Systematic Review of Dose–Volume Correlates for Structures Related to Late Swallowing Disturbances After Radiotherapy for Head and Neck Cancer

Post-operative intensity-modulated vs 3D conformal radiotherapy after conservative surgery for laryngeal tumours of the supraglottic region: a dosimetric analysis on 20 patients

Objective

To perform a dosimetric comparison between intensity modulated radiotherapy (IMRT) and 3D conformal radiotherapy in patients with locally advanced (stage III and IV) tumours of the supraglottic region treated with conservative surgery and post-operative radiotherapy.

Methods

An in-silico plan using a 3D conformal shrinking field technique was retrospectively produced for 20 patients and compared with actually delivered IMRT plans. Eighteen structures (arytenoids, constrictor muscles, base of tongue, floor of mouth, pharyngeal axis, oral cavity, submandibular glands and muscles of the swallowing functional units [SFU]) were considered.

Results

IMRT allowed a reduction of maximum and mean doses to 9 and 14 structures, respectively (p < .05).

Conclusions

IMRT achieved a reduction of unnecessary dose to the remnant larynx and the majority of surrounding SFUs. Further prospective analyses and correlations with functional clinical outcomes are required to confirm these dosimetric findings.

Impact of Radiation on Dysphagia-Related Structures: A Dosimetric and Clinical Comparative Analysis of Three-Dimensional Conformal Radiotherapy (3D-CRT) and Intensity-Modulated Radiation Therapy (IMRT) Techniques in Patients With Head and Neck Cancer

Introduction Head and neck squamous cell carcinoma (HNSCC) is a significant health concern in India, with around one million new cases annually. The prevalence of HNSCC is notably high in Asia, especially in India, due to habits like tobacco chewing, betel nut usage, and alcohol consumption. Treatment typically involves a combination of surgery, radiation, chemotherapy, and biological therapy, aiming for tumor control while preserving function and quality of life. However, survivors often face long-term side effects like difficulty swallowing, leading to complications such as aspiration pneumonia. Intensity-modulated radiotherapy (IMRT) has shown promise in improving outcomes by sparing critical swallowing structures. Efforts to minimize radiation-related dysphagia are crucial for enhancing patients' quality of life post-treatment. Our study focuses on examining dosimetric parameters associated with dysphagia aspiration, alongside evaluating dysphagia grades in both treatment groups using the RTOG scale. Material and methods Patients with histologically confirmed non-metastatic head and neck carcinomas were included in our study in November 2018-April 2020. A total of 56 patients were taken into our study with 28 in each arm. They underwent radical radiotherapy (RT) with a total dose of 66-70 Gy, with or without concurrent chemotherapy, meeting specific inclusion criteria and excluding those receiving reirradiation or with distant metastasis. Patients were divided into two groups: Group I received three-dimensional conformal radiotherapy (3D-CRT), and Group II received IMRT. Treatment planning involved immobilization, CT imaging, delineation of target volumes and organs at risk, and contouring of swallowing structures. Dose-volume histogram parameters (mean dose, maximum dose, V30, V70, V80, D50, and D80) were used to assess mean dose to swallowing structures outside the planning target volume (PTV), with a mean dose constraint of 50 Gy. Dysphagia was evaluated using the RTOG criteria at baseline, during treatment, and six months post-treatment. Statistical analysis was performed using SPSS, with significance set at p < 0.05. Results In our study, the mean age at presentation differed slightly between the IMRT and 3D-CRT arms: 58 years versus 55 years, respectively. A higher proportion of patients in both arms experienced symptoms for three to six months, with 53.6% in 3D-CRT and 42.9% in IMRT. Stage distribution varied, with IV being most common in 3D-CRT and stage II in IMRT. Approximately 56% of patients in both groups had a history of smoking. Significant differences were observed in spinal cord dose between 3DCRT and IMRT techniques (p < 0.001). Similarly, a significant difference was found in the mean dose received by dysphagia aspiration-related structures (DARSs) between the 3D-CRT and IMRT arms (p = 0.04). Patients in the IMRT arm exhibited superior dysphagia grades compared to those in the 3D-CRT arm, with statistical significance observed in the third month (p = 0.008) and sixth month (p = 0.048). Conclusion Our study found a notable decrease in the mean DARS dose and reduced dysphagia severity at three and six months in the IMRT group compared to the 3D-CRT group. However, due to the diverse study population, establishing a definitive correlation between the DARS dose and dysphagia severity was challenging. Future large-scale studies are needed to validate these findings for improved preservation of DARS structures.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Postoperative radiotherapy for supraglottic cancer on real-world data: can we reduce dose to lymph node levels?

PURPOSE

To evaluate prognosis for reducing postoperative radiotherapy (PORT) dose to lymph node levels of supraglottic cancer (SC) on real-world data.

METHOD AND MATERIALS

Patients were derived from two cancer centers. In center 1, the involved nodal levels (high-risk levels, HRL) and the next level received a dose of 60.06 Gy/1.82 Gy per fraction, while the other uninvolved levels (low-risk levels, LRL) received 50.96 Gy/1.82 Gy per fraction. In center 2, all received 50 Gy/2 Gy per fraction. The rates of high-risk levels control (HRC), regional control (RC), overall survival (OS), progression-free survival (PFS) and distant metastasis-free survival (DMFS) were calculated by Kaplan-Meier method.

RESULT

Totally, 124 patients were included (62 in center 1, 62 in center 2). Most patients (106, 85.5%) had a stage T3/N + tumor. The median follow-up was 45 months (range 1-163 months). There were no significant differences in terms of OS (p = 0.126), RC (p = 0.514), PFS (p = 0.195) and DMFS (p = 0.834). Most regional recurrences (4, 80%) occurred within three years of treatment, and all occurred within the target volumes. No regional failure occurred in HRL in center 1, while three (3/4) failures occurred in center 2. Dose reduction prescription to HRL led to a lower HRC rate (100% vs. 90.6%, p = 0.009). While the rates of LRL control (98.4%) were equal between the two centers.

CONCLUSION

Compared with a standard dose, the reduced dose to involved nodal levels showed inferior regional control for PORT, while uninvolved nodal levels showed equal outcomes. A dose of 50 Gy for HRL may be an unfavorable treatment option for SC.

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 .

Using dosimetric information to guide dysphagia management in patients with head and neck cancer: Clinicians' knowledge and experiences

Purpose: The use of dosimetric information to guide the management of dysphagia related to head and neck cancer (HNC) treatment is an emerging area of practice. In order to better meet the needs of people with dysphagia in HNC, it is important to explore how clinicians use this information to guide practice and also to identify factors that influence/discourage the use of dosimetric information.Method: A descriptive qualitative method was chosen and purposeful sampling with additional snowball sampling were used to recruit clinicians working within Australian cancer centres. To facilitate participation, clinicians were offered either a focus group or individual interview as a means to collect their perspectives. A total of 20 clinicians with varying years of clinical experience (range 2.5 - 29 years) were recruited. Eight participants took part in a focus group and 12 elected to participate in an individual interview. Content analysis was used to analyse transcripts.Result: Three main themes emerged from the transcripts: (1) clinician factors such as experience, confidence and knowledge and (2) clinical service factors such as staffing levels, clinical management pathways and system access influence use of dosimetric information; (3) patient factors such as demographics, surgical history and education needs influence dysphagia management plans.Conclusion: Speech-language pathologists' (SLPs') use of dosimetric information within HNC settings to direct patient management is emerging and varies between clinicians and workplaces. Given that dosimetric information potentially enables specialised dysphagia management planning for patients during their radiotherapy treatment, further education and training for speech-language pathologists in this area should be prioritised.

Assessment of gene expressions from squamous cell carcinoma of the head and neck to predict radiochemotherapy-related xerostomia and dysphagia

PURPOSE

We tested the hypothesis that gene expressions from biopsies of locally advanced head and neck squamous cell carcinoma (HNSCC) patients can supplement dose-volume parameters to predict dysphagia and xerostomia following primary radiochemotherapy (RCTx).

MATERIAL AND METHODS

A panel of 178 genes previously related to radiochemosensitivity of HNSCC was considered for nanoString analysis based on tumour biopsies of 90 patients with locally advanced HNSCC treated by primary RCTx. Dose-volume parameters were extracted from the parotid, submandibular glands, oral cavity, larynx, buccal mucosa, and lips. Normal tissue complication probability (NTCP) models were developed for acute, late, and for the improvement of xerostomia grade ≥2 and dysphagia grade ≥3 using a cross-validation-based least absolute shrinkage and selection operator (LASSO) approach combined with stepwise logistic regression for feature selection. The final signatures were included in a logistic regression model with optimism correction. Performance was assessed by the area under the receiver operating characteristic curve (AUC).

RESULTS

NTCP models for acute and late xerostomia and the improvement of dysphagia resulted in optimism-corrected AUC values of 0.84, 0.76, and 0.70, respectively. The minimum dose to the contralateral parotid was selected for both acute and late xerostomia and the minimum dose to the larynx was selected for dysphagia improvement. For the xerostomia endpoints, the following gene expressions were selected: RPA2 (cellular response to DNA damage), TCF3 (salivary gland cells development), GBE1 (glycogen storage and regulation), and MAPK3 (regulation of cellular processes). No gene expression features were selected for the prediction of dysphagia.

CONCLUSION

This hypothesis-generating study showed the potential of improving NTCP models using gene expression data for HNSCC patients. The presented models require independent validation before potential application in clinical practice.

The dosimetric and clinical advantages of the GTV-CTV-PTV margins reduction by 6 mm in head and neck squamous cell carcinoma: Significant acute and late toxicity reduction

PURPOSE

We aim to identify the dosimetric and clinical impact of reducing the total GTV-CTV-PTV margins in head-and-neck squamous cell carcinoma (HNSCC) treated with definitive (chemo)radiation.

MATERIALS AND METHODS

The acute and late toxicity and outcomes of 155 consecutive patients treated between February 2017 and March 2019 with GTV-CTV-PTV margins of 9 mm were compared to those of 155 consecutive patients treated with total margin of 15 mm margin, before April 2015. All patients were treated with VMAT with daily-image guidance using CBCT.

RESULTS

Reducing the GTV-CTV-PTV by 6 mm resulted in significant reduction of total irradiated volume (PTV-total) by a median of 28.1% and significant reduction of doses to all salivary glands (largest reduction ipsilateral parotid gland; median -9.6 Gy) and constrictor muscle (-6.1 Gy) with subsequent reduction of the incidence of overall acute grade 3 toxicity (47.7% for 9 mm and 66.5% for 15 mm groups, p = 0.001), grade 3 mucositis (18.1% vs. 35.5%, p < 0.001) and feeding tube-dependency at the end of treatment (24.5% vs. 40%, p = 0.005). The incidence of late grade ≥ 2 xerostomia and dysphagia were also significantly lower in the 9 mm group (31.7% vs. 58.6% p < 0.001, and 15.4% vs. 26.7%, p = 0.04). The 2-year rates of loco-regional control, disease-free and overall survival were 78.8% vs.75.8%, 70.9% vs. 64.4%, and 83.8% vs. 67.6%, (p > 0.05, all).

CONCLUSION

Reduction of the total GTV-CTV-PTV margins from 15 to 9 mm in HNSCC significantly reduced the irradiated volumes and the dose to salivary glands and constrictor muscle with significant reduction of radiation-related toxicity. The loco-regional control rates of both groups were comparable.

Early-Stage Glottic Squamous Cell Carcinoma in the Era of Image-Guided Radiotherapy

Early-stage squamous cell cancer (SCC) of the glottis has a good prognosis. Therefore, patients have long survival outcomes and may potentially suffer from late toxicities of radiotherapy. Radiotherapy with a conventional parallel-opposed-pair or anterior-oblique beam arrangements for stage 1 and 2 glottic SCC have field borders that traditionally cover the entire larynx, exposing organs-at-risk (e.g. carotid arteries, contralateral vocal cord, contralateral arytenoid and inferior pharyngeal constrictor muscles) to high radiation doses. The potential long-term risk of cerebrovascular events has attracted much attention to the dose that carotid arteries receive. Swallow and respiratory motion of laryngeal structures has been an important factor that previously limited reduction of the radiation treatment volume. Motion has been evaluated using multiple imaging modalities and this information has been used to calculate PTV margins for generation of more limited target volumes. This review discusses the current literature surrounding dose-effect relationships for various organs-at-risk and the late toxicities that are associated with them. This article also reviews the currently available data and effects of laryngeal motions on dosimetry to the primary target. We also review the current limitations and benefits of a more targeted approach of radiotherapy for early-stage glottic SCCs and the evolution of CT-based IGRT and MR-guided radiotherapy techniques that may facilitate a shift away from a conventional 3D-conformal radiotherapy approach.

Report on Late Toxicity in Head-and-Neck Tumor Patients with Long Term Survival after Radiochemotherapy

Simple Summary

Regular tumor follow-up care provided by ear-nose-throat specialists ends when patients reach 5-year survival, but radio-toxicity is a lifelong process. In this study, long-term head-and-neck cancer survivors undergoing tumor FU-care exceeding five years were analyzed for late onset symptoms after radio-(chemo-)therapy. Almost one third of these patients developed new radiation associated symptoms beyond the common 5-year tumor follow-up margin. Previous radiotherapy led to a two-fold increase for late-onset new complaints, especially after irradiation of the lymphatic pathways in the neck. These findings underline the need for a life-long tumor-follow-up care for long-term head-and-neck cancer survivors.

Abstract

Regular tumor follow-up care provided by ear-nose-throat (ENT) specialists ends when patients reach 5-year survival, but radiotoxicity is a continuous lifelong process. In this study, long-term head-and-neck cancer (HNC) survivors undergoing tumor follow-up (FU) care exceeding five years in a certified HNC center of a German university hospital were analyzed for newly diagnosed late sequelae after radio-(chemo-)therapy. Patients diagnosed with squamous cell carcinoma (SCC) of the oral cavity, larynx or oro-/hypopharynx receiving treatment between 1990 and 2010 with a tumor FU care beyond five years were reviewed retrospectively for signs of late sequelae after radio-(chemo-)therapy (R(C)T) including carotid artery stenosis, stenosis of the cranial esophagus, dysphagia, osteoradionecrosis, and secondary malignancies. Long-term survivors that solely received surgical treatment served as control. Of 1143 analyzed patients we identified 407 patients with an overall survival beyond five years, 311 with R(C)T and 96 patients without R(C)T. Furthermore, 221/1143 patients were lost to FU and the mortality rate within the first 5-years was 45%. Moreover, 27.7% of the long-term survivors were diagnosed with new onset late sequelae within the following five years. RT was significantly associated with a two-fold risk increase for newly diagnosed symptoms, especially after RT of the lymphatic pathways (LP) which showed a hazard ratio of 23.3 to develop alterations on the carotid arteries. Additional chemotherapy had no statistical correlation with any late onset toxicity nor did the mode of R(C)T (adjuvant/definitive). Although the validity of this study might be limited due to its retrospective nature and the dependence on the voluntary participation in a prolonged tumor FU, the results nevertheless provide the need to offer and encourage a tumor FU by ENT specialists exceeding the common 5-year margin. This could prevent secondary morbidities and improve quality of life for long-term cancer survivors.

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.

Effect of Pretreatment Dysphagia on Postchemoradiation Swallowing Function in Head and Neck Cancer

OBJECTIVES

Chemoradiation therapy (CRT) for head and neck cancer can have profound effects on swallowing function. Identification of risk factors for development of swallowing dysfunction after CRT may improve allocation of preventive strategies. The purpose of this study is to determine the association between pre-CRT dysphagia and post-CRT swallowing dysfunction.

STUDY DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

METHODS

Patients with head and neck cancer were evaluated before and 3 months after CRT. Dysphagia was assessed with the Eating Assessment Tool (EAT-10). Swallowing dysfunction was evaluated by a videofluoroscopic swallow study and the Penetration-Aspiration Scale and swallowing safety was evaluated by the Functional Oral Intake Scale. The association between pre-CRT EAT-10 scores and post-CRT swallowing dysfunction was evaluated.

RESULTS

The mean ± SD post-CRT Functional Oral Intake Scale score was 6.5 ± 1.2 for individuals with a pre-CRT EAT-10 score <3 and 5.3 ± 1.9 for those with a pre-CRT EAT-10 score ≥3 (P < .001). The mean post-CRT Penetration-Aspiration Scale score was 2.2 ± 1.5 for individuals with a pre-CRT EAT-10 score <3 and 3.8 ± 2.6 for those with a pre-CRT EAT-10 score ≥3 (P < .001). After multivariate analysis adjusting for age, tumor subsite, T classification, and primary surgery, pre-CRT dysphagia (EAT-10 ≥3) was an independent predictor of post-CRT aspiration (odds ratio, 4.19 [95% CI, 1.08-16.20]; P = .04) and feeding tube dependence (odds ratio, 3.54 [95% CI, 1.01-12.33]; P = .04).

CONCLUSION

The presence of dysphagia before chemoradiation for head and neck cancer is an independent predictor of swallowing dysfunction after completion of therapy. These results may help target intervention toward preventing swallowing dysfunction in high-risk individuals.

The Relationships Between Radiation Dosage and Long-term Swallowing Kinematics and Timing in Nasopharyngeal Carcinoma Survivors

This study aimed to investigate the relationship between intensity-modulated radiation therapy (IMRT) dosimetry and swallowing kinematic and timing measures. Thirteen kinematic and timing measures of swallowing from videofluoroscopic analysis were used as outcome measures to reflect swallowing function. IMRT dosimetry was accessed for thirteen swallowing-related structures. A cohort of 44 nasopharyngeal carcinoma (NPC) survivors at least 3 years post-IMRT were recruited. The cohort had a mean age of 53.2 ± 11.9 years, 77.3% of whom were male. There was an average of 68.24 ± 14.15 months since end of IMRT; 41 (93.2%) had undergone concurrent chemotherapy. For displacement measures, female sex and higher doses to the cricopharyngeus, glottic larynx, and base of tongue were associated with reduced hyolaryngeal excursion and pharyngeal constriction, and more residue. For timing measures, higher dose to the genioglossus was associated with reduced processing time at all stages of the swallow. The inferior pharyngeal constrictor emerged with a distinctly different pattern of association with mean radiation dosage compared to other structures. Greater changes to swallowing kinematics and timing were observed for pudding thick consistency than thin liquid. Increasing radiation dosage to swallowing-related structures is associated with reduced swallowing kinematics. However, not all structures are affected the same way, therefore organ sparing during treatment planning for IMRT needs to consider function rather than focusing on select muscles. Dose-response relationships should be investigated with a comprehensive set of swallowing structures to capture the holistic process of swallowing.

Inter-Observer Variation in Delineating the Pharyngeal Constrictor Muscle as Organ at Risk in Radiotherapy for Head and Neck Cancer

BACKGROUND AND PURPOSE

To evaluate the inter-observer variation (IOV) in pharyngeal constrictor muscle (PCM) contouring, and resultant impact on dosimetry and estimated toxicity, as part of the pre-trial radiotherapy trial quality assurance (RTQA) within DARS, a multicenter phase III randomized controlled trial investigating the functional benefits of dysphagia-optimized intensity-modulated radiotherapy (Do-IMRT) in pharyngeal cancers.

METHODS AND MATERIALS

Outlining accuracy of 15 clinicians' superior and middle PCM (SMPCM) and inferior PCM (IPCM) were retrospectively assessed against gold standards (GS) using volume, location, and conformity indices (CIs) on a pre-trial benchmark case of oropharyngeal cancer. The influence of delineation variability on dose delivered to the constrictor muscles with Do-IMRT and resultant normal tissue complication probability (NTCP) for physician-scored radiation-associated dysphagia at 6 months was evaluated.

RESULTS

For GS, SMPCM, and IPCM volumes were 13.51 and 1.67 cm3; corresponding clinician mean volumes were 12.18 cm3 (SD 3.0) and 2.40 cm3 (SD 0.9) respectively. High IOV in SMPCM and IPCM delineation was observed by the low DICE similarity coefficient value, along with high geographical miss index and discordance index values. Delineation variability did not significantly affect the mean dose delivered to the constrictors, relative to the GS plan. Mean clinician NTCP was 24.6% (SD 0.6), compared to the GS-NTCP of 24.7%.

CONCLUSIONS

Results from this benchmark case demonstrate that inaccurate PCM delineation existed, even with protocol guidelines. This did not impact on delivered dose to this structure with Do-IMRT, or on estimated swallowing toxicity, in this single benchmark case.

Intensity-modulated radiation therapy in head-and-neck carcinomas: Potential beyond sparing the parotid glands

Head-and-neck cancer (HNC) is in close proximity to several critical structures. Intensity-modulated radiation therapy (IMRT) has the potential of generating highly conformal and concave dose distributions around complex target and is ideally suited for HNC treatment. Conventionally, the focus of IMRT for HNC patients has been on prevention of radiation-induced parotid dysfunction. In the present article, we review the potential of IMRT to reduce the risk of posttreatment aspiration and dysphagia and spare submandibular gland. We also discuss the impact of IMRT on overall survival and quality of life (QoL) for HNC patients. Small retrospective and prospective studies show that reducing dose to adjoining organs at risks is feasible and decreases the risk of posttreatment dysphagia and aspiration without compromising local control. IMRT is associated with improved QoL in several important domains including swallowing, dry mouth, sticky saliva, social eating, and opening of the mouth; however, improvement in global QoL is inconsistent. Delivery of IMRT for HNC is associated with improved survival at nasopharyngeal subsite. Small studies demonstrate improved treatment outcomes with swallowing-sparing IMRT. These results now need validation within the prospective multicenter randomized controlled trial setting.

Phase I dose-escalation trial of S-1 combined with carbon-ion radiotherapy for sinonasal squamous cell carcinoma

This study aimed to determine the maximum tolerance dose (MTD) and to estimate the recommended dose (RD) of concomitant S-1 with carbon-ion radiotherapy (RT) for sinonasal squamous cell carcinoma (SCC). Nine patients with sinonasal SCC received carbon-ion RT with escalating doses of S-1 according to phase I methods. Doses of 40, 60 and 80 mg/m2/day were administered twice daily in dose levels 1, 2 and 3, respectively, from days 1 to 14 and 22 to 35. Carbon-ion RT was administered at a dose of 70.4 Gy (relative biological effectiveness) in 32 fractions, 5 days a week. Two patients developed grade 3 acute dermatitis. However, none developed dose-limiting toxicities. Therefore, the MTD of S-1 could not be determined; the RD was estimated to be 80 mg/m2/day with concurrent carbon-ion RT. Partial response and stable disease were noted in 5 and 4 patients, respectively. The 2-year overall survival and local control rates were 56 and 74%, respectively. Overall, 2 patients developed ≥grade 3 late toxicities; among them, 1 patient developed grade 3 cataract and the other developed grade 4 cataract, optic nerve disorder and hearing impairment. To the best of our knowledge, this phase I study is the first clinical trial to evaluate concomitant S-1 with carbon-ion RT for sinonasal SCC. The MTD of S-1 could not be determined, and the RD was estimated to be 80 mg/m2/day. This study demonstrated a manageable safety profile for this combination. The observed outcomes may facilitate further evaluation of this novel therapy.

Phase II study of de-intensified intensity-modulated radiotherapy and concurrent carboplatin/5-fluorouracil in lateralized p16-associated oropharyngeal carcinoma

PURPOSE

To assess cancer control and patient-reported outcomes (PROs) after de-intensified intensity-modulated radiotherapy (IMRT) in lateralized p16-associated oropharyngeal cancer (p16-OPC).

METHODS

Lateralized p16-OPC treated with radiotherapy and concurrent Carboplatin/5-fluorouracil between 2011 and 2014 were enrolled. De-intensified IMRT consisted in elective neck dose of 43.2 Gy/24 fractions and omission of contralateral retropharyngeal/level IV nodes. PROs were assessed using the EORTC QLC-C30 and QLQ-HN35 scales.

RESULTS

Twenty-nine patients were included. Median follow-up was 44 months. As per AJCC 7th Ed, 7%, 83% and 10% of patients had stage III, IVa and IVb. 5-year locoregional control and overall survival rates were 100% and 100%, respectively. Rates of acute were 52% and 35%, respectively. At 2 years post-treatment, 50% and 14% of patients had grade 1 xerostomia and dysgueusia, respectively. Most PROs scores returned to baseline within 8 months post-treatment.

CONCLUSION

De-intensified IMRT was associated with excellent cancer outcomes, and rapid recovery of PROs in lateralized p16-OPC.

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.

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

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

Deintensification of Adjuvant Treatment After Transoral Surgery in Patients With Human Papillomavirus-Positive Oropharyngeal Cancer: The Conception of the PATHOS Study and Its Development

PATHOS is a phase II/III randomized controlled trial (RCT) of risk-stratified, reduced intensity adjuvant treatment in patients undergoing transoral surgery (TOS) for human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC). The study opened in the UK in October 2015 and, after successful recruitment into the phase II, transitioned into phase III in the autumn of 2018. PATHOS aims to establish whether the de-intensification of adjuvant treatment in patients with favorable prognosis HPV-positive OPSCC will confer improved swallowing outcomes, whilst maintaining high rates of cure. In this article, we will outline the rationale for the study and how it aims to answer fundamentally important questions about the safety, effectiveness and functional outcomes of minimally invasive TOS techniques followed by adjuvant radiotherapy (RT) or chemo-radiotherapy (CRT) in this patient population.

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.

Swallowing disorders after treatment for head and neck cancer

Background

Dysphagia is a common consequence of treatment for head and neck cancer (HNC). The purpose of the study was to evaluate the prevalence of dysphagia in a group of patients treated for HNC in Slovenia, and to identify factors contributing to the development of dysphagia.

Patients and methods

One-hundred-nine consecutive patients treated for HNC at two tertiary centers were recruited during their follow-up visits. They fulfilled EORTC QLQ-H&N35 and “Swallowing Disorders after Head and Neck Cancer Treatment questionnaire” questionnaires. Patients with dysphagia were compared to those without it.

Results

Problems with swallowing were identified in 41.3% of the patients. Dysphagia affected their social life (in 75.6%), especially eating in public (in 80%). Dysphagia was found the most often in the patients with oral cavity and/or oropharyngeal cancer (in 57.6%) and in those treated less than 2 years ago (p = 0.014). In univariate analysis, a significant relationship was observed between dysphagia prevalence and some of the consequences of anti-cancer treatment (impaired mouth opening, sticky saliva, loss of smell, impaired taste, oral and throat pain, persistent cough, and hoarseness), radiotherapy (p = 0.003), and symptoms of gastroesophageal reflux (p = 0.027). After multiple regression modelling only persistent cough remained.

Conclusions

In order to improve swallowing abilities and, consequently, quality of life of the patients with HNC a systematic rehabilitation of swallowing should be organized. A special emphasis should be given to gastroesophageal reflux treatment before, during and after therapy for HNC

Practices, knowledge and inter-professional relationships between speech pathologists and radiation therapists managing patients with head and neck cancer

Introduction

This study examined knowledge and practices of speech pathologists (SPs) and radiation therapists (RTs) regarding plan optimisation for head and neck cancer (HNC) patients, and the potential impacts on swallowing function. The secondary aim was to explore the level of interaction occurring between these professional groups within cancer centres.

Methods

Two electronic surveys, with matched questions for SPs and RTs, explored: service/institutional demographics; clinician awareness, practices regarding plan optimisation to swallowing structures and; relationships and interactions between SPs and RTs in the management of HNC patients. Participant recruitment occurred through specialist professional networks with additional snowball sampling. Data were analysed with descriptive statistics and thematic analysis.

Results

A total of 32 SPs and 41 RTs completed surveys. All SPs and 50% of RTs were aware of dose‐dysphagia relationships, though SPs rarely used dosimetric information to inform patient management. Only 33% of RTs indicated that their centres actively constrain dose to swallowing structures, reporting that staffing skill mixtures and lack of prescription by the treating RO were restrictive factors. Both SPs and RTs acknowledged the importance of collaborating with colleagues (SPs/RTs) and felt they could assist their colleagues in devising patient management plans, though current collaboration/interaction was minimal.

Conclusions

Levels of awareness were found to be higher in SP group. Despite high levels of awareness, limited use of swallowing structure dose constraints and hence dosimetric information specific to swallowing was rarely used to optimise/guide multidisciplinary HNC acute care. Opportunities for enhanced collaboration between SPs and RTs should be considered.

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.

Optimising Radiation Therapy Dose to the Swallowing Organs at Risk: An In Silico Study of feasibility for Patients with Oropharyngeal Tumours

Recent evidence suggests that reducing radiotherapy dose delivered to specific anatomical swallowing structures [Swallowing Organs at Risk (SWOARs)] may improve swallowing outcomes post-treatment for patients with head and neck cancer. However, for those patients with tumours of the oropharynx, which typically directly overlap the SWOARs, reducing dose to these structures may be unachievable without compromising on the treatment of the disease. To assess the feasibility of dose reduction in this cohort, standard IMRT plans (ST-IMRT) and plans with reduced dose to the SWOARs (SW-IMRT) were generated for 25 oropharyngeal cancer patients (Brouwer et al. in Radiother Oncol 117(1):83-90, https://doi.org/10.1016/j.radonc.2015.07.041 , 2015; Christianen et al. in Radiother Oncol 101(3):394-402, https://doi.org/10.1016/j.radonc.2011.05.015 , 2011). ST-IMRT and SW-IMRT plans were compared for: mean dose to the SWOARs, volume of pharynx and larynx receiving 50 Gy and 60 Gy (V50 and V60 respectively) and overlap between the tumour volume and the SWOARs. Additionally, two different SWOARs delineation guidelines (Brouwer et al. in Radiother Oncol 117(1):83-90, https://doi.org/10.1016/j.radonc.2015.07.041 , 2015; Christianen et al. in Radiother Oncol 101(3):394-402, https://doi.org/10.1016/j.radonc.2011.05.015 , 2011) were used to highlight differences in calculated volumes between existing contouring guidelines. Agreement in SWOARs volumes between the two guidelines was calculated using a concordance index (CI). Despite a large overlap between the tumour and SWOARs, significant (p < 0.05) reductions in mean dose to 4 of the 5 SWOARs, and V50/V60 for the pharynx and larynx were achieved with SW-IMRT plans. Low CIs per structure (0.15-0.45) were found between the two guidelines highlighting issues comparing data between studies when different guidelines have been used (Hawkins et al. in Semin Radiat Oncol 28(1):46-52, https://doi.org/10.1016/j.semradonc.2017.08.002 , 2018; Brodin et al. in Int J Radiat Oncol Biol Phys 100(2):391-407, https://doi.org/10.1016/j.ijrobp.2017.09.041 , 2018). This study found reducing dose to the SWOARs is a feasible practice for patients with oropharyngeal cancer. However, future prospective research is needed to determine if the extent of dose reduction achieved equates to clinical benefits.

Dysphagia optimized radiotherapy to reduce swallowing dysfunction severity in patients undergoing treatment for head and neck cancer: A systematized scoping review

This study involved a systematized scoping review to coalesce current evidence on dysphagia outcomes achieved through active sparing of the swallowing structures in patients receiving radiotherapy for head and neck cancer. Eligible publications between 2007 and 2017 were reviewed and synthesized regarding participant demographics, treatment regimens, swallowing structures chosen for optimization, dosimetric constraints, and dysphagia measures. Nine prospective cohort studies were included. Key structures routinely spared included pharyngeal constrictor muscles (PCMs), glottic larynx (GL), supraglottic larynx (SGL), and esophageal inlet muscle. Shorter enteral feeding times and reductions in Common Terminology Criteria for Adverse Event (CTCAE) grade 3 dysphagia toxicity were observed when dose to the larynx (GL and SGL) and PCMs was constrained to < 50 and < 60 Gy, respectively. Emerging evidence supports "active" sparing of the swallowing structures at the time of radiotherapy planning to reduce dysphagia severity, with no compromise to planning target volumes and locoregional control rates.

Systematic review and meta-analysis of the impact of dosimetry to dysphagia and aspiration related structures

BACKGROUND

Technological advances in radiotherapy have allowed investigations into new methods to spare healthy tissue in those treated for head and neck cancer. This systematic review with meta-analysis demonstrates the effect that radiation has on swallowing.

METHODS

Selection and analysis of studies examining the effect of radiation to swallowing structures. A fixed effects meta-analysis calculated the pooled proportions for select outcomes of dysphagia, common across many studies.

RESULTS

The majority of the papers found a correlation between radiation dose to the swallowing structures and dysphagia, however a meta-analysis found the studies carried a significant degree of heterogeneity. The appraisal demonstrates the need for large-scale studies using a randomized design and instrumental dysphagia assessments.

CONCLUSIONS

Radiation dose to dysphagia and aspiration structures is correlated with incidence of dysphagia and aspiration. The variables in this population contribute to the heterogeneity within and cross studies and future studies should consider controlling for this.

Omitting Elective Irradiation of the Contralateral Retropharyngeal Nodes in Oropharyngeal Squamous Cell Carcinoma Treated with Intensity-modulated Radiotherapy

Introduction: The use of intensity-modulated radiation therapy (IMRT) in head and neck cancers has allowed for selective sparing of low-risk or uninvolved lymph nodes. In oropharyngeal cancers, the benefits and risks of omitting contralateral retropharyngeal lymph nodes (RPLN) remain uncertain. This study examines the outcomes of elective coverage of contralateral RPLN in oropharyngeal cancer treated with definitive IMRT.

Methods: We analyzed 54 patients with newly diagnosed unilateral tonsil or base of tongue squamous cell carcinoma with at most unilateral neck involvement (cN0-N2b) and no RPLN involvement. These patients had no prior head and neck irradiation and were treated with definitive radiotherapy or chemoradiotherapy between 2012 and 2017. Cumulative incidences of local/regional/distant failure were estimated using competing risks methodology, and overall survival (OS) was estimated using the Kaplan-Meier method.

Results: All patients received elective nodal coverage to the ipsilateral RPLN, and 38 (62%) patients did not receive elective treatment of the contralateral RPLN. There were no significant differences in baseline characteristics. There were no contralateral RPLN failures observed. When comparing patients who received contralateral RP treatment with those who did not, there were no significant differences in two-year local failure (23% vs. 9%, p = 0.09), regional failure (18% vs. 4%, p = 0.12), or distant failure (15% vs. 9%, p = 0.62). Two-year OS was 89%. Mean parotid dose was not significantly lower after sparing vs. treating the contralateral RPLN (median 25.6 vs. 32.7 Gy, p = 0.15).

Conclusions: The omission of contralateral RPLN irradiation in tonsil or tongue base carcinomas with unilateral neck involvement is safe without compromising disease control.

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

PURPOSE

Our primary aim was to prospectively validate retrospective dose-response models of chronic radiation-associated dysphagia (RAD) after intensity modulated radiotherapy (IMRT) for oropharyngeal cancer (OPC). The secondary aim was to validate a grade ≥2 cut-point of the published videofluoroscopic dysphagia severity (Dynamic Imaging Grade for Swallowing Toxicity, DIGEST) as radiation dose-dependent.

MATERIAL AND METHODS

Ninety-seven patients enrolled on an IRB-approved prospective registry protocol with stage I-IV OPC underwent pre- and 3-6 month post-RT videofluoroscopy. Dose-volume histograms (DVH) for swallowing regions of interest (ROI) were calculated. Dysphagia severity was graded per DIGEST criteria (dichotomized with grade ≥2 as moderate/severe RAD). Recursive partitioning analysis (RPA) and Bayesian Information Criteria (BIC) were used to identify dose-volume effects associated with moderate/severe RAD.

RESULTS

31% developed moderate/severe RAD (i.e. DIGEST grade ≥2) at 3-6 months after RT. RPA found DVH-derived dosimetric parameters of geniohyoid/mylohyoid (GHM), superior pharyngeal constrictor (SPC), and supraglottic region were associated with DIGEST grade ≥2 RAD. V61 ≥ 18.57% of GHM demonstrated optimal model performance for prediction of DIGEST grade ≥2.

CONCLUSION

The findings from this prospective longitudinal registry validate prior observations that dose to submental musculature predicts for increased burden of dysphagia after oropharyngeal IMRT. Findings also support dichotomization of DIGEST grade ≥2 as a dose-dependent split for use as an endpoint in trials or predictive dose-response analysis of videofluoroscopy results.

Prospective in silico study of the feasibility and dosimetric advantages of MRI-guided dose adaptation for human papillomavirus positive oropharyngeal cancer patients compared with standard IMRT

PURPOSE

We aim to determine the feasibility and dosimetric benefits of a novel MRI-guided IMRT dose-adaption strategy for human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPC).

MATERIALS/METHODS

Patients with locally advanced HPV+ OPC underwent pre-treatment and in-treatment MRIs every two weeks using RT immobilization setup. For each patient, two IMRT plans were created (i.e. standard and adaptive). The prescription dose for the standard plans was 2.12 Gy/fx for 33 fractions to the initial PTV. For adaptive plans, a new PTVadaptive was generated based on serial MRIs in case of detectable tumor shrinkage. Prescription dose to PTVadaptive was 2.12 Gy/fx to allow for maximum dose to the residual disease. Any previously involved volumes received minimally a floor dose of 50.16 Gy. Uninvolved elective nodal volumes were prescribed 50.16 Gy in 1.52 Gy/fx. Dosimetric parameters of organs at risk (OARs) were recorded for standard vs. adaptive plans. Normal tissue complication probability (NTCP) for toxicity endpoints was calculated using literature-derived multivariate logistic regression models.

RESULTS

Five patients were included in this pilot study, 3 men and 2 women. Median age was 58 years (range 45-69). Three tumors originated at the tonsillar fossa and two at the base of tongue. The average dose to 95% of initial PTV volume was 70.7 Gy (SD,0.3) for standard plans vs. 58.5 Gy (SD,2.0) for adaptive plans. The majority of OARs showed decrease in dosimetric parameters using adaptive plans vs. standard plans, particularly swallowing related structures. The average reduction in the probability of developing dysphagia ≥ grade2, feeding tube persistence at 6-month post-treatment and hypothyroidism at 1-year post-treatment was 11%, 4%, and 5%, respectively. The probability of xerostomia at 6-month was only reduced by 1% for adaptive plans vs. standard IMRT.

CONCLUSION

These in silico results showed that the proposed MRI-guided adaptive approach is technically feasible and advantageous in reducing dose to OARs, especially swallowing musculature.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Therapeutic Implications of the Genetic Landscape of Head and Neck Cancer

Large-scale sequencing studies of head and neck squamous cell carcinoma (HNSCC) have elucidated the genetic changes that characterize HNSCC. These findings have supported the development of therapeutic strategies that target key components of aberrant signaling pathways and immune dysregulation. Cumulative evidence suggests that these agents in combination with radiotherapy may have synergistic effects. This review highlights the predictive biomarkers that have been identified from HNSCC genomic studies and implications on the development of molecular-targeting agents that may effectively treat patients with HNSCC, especially when used in combination with radiation.

Radiation-induced acute dysphagia : Prospective observational study on 42 head and neck cancer patients

PURPOSE

Acute toxicity in head and neck (H&N) cancer patients treated with definitive radiotherapy (RT) has a crucial role in compliance to treatments. The aim of this study was to correlate doses to swallowing-associated structures and acute dysphagia.

METHODS

We prospectively analyzed 42 H&N cancer patients treated with RT. Dysphagia (grade ≥ 3) and indication for percutaneous endoscopic gastrostomy (PEG) insertion were classified as acute toxicity. Ten swallowing-related structures were considered for the dosimetric analysis. The correlation between clinical information and the dose absorbed by the contoured structures was analyzed. Multivariate logistic regression method using resampling methods (bootstrapping) was applied to select model order and parameters for normal tissue complication probability (NTCP) modelling.

RESULTS

A strong multiple correlation between dosimetric parameters was found. A two-variable model was suggested as the optimal order by bootstrap method. The optimal model (Rs = 0.452, p < 0.001) includes V₄₅ of the cervical esophagus (odds ratio [OR] = 1.016) and D_mean of the cricopharyngeal muscle (OR = 1.057). The model area under the curve was 0.82 (95% confidence interval 0.69-0.95).

CONCLUSION

Our results suggested that the absorbed dose to the cricopharyngeal muscle and cervical esophagus might play a relevant role in the development of acute RT-related dysphagia.

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

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

How to minimize morbidity in radiotherapy of pharyngolaryngeal tumors?

PURPOSE OF REVIEW

Radiotherapy is one of the most effective treatment modalities for head and neck cancer. However, because of the intricacy between tumors and normal tissues, it can induce morbidity, such as mucositis, dermatitis, xerostomia, dysphagia, hearing loss, vision impairment, skin fibrosis, and osteoradionecrosis of the jaw, and it can dramatically impact on patient quality of life.

RECENT FINDINGS

Throughout the last decade, significant improvements have been made in head and neck cancer radiotherapy, especially with the introduction on a routine basis of intensity-modulated radiotherapy.

SUMMARY

In this context, this review manuscript will focus on how the implementation of intensity-modulated radiotherapy influences treatment morbidity. Specifically, the issues of target volume and organ-at-risk delineation, sparing of organs at risk, tailored treatment intensity, adaptive treatment, and the use of proton therapy will be discussed.

DARS: a phase III randomised multicentre study of dysphagia- optimised intensity- modulated radiotherapy (Do-IMRT) versus standard intensity- modulated radiotherapy (S-IMRT) in head and neck cancer

BACKGROUND

Persistent dysphagia following primary chemoradiation (CRT) for head and neck cancers can have a devastating impact on patients' quality of life. Single arm studies have shown that the dosimetric sparing of critical swallowing structures such as the pharyngeal constrictor muscle and supraglottic larynx can translate to better functional outcomes. However, there are no current randomised studies to confirm the benefits of such swallow sparing strategies. The aim of Dysphagia/Aspiration at risk structures (DARS) trial is to determine whether reducing the dose to the pharyngeal constrictors with dysphagia-optimised intensity- modulated radiotherapy (Do-IMRT) will lead to an improvement in long- term swallowing function without having any detrimental impact on disease-specific survival outcomes.

METHODS/DESIGN

The DARS trial (CRUK/14/014) is a phase III multicentre randomised controlled trial (RCT) for patients undergoing primary (chemo) radiotherapy for T1-4, N0-3, M0 pharyngeal cancers. Patients will be randomised (1:1 ratio) to either standard IMRT (S-IMRT) or Do-IMRT. Radiotherapy doses will be the same in both groups; however in patients allocated to Do-IMRT, irradiation of the pharyngeal musculature will be reduced by delivering IMRT identifying the pharyngeal muscles as organs at risk. The primary endpoint of the trial is the difference in the mean MD Anderson Dysphagia Inventory (MDADI) composite score, a patient-reported outcome, measured at 12 months post radiotherapy. Secondary endpoints include prospective and longitudinal evaluation of swallow outcomes incorporating a range of subjective and objective assessments, quality of life measures, loco-regional control and overall survival. Patients and speech and language therapists (SLTs) will both be blinded to treatment allocation arm to minimise outcome-reporting bias.

DISCUSSION

DARS is the first RCT investigating the effect of swallow sparing strategies on improving long-term swallowing outcomes in pharyngeal cancers. An integral part of the study is the multidimensional approach to swallowing assessment, providing robust data for the standardisation of future swallow outcome measures. A translational sub- study, which may lead to the development of future predictive and prognostic biomarkers, is also planned.

TRIAL REGISTRATION

This study is registered with the International Standard Randomised Controlled Trial register, ISRCTN25458988 (04/01/2016).

[Head and neck intensity-modulated radiation therapy: Normal tissues dose constraints. Pharyngeal constrictor muscles and larynx]

Radio-induced pharyngolaryngeal chronic disorders may challenge the quality of life of head and neck cancer long survivors. Many anatomic structures have been identified as potentially impaired by irradiation and responsible for laryngeal edema, dysphonia and dysphagia. Some dose constraints might be plausible such as keeping the mean dose to the pharyngeal constrictor muscles under 50 to 55Gy, the mean dose to the supra-glottic larynx under 40 to 45Gy and, if feasible, the mean dose to the glottic larynx under 20Gy. A reduction of the dose delivered to the muscles of the floor of the mouth and the cervical esophagus would be beneficial as well. Nevertheless, the publications available do not provide an extensive enough level of proof. One should consider limiting as low as possible the dose delivered to these structures without compromising the quality of irradiation of the target tumor volumes.

Reduction of the dose of radiotherapy to the elective neck in head and neck squamous cell carcinoma; a randomized clinical trial. Effect on late toxicity and tumor control

BACKGROUND AND PURPOSE

A multi-center prospective randomized clinical trial has been performed investigating whether a reduction of the dose to the elective nodal sites in head and neck cancer delivered by intensity modulated radiotherapy (IMRT) would result in a reduction of late side effects without compromising tumor control.

MATERIALS AND METHODS

Two hundred patients were included. The prescription dose to the elective nodal volumes was a normalized iso-effective dose in 2Gy fractions (NID_2Gy) of 50Gy in the standard arm and of 40Gy in the experimental arm. Late toxicity was scored at 6, 12, 18 and 24months using the RTOG scoring system.

RESULTS

We observed a trend toward less dysphagia at 6months in the experimental arm, however this was not confirmed after longitudinal analysis. Regarding moderate salivary gland toxicity we observed lower incidence of salivary gland toxicity ⩾grade 1, at 6 (p=0.01) and 18months (p=0.03). After two years of follow up, we did not observe significant differences in estimated local failure rate (14.1% in the 40Gy arm vs 14.4% in the 50Gy arm), estimated regional failure rate (13.0% vs 5.5% in the 40 and the 50Gy arm respectively), estimated metastatic recurrence (13.4% vs 18.5% in the 40 and the 50Gy arm respectively), estimated disease-free survival (57.9% vs 65.3% in the 40 and the 50Gy arm respectively) nor estimated overall survival (72.0% vs 73.2% in the 40 and the 50Gy arm respectively).

CONCLUSIONS

In our study population there was no statistically significant difference regarding survival and estimated recurrence rates between both arms of this study. We found a trend toward less dysphagia at 6months (however not significant after longitudinal analysis) and found a significant reduction of any salivary gland toxicity at 6 and 18months in the 40Gy arm.

Is treatment de-escalation a reality in HPV related oropharyngeal cancer?

The incidence of HPV related oropharyngeal squamous cell carcinoma (OPSCC) is rapidly increasing. It is now well recognised as a distinct clinical and biologic entity, compared to traditional OPSCC. The majority of these patients have an excellent prognosis due to the chemo-radiosensitive nature of these tumours. The de-escalation of current treatment regimens have therefore been proposed in an attempt to reduce the long term treatment related morbidity of this much younger patient cohort. Several of the more pertinent points regarding safe de-escalation strategies are considered within this manuscript.

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

PURPOSE/OBJECTIVE(S)

We sought to identify swallowing muscle dose-response thresholds associated with chronic radiation-associated dysphagia (RAD) after IMRT for oropharyngeal cancer.

MATERIALS/METHODS

T1-4 N0-3 M0 oropharyngeal cancer patients who received definitive IMRT and systemic therapy were examined. Chronic RAD was coded as any of the following ⩾12months post-IMRT: videofluoroscopy/endoscopy detected aspiration or stricture, gastrostomy tube and/or aspiration pneumonia. DICOM-RT plan data were autosegmented using a custom region-of-interest (ROI) library and included inferior, middle and superior constrictors (IPC, MPC, and SPC), medial and lateral pterygoids (MPM, LPM), anterior and posterior digastrics (ADM, PDM), intrinsic tongue muscles (ITM), mylo/geniohyoid complex (MHM), genioglossus (GGM), masseter (MM), buccinator (BM), palatoglossus (PGM), and cricopharyngeus (CPM), with ROI dose-volume histograms (DVHs) calculated. Recursive partitioning analysis (RPA) was used to identify dose-volume effects associated with chronic-RAD, for use in a multivariate (MV) model.

RESULTS

Of 300 patients, 34 (11%) had chronic-RAD. RPA showed DVH-derived MHM V69 (i.e. the volume receiving⩾69Gy), GGM V35, ADM V60, MPC V49, and SPC V70 were associated with chronic-RAD. A model including age in addition to MHM V69 as continuous variables was optimal among tested MV models (AUC 0.835).

CONCLUSION

In addition to SPCs, dose to MHM should be monitored and constrained, especially in older patients (>62-years), when feasible.

The management of head and neck tumors with high technology radiation therapy

Squamous cell carcinoma is responsible for 90% of the head and neck cancers affecting over 600,000 people worldwide. Radiation therapy, surgery and chemotherapy are the most important treatment modalities in head and neck squamous cell carcinoma. The aim of this review is to summarize the recent innovations in head and neck radiation therapy, which intends to appreciate the cutting-edge intensity-modulated radiation therapy strategies to mitigate long-term toxicities and evaluate promising technologies in the field as adaptive treatment, dose painting and proton therapy.

Risk factors for late dysphagia after (chemo)radiotherapy for head and neck cancer: A systematic methodological review

BACKGROUND

The purpose of this systematic review was to identify the risk factors for late dysphagia in patients with head and neck cancer after (chemo)radiotherapy.

METHODS

The review was performed using search strategies, including PubMed, the Cochrane Library, and Embase databases. The effects of studies were combined with the study quality score using a best-evidence synthesis model.

RESULTS

Twenty observational studies were evaluated. According to the best-evidence synthesis criteria, there were 2 strong-evidence risk factors for late dysphagia, including the use of chemoradiotherapy (CRT) and the presence of hypopharyngeal carcinoma. We also identified 8 moderate-evidence, 17 limited-evidence, and 1 conflicting-evidence risk factors.

CONCLUSION

Although there is no conclusive evidence for dysphagia in patients with head and neck cancer after (chemo)radiotherapy, these data provide evidence to guide clinicians in patients who will have late dysphagia and to choose an optimal prophylactic strategy.