Beyond mean pharyngeal constrictor dose for beam path toxicity in non-target swallowing muscles: Dose-volume correlates of chronic radiation-associated dysphagia (RAD) after oropharyngeal intensity modulated radiotherapy

A new computed tomography-based approach to quantify swallowing muscle volume by measuring tongue muscle area in a single slice

BACKGROUND

Measuring the swallowing muscle mass with volume measurements is complex and time intensive; therefore, it is not used in clinical practice. However, it can be clinically relevant, for instance, in the case of sarcopenic dysphagia. The aim of the study was to develop a feasible and clinically applicable method to measure swallowing muscle mass.

METHODS

Data from 10 head and neck cancer patients were collected from the Oncological Life Study data-biobank of the University Medical Center Groningen. The pharyngeal constrictor, genioglossus, mylohyoid and geniohyoid complex muscles, as well as the tongue complex muscles, were delineated manually on routinely performed head and neck computed tomography scans. Axial and sagittal planes were used for volume and area measurements, respectively. Muscle density measurements were performed with and without Hounsfield unit thresholding. Correlations were assessed by Pearson correlation coefficients, and interobserver reliability was measured using intra-class correlation coefficients (ICCs).

RESULTS

Significant differences were observed between sagittal area measurements with and without Hounsfield unit thresholds for pharyngeal constrictor, tongue complex and the sum of the swallowing muscles (t > 6; P-value < 0.001). Stronger correlations emerged without Hounsfield unit thresholding. Strong positive and significant correlations were found between the total swallowing muscle mass volume and the sagittal area of the tongue complex muscles (r = 0.87, P-value < 0.05) and the sum of the sagittal areas of the pharyngeal constrictor and tongue complex muscles (r = 0.85, P-value < 0.05). The use of the Hounsfield unit threshold weakened correlations. Interobserver reliability was assessed and found to be fair to good for the pharyngeal constrictor muscle (ICC = 0.68, P-value < 0.05), excellent for the tongue complex muscles (ICC = 0.98, P-value < 0.05) and excellent for the total swallowing muscle area (ICC = 0.96, P-value < 0.05).

CONCLUSIONS

Single-slice delineation of the sagittal area of tongue complex muscle and pharyngeal constrictor muscle is a promising, fast, simple and clinically applicable method for measuring the total volume of the swallowing muscle mass in head and neck cancer patients without Hounsfield unit thresholding. These advancements and findings would help in the early and accurate diagnosis of definitive sarcopenic dysphagia.

Chemoradiation to the submental muscles alters hyoid movement during swallowing in a rat model

Hyolaryngeal dysfunction is a commonly reported swallowing problem after chemoradiation treatment for head and neck cancer. The displacement of the hyolaryngeal complex during swallowing protects the airway and assists in opening the upper esophageal sphincter. Activation of the submental muscles, specifically the mylohyoid and geniohyoid muscles, is thought to facilitate movement of the hyoid. The purpose of this study was to determine if targeted radiation to the submental muscles given concurrently with chemotherapy alters hyolaryngeal displacement 1 mo after treatment. We hypothesized that chemoradiation treatment would result in abnormal patterns of hyoid movement compared with controls. Furthermore, we propose that these changes are associated with alterations in bolus size and discoordination of the jaw during drinking. Eighteen rats underwent either chemoradiation, radiation, or no treatment. Radiation treatment was targeted to submental muscles using a clinical linear accelerator given in 12 fractions of 4 Gy (3 days per week). Cycles of 1 mg/kg of cisplatin were administered concurrently each week of radiation. One month posttreatment, videofluoroscopy swallow studies (VFSS) were performed in self-drinking rats using a fluoroscope customized with a high-speed camera. The hyoid, jaw, and hard palate were tracked during swallowing from VFSS. Hyoid kinematics were analyzed from the start to the end of hyoid movement, and parameters were compared with bolus size and jaw movement. Significant differences in hyoid retraction parameters were found postchemoradiation. Alterations in the trajectory of hyoid motion during swallowing were observed. The findings demonstrate early changes in hyoid motion during swallowing associated with chemoradiation treatment.NEW & NOTEWORTHY Chemoradiation treatment for head and neck cancer can cause functional impairments in swallowing, which can adversely affect quality of life. This study provides new evidence that chemoradiation targeted to the submental muscles provokes early adaptations in hyoid movement during swallowing, which correlate with changes in bolus size. We also demonstrate a method for tracking the hyoid during swallowing in a rat model of chemoradiation injury.

Swallowing-related muscle inflammation and fibrosis induced by a single dose of radiation exposure in mice

BACKGROUND

Although radiotherapy is commonly used to treat head and neck cancer, it may lead to radiation-associated dysphagia (RAD). There are various causes of RAD, however, the mechanism has not yet been fully identified. Currently, the only effective treatment for RAD is rehabilitation. Additionally, there are few available animal models of RAD, necessitating the development of new models to establish and evaluate RAD treatments. We hypothesize that radiation-induced neck muscle fibrosis could be one of the causes of RAD due to impairment of laryngeal elevation. Therefore, in this study, we focused on the changes in inflammation and fibrosis of the strap muscles (Sternohyoid, Sternothyroid, and Thyrohyoid muscles) after a single-dose irradiation. This research aims to provide a reference animal model for future studies on RAD.

RESULTS

Compared to control mice, those treated with 72-Gy, but not 24-Gy, irradiation had significantly increased tumor necrosis factor-α (TNF-α) (p < 0.01) and α-smooth muscle actin (αSMA) (p < 0.05) expression at 10 days and significantly increased expression levels of motif chemokine ligand-2 (CCL2), α-SMA, tumor growth factor-β1 (TGF-β1), type1 collagen, and interleukin-1β (IL-1β) (p < 0.05) in the muscles at 1 month by real-time PCR analysis. The results of immunohistochemistry showed that the deposition of type 1 collagen gradually increased in extracellular space after radiation exposure, and the positive area was significantly increased at 3 months compared to non-irradiated control.

CONCLUSIONS

A single dose of 72-Gy irradiation induced significant inflammation and fibrosis in the strap muscles of mice at 1 month, with immunohistochemical changes becoming evident at 3 months. This cervical irradiation-induced fibrosis model holds potential for establishing an animal model for RAD in future studies.

LEVEL OF EVIDENCE

N/A.

The role of surgery and deescalation for HPV-related oropharyngeal cancer

Recently published and ongoing trials are helping to define the role of transoral robotic surgery for oropharyngeal cancer. Evidence to date supports the use of surgery as a valuable tool in the multidisciplinary deescalation of low-risk human papillomavirus-related oropharyngeal squamous cell carcinoma.

Pharyngeal Constrictor Dose-Volume Histogram Metrics and Patient-Reported Dysphagia in Head and Neck Radiotherapy

AIMS

Head and neck radiotherapy long-term survival continues to improve and the management of long-term side-effects is moving to the forefront of patient care. Dysphagia is associated with dose to the pharyngeal constrictors and can be measured using patient-reported outcomes to evaluate its effect on quality of life. The aim of the present study was to relate pharyngeal constrictor dose-volume parameters with patient-reported outcomes to identify prognostic dose constraints.

MATERIALS AND METHODS

A 64-patient training cohort and a 24-patient testing cohort of oropharynx and nasopharynx cancer patients treated with curative-intent chemoradiotherapy were retrospectively examined. These patients completed the MD Anderson Dysphagia Inventory outcome survey at 12 months post-radiotherapy to evaluate late dysphagia: a composite score lower than 60 indicated dysphagia. The pharyngeal constrictor muscles were subdivided into four substructures: superior, middle, inferior and cricopharyngeal. Dose-volume histogram (DVH) metrics for each of the structure combinations were extracted. A decision tree classifier was run for each DVH metric to identify dose constraints optimising the accuracy and sensitivity of the cohort. A 60% accuracy threshold and feature selection method were used to ensure statistically significant DVH metrics were identified. These dose constraints were then validated on the 24-patient testing cohort.

RESULTS

Existing literature dose constraints only had two dose constraints performing above 60% accuracy and sensitivity when evaluated on our training cohort. We identified two well-performing dose constraints: the pharyngeal constrictor muscle D63% < 55 Gy and the superior-middle pharyngeal constrictor combination structure V31Gy < 100%. Both dose constraints resulted in ≥73% mean accuracy and ≥80% mean sensitivity on the training and testing patient cohorts. In addition, a pharyngeal constrictor muscle mean dose <57 Gy resulted in a mean accuracy ≥74% and mean sensitivity ≥60%.

CONCLUSION

Mid-dose pharyngeal constrictor muscle and substructure combination dose constraints should be used in the treatment planning process to reduce late patient-reported dysphagia.

Iterative Patient Testing of a Stimuli-Responsive Swallowing Activity Sensor to Promote Extended User Engagement During the First Year After Radiation: Multiphase Remote and In-Person Observational Cohort Study

BACKGROUND

Frequent sensor-assisted monitoring of changes in swallowing function may help improve detection of radiation-associated dysphagia before it becomes permanent. While our group has prototyped an epidermal strain/surface electromyography sensor that can detect minute changes in swallowing muscle movement, it is unknown whether patients with head and neck cancer would be willing to wear such a device at home after radiation for several months.

OBJECTIVE

We iteratively assessed patients' design preferences and perceived barriers to long-term use of the prototype sensor.

METHODS

In study 1 (questionnaire only), survivors of pharyngeal cancer who were 3-5 years post treatment and part of a larger prospective study were asked their design preferences for a hypothetical throat sensor and rated their willingness to use the sensor at home during the first year after radiation. In studies 2 and 3 (iterative user testing), patients with and survivors of head and neck cancer attending visits at MD Anderson's Head and Neck Cancer Center were recruited for two rounds of on-throat testing with prototype sensors while completing a series of swallowing tasks. Afterward, participants were asked about their willingness to use the sensor during the first year post radiation. In study 2, patients also rated the sensor's ease of use and comfort, whereas in study 3, preferences were elicited regarding haptic feedback.

RESULTS

The majority of respondents in study 1 (116/138, 84%) were willing to wear the sensor 9 months after radiation, and participant willingness rates were similar in studies 2 (10/14, 71.4%) and 3 (12/14, 85.7%). The most prevalent reasons for participants' unwillingness to wear the sensor were 9 months being excessive, unwanted increase in responsibility, and feeling self-conscious. Across all three studies, the sensor's ability to detect developing dysphagia increased willingness the most compared to its appearance and ability to increase adherence to preventive speech pathology exercises. Direct haptic signaling was also rated highly, especially to indicate correct sensor placement and swallowing exercise performance.

CONCLUSIONS

Patients and survivors were receptive to the idea of wearing a personalized risk sensor for an extended period during the first year after radiation, although this may have been limited to well-educated non-Hispanic participants. A significant minority of patients expressed concern with various aspects of the sensor's burden and its appearance.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03010150; https://clinicaltrials.gov/study/NCT03010150.

An Overview of Head and Neck Tumor Reirradiation: What Has Been Achieved So Far?

The recurrence rate of head and neck cancers (HNCs) after initial treatment may reach 70%, and poor prognosis is reported in most cases. Curative options for recurrent HNCs mainly depend on the treatment history and the recurrent tumor localization. Reirradiation for HNCs is effective and has been included in most guidelines. However, the option remains clinically challenging due to high incidence of severe toxicity, especially in cases of quick infield recurrence. Recent technical advances in radiation therapy (RT) provide the means for upgrade in reirradiation protocols. While the majority of hospitals stay focused on conventional and widely accessible modulated RTs, the particle therapy options emerge as tolerable and providing further treatment opportunities for recurrent HNCs. Still, the progress is impeded by high heterogeneity of the data and the lack of large-scale prospective studies. This review aimed to summarize the outcomes of reirradiation for HNCs in the clinical perspective.

Multi-organ spatial stratification of 3-D dose distributions improves risk prediction of long-term self-reported severe symptoms in oropharyngeal cancer patients receiving radiotherapy: development of a pre-treatment decision support tool

Purpose

Identify Oropharyngeal cancer (OPC) patients at high-risk of developing long-term severe radiation-associated symptoms using dose volume histograms for organs-at-risk, via unsupervised clustering.

Material and methods

All patients were treated using radiation therapy for OPC. Dose-volume histograms of organs-at-risk were extracted from patients' treatment plans. Symptom ratings were collected via the MD Anderson Symptom Inventory (MDASI) given weekly during, and 6 months post-treatment. Drymouth, trouble swallowing, mucus, and vocal dysfunction were selected for analysis in this study. Patient stratifications were obtained by applying Bayesian Mixture Models with three components to patient's dose histograms for relevant organs. The clusters with the highest total mean doses were translated into dose thresholds using rule mining. Patient stratifications were compared against Tumor staging information using multivariate likelihood ratio tests. Model performance for prediction of moderate/severe symptoms at 6 months was compared against normal tissue complication probability (NTCP) models using cross-validation.

Results

A total of 349 patients were included for long-term symptom prediction. High-risk clusters were significantly correlated with outcomes for severe late drymouth (p <.0001, OR = 2.94), swallow (p = .002, OR = 5.13), mucus (p = .001, OR = 3.18), and voice (p = .009, OR = 8.99). Simplified clusters were also correlated with late severe symptoms for drymouth (p <.001, OR = 2.77), swallow (p = .01, OR = 3.63), mucus (p = .01, OR = 2.37), and voice (p <.001, OR = 19.75). Proposed cluster stratifications show better performance than NTCP models for severe drymouth (AUC.598 vs.559, MCC.143 vs.062), swallow (AUC.631 vs.561, MCC.20 vs -.030), mucus (AUC.596 vs.492, MCC.164 vs -.041), and voice (AUC.681 vs.555, MCC.181 vs -.019). Simplified dose thresholds also show better performance than baseline models for predicting late severe ratings for all symptoms.

Conclusion

Our results show that leveraging the 3-D dose histograms from radiation therapy plan improves stratification of patients according to their risk of experiencing long-term severe radiation associated symptoms, beyond existing NTPC models. Our rule-based method can approximate our stratifications with minimal loss of accuracy and can proactively identify risk factors for radiation-associated toxicity.

Radiation induced changes in profibrotic markers in the submental muscles and their correlation with tongue movement

Swallowing impairment is a major complication of radiation treatment for oropharyngeal cancers. Developing targeted therapies that improve swallowing outcomes relies on an understanding of the mechanisms that influence motor function after radiation treatment. The purpose of this study was to determine whether there is a correlation between radiation induced changes in tongue movement and structural changes in irradiated submental muscles, as well as assess other possible causes for dysfunction. We hypothesized that a clinically relevant total radiation dose to the submental muscles would result in: a) quantifiable changes in tongue strength and displacement during drinking two months post treatment; and b) a profibrotic response and/or fiber type transition in the irradiated tissue. Sprague-Dawley adult male rats received radiation to the submental muscles at total dose-volumes known to provoke dysphagia in humans. A clinical linear accelerator administered 8 fractions of 8Gy for a total of 64Gy. Comparisons were made to sham-treated rats that received anesthesia only. Swallowing function was assessed using videofluoroscopy and tongue strength was analyzed via force lickometer. TGFβ1 expression was analyzed via ELISA. The amount of total collagen was analyzed by picrosirius red staining. Immunofluorescence was used to assess fiber type composition and size. Significant changes in licking function during drinking were observed at two months post treatment, including a slower lick rate and reduced tongue protrusion during licking. In the mylohyoid muscle, significant increases in TGFβ1 protein expression were found post radiation. Significant increases in the percentage of collagen content were observed in the irradiated geniohyoid muscle. No changes in fiber type expression were observed. Results indicate a profibrotic transition within the irradiated swallowing muscles that contributes to tongue dysfunction post-radiation treatment.

Deep Learning-Based Dose Prediction for Automated, Individualized Quality Assurance of Head and Neck Radiation Therapy Plans

PURPOSE

This study aimed to use deep learning-based dose prediction to assess head and neck (HN) plan quality and identify suboptimal plans.

METHODS AND MATERIALS

A total of 245 volumetric modulated arc therapy HN plans were created using RapidPlan knowledge-based planning (KBP). A subset of 112 high-quality plans was selected under the supervision of an HN radiation oncologist. We trained a 3D Dense Dilated U-Net architecture to predict 3-dimensional dose distributions using 3-fold cross-validation on 90 plans. Model inputs included computed tomography images, target prescriptions, and contours for targets and organs at risk (OARs). The model's performance was assessed on the remaining 22 test plans. We then tested the application of the dose prediction model for automated review of plan quality. Dose distributions were predicted on 14 clinical plans. The predicted versus clinical OAR dose metrics were compared to flag OARs with suboptimal normal tissue sparing using a 2 Gy dose difference or 3% dose-volume threshold. OAR flags were compared with manual flags by 3 HN radiation oncologists.

RESULTS

The predicted dose distributions were of comparable quality to the KBP plans. The differences between the predicted and KBP-planned D1%,D95%, and D99% across the targets were within -2.53% ± 1.34%, -0.42% ± 1.27%, and -0.12% ± 1.97%, respectively, and the OAR mean and maximum doses were within -0.33 ± 1.40 Gy and -0.96 ± 2.08 Gy, respectively. For the plan quality assessment study, radiation oncologists flagged 47 OARs for possible plan improvement. There was high interphysician variability; 83% of physician-flagged OARs were flagged by only one of 3 physicians. The comparative dose prediction model flagged 63 OARs, including 30 of 47 physician-flagged OARs.

CONCLUSIONS

Deep learning can predict high-quality dose distributions, which can be used as comparative dose distributions for automated, individualized assessment of HN plan quality.

Expert Consensus Statement: Management of Dysphagia in Head and Neck Cancer Patients

OBJECTIVE

To develop an expert consensus statement (ECS) on the management of dysphagia in head and neck cancer (HNC) patients to address controversies and offer opportunities for quality improvement. Dysphagia in HNC was defined as swallowing impairment in patients with cancers of the nasal cavity, paranasal sinuses, nasopharynx, oral cavity, oropharynx, larynx, or hypopharynx.

METHODS

Development group members with expertise in dysphagia followed established guidelines for developing ECS. A professional search strategist systematically reviewed the literature, and the best available evidence was used to compose consensus statements targeted at providers managing dysphagia in adult HNC populations. The development group prioritized topics where there was significant practice variation and topics that would improve the quality of HNC patient care if consensus were possible.

RESULTS

The development group identified 60 candidate consensus statements, based on 75 initial proposed topics and questions, that focused on addressing the following high yield topics: (1) risk factors, (2) screening, (3) evaluation, (4) prevention, (5) interventions, and (6) surveillance. After 2 iterations of the Delphi survey and the removal of duplicative statements, 48 statements met the standardized definition for consensus; 12 statements were designated as no consensus.

CONCLUSION

Expert consensus was achieved for 48 statements pertaining to risk factors, screening, evaluation, prevention, intervention, and surveillance for dysphagia in HNC patients. Clinicians can use these statements to improve quality of care, inform policy and protocols, and appreciate areas where there is no consensus. Future research, ideally randomized controlled trials, is warranted to address additional controversies related to dysphagia in HNC patients.

Current Evidence of a Deintensification Strategy for Patients with HPV-Related Oropharyngeal Cancer

Simple Summary

Human papillomavirus (HPV)-related oropharyngeal cancer represents a distinct disease entity, showing favorable treatment responses and survival outcomes. While the deintensification of treatment for HPV-related oropharyngeal cancer is widely considered necessary, details concerning patient selection and optimal strategies are undetermined. The heterogeneity of study populations and interventions in trials complicate the ability of physicians to apply the results in daily practice. The evolving landscape also requires physicians to consistently update the results of these trials. This article reviews the most recent evidence on the deintensification of HPV-related oropharyngeal cancer. We aim to provide physicians with some guidance regarding management options and assist researchers in appropriately designing trials in the future.

Abstract

Human papillomavirus (HPV)-related oropharyngeal cancer differs from HPV-negative oropharyngeal cancer in terms of etiology, epidemiology, and prognosis. Younger and lower comorbidity patient demographics and favorable prognosis allow HPV-related oropharyngeal cancer patients to anticipate longer life expectancy. Reducing long-term toxicities has become an increasingly important issue. Treatment deintensification to reduce toxicities has been investigated in terms of many aspects, and the reduction of radiotherapy (RT) dose in definitive treatment, replacement of platinum-based chemotherapy with cetuximab, response-tailored dose prescription after induction chemotherapy, and reduction of adjuvant RT dose after transoral surgery have been evaluated. We performed a literature review of prospective trials of deintensification for HPV-related oropharyngeal cancer. In phase II trials, reduction of RT dose in definitive treatment showed comparable survival outcomes to historical results. Two phase III randomized trials reported inferior survival outcomes for cetuximab-based chemoradiation compared with cisplatin-based chemoradiation. In a randomized phase III trial investigating adjuvant RT, deintensified RT showed noninferior survival outcomes in patients without extranodal extension but worse survival in patients with extranodal extension. Optimal RT dosage and patient selection require confirmation in future studies. Although many phase II trials have reported promising outcomes, the results of phase III trials are needed to change the standard treatment. Since high-level evidence has not been established, current deintensification should only be performed as part of a clinical study with caution. Implementation in clinical practice should not be undertaken until evidence from phase III randomized trials is available.

Magnetic Resonance Imaging-Based Delineation of Organs at Risk in the Head and Neck Region

Purpose

The aim of this article is to establish a comprehensive contouring guideline for treatment planning using only magnetic resonance images through an up-to-date set of organs at risk (OARs), recommended organ boundaries, and relevant suggestions for the magnetic resonance imaging (MRI)-based delineation of OARs in the head and neck (H&N) region.

Methods and Materials

After a detailed review of the literature, MRI data were collected from the H&N region of healthy volunteers. OARs were delineated in the axial, coronal, and sagittal planes on T2-weighted sequences. Every contour defined was revised by 4 radiation oncologists and subsequently by 2 independent senior experts (H&N radiation oncologist and radiologist). After revision, the final structures were presented to the consortium partners.

Results

A definitive consensus was reached after multi-institutional review. On that basis, we provided a detailed anatomic and functional description and specific MRI characteristics of the OARs.

Conclusions

In the era of precision radiation therapy, the need for well-built, straightforward contouring guidelines is on the rise. Precise, uniform, delineation-based, automated OAR segmentation on MRI may lead to increased accuracy in terms of organ boundaries and analysis of dose-dependent sequelae for an adequate definition of normal tissue complication probability.

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.

High Superior-Middle Pharyngeal Constrictor Muscle Mean Dose Correlates with Severe Late Lung Infection and Survival in Nasopharyngeal Cancer Patients

Purpose

The study aimed to evaluate 1) the correlation of doses of swallowing-related organs at risk (OAR) with severe swallowing-related late adverse effects (AE) in nasopharyngeal carcinoma (NPC) patients and 2) the effect of high mean doses of OARs on overall survival (OS).

Patients and Methods

This retrospective cohort study enrolled non-metastatic Stage I–IV NPC patients from January 2012 to June 2017. OAR mean doses and severe (≥G3) swallowing-related late AE (xerostomia, dysphagia, and lung infection) were evaluated by t-test and validated using receiver operating characteristic curves. The risk factors of OS were calculated by Cox regression methods.

Results

This study enrolled 185 (43 female, 142 male) NPC patients, mean age 52.4 years, primarily with Stage III (93, 50.3%) or Stage IV (67, 36.2%) disease. The mean doses of pharyngeal constrictor muscle (PCM), superior-middle PCM (SMPCM), and superior PCM (SPCM) were significantly higher in those with severe (≥G3) lung infection than in those without (65.7 vs 62.2 Gy, p = 0.036; 68.1 vs 64.2 Gy, p = 0.015; and 70.0 vs 65.9 Gy, p = 0.012, respectively). Patients with severe (≥G3) dysphagia had significant higher mean doses of base of tongue (56.2 vs 50.2 Gy, p = 0.008), laryngeal box (50.6 vs 46.4 Gy, p = 0.036), PCM (65.4 vs 62.1 Gy, p = 0.008), SMPCM (67.1 vs 64.2 Gy, p = 0.014), and SPCM (69.3 vs 65.8 Gy, p = 0.004). Mean SMPCM dose >64.9 Gy (adjusted hazard ratio [aHR] = 3.2, 95% confidence interval [CI] 1.2–8.8, p = 0.021), age >62 years (aHR = 2.7, 95% CI 1.1–6.9, p = 0.032), N3 status (aHR = 4.0, 95% CI 1.8–9.0, p = 001), and severe late AE of lung infection (aHR = 4.6, 95% CI 1.5–14.0, p = 0.007) significantly affected OS.

Conclusion

Severe lung infection and dysphagia were associated with significantly higher mean doses of PCM, SMPCM, and SPCM. Among these OARs, only a high SMPCM mean dose was a risk factor for OS in NPC patients.

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.

Improvement in Dysphagia Outcomes Following Clinical Target Volume Reduction in the De-ESCALaTE Study

AIMS

The De-ESCALaTE study showed an overall survival advantage for the administration of synchronous cisplatin chemotherapy with radiotherapy in low-risk oropharyngeal cancer when compared with synchronous cetuximab. During the trial, a radiotherapy quality assurance protocol amendment permitted centres to swap from the original radiotherapy contouring protocol (incorporating the whole oropharynx into the high-dose clinical target volume (CTV); anatomical protocol) to a protocol that incorporated the gross tumour volume with a 10 mm margin into the CTV (volumetric protocol). The purpose of this study was to examine both toxicity and tumour control related to this protocol amendment.

MATERIALS AND METHODS

Overall survival and recurrence at 2 years were used to compare tumour control in the two contouring cohorts. For toxicity, the cohorts were compared by both the number of severe (grades 3-5) and all grades acute and late toxicities. In addition, quality of life and swallowing were compared using EORTC-C30 and MD Anderson Dysphagia Inventory, respectively.

RESULTS

Of 327 patients included in this study, 185 were contoured according to the anatomical protocol and 142 by the volumetric protocol. The two cohorts were well balanced, with the exception of significantly more patients in the anatomical cohort undergoing prophylactic feeding tube insertion (P < 0.001). With a minimum of 2 years of follow-up there was no significant difference in overall survival or recurrence between the two contouring protocols. Similarly, there was no significant difference in the rate of reported severe or all grades acute or late toxicity and no sustained significant difference in quality of life. However, there was a significant difference in favour of volumetric contouring in several domains of the MD Anderson Dysphagia Inventory questionnaire at 1 year, which persisted to 2 years in the dysphagia functional (P = 0.002), dysphagia physical (P = 0.009) and dysphagia overall function (P = 0.008) domains.

CONCLUSION

In the context of the unplanned post-hoc analysis of a randomised trial, measurable improvement in long-term dysphagia has been shown following a reduction in the CTV. Further reductions in the CTV should be subject to similar scrutiny within the confines of a prospective study.

Development and external validation of a prediction model for tube feeding dependency for at least four weeks during chemoradiotherapy for head and neck cancer

BACKGROUND & AIMS

Patients who receive chemoradiotherapy or bioradiotherapy (CRT/BRT) for locally advanced head and neck squamous cell carcinoma (LAHNSCC) often experience high toxicity rates interfering with oral intake, causing tube feeding (TF) dependency. International guidelines recommend gastrostomy insertion when the expected use of TF exceeds 4 weeks. We aimed to develop and externally validate a prediction model to identify patients who need TF ≥ 4 weeks and would benefit from prophylactic gastrostomy insertion.

METHODS

A retrospective multicenter cohort study was performed in four tertiary head and neck cancer centers in the Netherlands. The prediction model was developed using data from University Medical Center Utrecht and the Netherlands Cancer Institute and externally validated using data from Maastricht University Medical Center and Radboud University Medical Center. The primary endpoint was TF dependency ≥4 weeks initiated during CRT/BRT or within 30 days after CRT/BRT completion. Potential predictors were extracted from electronic health records and radiotherapy dose-volume parameters were calculated.

RESULTS

The developmental and validation cohort included 409 and 334 patients respectively. Multivariable analysis showed predictive value for pretreatment weight change, texture modified diet at baseline, ECOG performance status, tumor site, N classification, mean radiation dose to the contralateral parotid gland and oral cavity. The area under the receiver operating characteristics curve for this model was 0.73 and after external validation 0.62. Positive and negative predictive value for a risk of 90% or higher for TF dependency ≥4 weeks were 81.8% and 42.3% respectively.

CONCLUSIONS

We developed and externally validated a prediction model to estimate TF-dependency ≥4 weeks in LAHNSCC patients treated with CRT/BRT. This model can be used to guide personalized decision-making on prophylactic gastrostomy insertion in clinical practice.

The PRO-ACTIVE trial protocol: a randomized study comparing the effectiveness of PROphylACTic swallow InterVEntion for patients receiving radiotherapy for head and neck cancer

BACKGROUND

Swallowing therapy is commonly provided as a treatment to lessen the risk or severity of dysphagia secondary to radiotherapy (RT) for head and neck cancer (HNC); however, best practice is not yet established. This trial will compare the effectiveness of prophylactic (high and low intensity) versus reactive interventions for swallowing in patients with HNC undergoing RT.

METHODS

This multi-site, international randomized clinical trial (RCT) will include 952 adult patients receiving radiotherapy for HNC and who are at high risk for post-RT dysphagia. Participants will be randomized to receive one of three interventions for swallowing during RT: RE-ACTIVE, started promptly if/when dysphagia is identified; PRO-ACTIVE EAT, low intensity prophylactic intervention started before RT commences; or, PRO-ACTIVE EAT+EXERCISE, high intensity prophylactic intervention also started before RT commences. We hypothesize that the PRO-ACTIVE therapies are more effective than late RE-ACTIVE therapy; and, that the more intensive PRO-ACTIVE (EAT + EXERCISE) is superior to the low intensive PRO-ACTIVE (EAT). The primary endpoint of effectiveness is duration of feeding tube dependency one year post radiation therapy, selected as a pragmatic outcome valued equally by diverse stakeholders (e.g., patients, caregivers and clinicians). Secondary outcomes will include objective measures of swallow physiology and function, pneumonia and weight loss, along with various patient-reported swallowing-related outcomes, such as quality of life, symptom burden, and self-efficacy.

DISCUSSION

Dysphagia is a common and potentially life-threatening chronic toxicity of radiotherapy, and a priority issue for HNC survivors. Yet, the optimal timing and intensity of swallowing therapy provided by a speech-language pathologist is not known. With no clearly preferred strategy, current practice is fraught with substantial variation. The pragmatic PRO-ACTIVE trial aims to specifically address the decisional dilemma of when swallowing therapy should begin (i.e., before or after a swallowing problem develops). The critical impact of this dilemma is heightened by the growing number of young HNC patients in healthcare systems that need to allocate resources most effectively. The results of the PRO-ACTIVE trial will address the global uncertainty regarding best practice for dysphagia management in HNC patients receiving radiotherapy.

TRIAL REGISTRATION

The protocol is registered with the US Patient Centered Outcomes Research Institute, and the PRO-ACTIVE trial was prospectively registered at ClinicalTrials.gov , under the identifier NCT03455608 ; First posted: Mar 6, 2018; Last verified: Jun 17, 2021. Protocol Version: 1.3 (January 27, 2020).

Proton Therapy in Head and Neck Cancer Treatment: State of the Problem and Development Prospects (Review)

Proton therapy (PT) due to dosimetric characteristics (Bragg peak formation, sharp dose slowdown) is currently one of the most high-tech techniques of radiation therapy exceeding the standards of photon methods.

In recent decades, PT has traditionally been used, primarily, for head and neck cancers (HNC) including skull base tumors. Regardless of the fact that recently PT application area has significantly expanded, HNC still remain a leading indication for proton radiation since PT’s physic-dosimetric and radiobiological advantages enable to achieve the best treatment results in these tumors.

The present review is devoted to PT usage in HNC treatment in the world and Russian medicine, the prospects for further technique development, the assessment of PT’s radiobiological features, a physical and dosimetric comparison of protons photons distribution. The paper shows PT’s capabilities in the treatment of skull base tumors, HNC (nasal cavity, paranasal sinuses, nasopharynx, oropharynx, and laryngopharynx, etc.), eye tumors, sialomas. The authors analyze the studies on repeated radiation and provide recent experimental data on favorable profile of proton radiation compared to the conventional radiation therapy.

The review enables to conclude that currently PT is a dynamic radiation technique opening up new opportunities for improving therapy of oncology patients, especially those with HNC.

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.

Manual Therapy for Fibrosis-Related Late Effect Dysphagia in head and neck cancer survivors: the pilot MANTLE trial

INTRODUCTION

Late dysphagia that develops or persists years after head and neck cancer (HNC) is a disabling survivorship issue. Fibrosis is thought to stiffen connective tissues and compress peripheral nerve tracts, thereby contributing to diminished strength, flexibility, and in some cases denervation of swallowing muscles. Manual therapy (MT) is used in cancer survivors for pain and other indications, but it is unknown if increasing blood flow, flexibility and cervical range of motion (CROM) in the head and neck may improve late dysphagia.

METHODS AND ANALYSIS

Manual Therapy for Fibrosis-Related Late Effect Dysphagia (MANTLE) is a National Cancer Institute-funded prospective single-arm pilot trial evaluating the feasibility, safety and therapeutic potential of MT in patients with late dysphagia after radiotherapy (RT) for HNC. Disease-free survivors ≥2 years after curative-intent RT for HNC with at least moderate dysphagia and grade ≥2 Common Terminology Criteria for Adverse Events version 4.0 fibrosis are eligible. The target sample size is 24 participants who begin the MANTLE programme. MANTLE is delivered in 10 MT sessions over 6 weeks with an accompanying home exercise programme (HEP). Patients then transition to a 6-week post-washout period during which they complete the HEP and then return for a final post-washout evaluation. Feasibility (primary endpoint) and safety will be examined. Serial assessments include CROM, modified barium swallow studies, quantitative MRI, electromyography (optional) and patient-reported outcomes as secondary, tertiary and exploratory endpoints.

ETHICS AND DISSEMINATION

The research protocol and informed consent document was approved by the Institutional Review Board at the University of Texas MD Anderson Cancer Center. Findings will be disseminated through peer-reviewed publication that will be made publicly available on PubMed Central on acceptance for publication, in compliance with NIH public access policy.

TRIAL REGISTRATION NUMBER

NCT03612531.

Radiation-induced swallowing dysfunction in patients with head and neck cancer: A literature review

Swallowing dysfunction is a prevailing state following radiotherapy in patients with head and neck cancer. Following the advancement of cancer treatment in recent years, the survival rate of head and neck cancer has gradually increased. Simultaneously, patients with head and neck cancer suffer due to the long-duration and more prominent swallowing dysfunction states. Based on an extensive literature review, we aimed to explore the mechanisms, risk factors, and clinical evaluations of swallowing dysfunction and their related symptoms following radiotherapy. These include functional changes of the muscles, trismus, xerostomia, neuropathy, and lymphedema. When swallowing dysfunction occurs, patients usually seek medical help and are referred for rehabilitation therapy, such as muscle strengthening and tongue resistance exercise. Furthermore, clinicians should discuss with patients how and when to place the feeding tube. Only through detailed evaluation and management can swallowing dysfunction resolve and improve the quality of life of patients with head and neck cancer following radiotherapy.

Late radiation effects in survivors of head and neck cancer: State of the science

Head and neck squamous cell carcinoma is one of the most common neoplasms. Radiotherapy (RT) plays an essential role in the management of such cases. Despite advances in the technique, hyposalivation, xerostomia, dysphagia, trismus, radiation caries, and osteoradionecrosis remain significant late complications of RT. The aim of this narrative review was to summarize and update the main findings related to late side effects of radiotherapy in survivors of head and neck cancer (HNC). Such effects limit the ability to speak, ingest food and medications, and breathe and also exert a negative impact on social well-being and quality of life. This review highlights research in the field for both researchers and clinicians, assisting in the prevention and management of these adverse conditions. The findings can contribute to improving preventive management and multidisciplinary interventions for HNC patients.

Swallowing dysfunction following radiation to the rat mylohyoid muscle is associated with sensory neuron injury

Radiation-based treatments for oropharyngeal and hypopharyngeal cancers result in impairments in swallowing mobility, but the mechanisms behind the dysfunction are not clear. The purpose of this study was to determine if we could establish an animal model of radiation-induced dysphagia in which mechanisms could be examined. We hypothesized that 1) radiation focused at the depth of the mylohyoid muscle would alter normal bolus transport and bolus size and 2) radiation to the mylohyoid muscle will induce an injury/stress-like response in trigeminal sensory neurons whose input might modulate swallow. Rats were exposed to 48 or 64 Gy of radiation to the mylohyoid given 8 Gy in 6 or 8 fractions. Swallowing function was evaluated by videofluoroscopy 2 and 4 wk following treatment. Neuronal injury/stress was analyzed in trigeminal ganglion by assessing activating transcription factor (ATF)3 and GAP-43 mRNAs at 2, 4, and 8 wk post treatment. Irradiated rats exhibited decreases in bolus movement through the pharynx and alterations in bolus clearance. In addition, ATF3 and GAP-43 mRNAs were upregulated in trigeminal ganglion in irradiated rats, suggesting that radiation to mylohyoid muscle induced an injury/stress response in neurons with cell bodies that are remote from the irradiated tissue. These results suggest that radiation-induced dysphagia can be assessed in the rat and radiation induces injury/stress-like responses in sensory neurons.NEW & NOTEWORTHY Radiation-based treatments for head and neck cancer can cause significant impairments in swallowing mobility. This study provides new evidence supporting the possibility of a neural contribution to the mechanisms of swallowing dysfunction in postradiation dysphagia. Our data demonstrated that radiation to the mylohyoid muscle, which induces functional deficits in swallowing, also provokes an injury/stress-like response in the ganglion, innervating the irradiated muscle.

Risk and Rate of Occult Contralateral Nodal Disease in Surgically Treated Patients With Human Papillomavirus-Related Squamous Cell Carcinoma of the Base of the Tongue

Importance

The optimal treatment strategy for patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) of the base of the tongue (BOT) has not been sufficiently studied.

Objective

To investigate the rate of and risk factors for occult contralateral nodal disease in patients with HPV-related BOT OPSCC undergoing transoral surgery and bilateral neck dissections.

Design, Setting, and Participants

This retrospective case series reviewed the medical records of patients with HPV-related BOT OPSCC who underwent transoral surgery and bilateral neck dissections from January 1, 2002, through December 31, 2018, at the tertiary care center of Washington University School of Medicine in St Louis. Patients had a median follow-up of 30.0 months (interquartile range, 11.0-60.4 months). Patients with recurrent disease or multiple synchronous OPSCC primary tumors were excluded for a total of 89 patients. Data were analyzed from January 1 through June 1, 2019.

Main Outcomes and Measures

The primary outcome was the rate of contralateral occult nodal disease. Secondary outcomes were potential risk factors for contralateral occult nodal disease and regional recurrence rates.

Results

Eighty-nine patients were included in the series, of whom 81 (91.0%) were men. The mean (SD) age was 60 (9) years. Overall, 34 patients (38.2%) had pathologic contralateral nodal metastases. Seventy patients had no clinical evidence of contralateral nodal disease. Of these 70, occult nodes were identified in 15 (21.4%). Risk of contralateral disease was higher when the primary tumor crossed midline (odds ratio, 6.23; 95% CI, 1.71-22.77). Of the 55 patients with no occult disease identified, only 2 (3.6%) received radiotherapy to the contralateral neck, and no regional recurrence of disease was noted.

Conclusions and Relevance

Given the rate of occult contralateral nodal disease of 21.4%, it appears that contralateral elective neck dissection or radiotherapy should be recommended in patients with HPV-related BOT OPSCC. Patients with a pathologically negative result of contralateral neck dissection may not benefit from radiotherapy to that nodal basin. Future prospective investigations should evaluate functional and oncologic outcomes of contralateral elective neck dissection compared with elective radiotherapy in the contralateral neck for HPV-related BOT OPSCC.

Healthcare resource utilization following unilateral versus bilateral radiation therapy for oropharyngeal carcinoma

PURPOSE

To describe differences in healthcare resource utilization between patients treated with bilateral vs. unilateral neck radiation therapy (RT) for lateralized oropharyngeal cancer.

METHODS

A propensity score matching strategy was used to identify two otherwise clinically similar cohorts of tonsillar cancer patients treated with either bilateral or unilateral neck RT. Cohorts were matched based on similar propensity scores for age, sex, ECOG performance status, pack-year smoking history, cT-category, cN-category, HPV-status, and use of concurrent chemotherapy. Short term (from start of RT to 3 months following end of RT) resource utilization included: 1) outpatient supportive care visits, 2) hospital admission, and 3) interventions (feeding tube insertion and outpatient intravenous hydration). Long-term resource utilization included feeding tube dependency at 1-year.

RESULTS

Among 559 patients with tonsillar cancer treated between 2004-2017, propensity score matching identified a unilateral neck RT cohort (n = 81) and bilateral neck RT cohort (n = 81) with similar clinical and treatment characteristics. Bilateral neck RT was associated with a higher likelihood of hospitalization (33% vs 12%, p < 0.01), outpatient IV hydration (33% vs 17%, p = 0.03), and feeding tube insertion (33% vs 10%, p < 0.001); a greater number of total days of hospitalization (110 vs 47 days, p < 0.01) and outpatient IV hydration (135 vs 72 days, p = 0.02); and higher total number of supportive clinic visits (1226 vs 1053 days, p = 0.04). In the long-term, bilateral RT was associated with higher rate of feeding tube dependency at 1-year (7% vs 0%, p < 0.001).

CONCLUSION

Bilateral RT for tonsillar cancer resulted in significant increase in health resource utilization.

The effect of designing a rotational planning target volume on sparing pharyngeal constrictor muscles in patients with oropharyngeal cancer

BACKGROUND

Planning target volume (PTV) has been used to account for variations in tissue, patient and beam position. In oropharyngeal cancers, an isotropic expanded PTV has been used.

AIM

The aim of this study was to design a new margin formula that would cover the space occupied by an oropharyngeal clinical target volume (CTV) with ±5-degree rotation around the spine in order to reduce the pharyngeal constrictors overlap with PTV compared to an isotropic expanded PTV.

METHODS

We retrospectively evaluated 20 volumetric-modulated arc therapy (VMAT) plans. In order to perform an off-axis rotation, a hypothetical point was placed through the center of the cervical spinal canal and the image was then rotated around the longitudinal axis ±5 degrees. This created a new set of CTVs that were combined to form the new rotational PTV. The overlap between the pharyngeal constrictor muscles (PCMs) and both PTVs was then evaluated.

RESULTS

The new rotational PTV causes reduction in the superior PCM overlap in the base of tongue (BOT) lesions compared to tonsillar lesion, 57.8% vs 25.8%, P = 0.01, as well as middle PCM overlap, 73% vs 49%, P = 0.04. Average percent change for PTV volume and overlap with the superior, middle, and inferior PCMs are as followed: -19%, -37%, -59.4%, and -45.2. The smallest isotropic expansion that covers the new rotational PTV was between 3 and 5mm with the average tumor center shift of 0.49 cm.

CONCLUSION

This new rotational PTV causes significant reduction of the overlap volume between PCMs and PTVs in order to spare the PCMs compared to isotropic expanded PTV.

Simultaneous Reduction of Volume and Dose in Clinical Target Volume for Nasopharyngeal Cancer Patients

PURPOSE

To compare the treatment outcome and severe late adverse effects (AEs) between conventional volume and dose (CVD) and simultaneously reduced volume and dose (SRVD) of clinical target volume treatments in patients with nasopharyngeal carcinoma.

METHODS AND MATERIALS

This retrospective cohort study enrolled patients with nonmetastatic stage II to IV nasopharyngeal cancer from a single institute. Survival endpoints and severe (≥grade 3) late AEs and comorbidity were compared between groups. The correlation of severe late AEs, comorbidity, and overall survival (OS) were evaluated using Kaplan-Meier and Cox regression methods.

RESULTS

From January 2012 to June 2017, this study enrolled 178 patients, 64 in the CVD group and 114 in the SRVD group. The 2 groups did not differ significantly in patient characteristics except for mean follow-up time (37.6 vs 48.8 months; P = .01). The SRVD group did not significantly differ from the CVD group in local control survival (82.0% vs 78.4%; P = .85), regional control survival (89.9% vs 86.0%; P = .62), or disease-free survival (76.4% vs 66.9%; P = .67). The SRVD group had significantly better OS (93.9% vs 67.0%; P < .001) and salvage survival (79.3% vs 20.7%; P < .01) and a significantly lower ratio of severe lung infection (1 of 113 vs 5 of 59; P = .02). The SRVD group had a significantly lower risk of mortality (hazard ratio [HR], 0.3; P = .03). The factors associated with a significantly higher risk of mortality were N3 (regional lymph node stage status of N3) (HR, 3.0; P = .02); comorbidities of diabetes, coronary artery disease, or chronic kidney disease (grades 2-3) (HR, 3.8; P = .009), and severe lung infection (HR, 6.3; P = .007).

CONCLUSIONS

Simultaneously reduced volume and dose of clinical target volumes did not impair locoregional control or disease-free survival. The benefits of SRVD treatment may include significant reduction in severe late AEs, particularly lung infection, dysphagia, and xerostomia. However, additional studies with longer patient follow-up are required to confirm these benefits.

Superior prognosis stratification for stage III colon cancer using log odds of positive lymph nodes (LODDS) compared to TNM stage classification: the Japanese study group for postoperative follow-up of colorectal cancer

OBJECTIVES

The aim of this study is to examine whether prognosis stratification in staging of Stage III colon cancer using T factor and log odds of positive lymph nodes (LODDS) categories is superior to that of the TNM staging system.

MATERIALS AND METHODS

The subjects were 5,919 patients with Stage III colon cancer who underwent curative resection at 24 Japanese institutions. Univariate analysis of LODDS categories and clinicopathologic factors was conducted using a Cox proportional hazards regression model for cancer-specific survival (CSS). Independent prognostic factors for CSS were extracted in multivariate analysis using factors with significance in univariate analysis. Effect sizes of risk factors for CSS were compared using the LogWorth statistic. Combinations of T factor and LODDS categories were used to create L-stage subgroups A, B and C. Stratification of prognosis with L-stage and TNM was compared using the Akaike information criterion (AIC).

RESULTS

In multivariate analysis, LODDS was identified as an independent prognostic factor, together with age, maximum tumor diameter, histopathological grade, L, V, pT, and pN. The LogWorth of LODDS was 17.149, which was the second highest after pT (31.562), and that of pN was 7.434. The 5-year CSS was 96.5%, 88.5%, and 66.6% in TNM stages IIIA, IIIB, and IIIC, respectively, and 96.0%, 87.6%, and 59.3% in L-stage A, B, and C, respectively (p < 0.0001). AICs for TNM and L-stage were 14,795.5 and 14,707.8, respectively.

CONCLUSIONS

Prognosis stratification of the stage classification for Stage III colon cancer was superior with L-stage compared to TNM stage classification.

Cytokine and Growth Factor Response in a Rat Model of Radiation Induced Injury to the Submental Muscles

Submental muscles (i.e., mylohyoid and geniohyoid) play a vital role during swallowing, protecting the airway from ingested material. To design therapies to reduce the functional deficits associated with radiation treatment relies in part on our understanding of the changes in the cytokine and growth factor response that can impact muscle function. The purpose of this study is to quantify changes in the inflammatory, pro-fibrotic, and pro-angiogenic factors following 48 Gy of fractionated radiation to the mylohyoid muscle. We hypothesized that (1) irradiation will provoke increases in TGF-1β and MMP-2 mRNA in the mylohyoid muscle; and (2) muscles surrounding the target location (i.e., geniohyoid and digastric muscles) will exhibit similar alterations in their gene expression profiles. Rats were exposed to 6 fractions of 8 Gy using a 6 MeV electron beam on a clinical linear accelerator. The highest dose curve was focused at the mylohyoid muscle. After 2- and 4-weeks post-radiation, the mylohyoid, geniohyoid, and digastric muscles were harvested. Expression of TNF-α, IFNγ, IL-1β, IL-6, TGF-1β, VEGF, MMP-2, and MMP-9 mRNA was analyzed via PCR and/or RT-PCR. TGF-1β, MMP-2, and IL-6 expression was upregulated in the irradiated mylohyoid compared to non-irradiated controls. No notable changes in TNF-α, IFNγ, and IL-1β mRNA expression were observed in irradiated muscles. Differing expression profiles were found in the surrounding muscles post-radiation. Results demonstrated that irradiation provokes molecular signals involved in the regulation of wound healing, which could lead to fibrosis or atrophy in the swallowing muscle after radiation.

Dose-volume correlates of the prevalence of patient-reported trismus in long-term survivorship after oropharyngeal IMRT: A cross-sectional dosimetric analysis

PURPOSE

To ascertain the dose-toxicity relationship for the prevalence of self-reported trismus in long-term survivors after intensity-modulated radiotherapy (IMRT) for oropharyngeal carcinoma (OPC).

MATERIALS AND METHODS

Self-reported mouth opening was ascertained prospectively via a cross-sectional survey of OPC survivors using the intraoral finger-test. RT dose-volume histograms (DVHs) were generated for the following masticatory regions of interest: medial pterygoid, lateral pterygoid, and masseter muscles which were designated as ipsilateral or contralateral to the primary tumor. Trismus was defined as self-reported mouth opening of <3 finger-widths. Recursive partitioning analysis (RPA) was performed to identify the dose-volume thresholds associated with late trismus.

RESULTS

At a median follow-up time of 72 months (95% CI 68-74), 168 of the 587 (29%) survey respondents reported late trismus. Multivariate analysis demonstrated a significant association between late trismus and the following clinical variables: tonsillar primary site, advanced T stage, or higher total RT dose. RPA showed DVH-derived ipsilateral lateral pterygoid (ILP) mean dose of 61 Gy and volume receiving 27 Gy of at least 98.6% were independently associated with late trismus. The association between the ILP dosimetric parameters and the prevalence of late trismus was maintained after adjustment for clinical variables.

CONCLUSION

The integral dose of IMRT results in unavoidable low/intermediate dose to non-target masticatory muscles that is associated with increased prevalence of late trismus in OPC survivors. Whenever clinically and technically applicable, applying the proposed dosimetric constraints to the ILP (V27 <98.6 and D_mean <61 Gy) may reduce the prevalence of late trismus after IMRT for OPC patients.

Automatic registration of 2D MR cine images for swallowing motion estimation

PURPOSE

To automate the estimation of swallowing motion from 2D MR cine images using deformable registration for future applications of personalized margin reduction in head and neck radiotherapy and outcome assessment of radiation-associated dysphagia.

METHODS

Twenty-one patients with serial 2D FSPGR-MR cine scans of the head and neck conducted through the course of definitive radiotherapy for oropharyngeal cancer. Included patients had at least one cine scan before, during, or after radiotherapy, with a total of 52 cine scans. Contours of 7 swallowing related regions-of-interest (ROIs), including pharyngeal constrictor, epiglottis, base of tongue, geniohyoid, hyoid, soft palate, and larynx, were manually delineated from consecutive frames of the cine scan covering at least one swallowing cycle. We applied a modified thin-plate-spline robust-point-matching algorithm to register the point sets of each ROI automatically over frames. The deformation vector fields from the registration were then used to estimate the motion during swallowing for each ROI. Registration errors were estimated by comparing the deformed contours with the manual contours.

RESULTS

On average 22 frames of each cine scan were contoured. The registration for one cine scan (7 ROIs over 22 frames) on average took roughly 22 minutes. A number of 8018 registrations were successfully batch processed without human interaction after the contours were drawn. The average registration error for all ROIs and all patients was 0.36 mm (range: 0.06 mm- 2.06 mm). Larynx had the average largest motion in superior direction of all structures under consideration (range: 0.0 mm- 58.7 mm). Geniohyoid had the smallest overall motion of all ROIs under consideration and the superior-inferior motion was larger than the anterior-posterior motion for all ROIs.

CONCLUSION

We developed and validated a deformable registration framework to automate the estimation of swallowing motion from 2D MR cine scans.

A spatial neighborhood methodology for computing and analyzing lymph node carcinoma similarity in precision medicine

Precision medicine seeks to tailor therapy to the individual patient, based on statistical correlates from patients who are similar to the one under consideration. These correlates can and should go beyond genetics, and in general, beyond tabular or array data that can be easily represented computationally and compared. For example, in many types of cancer, cancer treatment and toxicity depend in large measure on the spatial disease spread-e.g., metastasizes to regional lymph nodes in head and neck cancer. However, there is currently a lack of methodology for integrating spatial information when considering patient similarity. We present a novel modeling methodology for the comparison of cancer patients within a cohort, based on the spatial spread of the lymph nodes affected in each patient. The method uses a topological map, bigrams, and hierarchical clustering to group patients based on their similarity. We compare this approach against a nonspatial (categorical) similarity approach where patients are binned solely by their affected nodes. We present similarity results on a 582 head and neck cancer patient cohort, along with two visual abstractions for analysis of the results, and we present clinician feedback. Our novel methodology partitions a patient cohort into clinically meaningful groups more susceptible to treatment side-effects. Such spatially-aware similarity approaches can help maximize the effectiveness of each patient's treatment.

The Changes in Pharyngeal Constrictor Muscles Related to Head and Neck Radiotherapy: A Systematic Review

It is well known that radiation damage of the pharyngeal constrictor muscles, the glottic larynx, and the supraglottic larynx may lead to dysphagia, an unwanted effect of head and neck radiotherapy. The reduction of radiotherapy-induced dysphagia might be achieved by adaptive radiotherapy. Although the number of studies concerning adaptive radiotherapy of head and neck cancer is continuously increasing, there are only a few studies concerning changes in dysphagia-related structures during radiotherapy.The goal of this review is to summarize the current knowledge about volumetric, dosimetric, and other changes of the pharyngeal constrictor muscles associated with head and neck radiotherapy. A literature search was performed in the MEDLINE database according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The conclusions of 8 studies that passed the criteria indicate a significant increase in the volume and the thickness of the pharyngeal constrictor muscles during radiotherapy. Moreover, the changes in magnetic resonance imaging signal intensity of the pharyngeal constrictor muscles correlate with the absorbed dose (typically higher than 50 Gy) and also with the grade of dysphagia. This systematic review presents 2 variables, which are suitable for estimation of radiotherapy-related pharyngeal constrictor muscles changes-magnetic resonance imaging signal intensity and the thickness. In the case of the thickness, there is no consensus in the level of the measurement-C2 vertebra, C3 vertebra, and the middle of the craniocaudal axis are used. It seems that reference to a position associated with a vertebral body could be more reproducible and beneficial for future research. Although late pharyngeal toxicity remains a challenge in head and neck cancer treatment, better knowledge of radiotherapy-related changes in the pharyngeal constrictor muscles contributes to adaptive radiotherapy development and thus improves the treatment results.

Interactive website for head and neck cancer patients: Adherence and coping program to prevent dysphagia after radiation

INTRODUCTION

Pharyngeal and laryngeal cancers are highly curable; however survivors are at high risk for long-term dysphagia after radiation. To address lack of access to preventive care in community settings, we developed a responsive web-based application to help patients adhere to preventive swallowing exercises and cope with radiation side effects. We conducted an interim study analysis to determine website usage characteristics and to examine the effect size for future trials.

METHODS

Pharyngeal and laryngeal cancer patients were recruited for enrollment by speech language pathologists before primary radiation and introduced to the interactive website. The program (English and Spanish) features tracking logs for preventive exercises, instructional videos, patient stories and search features. Patients' self-reported swallowing function was assessed with the MD Anderson Dysphagia Inventory (MDADI) at baseline and at 6 months. Adherence to preventive exercises was assessed during the 10 week intervention. Number of unique website visits, total duration of website exposure, and rankings of the most popular webpages were calculated. Preliminary regression models were run using adherence and MDADI as outcomes.

RESULTS

Of the 160 enrolled, 96 had 10-week adherence data and 61 had 6-month MDADI data. The average age was 63 (SD = 12.26), 49.4% were from rural counties, 44% had a high school education or lower, and 42% reported annual income of $30,000 or less. The average number of visits was 5.49 (SD = 9.96) and the average total time spent with the website was 41.09 min (SD =88.48). Preliminary analyses indicated that number of unique visits to the website was independently associated with increased adherence to preventive exercises (p = .001-.008).

CONCLUSION

Our website showed significant effects in promoting adherence to swallowing exercises. However, our return visit rate showed that the platform needs improvement in navigability and usability for this older population undergoing challenging treatment in community settings with low resources.

Organ Preservation and Late Functional Outcome in Oropharyngeal Carcinoma: Rationale of EORTC 1420, the "Best of" Trial

Dysphagia represents one of the most serious adverse events after curative-intent treatments with a tremendous impact on quality of life in patients with head and neck cancers. Novel surgical and radiation therapy techniques have been developed to better preserve swallowing function, while not negatively influencing local control and/or overall survival. This review focuses on the current literature of swallowing outcomes after curative treatment strategies. Available results from recent studies relevant to this topic are presented, demonstrating the potential role of new treatment modalities for early- and intermediate-stage oropharyngeal cancers. Based on this, we present the rationale and design of the currently active EORTC 1420 "Best of" trial, and highlight the potential of this study to help prioritizing either surgery- or radiation-based treatment modalities for the treatment of oropharyngeal cancer in the future.

Radiation-Induced Hypothyroidism After Radical Intensity Modulated Radiation Therapy for Oropharyngeal Carcinoma

PURPOSE

To evaluate 2 published normal tissue complication probability models for radiation-induced hypothyroidism (RHT) on a large cohort of oropharyngeal carcinoma (OPC) patients who were treated with intensity-modulated radiation therapy (IMRT).

METHODS AND MATERIALS

OPC patients treated with retrievable IMRT Digital Imaging and Communications in Medicine (DICOMs) data and available baseline and follow-up thyroid function tests were included. Mean dose (Dmean) to the thyroid gland (TG) and its volume were calculated. The study outcome was clinical HT at least 6 months after radiation therapy, which was defined as grade ≥2 HT per Common Terminology Criteria for Adverse Events grading system (symptomatic hypothyroidism that required thyroid replacement therapy). Regression analyses and Wilcoxon rank-sum test were used. Receiver operating characteristic curves and area under the curve for the fitted model were calculated.

RESULTS

In the study, 360 OPC patients were included. The median age was 58 years. Most tumors (51%) originated from the base of tongue. IMRT-split field was used in 95%, and median radiation therapy dose was 69.96 Gy. In the study, 233 patients (65%) developed clinical RHT that required thyroid replacement therapy. On multivariate analysis higher Dmean and smaller TG volume maintained the statistically significant association with the risk of clinical RHT (P < .0001). Dmean was significantly higher in patients with clinical RHT versus those without (50 vs 42 Gy, P < .0001). Patients with RHT had smaller TG volume compared with those without (11.8 compared with 12.8 mL, P < .0001). AUC of 0.72 and 0.66 were identified for fitted model versus for the applied Boomsma et al and Cella et al models, respectively.

CONCLUSIONS

Volume and Dmean of the TG are important predictors of clinical RHT and shall be integrated into normal tissue complication probability models for RHT. Dmean and thyroid volume should be considered during the IMRT plan optimization in OPC patients.

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.

Modeling symptom drivers of oral intake in long-term head and neck cancer survivors

PURPOSE

This study examined the relationship between self-reported symptom severity and oral intake in long-term head and neck cancer (HNC) survivors.

METHODS

An observational survey study with retrospective chart abstraction was conducted. HNC patients who had completed an MD Anderson Symptom Inventory-Head and Neck (MDASI-HN) questionnaire and also had clinician graded oral intake ratings (Functional Oral Intake Scale [FOIS]) were included. Correlation coefficients were computed. FOIS scores were regressed on MDASI-HN symptom items using stepwise backwards elimination for multivariate models.

RESULTS

One hundred and fifty-two survey pairings were included in the analysis (median 44 months follow-up, range 7-198). Per FOIS, 28% of survivors maintained a total oral diet with no restrictions, 67% reported a restricted oral diet (without tube), 3% were partially tube-dependent with some oral intake, and 2% were NPO. Of the 22 symptom items, the most severe items in decreasing order were dry mouth, difficulty swallowing\chewing, problems with mucus, tasting food, and choking/coughing. Significant bivariate correlations, after Bonferroni correction for multiple comparisons, were present for 8 of 22 symptoms with FOIS. On multivariate analysis, symptom severity for difficulty swallowing and problems with teeth/gums remained significantly associated with FOIS.

CONCLUSIONS

Oral intake in HNC survivorship is a multidimensional issue and functional outcome that is impacted not only by dysphagia but also by dental status. Symptom drivers of oral intake likely differ in acute survivorship. Nonetheless, these findings highlight the lack of specificity in this end point and also the need for multidisciplinary supportive care to optimize oral intake in survivors.

Perspectives on optimizing radiotherapy dose to the dysphagia/aspiration-related structures for patients with head and neck cancer

PURPOSE OF REVIEW

The purpose of this study is to provide an overview on the methodologies, outcomes and clinical implications of studies that have investigated swallowing outcomes after head and neck cancer (HNC) treatment when reducing radiotherapy dose to specific dysphagia/aspiration-related structures (DARS).

RECENT FINDINGS

Overall, there is limited recent evidence, with a lack of high-quality studies, which examine the outcomes of DARS-optimized radiotherapy treatment. Large variations exist in the methodology of these studies in regards to which DARS are delineated and how swallowing outcomes are measured. Consequently, there is a wide range of dose limits recommended to a variety of DARS structures. Despite these limitations, there appears to be a general consensus that optimizing dose to the DARS will result in some reduction of dysphagia after radiotherapy without compromising on treatment to the tumour.

SUMMARY

More rigorous study must be completed to determine the true extent of clinical benefit from this practice. Institutions must take into consideration the limitations of the evidence as well as logistical costs of implementing this technique into practice. However, optimizing dose to the DARS appears to be a well-tolerated practice that may have substantial positive benefits for patients' swallowing function and quality of life after HNC treatment.

Framework for Speech-Language Pathology Services in Patients with Oral Cavity and Oropharyngeal Cancers

This article provides a framework speech-language pathology services to optimize functional outcomes of patients with oral cavity and oropharyngeal cancers. Key principles include (1) a proactive rehabilitation model that minimizes intervals of disuse or inactivity of speech and swallowing systems, (2) standardized evaluation paradigms that combine objective instrumental assessments with patient-reported outcome measures, and (3) systematic methods for surveillance and intensive rehabilitation for late dysphagia.

Fatigue following radiation therapy in nasopharyngeal cancer survivors: A dosimetric analysis incorporating patient report and observer rating

PURPOSE

To explore for fatigue-related regions and the radiotherapy (RT) dose-fatigue relationship in nasopharyngeal cancer (NPC) survivors.

METHODS

Eighty disease-free NPC survivors completed the MD Anderson Symptom Inventory-Head and Neck module (MDASI-HN) after RT. Fatigue was evaluated by the MDASI-HN fatigue item (MDASI-HN-F) and Common Terminology Criteria for Adverse Events v3.0 (CTC-AE), between 6 and 36 months after RT to determine the presence of chronic fatigue. Skull base MRIs and planning CT/RT dose were retrievable for 56 patients. Dosimetric data were extracted for 10 MRI-defined potential fatigue at-risk structures (FARS): brainstem (BS), pituitary gland (PG), hypothalamus (HT), basal ganglia, internal capsule, pineal gland, sub-thalamic nuclei, thalamus, substantia nigra, and hippocampus (HC). Recursive partitioning analysis (RPA) was used to identify dose-volume effects associated with chronic fatigue.

RESULTS

56 pts formed the cohort. Thirty patients (54%) reported any fatigue per MDASI-HN-F. Thirty-three pts (59%) had any fatigue by CTC-AE. The maximum point doses (Dmax) for PG, BS, HC, and HT were numerically higher in patients with fatigue. Dmax and Dmean of the PG were significantly higher in patients with chronic fatigue, p ≤ 0.01. A dose-volume threshold of PG V52 Gy ≥16% (LogWorth 2.4, AUC 0.7) was identified on RPA, and potential sensitivity to the PG doses was observed in younger patients (<53 years-old).

CONCLUSION

A dose-fatigue relationship was identified for the pituitary gland, both patient-reported and observer ratings. We recommend limiting the Dmax of PG to <54 Gy and V52 Gy to <16%, particularly in young NPC patients, during plan optimization when achievable.

A prospective longitudinal assessment of MRI signal intensity kinetics of non-target muscles in patients with advanced stage oropharyngeal cancer in relationship to radiotherapy dose and post-treatment radiation-associated dysphagia: Preliminary findings from a randomized trial

PURPOSE

To assess quantitative signal intensity (SI) kinetics obtained from serial MRI of swallowing muscles as a potential imaging biomarker of radiation-induced dysphagia in oropharyngeal cancer (OPC) patients receiving radiotherapy (RT).

METHODS

Patients were enrolled under an IRB approved Phase II/III randomized trial. Patients underwent serial MRIs at pre-, mid-, and post-RT. Normalized T1, T1+ contrast (T1 + C), and T2 SI for swallowing muscle volumes-of-interest (VOIs) were collected and delta SI changes (Δ) were calculated. Mid- and post-RT SI relative to baseline were assessed and correlations between radiation dose and percent change in SI were calculated. Independent samples' t-tests were used to compare the percent change of SI between patients divided into two groups based on dysphagia status post-RT.

RESULTS

Forty-six patients with stage III/IV HPV+ OPC were included in this study. Relative to baseline, mean T2 and T1 + C SIs for middle pharyngeal constrictor were both significantly higher at mid- and post-RT (p < 0.004 for all). Superior pharyngeal constrictor also showed a significant increase in T1 + C SI at mid-RT (p = 0.0004). Additional muscle VOIs showed significant changes post-RT, but not earlier at mid-RT. Both mid- and post-RT doses were significantly correlated with the percent change of normalized T2 and T1 + C SI for examined muscle VOIs (p < 0.002). Mean percent changes of normalized T2 SI at mid-RT relative to baseline for all muscle VOIs were significantly higher in patients who developed grade ≥2 dysphagia relative to patients with no/mild dysphasia (mean Δ%: 8.2% vs 1.9%; respectively, p = 0.002). However, at post-RT, these changes were only significant in T1 SI (11.2% vs -1.3%; p < 0.0001).

CONCLUSION

Signal intensity kinetics of radiation injury can be broadly correlated with the functional muscular defect. Serial MRI during the course of RT may provide an opportunity to quantitatively track muscular pathology for subclinical detection of patients at high risk to develop dysphagia.

Two-year prevalence of dysphagia and related outcomes in head and neck cancer survivors: An updated SEER-Medicare analysis

BACKGROUND

The aim of the study was to examine prevalence of dysphagia at the population level in head and neck cancer (HNC) survivors.

METHODS

Surveillance, Epidemiology, and End Results-Medicare claims among 16 194 patients with HNC (2002-2011) were analyzed to estimate 2-year prevalence of dysphagia, stricture, and aspiration pneumonia, and derive treatment- and site-specific estimates.

RESULTS

Prevalence of dysphagia, stricture, pneumonia, and aspiration pneumonia was 45.3% (95% confidence interval [CI]: 44.5-46.1), 10.2% (95% CI: 9.7-10.7), 26.3% (95% CI: 25.6-26.9), and 8.6% (95% CI: 8.2-9.1), respectively. Dysphagia increased by 11.7% over the 10-year period (P < .001). Prevalence was highest after chemoradiation and multimodality therapy.

CONCLUSION

Comparing to published rates using similar methodology the preceding decade (1992-1999), prevalence of dysphagia based on claims data was similar in 2002-2011 in this study. These results suggest persistence of dysphagia as a highly prevalent morbidity, even in the decade in which highly conformal radiotherapy and minimally invasive surgeries were popularized.

Functional Swallowing Units (FSUs) as organs-at-risk for radiotherapy. PART 1: Physiology and anatomy

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.