Acute symptoms during the course of head and neck radiotherapy or chemoradiation are strong predictors of late dysphagia

The impact of pretreatment symptom burden on long-term quality of life following head and neck radiation: A prospective longitudinal study

BACKGROUND

This study characterized the impact of baseline symptom burden on long-term quality-of-life in patients receiving head and neck radiation therapy (RT).

METHODS

The Vanderbilt Head and Neck Symptom Survey was collected prior to head and neck RT and at follow-up visits. Responses were divided into symptom clusters of toxicities and scored from 0 (asymptomatic) to 10 (severe). Patients with responses at baseline and 1-year or 2-year follow-up were stratified by scores ≤1 or >1 and compared using the Mann-Whitney U-test.

RESULTS

At 1-year follow-up (n = 75), patients with higher baseline scores had greater symptom burden for every cluster except in taste/smell. At 2-year follow-up (n = 47), patients with higher baseline scores had greater symptom burden for every cluster except in nutrition, dry mouth, trismus, neck tightness, and hearing.

CONCLUSION

The Vanderbilt Head and Neck Symptom Survey demonstrated a relationship between baseline symptom burden and long-term quality-of-life and might be useful as a screening tool.

The effectiveness of interprofessional peer-led teaching and learning for therapeutic radiography students and Speech and Language Therapy students

BACKGROUND

Therapeutic Radiographers (RT) and Speech and Language Therapists (SLT) work closely together in caring for people with head and neck cancer and need a strong understanding of each others' roles. Peer teaching has been shown to be one of the most effective methods of teaching; however, no studies to date, have involved RT and SLT students. This research aims to establish the effectiveness and perceptions of peer-led teaching between undergraduate RT and SLT students in Ulster University.

METHODS

Twenty SLT students and 14 RT students participated. Knowledge tests were taken online before the peer-led teaching session (T1), after the session (T2) and 3 months later (T3). Students' perceptions of the experience were collected at the end of the session. Wilcoxon signed-rank tests were used to analyse the impact of the intervention on knowledge scores. Qualitative content analysis was used for open text response data.

RESULTS

RT students' own professional knowledge score at T2 was statistically significantly higher than the score at T1; the score at T3 was not deemed to be statistically significantly higher. RT students' SLT knowledge score at T2 and T3 was found to be statistically significantly higher than the score at T1. SLT students' own professional knowledge score was not statistically significantly higher at T2 or T3 than T1. They did have a statistically significantly higher score at T2 on the RT test, but score at T3 was not deemed to be statistically significantly higher. The majority of students across both professions agreed or strongly agreed that the peer-led teaching experience had a positive impact on their learning.

CONCLUSION

This investigation highlights the benefits of an interprofessional peer-led teaching intervention for RT and SLT students and the findings add to the evidence of more objective study of knowledge gain as a result of interprofessional peer teaching.

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.

Tongue electrical impedance myography correlates with functional, neurophysiologic, and clinical outcome measures in long-term oropharyngeal cancer survivors with and without hypoglossal neuropathy: An exploratory study

BACKGROUND

This pilot study analyzed correlations between tongue electrical impedance myography (EIM), standard tongue electromyography (EMG), and tongue functional measures in N = 4 long-term oropharyngeal cancer (OPC) survivors.

METHODS

Patients were screened for a supportive care trial (NCT04151082). Hypoglossal nerve function was evaluated with genioglossus needle EMG, functional measures with the Iowa oral performance instrument (IOPI), and multi-frequency tissue composition with tongue EIM.

RESULTS

Tongue EIM conductivity was higher for patients with EMG-confirmed cranial nerve XII neuropathy than those without (p = 0.005) and in patients with mild versus normal EMG reinnervation ratings (16 kHz EIM: p = 0.051). Tongue EIM correlated with IOPI strength measurements (e.g., anterior maximum isometric lingual strength: r2  = 0.62, p = 0.020).

CONCLUSIONS

Tongue EIM measures related to tongue strength and the presence of XII neuropathy. Noninvasive tongue EIM may be a convenient adjunctive biomarker to assess tongue health in OPC survivors.

Hitting the Target: Developing High-quality Evidence for Proton Beam Therapy Through Randomised Controlled Trials

The National Health Service strategy for the delivery of proton beam therapy (PBT) in the UK provides a unique opportunity to deliver high-quality evidence for PBT through randomised controlled trials (RCTs). We present a summary of three UK PBT RCTs in progress, including consideration of their key design characteristics and outcome assessments, to inform and support future PBT trial development. The first three UK multicentre phase III PBT RCTs (TORPEdO, PARABLE and APPROACH), will compare PBT with photon radiotherapy for oropharyngeal squamous cell carcinoma, breast cancer and oligodendroglioma, respectively. All three studies were designed by multidisciplinary teams, which combined expertise from clinicians, clinical trialists and scientists with strong patient advocacy and guidance from national radiotherapy research networks and international collaborators. Consistent across all three studies is a focus on the reduction of long-term radiotherapy-related toxicities and an evaluation of patient-reported outcomes and health-related quality of life, which will address key uncertainties regarding the clinical benefits of PBT. Innovative translational components will provide insights into mechanisms of toxicity and help to frame the key future research questions regarding PBT. The UK radiotherapy research community is developing and delivering an internationally impactful PBT research portfolio. The combination of data from RCTs with prospectively collected data from a national PBT outcomes registry will provide an innovative, high-quality repository for PBT research and the platform to design and deliver future trials of PBT.

Metabolomics analysis of pathways underlying radiation-induced salivary gland dysfunction stages

Salivary gland hypofunction is an adverse side effect associated with radiotherapy for head and neck cancer patients. This study delineated metabolic changes at acute, intermediate, and chronic radiation damage response stages in mouse salivary glands following a single 5 Gy dose. Ultra-high performance liquid chromatography-mass spectrometry was performed on parotid salivary gland tissue collected at 3, 14, and 30 days following radiation (IR). Pathway enrichment analysis, network analysis based on metabolite structural similarity, and network analysis based on metabolite abundance correlations were used to incorporate both metabolite levels and structural annotation. The greatest number of enriched pathways are observed at 3 days and the lowest at 30 days following radiation. Amino acid metabolism pathways, glutathione metabolism, and central carbon metabolism in cancer are enriched at all radiation time points across different analytical methods. This study suggests that glutathione and central carbon metabolism in cancer may be important pathways in the unresolved effect of radiation treatment.

Association between radiation dose to organs at risk and acute patient reported outcome during radiation treatment for head and neck cancers

BACKGROUND

Associations between patient-reported outcomes and dose to organs at risk (OARs) may promote management and guide future investigations.

METHODS

We retrospectively evaluated PROs and OAR dose in head and neck (H&N) cancer.

RESULTS

In 169 patients, we identified weak associations between: "Difficulty swallowing/chewing" and increased mean RT dose to the oral cavity, larynx, pharyngeal constrictor muscles (PCM) and contralateral parotid; "choking/coughing" and larynx mean dose; "problems with mucus in mouth and throat" and oral cavity, contralateral parotid mean dose and parotid V30, contralateral submandibular gland and PCM mean dose; "difficulty with voice/speech" and oral cavity, contralateral parotid, contralateral submandibular gland and larynx mean dose; and "dry mouth" and ipsilateral submandibular gland, oral cavity and PCM mean dose.

CONCLUSION

We identified weak associations between PRO and dose to OARs-these data can guide on treatment management, patient counseling, and serve as a baseline for future investigations.

Similar long-term swallowing outcomes for accelerated, mildly-hypofractionated radiotherapy compared to conventional fractionation in oropharynx cancer: a multi-centre study

BACKGROUND AND PURPOSE

There is renewed interest in hypofractionated radiotherapy, but limited data and a lack of consensus to support use for head and neck cancer. In this multicentre analysis we compared outcomes for patients with oropharynx squamous cell carcinoma (OPSCC) treated with conventional and accelerated, mildly hypofractionated radiotherapy without chemotherapy.

MATERIALS AND METHODS

A multi-centre, observational study of consecutive OPSCCs treated between 2015 and 2018. Patients underwent curative-intent radiotherapy (oropharynx and bilateral neck) using conventionally fractionated (70 Gy in 35 fractions over 7 weeks, n = 97) or accelerated, mildly hypofractionated (65-66 Gy in 30 fractions over 6 weeks, n = 136) radiotherapy without chemotherapy. Locoregional control (LRC) and overall survival (OS) were compared. Patients alive and cancer-free at a minimum of 2 years post-radiotherapy (n = 151, 65%) were sent an MD Anderson Dysphagia Inventory (MDADI) questionnaire to assess swallow function.

RESULTS

LRC and OS were similar across schedules (p = 0.78 and 0.95 respectively, log-rank test). Enteral feeding rates during radiotherapy appeared higher in the 7-week group though this did not reach statistical significance (59% vs 48%, p = 0.08). Feeding rates were similar at 1 year post radiotherapy for both groups (10% vs 6%, p = 0.27). 107 patients returned MDADI questionnaires (71%); there were no differences between the 6- and 7-week groups for median global (60.0 vs 60.0, p = 0.99) and composite (65.8 vs 64.2, p = 0.44) MDADI scores.

CONCLUSION

Patients with OPSCC treated with radiotherapy alone have similar swallowing outcomes, LRC and OS following accelerated, mild hypofractionation and standard fractionation schedules, supporting its use as a standard-of-care option for patients unsuitable for concurrent chemotherapy.

Dosimetric Results for Adjuvant Proton Radiation Therapy of HPV-Associated Oropharynx Cancer

Purpose

One significant advantage of proton therapy is its ability to improve normal tissue sparing and toxicity mitigation, which is relevant in the treatment of oropharyngeal squamous cell carcinoma (OPSCC). Here, we report our institutional experience and dosimetric results with adjuvant proton radiation therapy (PRT) versus intensity-modulated radiotherapy (IMRT) for Human Papilloma Virus (HPV)-associated OPSCC.

Materials and Methods

This was a retrospective, single institutional study of all patients treated with adjuvant PRT for HPV-associated OPSCC from 2015 to 2019. Each patient had a treatment-approved equivalent IMRT plan to serve as a reference. Endpoints included dosimetric outcomes to the organs at risk (OARs), local regional control (LRC), progression-free survival (PFS), and overall survival (OS). Descriptive statistics, a 2-tailed paired t test for dosimetric comparisons, and the Kaplan-Meier method for disease outcomes were used.

Results

Fifty-three patients were identified. Doses delivered to OARs compared favorably for PRT versus IMRT, particularly for the pharyngeal constrictors, esophagus, larynx, oral cavity, and submandibular and parotid glands. The achieved normal tissue sparing did not negatively impact disease outcomes, with 2-year LRC, PFS, and OS of 97.0%, 90.3%, and 97.5%, respectively.

Conclusion

Our study suggests that meaningful normal tissue sparing in the postoperative setting is achievable with PRT, without impacting disease outcomes.

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.

Swallowing, nutritional status, and salivary flow in patients after head and neck cancer treatment, a pilot study

Determine the relationship between swallowing function, nutritional status, and salivary flow in patients after head and neck cancer treatment. This pilot study included 17 patients. Swallowing was assessed through videofluoroscopy and surface electromyography (sEMG), nutritional status through anthropometry and dietary assessment, and salivary flow both with and without mechanical stimulation. Test analysis showed that 66.7% of patients had functional limitations in swallowing in 58.3%, 66.7%, and 58.3% residue scale with an average of a line of barium on a structure for pudding, honey, and liquid consistencies, respectively. Laryngeal penetration was found in 8.3% during the swallowing of liquid. Surface electromyography (sEMG) showed above normal values for muscle activity time during the swallowing of pudding. Anthropometric assessment and muscle and adipose tissue indicated eutrophy. Salivary flow test with mechanical stimulus showed that 82.3% of patients' salivary production was well below the appropriate level. There was a significant correlation between muscle tissue reserve and muscle activity time during swallowing in the studied muscles (left masseter p = 0.003, right masseter p = 0.001, suprahyoid p = 0.001, orbicularis oris = 0.020), all in pudding consistency. This pilot study confirmed the relationship between swallowing and nutritional status for its participants, showing that appropriate protein intake influences muscle activity during swallowing in head and neck cancer survivors.

Assessment of cough in head and neck cancer patients at risk for dysphagia-An overview

BACKGROUND

This literature review explores the terminology, the neurophysiology, and the assessment of cough in general, in the framework of dysphagia and regarding head and neck cancer patients at risk for dysphagia. In the dysphagic population, cough is currently assessed perceptually during a clinical swallowing evaluation or aerodynamically.

RECENT FINDINGS

Recent findings have shown intra and inter-rater disagreements regarding perceptual scoring of cough. Also, aerodynamic measurements are impractical in a routine bedside assessment. Coughing, however, is considered to be a clinically relevant sign of aspiration and dysphagia in head and cancer patients treated with concurrent chemoradiotherapy.

CONCLUSION

This article surveys the literature regarding the established cough assessment and stresses the need to implement innovative methods for assessing cough in head and neck cancer patients treated with concurrent chemoradiotherapy at risk for dysphagia.

Modelling Radiation-Induced Salivary Dysfunction during IMRT and Chemotherapy for Nasopharyngeal Cancer Patients

BACKGROUND

Radiation-induced xerostomia is one of the most prevalent adverse effects of head and neck cancer treatment, and it could seriously affect patients' qualities of life. It results primarily from damage to the salivary glands, but its onset and severity may also be influenced by other patient-, tumour-, and treatment-related factors. We aimed to build and validate a predictive model for acute salivary dysfunction (aSD) for locally advanced nasopharyngeal carcinoma (NPC) patients by combining clinical and dosimetric factors.

METHODS

A cohort of consecutive NPC patients treated curatively with IMRT and chemotherapy at 70 Gy (2-2.12 Gy/fraction) were utilised. Parotid glands (cPG, considered as a single organ) and the oral cavity (OC) were selected as organs-at-risk. The aSD was assessed at baseline and weekly during RT, grade ≥ 2 aSD chosen as the endpoint. Dose-volume histograms were reduced to the Equivalent Uniform Dose (EUD). Dosimetric and clinical/treatment features selected via LASSO were inserted into a multivariable logistic model. Model validation was performed on two cohorts of patients with prospective aSD, and scored using the same schedule/scale: a cohort (NPC_V) of NPC patients (as in model training), and a cohort of mixed non-NPC head and neck cancer patients (HNC_V).

RESULTS

The model training cohort included 132 patients. Grade ≥ 2 aSD was reported in 90 patients (68.2%). Analyses resulted in a 4-variables model, including doses of up to 98% of cPG (cPG_D98%, OR = 1.04), EUD to OC with n = 0.05 (OR = 1.11), age (OR = 1.08, 5-year interval) and smoking history (OR = 1.37, yes vs. no). Calibration was good. The NPC_V cohort included 38 patients, with aSD scored in 34 patients (89.5%); the HNC_V cohort included 93 patients, 77 with aSD (92.8%). As a general observation, the incidence of aSD was significantly different in the training and validation populations (p = 0.01), thus impairing calibration-in-the-large. At the same time, the effect size for the two dosimetric factors was confirmed. Discrimination was also satisfactory in both cohorts: AUC was 0.73, and 0.68 in NPC_V and HNC_V cohorts, respectively.

CONCLUSION

cPG D98% and the high doses received by small OC volumes were found to have the most impact on grade ≥ 2 acute xerostomia, with age and smoking history acting as a dose-modifying factor. Findings on the development population were confirmed in two prospectively collected validation populations.

Can the Risk of Dysphagia in Head and Neck Radiation Therapy Be Predicted by an Automated Transit Fluence Monitoring Process During Treatment? A First Comparative Study of Patient Reported Quality of Life and the Fluence-Based Decision Support Metric

PURPOSE/OBJECTIVE(S)

The additional personnel and imaging procedures required for Adaptive Radiation Therapy (ART) pose a challenge for a broad implementation. We hypothesize that a change in transit fluence during the treatment course is correlated with the change of quality of life and thus can be used as a replanning trigger.

MATERIALS/METHODS

Twenty-one head and neck cancer (HNC) patients filled out an MD Anderson Dysphagia Inventory (MDADI) questionnaire, before-and-after the radiotherapy treatment course. The transit fluence was measured by the Watchdog (WD) in-vivo portal dosimetry system. The patients were monitored with daily WD and weekly CBCTs. The region of interest (ROI) of each patient was defined as the outer contour of the patient between approximate spine levels C1 to C4, essentially the neck and mandible inside the beam's eye view. The nth day integrated transit fluence change, Δϕ_n, and the volume change, ΔV_ROI, of the ROI of each patient was calculated from the corresponding WD and CBCT measurements. The correlation between MDADI scores and age, gender, planning mean dose to salivary glands <D_sg>, weight change ΔW, ΔV_ROI, and Δϕ_n, were analyzed using the ranked-Pearson correlation.

RESULTS

No statistically significant correlation was found for age, gender and ΔW. <D_sg> was found to have clinically important correlation with functional MDADI (ρ = -0.39, P = 0.081). ΔV_ROI was found to have statistically significant correlation of 0.44, 0.47 and 0.44 with global, physical and functional MDADI (P-value < 0.05). Δϕ_n was found to have statistically significant ranked-correlation (-0.46, -0.46 and -0.45) with physical, functional and total MDADI (P-value < 0.05).

CONCLUSION

A transit fluence based decision support metric (DSM) is statistically correlated with the dysphagia risk. It can not only be used as an early signal in assisting clinicians in the ART patient selection for replanning, but also lowers the resource barrier of ART implementation.

Exploring the Interplay Between Radiotherapy Dose and Physiological Changes in the Swallowing Mechanism in Patients Undergoing (Chemo)radiotherapy for Oropharynx Cancer

This study explored associative relationships between radiotherapy dose volumes delivered to the dysphagia aspiration risk structures (DARS) and swallowing physiological disturbance at 3 months post treatment in a homogenous cohort of patients who received (chemo)radiotherapy ((C)RT) for oropharyngeal head and neck cancer (HNC). Participants(n = 53) were a subgroup of patients previously recruited as part of a prospective randomised trial, and had undergone physiological swallowing assessment using videofluroscopic swallowing study (VFSS) at 3 months post (C)RT. The extended oral cavity (EOC), supraglottic larynx (SGL), glottic larynx (GL), cricopharyngeal inlet (CI), and pharyngeal constrictor muscles (PCM) were contoured as per international consensus guidelines and dose volume histograms (DVHs) were generated for each structure. Each DVH was analysed to reveal mean, maximum and partial radiotherapy doses of V₄₀, V₅₀ and V₆₀ for each structure. Physiological swallowing function on VFSS was rated using the Modified Barium Swallow Impairment Profile (MBSImP). A binary logistic regression model was used to establish associative relationships between radiotherapy dose to the DARS and physiological changes within the swallowing mechanism. Structures that received the largest volumes of radiotherapy dose were the PCM and SGL. Significant relationships were found between the proportion of the EOC, SGL, GL and PCMs that received radiotherapy doses > 40 Gy, > 50 Gy and > 60 Gy and the likelihood of a moderate-severe physiological swallowing impairment (on the MBSImP). Whilst the current study was exploratory in nature, these preliminary findings provide novel evidence to suggest structure-specific associative relationships between radiotherapy dose and impacts to corresponding swallow physiology in patients with oropharyngeal HNC.

Radiation-Induced Salivary Gland Dysfunction: Mechanisms, Therapeutics and Future Directions

Salivary glands sustain collateral damage following radiotherapy (RT) to treat cancers of the head and neck, leading to complications, including mucositis, xerostomia and hyposalivation. Despite salivary gland-sparing techniques and modified dosing strategies, long-term hypofunction remains a significant problem. Current therapeutic interventions provide temporary symptom relief, but do not address irreversible glandular damage. In this review, we summarize the current understanding of mechanisms involved in RT-induced hyposalivation and provide a framework for future mechanistic studies. One glaring gap in published studies investigating RT-induced mechanisms of salivary gland dysfunction concerns the effect of irradiation on adjacent non-irradiated tissue via paracrine, autocrine and direct cell-cell interactions, coined the bystander effect in other models of RT-induced damage. We hypothesize that purinergic receptor signaling involving P2 nucleotide receptors may play a key role in mediating the bystander effect. We also discuss promising new therapeutic approaches to prevent salivary gland damage due to RT.

[Late toxicity following primary conservative treatment : Dysphagia and xerostomia]

Dysphagia and xerostomia are still among the most important acute and late side effects of radiotherapy. Technical developments over the past two decades have led to improved diagnostics and recognition as well as understanding of the causes of these side effects. Based on these findings and advances in both treatment planning and irradiation techniques, the incidence and severity of treatment-associated radiogenic late sequelae could be clearly reduced by the use of intensity-modulated radiotherapy (IMRT), which could contribute to marked long-term improvements in the quality of life in patients with head and neck cancer. Highly conformal techniques, such as proton therapy have the potential to further reduce treatment-associated side effects in head and neck oncology and are currently being prospectively tested within clinical trial protocols at several centers.

Missed radiation therapy sessions in first three weeks predict distant metastasis and less favorable outcomes in surgically treated patients with oral cavity squamous cell carcinoma

Background

We sought to investigate the prognostic impact of missed RT sessions in patients who had undergone surgery for oral cavity squamous cell carcinoma (OCSCC).

Methods

The study sample consisted of 905 patients with surgically treated OCSCC who fulfilled criteria of RT course ≤8 weeks. The study participants were divided into three groups based on the characteristics of missed RT, as follows: 1) early missed RT, 2) late missed RT, and 3) RT as scheduled.

Results

The 5-year overall survival (OS) rates in the early missed RT, late missed RT, and RT as scheduled groups were 53.0, 58.1, and 64.5%, respectively (p = 0.046). In multivariate analysis, early missed RT was independently associated with both OS (hazard ratio (HR) = 1.486; 95% confidence interval (CI): 1.122–1.966; p = 0.006) and the occurrence of distant metastasis (HR = 1.644; 95% CI: 1.047–2.583; p = 0.031).

Conclusion

Early missed RT was independently associated with a higher occurrence of distant metastasis and less favorable OS in patients who had undergone surgery for OCSCC.

Cervical Fibrosis as a Predictor of Dysphagia

OBJECTIVE

Radiotherapy of head and neck cancer (HNCA) causes dysfunction through radiation-induced fibrosis (RIF). We hypothesize that the degree of cervical fibrosis is associated with swallowing dysfunction. This study evaluated the association between cervical fibrosis and swallowing dysfunction in patients after radiation therapy for HNCA.

STUDY DESIGN

Cross sectional study.

METHODOLOGY

A convenience sample of patients with dysphagia who were at least 1 year post radiation therapy for HNCA underwent simultaneous cervical ultrasound (US) and video-fluroscopic swallow study (VFSS). US determinants of fibrosis were measurements of sternocleidomastoid fascia (SCMF) thickness bilaterally at the level of the cricoid. Primary and secondary outcome variables on VFSS were pharyngeal constriction ratio, a validated measure of pharyngeal contractility, and penetration aspiration scale (PAS). A qualitative assessment of lateral neck rotation was performed as a functional measure of neck fibrosis.

RESULTS

Simultaneous cervical US and VFSS examinations were performed on 18 patients with a history of radiotherapy for HNCA and on eight controls. The mean (±SD) age of the entire cohort (N = 26) was 66 (±10) years. Individuals with a history of radiation had significantly thinner mean SCMF (0.26 [±0.04 mm]) compared to controls (0.48 [±0.06 mm]; P < .05). Individuals with thinner SCMF were more likely to have moderate to severe restriction in lateral neck rotation, a higher PCR, and a higher PAS (P < .05).

CONCLUSION

Thinner sternocleidomastoid fascia on ultrasound in patients having undergone radiotherapy for head and neck cancer was associated with reduced lateral neck movement, poorer pharyngeal constriction and greater penetration/aspiration scale. The data suggest that cervical fibrosis is associated with swallowing dysfunction in head and neck cancer survivors and support the notion that, "As the neck goes, so does the swallow."

LEVEL OF EVIDENCE

3. Laryngoscope, 131:548-552, 2021.

Yusop NB, Ibrahim Z, Abdul Rahman Z, Jamhuri N. Changes in Nutrition Impact Symptoms, Nutritional and Functional Status during Head and Neck Cancer Treatment

Background: The purpose of this study is to evaluate changes in nutrition impact symptoms (NIS) and nutritional and functional status that occur throughout radiotherapy in head and neck cancer (HNC) patients. Methods: A prospective observational study of HNC inpatients who underwent radiotherapy with or without chemotherapy were recruited to participate. Fifty patients were followed for the periods before, in the middle and at the end of radiotherapy. Nutritional parameters were collected throughout radiotherapy. Results: According to Patient-Generated Subjective Global Assessment (PG-SGA), there was an increase from a baseline of 56% malnourished HNC patients to 100% malnourished with mean weight loss of 4.53 ± 0.41kg (7.39%) at the end of radiotherapy. Nutritional parameters such as muscle mass, fat mass, body mass index, dietary energy and protein intake decrease significantly (p < 0.0001) while NIS score, energy and protein intake from oral nutritional supplements (ONS) increased significantly (p < 0.0001). Hand grip strength did not differ significantly. All HNC patients experienced taste changes and dry mouth that required ONS at the end of treatment. ONS compliance affected the percentage of weight loss (p = 0.013). Conclusions: The intensive nutritional care time point was the middle of RT. The PG-SGA and NIS checklist are useful for monitoring nutrition for HNC patients.

Prophylactic percutaneous endoscopic gastrostomy in patients with head and neck cancer: Influence on nutritional status, utilisation rate and complications

BACKGROUND

Patients with head and neck cancer (HNC) are at high risk for malnutrition because of tumour localisation and therapy. Prophylactic percutaneous endoscopic gastrostomy (PEG) tube placement is common practice to prevent malnutrition.

OBJECTIVE

To investigate the benefits of prophylactic PEG tube placement for HNC patients in terms of the influence on patients' nutritional status, utilisation rate, complications and to identify the predictors of PEG tube utilisation.

METHODS

All consecutive HNC patients who underwent prophylactic PEG tube insertion between 1 January 2011 and 31 December 2012 prior to therapy were enrolled. The PEG tube utilisation rate, complications, the patients' nutritional status and tumour therapy were evaluated with the help of electronic patient charts and telephone interviews.

RESULTS

A total of 181 patients (48 female, median 67.5 years) were included. The PEG utilisation rate in the entire cohort was 91.7%. One hundred and forty-nine patients (82.3%) used the PEG tube for total enteral nutrition, 17 patients (9.4%) for supplemental nutrition and 15 patients (8.3%) made no use of the PEG tube. Peristomal wound infections were the most common complications (40.3%) in this study. A high Nutritional Risk Screening (NRS) score prior to tube insertion was found to be independently associated with PEG utilisation. No significant weight changes were observed across the three patient subgroups.

CONCLUSIONS

The overall PEG tube utilisation rate was high in this study. However, given the high rate of infections, diligent patient selection is crucial in order to determine which patients benefit most from prophylactic PEG tube insertion.

Frequency and Evolution of Acute Oral Complications in Patients Undergoing Radiochemotherapy Treatment for Head and Neck Squamous Cell Carcinoma

Despite its effectiveness, radiochemotherapy treatment in the head and neck region is accompanied by acute oral complications such as oral mucositis, dysphagia, xerostomia, and dysgeusia. The aim of this study was to analyze and prospectively assess the frequency and evolution of acute oral complications during radiochemotherapy in patients diagnosed with squamous cell carcinoma in the head and neck region. We have analyzed oral complications of 20 patients during 6 weeks of radiochemotherapy treatment for squamous cell carcinoma. Oral mucositis was evaluated according to the World Health Organization criteria, dysphagia, and dysgeusia according to the National Cancer Institute Common Toxicity Criteria, and xerostomia according to parameters set by the Seminars in Radiation Oncology. Mucositis was first observed in the second week and all patients presented some degree of mucositis in the fourth week of radiotherapy. Xerostomia and dysphagia were initially reported already in the first week of radiotherapy. All patients presented xerostomia in the fourth week; however, dysphagia was observed in all patients, only in the sixth week. Dysgeusia was first observed in the second week, becoming more severe in the third week. Acute oral complications can be observed throughout the treatment, but the third week of radiotherapy seems to represent a critical week, regardless of the grade of the complication. The sixth week presents the worst grades of these complications. Knowledge about the natural course of oral complications during radiotherapy is important to develop better strategies for treatment and improve the patients' quality of life.

Quality of life of patients with head and neck cancer after prophylactic percutaneous-gastrostomy

BACKGROUND

HNC patients often experience weight loss during treatment. To date, there is only limited data on patient quality of life (QLQ) and subjective benefit of the PEG insertion.

OBJECTIVE

To investigate the nutritional status, QLQ, and overall benefit.

METHODS

181 patients fitting our inclusion criteria (01/2012-12/2012) were enrolled. Utilization rate, nutritional status, QLQ, and subjective PEG assessment were determined with electronic charts and the Quality of life-questionnaire (EORTC-QLQ-C30).

RESULTS

The utilization rate of the entire cohort was 91.7%. The PEG was used full-time by 149 patients. No statistical differences in QLQ were observed between the groups. Of the patients that used the PEG entirely (99.7%), partially (85.3%) or not all (55.3%) would 99.7%, 85.3 and 55.8% undergo the procedure in the future if necessary.

CONCLUSIONS

QLQ was not significantly reduced by insertion. Especially patients using the PEG full-time had an objective and subjective benefit from the inserted PEG tube.

Nutritional experiences in head and neck cancer patients

OBJECTIVE

Extensive research has documented the negative nutritional impact of head neck cancer (HNC) treatment, but few studies have addressed the patients' experiences. The purpose of this study was to describe how patients with HNC experience the nutritional situation and perceive nutritional support from diagnosis to the post-treatment phase.

METHODS

Patients with HNC were recruited from a randomised pilot study. Individual interviews were conducted after radiotherapy with 10 participants aged 49 - 70 years and analysed by qualitative content analysis.

RESULTS

Undergoing surgery was experienced as a poor nutritional starting point for the upcoming radiotherapy. During radiotherapy, increasing side effects made the participants customise their meals to improve food intake. About halfway through radiotherapy, virtually no food intake was experienced and hospital admissions and initiations of tube-feeding occurred in this period. Oral nutritional supplements were recommended for all, but eventually became unbearable to ingest. When radiotherapy was finally completed, the participants felt discouraged about the persistent side effects preventing them from resume eating. The participants missed tailored information about development of side effects and involvement of a dietitian when reflecting on the treatment-period.

CONCLUSION

The comprehensive nutritional problems experienced by patients with HNC require early nutritional assessments and improved individually tailored nutritional support.

Efficacy of exercise therapy during radiotherapy to prevent reduction in mouth opening in patients with head and neck cancer: A randomized controlled trial

OBJECTIVE

The aim of this study was to compare the efficacy of 2 protocols of exercise therapy to avoid reduction in mouth opening (MO) in patients undergoing radiotherapy for head and neck cancer.

STUDY DESIGN

This was a randomized, controlled, double-blind, 3-arm, parallel-group, prevention clinical trial. Ninety patients were randomized into 3 groups to perform exercises during radiotherapy treatment: intervention group 1 (G1); intervention group 2 (G2); and control group (CG). Maximum MO was measured before (T0), immediately after (T1), and at 12 months (T2) after completion of radiotherapy treatment. Generalized estimating equations model complemented by the least significant difference test was applied to group comparisons.

RESULTS

There was no significant difference in MO measure between the groups at the 3 assessment time points (P = .264). The difference in MO measure from baseline to 12 months after having completed radiotherapy was -1 mm in CG (95% confidence interval [CI] -4.0 to 2.0); 1.3 mm in G1 (95% CI -1.7 to 4.3); and 0.5 mm in G2 (95% CI -3.4 to 4.4).

CONCLUSIONS

It was not possible to conclude that the exercise protocols performed in this study are more effective than the usual guidance to prevent reduction in MO in patients undergoing radiotherapy for head and neck cancer.

The prevalence of patient-reported dysphagia and oral complications in cancer patients

PURPOSE

Research investigating swallowing problems (dysphagia) and complications within the oral cavity in non-head and neck cancer patients is limited. The purpose of this study was to determine the prevalence of patient-reported dysphagia and oral complications in all cancer patients and to examine the relationships between cancer types, oral complications and dysphagia.

METHODS

A cross-sectional study was conducted at a specialist cancer centre in Australia. Data on patient-reported dysphagia and oral complications were collected using the Vanderbilt Head and Neck Symptom Survey (version 2.0) which was completed by participants in one of three settings: inpatients, ambulatory patients receiving chemotherapy, or ambulatory patients receiving radiotherapy.

RESULTS

Data were collected on 239 patients, receiving treatment for 14 cancer types. The proportion of patients who reported dysphagic symptoms were as follows: any dysphagia (54%); dysphagia for liquids (20%); and dysphagia for solids (46%). Significantly more head and neck patients and significantly fewer breast patients reported dysphagia, but there were no differences between other tumour types. Oral symptoms across all cancer types were reported at the following rates: taste changes (62%); xerostomia (56%); voice changes (37%); smell changes (35%); thick mucous (33%); difficulty with teeth/dentures (25%); mouth/throat pain (20%); and trismus (19%).

CONCLUSIONS

This is the first time comprehensive data on dysphagia and oral complications across all cancer patients have been collected. We have identified that dysphagic symptoms and oral complications-which have implications for quality of life and function-are common in all cancer patients, not just those with head and neck cancer.

Reducing Late Dysphagia for Head and Neck Cancer Survivors with Oral Gel: A Feasibility Study

Dysphagia is a significant late morbidity following treatment with radiotherapy (RT) for head and neck squamous cell carcinomas (HNSCC). The purpose of this feasibility study was to test a gel-based saliva substitute to reduce the subjective assessment of dysphagia while eating food items varying in size and texture. Eligible study subjects treated with curative intended RT and suffering from dysphagia and xerostomia were recruited from the outpatient clinic during a two-month period. Nineteen subjects consented to participation and completed the EORTC QLQ-H&N35 questionnaire and three test meals. A Numeric Rating Scale (NRS) was used for subjective assessment of dysphagia during all test meals. All data on patient, tumor, and treatment characteristics were obtained from the Danish Head and Neck Cancer (DAHANCA) database. NRS data suggested reduction of dysphagia after application of the oral gel. The swallowing dysfunctions, discomfort while swallowing (p = 0.008), stuck food items (p = 0.02), and multiple attempts of clearing the throat (p = 0.05), improved significantly for soft and regular items. Both small- and large-sized food items were tested. EORTC QLQ-H&N35 showed improvement regarding eating problems (p = 0.03) and social eating (p = 0.02). No episodes of food aspiration were recorded during the test meals. Late dysphagia reduces QOL and is an important morbidity following RT. In this feasibility study, the oral gel was able to reduce dysphagia while eating soft and selected regular food items. Eating-related EORTC QLQ-H&N35 items also improved, indicating a beneficial reduction in dysphagia after application of the oral gel.

Quality of Life of Postoperative Photon versus Proton Radiation Therapy for Oropharynx Cancer

Purpose:

Quality of life (QOL) for patients with oropharyngeal squamous cell cancer is negatively affected by conventional radiation (RT) owing to radiation exposure to normal tissues. Proton therapy, via pencil beam scanning (PBS), can better spare many of these tissues, and may thereby improve QOL.

Patients and Methods:

Patient-reported outcomes were prospectively collected from patients treated from April 2013 to April 2015. Patients were treated with PBS or intensity-modulated radiation therapy (IMRT) via volumetric arc therapy after transoral robotic surgery. Validated QOL questionnaires were collected before RT, and 3, 6, and 12 months post RT.

Results:

Sixty-four patients were treated with adjuvant RT after transoral robotic surgery, 33 (52%) with volumetric arc therapy, and 31 (48%) with PBS. Both groups were similar in terms of age, site, stage, and dose delivered. Patients receiving PBS had significantly less dose to many normal structures than those receiving IMRT. These dosimetric advantages with PBS were reflected in higher scores in head and neck specific, as well as general, QOL measures. Most notable was significantly less xerostomia with PBS, on multiple patient-reported outcomes at multiple timepoints (6 and 12 months).

Conclusion:

Pencil beam scanning, when compared to IMRT, confers a significant dosimetric advantage to many normal organs at risk, with a corresponding benefit in multiple patient-reported QOL parameters in patients receiving adjuvant RT for oropharyngeal squamous cell cancer.

Unilateral cochlea sparing in locoregionally advanced head and neck cancer: a planning study

BACKGROUND

Cochlea sparing can reduce late ototoxicity in head and neck cancer patients treated with cisplatin-based radiochemotherapy. In this situation, a mean cochlear dose (MCD) constraint of 10 Gy has been suggested by others based on the dose-effect relationship of clinical data. We aimed to investigate whether this is feasible for primary and postoperative radiochemotherapy in locoregionally advanced tumors without compromising target coverage.

PATIENTS AND METHODS

Ten patients treated with definitive and ten patients treated with adjuvant intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy were investigated. The cochleae and a planning risk volume (PRV) with a 3 mm margin were newly delineated, whereas target volumes and other organs at risk were not changed. The initial plan was recalculated with a constraint of 10 Gy (MCD) on the low-risk side. The quality of the resulting plan was evaluated using the difference in the equivalent uniform dose (EUD).

RESULTS

A unilateral MCD of below 10 Gy could be achieved in every patient. The mean MCD was 6.8 Gy in the adjuvant cohort and 7.6 Gy in the definitive cohort, while the non-spared side showed a mean MCD of 18.7 and 30.3 Gy, respectively. The mean PRV doses were 7.8 and 8.4 Gy for the spared side and 18.5 and 29.8 Gy for the non-spared side, respectively. The mean EUD values of the initial and recalculated plans were identical. Target volume was not compromised.

CONCLUSION

Unilateral cochlea sparing with an MCD of less than 10 Gy is feasible without compromising the target volume or dose coverage in locoregionally advanced head and neck cancer patients treated with IMRT. A prospective evaluation of the clinical benefit of this approach as well as further investigation of the dose-response relationship for future treatment modification appears promising.

Assessing Novel Drugs and Radiation Technology in the Chemoradiation of Oropharyngeal Cancer

Integrating immunotherapy, proton therapy and biological dose escalation into the definitive chemoradiation of oropharyngeal cancer poses several challenges. Reliable and reproducible data must be obtained in a timely fashion. However, despite recent international radiotherapy contouring guidelines, controversy persists as to the applicability of such guidelines to all cases. Similarly, a lack of consensus exists concerning both the definition of the organ at risk for oral mucositis and the most appropriate endpoint to measure for this critical toxicity. Finally, the correlation between early markers of efficacy such as complete response on PET CT following treatment and subsequent survival needs elucidation for biological subsets of oropharyngeal cancer.

Oral shedding of human herpesviruses in patients undergoing radiotherapy/chemotherapy for head and neck squamous cell carcinoma is not affected by xerostomia

Background: Xerostomia is a very relevant and frequent complication of radiotherapy, causing the irradiated oral mucosa to be affected by bacterial, fungal and viral infections.

Objective: The objective of this study was to evaluate a possible relationship between oral shedding of human herpesviruses and xerostomia in patients with squamous cell carcinoma of head and neck submitted to radio/chemotherapy.

Methods: In this study, oral rinse samples were collected weekly from 20 patients during radiotherapy. The samples were submitted to PCR and enzymatic digestion for detection of human herpesviruses. Xerostomia was evaluated according to the Seminars in Radiation Oncology criteria.

Results: There was a higher frequency of grade 1 xerostomia (51.4%), observed first in the 1st week of radiotherapy. In the 4th week of radiotherapy, all patients presented some degree of xerostomia. Analysis of herpesviruses showed oral shedding of EBV, HHV-6 and HHV-7 in all weeks. Considering all the periods, the highest frequency was in patients with EBV excretion (55.0%), which was significantly higher than that of other viruses.

Conclusion: We observed that oral shedding of herpesviruses was not affected by xerostomia as there was a progression in their excretion, even with the evolution of xerostomia. This suggested that there is a local replication in the oral cavity that is not completely dependent of salivary excretion.

Altered eating: a definition and framework for assessment and intervention

Background

Eating can be a significant challenge for cancer survivors; however, to date there is no systematic way of assessing and addressing food related quality of life in this group. The purpose of our study was to develop a framework for doing so.

Methods

Over the course of 6 years in participant-led food workshops, we worked alongside 25 head and neck cancer (HNC) survivors and their partners, employing video-reflexive ethnographic (VRE) methods. The current study reports on data from the two summative workshops of this series where we worked with participants to cohere the emergent themes. Video and transcripts were reviewed and coded with participants and stakeholders according to domains of life that were affected by food. Three of the authors, one of whom is both survivor and researcher, arrived at the consensus framework.

Results

Seven areas of life were identified as affecting, or being affected by, altered eating. Three were physiological: anatomical, functional and sensory. Two captured the cognitive and behavioural labour of eating. Social life and identity were altered. The foregoing had an enduring emotional impact.

Conclusions

Altered eating has physical, emotional and social consequences. The altered eating framework provides a systematic way of exploring those consequences with individual survivors. This framework has the potential to improve both the assessment and treatment of altered eating, to benefit food-related quality of life.

Incorporating spatial dose metrics in machine learning-based normal tissue complication probability (NTCP) models of severe acute dysphagia resulting from head and neck radiotherapy

Severe acute dysphagia commonly results from head and neck radiotherapy (RT). A model enabling prediction of severity of acute dysphagia for individual patients could guide clinical decision-making. Statistical associations between RT dose distributions and dysphagia could inform RT planning protocols aiming to reduce the incidence of severe dysphagia. We aimed to establish such a model and associations incorporating spatial dose metrics. Models of severe acute dysphagia were developed using pharyngeal mucosa (PM) RT dose (dose-volume and spatial dose metrics) and clinical data. Penalized logistic regression (PLR), support vector classification and random forest classification (RFC) models were generated and internally (173 patients) and externally (90 patients) validated. These were compared using area under the receiver operating characteristic curve (AUC) to assess performance. Associations between treatment features and dysphagia were explored using RFC models. The PLR model using dose-volume metrics (PLRstandard) performed as well as the more complex models and had very good discrimination (AUC = 0.82) on external validation. The features with the highest RFC importance values were the volume, length and circumference of PM receiving 1 Gy/fraction and higher. The volumes of PM receiving 1 Gy/fraction or higher should be minimized to reduce the incidence of severe acute dysphagia.

Does the total dysphagia risk score correlate with swallowing function examined by videofluoroscopy?

OBJECTIVE

The purpose of this study was to correlate the total dysphagia risk score (TDRS) with swallowing function as measured by videofluoroscopy of swallowing using the swallowing performance scale (SPS) and the penetration aspiration scale (PAS).

METHODS

63 patients from two different centres treated with radiotherapy for head and neck cancer were evaluated in the current study. Swallowing videofluoroscopies at baseline, 6 and 12 months following radiotherapy were evaluated by two observers. The TDRS of all patients was calculated and correlated with the consensus PAS and SPS scores of the two observers.

RESULTS

Regarding the PAS scale, we did not observe a significant correlation with the TDRS. Regarding SPS, we found a significant correlation at 6 months (p = 0.01) and a borderline significant correlation at 12 months (p = 0.05). We observed statistically lower SPS scores for patients in the intermediate-risk category when compared to the high-risk category. When we compared low vs high TDRS risk patients, we did not observe a significant difference regarding SPS scores. When comparing low- vs intermediate-risk patients, we observed higher SPS scores in the low-risk group (p = 0.01). When the low- and intermediate-risk patients were grouped together, we observed less swallowing problems as measured by SPS in the low and intermediate group when compared to the high-risk group (p = 0.05) at 6 months.

CONCLUSION

Patients with high-risk TDRS scores have higher SPS scores when compared to the intermediate group and the intermediate- and low-risk group together. However, low-risk patients in our patient cohort could not be distinguished from high or intermediate-risk patients. Advances in knowledge: TDRS was never correlated with videofluoroscopies in past studies. The hypothesis of this paper was to see if the TDRS could guide us to see which patients are at risk for high scores on SPS and PAS and might need a videofluoroscopic examination in the follow up. Given the poor correlations in our study, however, we cannot recommend the use of the TDRS to select patients who might benefit from the additional information provided by videofluoroscopies.

Treatment of late sequelae after radiotherapy for head and neck cancer

Radiotherapy (RT) is used to treat approximately 80% of patients with cancer of the head and neck. Despite enormous advances in RT planning and delivery, a significant number of patients will experience radiation-associated toxicities, especially those treated with concurrent systemic agents. Many effective management options are available for acute RT-associated toxicities, but treatment options are much more limited and of variable benefit among patients who develop late sequelae after RT. The adverse impact of developing late tissue damage in irradiated patients may range from bothersome symptoms that negatively affect their quality of life to severe life-threatening complications. In the region of the head and neck, among the most problematic late effects are impaired function of the salivary glands and swallowing apparatus. Other tissues and structures in the region may be at risk, depending mainly on the location of the irradiated tumor relative to the mandible and hearing apparatus. Here, we review the available evidence on the use of different therapeutic strategies to alleviate common late sequelae of RT in head and neck cancer patients, with a focus on the critical assessment of the treatment options for xerostomia, dysphagia, mandibular osteoradionecrosis, trismus, and hearing loss.

Voxel-based analysis unveils regional dose differences associated with radiation-induced morbidity in head and neck cancer patients

The risk of radiation-induced toxicity in patients treated for head and neck (HN) cancer with radiation therapy (RT) is traditionally estimated by condensing the 3D dose distribution into a monodimensional cumulative dose-volume histogram which disregards information on dose localization. We hypothesized that a voxel-based approach would identify correlations between radiation-induced morbidity and local dose release, thus providing a new insight into spatial signature of radiation sensitivity in composite regions like the HN district. This methodology was applied to a cohort of HN cancer patients treated with RT at risk of radiation-induced acute dysphagia (RIAD). We implemented an inter-patient elastic image registration framework that proved robust enough to match even the most elusive HN structures and to provide accurate dose warping. A voxel-based statistical analysis was then performed to test regional dosimetric differences between patients with and without RIAD. We identified a significantly higher dose delivered to RIAD patients in two voxel clusters in correspondence of the cricopharyngeus muscle and cervical esophagus. Our study goes beyond the well-established organ-based philosophy exploring the relationship between radiation-induced morbidity and local dose differences in the HN region. This approach is generally applicable to different HN toxicity endpoints and is not specific to RIAD.