered using non-uniform dose distributions selectively aimed at reducing the dose to critical organs-at-risk while still adequately covering the tumor target. Dose-volume constraints for the different risk organs play a vital role in one's ability to devise the best IMRT treatment plan for a head and neck cancer patient. To this end, it is pivotal to have access to the latest and most relevant dose constraints available and as such the goal of this review is to provide a summary of suggested dose-volume constraints for head and neck cancer RT that have been published after the QUANTEC reports were made available in early 2010.

Predictors of Patient-Reported Dysphagia Following IMRT Plus Chemotherapy in Oropharyngeal Cancer

The aim of this cross-sectional study is to evaluate the factors associated with patient-reported dysphagia in patients affected by locally advanced oropharyngeal cancer (OPC) treated with definitive intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy (CHT), with or without induction CHT. We evaluated 148 OPC patients treated with IMRT and concurrent CHT, without evidence of disease and who had completed their treatment since at least 6 months. At their planned follow-up visit, patients underwent clinical evaluation and completed the M.D. Anderson dysphagia inventory (MDADI) questionnaire. The association between questionnaire composite score (MDADI-CS) and different patients' and tumor's characteristics and treatments (covariates) was investigated by univariable and multivariable analyses, the latter including only covariates significant at univariable analysis. With a median time from treatment end of 30 months [range 6-74 months, interquartile range (IQR) 16-50 months], the median (IQR) MDADI-CS was 72 (63-84). The majority of patients (82.4%) had a MDADI-CS ≥ 60. At multivariable analysis, female gender, human papilloma virus (HPV)-negative status, and moderate and severe clinician-rated xerostomia were significantly associated with lower MDADI-CS. Patient-perceived dysphagia was satisfactory or acceptable in the majority of patients. HPV status and xerostomia were confirmed as important predictive factors for swallowing dysfunction after radiochemotherapy. Data regarding female gender are new and deserve further investigation.

Clinical factors impacting on late dysphagia following radiotherapy in patients with head and neck cancer

OBJECTIVE

Patient and treatment characteristics of patients with head and neck cancer (HNSCC) were correlated with dysphagia scored on swallowing-videofluoroscopy (VFS) and with patient- and physician-scored dysphagia.

METHODS

63 HNSCC patients treated with radiotherapy (RT) were evaluated at baseline, and 6 and 12 months post-RT. VFS was scored with Penetration Aspiration Scale (PAS) and Swallowing Performance Scale (SPS). Physician- and patient-scored dysphagia were prospectively recorded according to Common Terminology Criteria for Adverse Events scoring system, Radiation Therapy Oncology Group/EORTC scoring system and European Organization for Research and Treatment of Cancer Quality of Life questionnaire (EORTC-QLQ H&N35).

RESULTS

Univariable analysis revealed a significant association between tumour-subsite and higher SPS (p = 0.02) and patient-scored dysphagia (p = 0.02) at baseline. At 12 months, tumour-subsite was significantly associated with higher PAS and SPS. Multivariable analysis and pairwise comparison showed that hypopharyngeal cancer and carcinoma of unknown primary  were associated with higher SPS at baseline and at 12 months, respectively (p = 0.03 and p = 0.01). Upfront neck dissection (UFND) was significantly associated with higher SPS and physician-scored dysphagia in univariable analysis at all timepoints. At 12 months, there was also a significant association with higher PAS (p < 0.01) and patient-scored dysphagia (p < 0.01). After multivariable analysis, the association between UFND and higher PAS (p < 0.01) and SPS (p < 0.01) remained significant at 12 months.

CONCLUSION

Hypopharyngeal tumours and carcinoma of unknown primary were related to more dysphagia at baseline and at 12 months, respectively. Furthermore, UFND was associated with more severe dysphagia scored by physicians and patients and on VFS at 12 months. Advances in knowledge: This is the first paper reporting a significant link between UFND and late dysphagia scored with VFS. We advocate abandoning UFND and preserving neck dissection as a salvage option post-RT.

Tongue-out versus tongue-in position during intensity-modulated radiotherapy for base of tongue cancer: Clinical implications for minimizing post-radiotherapy swallowing dysfunction

BACKGROUND

The purpose of this study was to assess whether different tongue positions change the radiation doses to swallowing organs at risks: the pharyngeal constrictor, oral cavity, and larynx during intensity-modulated radiotherapy (IMRT) for base of tongue (BOT) cancer.

METHODS

IMRT plans with Tongue-out (IMRT-TO) and tongue-in position (IMRT-TI) was compared in 3 cases.

RESULTS

Distance from BOT to pharyngeal constrictor was increased to 1.8 ± 0.8 cm with IMRT-TO from 0.9 ± 0.6 cm with IMRT-TI (P < .01). Compared to IMRT-TI, IMRT-TO significantly decreased the radiation dose to the anterior oral cavity, oral tongue, superior pharyngeal constrictor, middle pharyngeal constrictor, and supraglottic larynx (all P ≤ .04). IMRT-TO also had a smaller volume irradiated than IMRT-TI to the anterior oral cavity and the oral tongue receiving ≥30 Gy (V30) and V35, and superior pharyngeal constrictor and middle pharyngeal constrictor for V55 and V65 (all P ≤ .04).

CONCLUSION

Dosimetric advantage with IMRT-TO over IMRT-TI may potentially reduce post-IMRT swallowing dysfunction in selected patients with BOT cancer.