Radiotherapy dose-volume parameters predict videofluoroscopy-detected dysphagia per DIGEST after IMRT for oropharyngeal cancer: Results of a prospective registry

Association of Tongue Strength and Maximum Incisal Opening with Oral Intake in Persons with Head and Neck Cancer Treated with Radiotherapy: A Retrospective Study

Persons treated with radiotherapy (RT) for cancer of the head and neck (HNC) may experience limited oral intake at treatment completion. The purpose of this retrospective study was to examine the contributions of tongue strength and maximum incisal opening (MIO) to oral intake in a cohort of veterans treated for HNC. Medical records of veterans diagnosed with HNC treated with RT who were seen by the Speech Pathology Service prior to and throughout treatment per usual care were reviewed for this study; eighty-two records met the inclusion criteria for analysis. Tongue strength in kPa, MIO in mm, feeding tube status at completion of RT, and food and liquid consistencies consumed at completion of RT were among the data abstracted from the records. Most veterans (67%) did not have a feeding tube present at the completion of RT and reported drinking thin liquids (84.2%) at treatment completion. Eighteen percent reported including all food consistencies in their diet at the end of treatment. Both MIO and tongue strength decreased after treatment. Greater tongue strength during RT and larger MIO at the completion of RT were predictive of improved functional outcomes for oral intake at the end of treatment. This study provides evidence of the importance of increasing tongue strength and MIO during treatment with RT, and supports an important focus for intervention by speech-language pathologists.

Clinical Implementation of DIGEST as an Evidence-Based Practice Tool for Videofluoroscopy in Oncology: A Six-Year Single Institution Implementation Evaluation

Clinical implementation of evidence-based practice (EBP) tools is a healthcare priority. The Dynamic Grade of Swallowing Toxicity (DIGEST) is an EBP tool developed in 2016 for videofluoroscopy in head and neck (H&N) oncology with clinical implementation as a goal. We sought to examine: (1) feasibility of clinical implementation of DIGEST in a national comprehensive cancer center, and (2) fidelity of DIGEST adoption in real-world practice. A retrospective implementation evaluation was conducted in accordance with the STARI framework. Electronic health record (EHR) databases were queried for all consecutive modified barium swallow (MBS) studies conducted at MD Anderson Cancer Center from 2016 to 2021. Implementation outcomes included: feasibility as measured by DIGEST reporting in EHR (as a marker of clinical use) and fidelity as measured by accuracy of DIGEST reporting relative to the decision-tree logic (penetration-aspiration scale [PAS], residue, and Safety [S] and Efficiency [E] grades). Contextual factors examined included year, setting, cancer type, MBS indication, and provider. 13,055 MBS were conducted by 29 providers in 7,842 unique patients across the lifespan in diverse oncology populations (69% M; age 1-96 years; 58% H&N cancer; 10% inpatient, 90% outpatient). DIGEST was reported in 12,137/13,088 exams over the 6-year implementation period representing 93% (95% CI: 93-94%) adoption in all exams and 99% (95% CI: 98-99%) of exams excluding the total laryngectomy population (n = 730). DIGEST reporting varied modestly by year, cancer type, and setting/provider (> 91% in all subgroups, p < 0.001). Accuracy of DIGEST reporting was high for overall DIGEST (incorrect SE profile 1.6%, 200/12,137), DIGEST-safety (incorrect PAS 0.4% 51/12,137) and DIGEST-efficiency (incorrect residue 1.2%, 148/12,137). Clinical implementation of DIGEST was feasible with high fidelity in a busy oncology practice across a large number of providers. Adoption of the tool across the lifespan in diverse cancer diagnoses may motivate validation beyond H&N oncology.

Hypoxia-Directed Treatment of Human Papillomavirus-Related Oropharyngeal Carcinoma

PURPOSE

Standard curative-intent chemoradiotherapy for human papillomavirus (HPV)-related oropharyngeal carcinoma results in significant toxicity. Since hypoxic tumors are radioresistant, we posited that the aerobic state of a tumor could identify patients eligible for de-escalation of chemoradiotherapy while maintaining treatment efficacy.

METHODS

We enrolled patients with HPV-related oropharyngeal carcinoma to receive de-escalated definitive chemoradiotherapy in a phase II study (ClinicalTrials.gov identifier: NCT03323463). Patients first underwent surgical removal of disease at their primary site, but not of gross disease in the neck. A baseline 18F-fluoromisonidazole positron emission tomography scan was used to measure tumor hypoxia and was repeated 1-2 weeks intratreatment. Patients with nonhypoxic tumors received 30 Gy (3 weeks) with chemotherapy, whereas those with hypoxic tumors received standard chemoradiotherapy to 70 Gy (7 weeks). The primary objective was achieving a 2-year locoregional control (LRC) of 95% with a 7% noninferiority margin.

RESULTS

One hundred fifty-eight patients with T0-2/N1-N2c were enrolled, of which 152 patients were eligible for analyses. Of these, 128 patients met criteria for 30 Gy and 24 patients received 70 Gy. The 2-year LRC was 94.7% (95% CI, 89.8 to 97.7), meeting our primary objective. With a median follow-up time of 38.3 (range, 22.1-58.4) months, the 2-year progression-free survival (PFS) and overall survival (OS) rates were 94% and 100%, respectively, for the 30-Gy cohort. The 70-Gy cohort had similar 2-year PFS and OS rates at 96% and 96%, respectively. Acute grade 3-4 adverse events were more common in 70 Gy versus 30 Gy (58.3% v 32%; P = .02). Late grade 3-4 adverse events only occurred in the 70-Gy cohort, in which 4.5% complained of late dysphagia.

CONCLUSION

Tumor hypoxia is a promising approach to direct dosing of curative-intent chemoradiotherapy for HPV-related carcinomas with preserved efficacy and substantially reduced toxicity that requires further investigation.

Dysphagia at 1 Year is Associated With Mean Dose to the Inferior Section of the Brain Stem

PURPOSE

Dysphagia is a common toxicity after head and neck (HN) radiation therapy that negatively affects quality of life. We explored the relationship between radiation therapy dose to normal HN structures and dysphagia 1 year after treatment using image-based datamining (IBDM), a voxel-based analysis technique.

METHODS AND MATERIALS

We used data from 104 patients with oropharyngeal cancer treated with definitive (chemo)radiation therapy. Swallow function was assessed pretreatment and 1 year posttreatment using 3 validated measures: MD Anderson Dysphagia Inventory (MDADI), performance status scale for normalcy of diet (PSS-HN), and water swallowing test (WST). For IBDM, we spatially normalized all patients' planning dose matrices to 3 reference anatomies. Regions where the dose was associated with dysphagia measures at 1 year were found by performing voxel-wise statistics and permutation testing. Clinical factors, treatment variables, and pretreatment measures were used in multivariable analysis to predict each dysphagia measure at 1 year. Clinical baseline models were found using backward stepwise selection. Improvement in model discrimination after adding the mean dose to the identified region was quantified using the Akaike information criterion. We also compared the prediction performance of the identified region with a well-established association: mean doses to the pharyngeal constrictor muscles.

RESULTS

IBDM revealed highly significant associations between dose to distinct regions and the 3 outcomes. These regions overlapped around the inferior section of the brain stem. All clinical models were significantly improved by including mean dose to the overlap region (P ≤ .006). Including pharyngeal dosimetry significantly improved WST (P = .04) but not PSS-HN or MDADI (P ≥ .06).

CONCLUSIONS

In this hypothesis-generating study, we found that mean dose to the inferior section of the brain stem is strongly associated with dysphagia 1 year posttreatment. The identified region includes the swallowing centers in the medulla oblongata, providing a possible mechanistic explanation. Further work including validation in an independent cohort is required.

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.

Head and Neck Radiation Therapy Patterns of Practice Variability Identified as a Challenge to Real-World Big Data: Results From the Learning from Analysis of Multicentre Big Data Aggregation (LAMBDA) Consortium

Purpose

Outside of randomized clinical trials, it is difficult to develop clinically relevant evidence-based recommendations for radiation therapy (RT) practice guidelines owing to lack of comprehensive real-world data. To address this knowledge gap, we formed the Learning from Analysis of Multicenter Big Data Aggregation consortium to cooperatively implement RT data standardization, develop software solutions for data analysis, and recommend clinical practice change based on real-world data analyzed. The first phase of this "Big Data" study aimed at characterizing variability in clinical practice patterns of dosimetric data for organs at risk (OARs) that would undermine subsequent use of large-scale, electronically aggregated data to characterize associations with outcomes. Evidence from this study was used as the basis for practical recommendations to improve data quality.

Methods and Materials

Dosimetric details of patients with head and neck cancer treated with radiation therapy between 2014 and 2019 were analyzed. Institutional patterns of practice were characterized, including structure nomenclature, volumes, and frequency of contouring. Dose volume histogram (DVH) distributions were characterized and compared with institutional constraints and literature values.

Results

Plans for 4664 patients treated to a mean plan dose of 64.4 ± 13.2 Gy in 32 ± 4 fractions were aggregated. Before implementation of TG-263 guidelines in each institution, there was variability in OAR nomenclature across institutions and structures. With evidence from this study, we identified a targeted and practical set of recommendations aimed at improving the quality of real-world data.

Conclusions

Quantifying similarities and differences among institutions for OAR structures and DVH metrics is the launching point for next steps to investigate potential relationships between DVH parameters and patient outcomes.

Discriminant Ability of the Eating Assessment Tool-10 to Detect Swallowing Safety and Efficiency Impairments

OBJECTIVES/HYPOTHESIS

Quick, sensitive dysphagia screening tools are necessary to identify high-risk patients for further evaluation in busy multidisciplinary amyotrophic lateral sclerosis (ALS) clinics. We examined the relationship between self-perceived dysphagia using the validated Eating Assessment Tool-10 (EAT-10) and videofluoroscopic analysis of swallowing safety and efficiency.

STUDY DESIGN

Prospective, observational, longitudinal study.

METHODS

Individuals with ALS completed the EAT-10 and a videofluoroscopic swallowing study. Duplicate, independent, blinded analyses of the validated Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) scale were performed to index swallowing safety and efficiency (mild dysphagia: DIGEST ≥ 1, moderate dysphagia: DIGEST ≥ 2). A between-groups analysis of variance with Games-Howell test for post-hoc pairwise comparisons was performed to examine EAT-10 scores across dysphagia severity levels. Receiver operator characteristic curve analysis, area under the curve (AUC), sensitivity, specificity, positive-negative predictive values (PPV, NPV), and odds ratios (OR) were derived.

RESULTS

Four hundred and thirty five paired EAT-10 and DIGEST scores were analyzed. Mean EAT-10 score was 8.48 (95% confidence interval [CI]: 7.63-9.33). Individuals with dysphagia demonstrated higher EAT-10 scores (mild: 4.1 vs. 11.3, moderate: 6.0 vs. 17.5, P < .001). Mean EAT-10 scores increased across DIGEST levels (D0: 4.1, D1: 7.9, D2: 15.1, D3: 20.4, D4: 39.0). For mild dysphagia, an EAT-10 cut score of 3 was optimal: AUC 0.74 (95% CI: 0.69-0.78; sensitivity: 77%; specificity: 53%; PPV: 71%; NPV: 60%; OR: 3.5). An EAT-10 cut score of 7 optimized detection of moderate dysphagia: AUC 0.83 (95% CI: 0.78-0.87; sensitivity: 81%; specificity: 66%; PPV: 39%; NPV: 93%; OR: 8.1).

CONCLUSION

The EAT-10 is an easy-to-administer dysphagia screening tool with good discriminant ability for use in ALS clinics.

LEVEL OF EVIDENCE

2 Laryngoscope, 132:2319-2326, 2022.

Estimating the optimal linear combination of predictors using spherically constrained optimization

BACKGROUND

In the context of a binary classification problem, the optimal linear combination of continuous predictors can be estimated by maximizing the area under the receiver operating characteristic curve. For ordinal responses, the optimal predictor combination can similarly be obtained by maximization of the hypervolume under the manifold (HUM). Since the empirical HUM is discontinuous, non-differentiable, and possibly multi-modal, solving this maximization problem requires a global optimization technique. Estimation of the optimal coefficient vector using existing global optimization techniques is computationally expensive, becoming prohibitive as the number of predictors and the number of outcome categories increases.

RESULTS

We propose an efficient derivative-free black-box optimization technique based on pattern search to solve this problem, which we refer to as Spherically Constrained Optimization Routine (SCOR). Through extensive simulation studies, we demonstrate that the proposed method achieves better performance than existing methods including the step-down algorithm. Finally, we illustrate the proposed method to predict the severity of swallowing difficulty after radiation therapy for oropharyngeal cancer based on radiation dose to various structures in the head and neck.

CONCLUSIONS

Our proposed method addresses an important challenge in combining multiple biomarkers to predict an ordinal outcome. This problem is particularly relevant to medical research, where it may be of interest to diagnose a disease with various stages of progression or a toxicity with multiple grades of severity. We provide the implementation of our proposed SCOR method as an R package, available online at https://CRAN.R-project.org/package=SCOR .

Adhering to Eat and Exercise Status During Radiotherapy for Oropharyngeal Cancer for Prevention and Mitigation of Radiotherapy-Associated Dysphagia

Importance

Previously published work reported independent benefit of maintenance of oral intake (eat) and swallowing exercise adherence (exercise) during radiotherapy (RT) on diet and functional outcomes. The current study seeks to validate the authors' previously published findings in a large contemporary cohort of patients with oropharynx cancer (OPC) and address limitations of the prior retrospective study using prospective, validated outcome measures.

Objective

To examine the longitudinal association of oral intake and swallowing exercise using validated, clinician-graded and patient-reported outcomes.

Design, Setting, and Participants

Secondary analysis of a prospective OPC registry including patients who underwent primary RT/chemoradiotherapy (CRT) or primary transoral robotic surgery plus RT/CRT for OPC at a single-institution comprehensive cancer center.

Exposures

Adherence to speech pathology swallowing intervention during RT coded as (1) eat: oral intake at end of RT (nothing by mouth [NPO]; partial oral intake [PO], with feeding tube [FT] supplement; full PO); and (2) exercise: swallowing exercise adherence (nonadherent vs partial/full adherence).

Main Outcomes and Measures

Feeding tube and diet (Performance Status Scale for Head and Neck Cancer) patient-reported swallowing-related quality of life (MD Anderson Dysphagia Inventory; MDADI) and clinician-graded dysphagia severity grade (videofluoroscopic Dynamic Imaging Grade of Swallowing Toxicity; DIGEST) were collected at baseline, 3 to 6 months, and 18 to 24 months post-RT.

Results

A total of 595 patients (mean [SD] age, 65 [10] years; 532 [89%] male) who underwent primary RT (111 of 595 [19%]), CRT (434 of 595 [73%]), or primary transoral robotic surgery plus RT/CRT (50 of 595 [8%]) were included in this cohort study. At the end of RT, 55 (9%) patients were NPO, 115 (19%) were partial PO, 425 (71%) were full PO, and 340 (57%) reported exercise adherence. After multivariate adjustment, subacute return to solid diet and FT were independently associated with oral intake (odds ratio [OR], 2.0; 95% CI, 1.0-4.1; OR, 0.1; 95% CI, 0.0-0.2, respectively) and exercise (OR, 2.9; 95% CI, 1.9-4.5; OR, 0.3; 95% CI, 0.1-0.5, respectively). Subacute MDADI (β = 6.5; 95% CI, 1.8-11.2), FT duration (days; β = -123.4; 95% CI, -148.5 to -98.4), and less severe dysphagia per DIGEST (OR, 0.6; 95% CI, 0.3-1.0) were independently associated with oral intake, while exercise was independently associated with less severe laryngeal penetration/aspiration per DIGEST-safety (OR, 0.7; 95% CI, 0.4-1.0). DIGEST grade associations with oral intake were not preserved long-term; however, exercise was associated with a higher likelihood of solid diet intake and better swallow safety per DIGEST.

Conclusions and Relevance

The findings of this cohort study extend the authors' previously published findings that oral intake and swallowing exercise during RT are associated with favorable functional outcomes, now demonstrated with broader domains of function using validated measures. Patterns of benefit differed in this study. Specifically, better subacute recovery of swallow-related quality of life and less severe dysphagia were found among patients who maintained oral intake independent of exercise adherence, and shorter FT utilization and better long-term diet and swallowing safety were found among those who exercised independent of oral intake.

Swallowing After Primary TORS and Unilateral or Bilateral Radiation for Low- to Intermediate-Risk Tonsil Cancer

OBJECTIVE

The primary course of treatment for patients with low- to intermediate-risk tonsil cancer has evolved with a shift toward primary transoral robotic surgery (TORS) or radiation therapy (RT). While favorable outcomes have been reported after deintensification via unilateral TORS or RT (uniRT), comparisons of functional outcomes between these treatments are lacking. We compared clinical outcomes (Dynamic Imaging Grade of Swallowing Toxicity [DIGEST] and feeding tube [FT]) and patient-reported swallowing outcomes (MD Anderson Dysphagia Inventory [MDADI]) based on primary treatment strategy: TORS, uniRT, or bilateral RT (biRT).

STUDY DESIGN

Secondary analysis of prospective cohort.

SETTING

Single institution.

METHODS

The study sample comprised 135 patients with HPV/p16+ T1-T3, N0-2b (American Joint Committee on Cancer, seventh edition), N0-1 (eighth edition) squamous cell carcinoma of the tonsil were sampled from a prospective registry. Modified barium swallow studies graded per DIGEST, FT placement and duration, and MDADI were collected.

RESULTS

Baseline DIGEST grade significantly differed among treatment groups, with higher dysphagia prevalence in the TORS group (34%) vs the biRT group (12%, P = .04). No significant group differences were found in DIGEST grade or dysphagia prevalence at subacute and longitudinal time points (P = .41). Mean MDADI scores were similar among groups at baseline (TORS, 92; uniRT, 93; biRT, 93; P = .90), subacute (TORS, 83; uniRT, 88; biRT, 82; P = .38) and late time points (TORS, 86; uniRT, 86; biRT, 87; P = .99). FT placement and duration significantly differed among primary treatment groups (FT [median days]: TORS, 89% [3]; uniRT, 8% [82]; biRT, 37% [104]; P < .001).

CONCLUSION

While TORS and uniRT offer optimal functional outcomes related to dysphagia, results suggest that no measurable clinician-graded or patient-reported differences in swallow outcomes exist among these primary treatment strategies and biRT. Aside from baseline differences that drive treatment selection, differences in FT rate and duration by primary treatment strategy likely reflect diverse toxicities beyond dysphagia.

Refining measurement of swallowing safety in the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) criteria: Validation of DIGEST version 2

BACKGROUND

Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) is a validated method to grade the severity of pharyngeal swallowing impairment as a toxicity of cancer based on the degree and patterns of penetration/aspiration and pharyngeal residue over a standardly acquired radiographic modified barium swallow (MBS) study. Since its implementation in 2016, areas for the refinement of grading mild safety impairments have been identified by clinical and research users. The objective of this study was to assess the performance and validity of refined DIGEST_safety grading criteria (per DIGEST version 2 [DIGEST_v2 ]).

METHODS

Refined safety criteria were developed and vetted with clinical and research users. DIGEST_v2 included 2 changes to the safety criteria. All MBSs with blinded DIGEST version 1 grading were sampled from a registry database (1331 patients underwent MBS over the period of December 2005 to July 2019). New criteria were applied to derive DIGEST_safety grading version 2. Measures of criterion validity, including the MD Anderson Dysphagia Inventory [MDADI] composite score, the Modified Barium Swallow Impairment Profile (MBSImP) pharyngeal total, the MBSImP hyolaryngeal components (items 8-11), and the Performance Status Scale for Head and Neck Cancer Patients [PSS-HN] diet, were correlated with DIGEST_safety and overall DIGEST grades from versions 1 and 2 and were compared pairwise between reassigned grades.

RESULTS

With the application of version 2 safety criteria, 112 of 1331 examinations (8.4%) and 79 of 1331 examinations (5.9%) changed in their DIGEST_safety and overall grades, respectively. The safety and overall DIGEST grades (versions 1 and 2) significantly correlated with criterion measures, including the MBSImP pharyngeal total, laryngeal MBSImP parameters of interest, MDADI, and PSS-HN (P < .0001); correlations maintained a similar magnitude between versions 1 and 2. Forty-six upgraded examinations (reassigned from safety grade 1 per version 1 to grade 2 per version 2) performed similarly to other safety grade 2 examinations (version 1), and this was likewise true for 66 downgraded examinations (reassigned from safety grade 1 per version 1 to grade 0 per version 2).

CONCLUSIONS

Refined criteria defining mild safety impairments with the DIGEST methodology changed grades in small numbers of examinations. DIGEST_v2 criteria maintained criterion validity, demonstrated ordinality, and improved the performance of the method in these rare scenarios.

LAY SUMMARY

Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) is a method developed and validated by the investigators in 2016 to grade the severity of pharyngeal swallowing dysfunction (dysphagia) with a decision tree or flowsheet to guide the clinician's review of a standard radiographic modified barium swallow study. This work reports on the validity of updated DIGEST criteria (version 2) that incorporate 2 modifications to the decision tree.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

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.

Risk and Clinical Risk Factors Associated With Late Lower Cranial Neuropathy in Long-term Oropharyngeal Squamous Cell Carcinoma Survivors

Importance

Lower cranial neuropathy (LCNP) is a rare, but permanent, late effect of radiotherapy and other cancer therapies. Lower cranial neuropathy is associated with excess cancer-related symptoms and worse swallowing-related quality of life. Few studies have investigated risk and clinical factors associated with late LCNP among patients with long-term survival of oropharyngeal squamous cell carcinoma (OPSCC survivors).

Objective

To estimate the cumulative incidence of and identify clinical factors associated with late LCNP among long-term OPSCC survivors.

Design, Setting, and Participants

This single-institution cohort study included disease-free adult OPSCC survivors who completed curative treatment from January 1, 2000, to December 31, 2013. Exclusion criteria consisted of baseline LCNP, recurrent head and neck cancer, treatment at other institutions, death, and a second primary, persistent, or recurrent malignant neoplasm of the head and neck less than 3 months after treatment. Median survival of OPSCC among the 2021 eligible patients was 6.8 (range, 0.3-18.4) years. Data were analyzed from October 12, 2019, to November 13, 2020.

Main Outcomes and Measures

Late LCNP events were defined by neuropathy of the glossopharyngeal, vagus, and/or hypoglossal cranial nerves at least 3 months after cancer therapy. Cumulative incidence of LCNP was estimated using the Kaplan-Meier method, and multivariable Cox proportional hazards models were fit.

Results

Among the 2021 OPSCC survivors included in the analysis of this cohort study (1740 [86.1%] male; median age, 56 [range, 28-86] years), 88 (4.4%) were diagnosed with late LCNP, with median time to LCNP of 5.4 (range, 0.3-14.1) years after treatment. Cumulative incidence of LCNP was 0.024 (95% CI, 0.017-0.032) at 5 years, 0.061 (95% CI, 0.048-0.078) at 10 years, and 0.098 (95% CI, 0.075-0.128) at 15 years of follow-up. Multivariable Cox proportional hazards regression identified T4 vs T1 classification (hazard ratio [HR], 3.82; 95% CI, 1.85-7.86) and accelerated vs standard radiotherapy fractionation (HR, 2.15; 95% CI, 1.34-3.45) as independently associated with late LCNP status, after adjustment. Among the subgroup of 1986 patients with nonsurgical treatment, induction chemotherapy regimens including combined docetaxel, cisplatin, and fluorouracil (TPF) (HR, 2.51; 95% CI, 1.35-4.67) and TPF with cetuximab (HR, 5.80; 95% CI, 1.74-19.35) along with T classification and accelerated radiotherapy fractionation were associated with late LCNP status after adjustment.

Conclusions and Relevance

This single-institution cohort study found that, although rare in the population overall, cumulative risk of late LCNP progressed to 10% during the survivors' lifetime. As expected, clinical factors associated with LCNP primarily reflected greater tumor burden and treatment intensity. Further efforts are necessary to investigate risk-reduction strategies as well as surveillance and management strategies for this disabling late effect of cancer treatment.

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.

Dysphagia profiles after primary transoral robotic surgery or radiation for oropharyngeal cancer: A registry analysis

OBJECTIVE

To describe the physiologic swallowing impairments (MBSImP™©) associated with safety/efficiency impairments (DIGEST_safety /DIGEST_efficiency grades) at 3-6 months after transoral robotic surgery (TORS) or radiation therapy (RT).

STUDY DESIGN

Secondary analysis of registry data.

SETTING

Single, academic institution.

METHODS

Two hundred and fifty-seven patients with HPV+ oropharynx cancer were stratified by primary treatment (75 TORS, 182 RT). Modified barium swallow studies were analyzed at baseline and 3-6 months using MBSImP scores and DIGEST_safety /DIGEST_efficiency grades. DIGEST_safety /DIGEST_efficiency grades and MBSImP were compared groupwise and associations between DIGEST_safety /DIGEST_efficiency grades and MBSImP were explored by ordinal logistic regression. Exploratory analyses were stratified by multimodality treatment.

RESULTS

Neither DIGEST_safety /DIGEST_efficiency differed significantly between groups at baseline or 3-6 months. Laryngeal vestibule closure was impaired more frequently in the RT group (RT: 41% vs. TORS: 27%; p = 0.02) while the TORS group had significantly more pharyngeal contraction impairment (63%; p < 0.001) compared to RT at 3-6 months.

CONCLUSION

The results suggest a focal injury associated with DIGEST_safety /DIGEST_efficiency post-TORS in contrast to a low-level diffuse physiologic impairment associated with post-RT dysphagia.

Early MRI Blood Volume Changes in Constrictor Muscles Correlate With Postradiation Dysphagia

PURPOSE

Predicting individual patient sensitivity to radiation therapy (RT) for tumor control or normal tissue toxicity is necessary to individualize treatment planning. In head and neck cancer, radiation doses are limited by many nearby critical structures, including structures involved in swallowing. Previous efforts showed that imaging parameters correlate with RT dose; here, we investigate the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) blood volume (BV) changes in predicting dysphagia.

METHODS AND MATERIALS

This study included 32 patients with locally advanced oropharyngeal squamous cell carcinoma treated with definitive chemoradiation on an institutional protocol incorporating baseline and early midtreatment DCE-MRI. BV maps of the pharyngeal constrictor muscles (PCM) were created, and BV increases midtreatment were correlated with the following parameters at 3 and 12 months post-RT: RT dose, Dynamic Imaging Grade of Swallowing Toxicity swallow score, aspiration frequency, European Organisation for Research and Treatment of Cancer HN35 patient-reported outcomes, physician-reported dysphagia, and feeding tube (FT) dependence.

RESULTS

The mean BV to the PCMs increased from baseline to fraction 10, which was significant for the superior PCM (P = .006) and middle PCM (P < .001), with a trend in the inferior PCM where lower mean doses were seen (P = .077). The factors associated with FT dependence at 3 months included BV increases in the total PCM (correlation, 0.48; P = .006) and middle PCM (correlation, 0.50; P = .004). A post-RT increase in aspiration was associated with a BV increase in the superior PCM (correlation, 0.44; P = .013),and the increase in the total PCMs was marginally significant (correlation, 0.34; P = .06). The best-performing models of FT dependence (area under the receiver operating curve [AUC] = 0.84) and aspiration increases (AUC = 0.78) included BV increases as well as a mean RT dose to middle PCM.

CONCLUSIONS

Our results suggest that midtreatment BV increases derived from DCE-MRI are an early predictor of dysphagia. Further investigation of these promising imaging markers to assess individual patient sensitivity to treatment and the patient's subsequent risk of toxicities is warranted to improve personalization of RT planning.

The impact of tongue-deviating and tongue-depressing oral stents on long-term radiation-associated symptoms in oropharyngeal cancer survivors

OBJECTIVES

To evaluate whether the use of oral stents during intensity modulated radiation therapy (IMRT) for oropharyngeal cancer (OPC) is associated with long-term patient reported symptoms.

MATERIALS AND METHODS

Data was obtained from a prospective observational study of disease-free head and neck cancer survivors. Radiation-associated patient reported symptoms were assessed using the MD Anderson Symptom Inventory Head and Neck module (MDASI-HN). Scores of ≥5 (11-point Likert scale, 0-10) were considered moderate/severe. Stratification was performed regarding IMRT volume (uni- versus bilateral neck) and stent utilization, with non-parametric analyses between groups.

RESULTS

462 OPC survivors formed the cohort (54% tonsil, 46% base of tongue primaries). A tongue-deviating stent was used in 17%, tongue-depressing stent in 46%, and no stent in 37%. Median prescribed dose to the high dose clinical target volume was 66.0 Gy. Median follow-up from RT to MDASI-HN assessment was 68 months. Twenty percent had received unilateral neck RT (all had tonsil primaries), in whom a significant improvement in the proportion of patients with moderate/severe taste impairment (2% vs. 15%, p = 0.047) and lack of appetite (0% vs. 9%, p = 0.019) was associated with the use of tongue-deviating stents compared to no oral stent. In those who had received bilateral neck RT, a significant improvement in the proportion of patients with moderate/severe difficulty swallowing/chewing was associated with use of a tongue-depressing stent (21% vs. 31% without oral stent, p = 0.013).

CONCLUSION

Disease-site specific select use of oral stents during IMRT was associated with reduced long-term patient reported symptoms in OPC survivors.

Characterization of very late dysphagia after chemoradiation for oropharyngeal squamous cell carcinoma

OBJECTIVES

Improved prognosis for p16+ oropharyngeal squamous cell carcinoma (OPSCC) has led to efforts to mitigate long-term complications of treatment, which remains poorly defined in late survivors. Here we characterize very late dysphagia in OPSCC.

MATERIALS AND METHODS

Long-term review of 93 p16+ OPSCC patients treated with chemoradiation was performed. We scored videofluoroscopic swallow studies (VFSS) according to the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) scale. Very late dysphagia was defined >2.5 years from end of treatment. Fine-Gray regression models were used to assess dysphagia with competing risk of death.

RESULTS

Median follow up was 10.5 years. 402 total VFSS were assessed (median 4 per patient, range 0-8). 15.1% of patients had a DIGEST score ≥2 very late after treatment. Very late DIGEST score ≥2 correlated with T-stage (HR 1.7, p = 0.049), second cancer (HR 6.5, p = 0.004), superior pharyngeal constrictor dose (HR 1.11, p = 0.050), total tongue dose (HR 1.07, p = 0.045), but not hypoglossal nerve dose (p > 0.2). Seven patients (7.5%) had late progressive dysphagia, defined as DIGEST score that increased by ≥2 beyond one year after treatment, and this correlated with higher ipsilateral hypoglossal nerve D1cc dose (75 vs 72 Gy, p = 0.037).

CONCLUSION

In p16+ OPSCC patients treated with definitive chemoradiation, at least 7.5% developed late progressive dysphagia, and 15.1% experienced moderate dysphagia >2.5 years from treatment. Our study suggests that dose to tongue musculature may be associated with very late dysphagia, and hypoglossal nerve dose may be associated with late progressive dysphagia. More intensive long-term dysphagia survivorship monitoring is suggested.

Prospective longitudinal patient-reported outcomes of swallowing following intensity modulated proton therapy for oropharyngeal cancer

BACKGROUND AND PURPOSE

With an enlarging population of long-term oropharyngeal cancer survivors, dysphagia is an increasingly important toxicity following oropharynx cancer treatment. While lower doses to normal surrounding structures may be achieved with intensity modulated proton therapy (IMPT) compared to photon-based radiation, the clinical benefit is uncertain.

METHODS AND MATERIALS

Seventy-one patients with stage III/IV oropharyngeal cancer (AJCC 7th edition) undergoing definitive IMPT on a longitudinal prospective cohort study who had completed the MD Anderson Dysphagia Inventory (MDADI) at pre-specified time points were included.

RESULTS

The majority of patients had HPV-positive tumors (85.9%) and received bilateral neck radiation (81.4%) with concurrent systemic therapy (61.8%). Mean composite MDADI scores decreased from 88.2 at baseline to 59.6 at treatment week 6, and then increased to 74.4 by follow up week 10, 77.0 by 6 months follow up, 80.5 by 12 months follow up, and 80.1 by 24 months follow up. At baseline, only 5.6% of patients recording a poor composite score (lower than 60), compared to 61.2% at treatment week 6, 19.1% at follow up week 10, 13.0% at 6 months follow up, 13.5% at 1 year follow up, and 11.1% at 2 years follow up.

CONCLUSIONS

Patient reported outcomes following IMPT for oropharyngeal cancer demonstrates decreased swallowing function at completion of treatment with relatively rapid recovery by 10 weeks follow up and steady improvement through 2 years. The results are comparable to similar longitudinal studies of photon-based radiotherapy for oropharynx cancer, and suggest that IMPT confers no additional excess toxicity related to swallowing.

Assessing patient-reported symptom burden of long-term head and neck cancer survivors at annual surveillance in survivorship clinic

BACKGROUND

This study reports long-term head and neck cancer (HNC) patient-reported symptoms using the MD Anderson Symptom Inventory Head and Neck Cancer Module (MDASI-HN) in a large cohort of HNC survivors.

METHODS

MDASI-HN results were prospectively collected from an institutional survivorship database. Associations with clinicopathologic data were analyzed using χ² , Mann-Whitney, and univariate regression.

RESULTS

Nine hundred and twenty-eight patients were included. Forty-six percent had oropharyngeal primary tumors. Eighty-two percent had squamous cell carcinoma. Fifty-six percent of patients had ablative surgery and 81% had radiation therapy as a component of treatment. The most severe symptoms were xerostomia and dysphagia. Symptom scores were worst for hypopharynx and varied by subsite. Patients treated with chemoradiation or surgery followed by radiation ± chemotherapy reported the worst symptoms while patient treated with surgery plus radiation ± chemotherapy reported the worst interference.

CONCLUSION

HNC survivors describe their long-term symptom burden and inform efforts to improve care many years into survivorship.

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.

Combination of a Big Data Analytics Resource System With an Artificial Intelligence Algorithm to Identify Clinically Actionable Radiation Dose Thresholds for Dysphagia in Head and Neck Patients

Purpose

We combined clinical practice changes, standardizations, and technology to automate aggregation, integration, and harmonization of comprehensive patient data from the multiple source systems used in clinical practice into a big data analytics resource system (BDARS). We then developed novel artificial intelligence algorithms, coupled with the BDARS, to identify structure dose volume histograms (DVH) metrics associated with dysphagia.

Methods and Materials

From the BDARS harmonized data of ≥22,000 patients, we identified 132 patients recently treated for head and neck cancer who also demonstrated dysphagia scores that worsened from base line to a maximum grade ≥2. We developed a method that used both physical and biologically corrected (α/β = 2.5) DVH curves to test both absolute and percentage volume based DVH metrics. Combining a statistical categorization algorithm with machine learning (SCA-ML) provided more extensive detailing of response threshold evidence than either approach alone. A sensitivity guided, minimum input, machine learning (ML) model was iteratively constructed to identify the key structure DVH metric thresholds.

Results

Seven swallowing structures producing 738 candidate DVH metrics were ranked for association with dysphagia using SCA-ML scoring. Structures included superior pharyngeal constrictor (SPC), inferior pharyngeal constrictor (IPC), larynx, and esophagus. Bilateral parotid and submandibular gland (SG) structures were categorized by relative mean dose (eg, SG_high, SG_low) as a dose versus tumor centric analog to contra and ipsilateral designations. Structure DVH metrics with high SCA-ML scores included the following: SPC: D20% (equivalent dose [EQD2] Gy) ≥47.7; SPC: D25% (Gy) ≥50.4; IPC: D35% (Gy) ≥61.7; parotid_low: D60% (Gy) ≥13.2; and SG_high: D35% (Gy) ≥61.7. Larynx: D25% (Gy) ≥21.2 and SG_low: D45% ≥28.2 had high SCA-ML scores but were segmented on less than 90% of plans. A model based on SPC: D20% (EQD2 Gy) alone had sensitivity and area under the curve of 0.88 ± 0.13 and 0.74 ± 0.17, respectively.

Conclusions

This study provides practical demonstration of combining big data with artificial intelligence to increase volume of evidence in clinical learning paradigms.

Preliminary Simulation Study of Carotid Artery and Pharyngeal Constrictor Muscle Sparing-Radiotherapy in Glottic Carcinoma

Background:

This preliminary simulation study aimed to compare the dosimetric outcomes of carotid arteries (CAs) and pharyngeal constrictor muscle (PCM) in patients with T1N0M0 glottic carcinoma undergoing helical tomotherapy-intensity modulated radiotherapy (HT-IMRT) and 3-dimensional conformal radiotherapy (3D-CRT) plans.

Methods:

In addition to the clinical target volume (CTV) which was defined as the entire larynx, the CAs and PCM of 11 glottic carcinoma patients were delineated. The CTV was uniformly expanded 5 mm to create a planning target volume (PTV) relative to the PCM and at a distance of 2 mm from the CA. The dosimetric characteristics in HT-IMRT and lateral opposed fields-based 3D-CRT plans were analyzed.

Results:

Median D_95%and V_100% of PTV were significantly higher in HT-IMRT (p < 0.001) compared to 3D-CRT. The right/left CA dosimetric outcomes, including the mean doses (20.7/21.5 Gy versus 48.7/50.5 Gy), D_max (53.6/52.0 Gy versus 67.4/67.7 Gy), V₃₀ (25.0/27.1% versus 77.6/80.3%), V₄₀ (8.0/7.9% versus 74.6/71.9%), and V₅₀ (2.0/1.2% versus 70.0/71.6%) were also significantly lower in HT-IMRT (p < 0.05), similar to the mean PCM doses (49.6 Gy versus 62.6 Gy for 3D-CRT;p < 0.001), respectively.

Conclusions:

Our present results demonstrated the feasibility of simultaneous sparing of the CAs and PCM in HT-IMRT- compared to 3D-CRT plans in glottic carcinoma patients undergoing definitive radiotherapy.

Dysphagia After Primary Transoral Robotic Surgery With Neck Dissection vs Nonsurgical Therapy in Patients With Low- to Intermediate-Risk Oropharyngeal Cancer

Importance

A major goal of primary transoral robotic surgery (TORS) for oropharyngeal cancer is to optimize swallowing outcomes by personalized treatment based on pathologic staging. However, swallowing outcomes after TORS are uncertain, as are the outcomes compared with nonsurgical options.

Objectives

To estimate rates of acute dysphagia and recovery after TORS and to compare swallowing outcomes by primary treatment modality (TORS or radiotherapy).

Design, Setting, and Participants

This case series study was a secondary analysis of prospective registry data from 257 patients enrolled from March 1, 2015, to February 28, 2018, at a single academic institution who, according to the AJCC Staging Manual, 7th edition TNM classification, had low- to intermediate-risk human papillomavirus-related oropharyngeal squamous cell carcinoma possibly resectable by TORS.

Exposure

Patients were stratified by primary treatment (75 underwent TORS and 182 received radiotherapy).

Main Outcomes and Measures

Modified barium swallow (MBS) studies graded per Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) and the MD Anderson Symptom Inventory-Head and Neck Module (MDASI-HN) questionnaires were administered at standard intervals. Prevalence and severity of dysphagia were estimated per DIGEST before and after TORS and 3 to 6 months after treatment. Moderate-severe dysphagia (DIGEST grade ≥2) was assessed using logistic regression and compared by primary treatment group. The MDASI swallowing symptom severity item scores during and after radiotherapy were compared using generalized estimating equations by treatment status at the start of radiotherapy, after induction, and after TORS.

Results

A total of 257 patients (mean [SD] age, 59.54 [9.07] years; 222 [86.4%] male) were included in the study. Dysphagia severity (per DIGEST) was significantly worse after TORS (r = -0.63; 95% CI, -0.78 to -0.44): 17 patients (22.7%; 95% CI, 13.8%-33.8%) had moderate-severe (DIGEST grade ≥2) acute post-TORS dysphagia significantly associated with primary tumor volume (odds ratio, 1.43; 95% CI, 1.11-1.84). DIGEST improved by 3 to 6 months but remained worse than that at baseline; at 3 to 6 months, the number of patients with DIGEST grade 2 or higher dysphagia was 5 (6.7%; 95% CI, 2.2%-14.9%) after primary TORS and 29 (15.9%; 95% CI, 10.9%-22.1%) after radiotherapy. At the start of radiotherapy, MDASI swallowing symptom severity item scores were significantly worse in the post-TORS group compared with postinduction (mean [SD] change, 2.6 [1.1]) and treatment-naive (mean [SD] change, 1.7 [0.3]) patients. This result inverted at radiotherapy end, and all groups converged at 3 to 6 months.

Conclusions and Relevance

Subacute swallowing outcomes were similar regardless of primary treatment modality among patients with low- to intermediate-risk oropharyngeal squamous cell carcinoma.

Use of the Penetration-Aspiration Scale in Dysphagia Research: A Systematic Review

The penetration-aspiration scale (PAS) is an 8-point scale used to characterize the depth and response to airway invasion during videofluoroscopy. Though widely used in the field of deglutition, there is a lack of consensus regarding the statistical properties of the scale. In order to better understand the state of the literature and the statistical use of the PAS, a systematic review was undertaken to descriptively examine trends in statistical and reporting practices of the PAS since its inception. Online databases were searched for studies citing the original PAS article, which yielded 754 unique articles. Of these, 183 studies were included in the review. Results showed inconsistencies in the statistical use of the scale; 79 studies treated the PAS as ordinal, 71 as categorical, and 49 as interval. Ten types of categorizations were identified. Reporting of power analyses (9%), as well as inter- (26%) and intra-rater (17%) reliability, was uncommon. Among studies that administered multiple bolus volumes or consistencies, 55% reported PAS analyses at the participant/group level only. This review confirms the existence of discrepancies in the statistical treatment of the PAS. A lack of consensus among researchers limits comparisons between studies. The approach to handling this scale dictates the statistical tests used, potentially affecting results and interpretations. Consistent application of statistically sound approaches to PAS analyses is vital for the future of deglutition research.

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

Background and purpose

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

Materials and methods

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

Results

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

Conclusion

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

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.