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

Risk prediction models for dysphagia after radiotherapy among patients with head and neck cancer: a systematic review and meta-analysis

Background

Predictive models can identify patients at risk and thus enable personalized interventions. Despite the increasing number of prediction models used to predict the risk of dysphagia after radiotherapy in patients with head and neck cancer (HNC), there is still uncertainty about the effectiveness of these models in clinical practice and about the quality and applicability of future studies. The aim of this study was to systematically evaluate and analyze all predictive models used to predict dysphagia in patients with HNC after radiotherapy.

Methods

PubMed, Cochrane Library, EMbase and Web of Science databases were searched from database establishment to August 31, 2024. Data from selected studies were extracted using predefined tables and the quality of the predictive modelling studies was assessed using the PROBAST tool. Meta-analysis of the predictive performance of the model was performed using the "metafor" package in R software.

Results

Twenty-five models predicting the risk of dysphagia after radiotherapy in patients with HNC were included, covering a total of 8,024 patients. Common predictors include mean dose to pharyngeal constrictor muscles, treatment setting, and tumor site. Of these models, most were constructed based on logistic regression, while only two studies used machine learning methods. The area under the receiver operating characteristic curve (AUC) reported values for these models ranged from 0.57 to 0.909, with 13 studies having a combined AUC value of 0.78 (95% CI: 0.74-0.81). All studies showed a high risk of bias as assessed by the PROBAST tool.

Conclusion

Most of the published prediction models in this study have good discrimination. However, all studies were considered to have a high risk of bias based on PROBAST assessments. Future studies should focus on large sample size and rigorously designed multicenter external validation to improve the reliability and clinical applicability of prediction models for dysphagia after radiotherapy for HNC.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42024587252.

Prediction of the need of enteral nutrition during radiation therapy for head and neck cancers

INTRODUCTION

Patients with a head and neck (HN) cancer undergoing radiotherapy risk critical weight loss and oral intake reduction leading to enteral nutrition. We developed a predictive model for the need for enteral nutrition during radiotherapy in this setting. Its performances were reported on a real-world multicentric cohort.

MATERIAL AND METHODS

Two models were trained on a prospective monocentric cohort of 230 patients. The first model predicted an outcome combining severe or early fast weight loss, or severe oral intake impairment (grade 3 anorexia or dysphagia or the prescription of enteral nutrition). The second outcome only combined oral intake impairment criteria. We trained a gradient boosted tree with a nested cross validation for Bayesian optimization on a prospective cohort and predictive performances were reported on the external multicentric real-world cohort of 410 patients from 3 centres. Predictions were explainable for each patient using Shapley values.

RESULTS

For the first and second outcome, the model yielded a ROC curve AUC of 81 % and 80%, an accuracy of 77 % and 77 %, a positive predictive value of 77 % and 72 %, a specificity of 78 % and 79 % and a sensitivity of 75 % and 73 %. The negative predictive value was 80 % and 80 %. For each patient, the underlying Shapley values of each clinical predictor to the prediction could be displayed. Overall, the most contributing predictor was concomitant chemotherapy.

CONCLUSION

Our predictive model yielded good performance on a real life multicentric validation cohort to predict the need for enteral nutrition during radiotherapy for HN cancers.

Proton Radiation Therapy: A Systematic Review of Treatment-Related Side Effects and Toxicities

Cancer is the second leading cause of death worldwide. Around half of all cancer patients undergo some type of radiation therapy throughout the course of their treatment. Photon radiation remains (RT) the most widely utilized modality of radiotherapy despite recent advancements in proton radiation therapy (PBT). PBT makes use of the particle's biological property known as the Bragg peak to better spare healthy tissue from radiation damage, with data to support that this treatment modality is less toxic than photon RT. Hence, proton radiation dosimetry looks better compared to photon dosimetry; however, due to proton-specific uncertainties, unexpected acute, subacute, and long-term toxicities can be encountered. Reported neurotoxicity resulting from proton radiation treatments include radiation necrosis, moyamoya syndrome, neurosensory toxicities, brain edema, neuromuscular toxicities, and neurocognitive toxicities. Pulmonary toxicities include pneumonitis and fibrosis, pleural effusions, and bronchial toxicities. Pericarditis, pericardial effusions, and atrial fibrillations are among the cardiac toxicities related to proton therapy. Gastrointestinal and hematological toxicities are also found in the literature. Genitourinary toxicities include urinary and reproductive-related toxicities. Osteological, oral, endocrine, and skin toxicities have also been reported. The side effects will be comparable to the ones following photon RT, nonetheless at an expected lower incidence. The toxicities collected mainly from case reports and clinical trials are described based on the organs affected and functions altered.

Predict nutrition-related adverse outcomes in head and neck cancer patients undergoing radiotherapy: A systematic review

BACKGROUND

Acute nutrition-related adverse outcomes are common in head and neck cancer patients undergoing radiotherapy. Predictive models can assist in identifying high-risk patients to enable targeted intervention. We aimed to systematically evaluate predictive models for predicting severe acute nutritional symptoms, insufficient intake, tube feeding, sarcopenia, and weight loss.

METHODS

We searched PubMed, Web of Science, EBSCO, Embase, WanFang, CNKI, and SinoMed. We selected studies developing predictive models for the aforementioned outcomes. Data were extracted using a predefined checklist. Risk of bias and applicability assessment were assessed using the Prediction model Risk of Bias Assessment Tool. A narrative synthesis was conducted to summarize the model characteristics, risk of bias, and performance.

RESULTS

A total of 2941 studies were retrieved and 19 were included. Study outcome measure were different symptoms (n = 11), weight loss (n = 5), tube feeding (n = 3), and symptom or tube feeding (n = 1). Predictive factors mainly encompassed sociodemographic data, disease-related data, and treatment-related data. Seventeen studies reported area under the curve or C-index values ranging from 0.610 to 0.96, indicating moderate to good predictive performance. However, candidate predictors were incomplete, outcome measures were diverse, and the risk of bias was high. Most of them used traditional model development methods, and only two used machine learning.

CONCLUSIONS

Most current models showed moderate to good predictive performance. However, predictors are incomplete, outcome are inconsistent, and the risk of bias is high. Clinicians could carefully select the models with better model performance from the available models according to their actual conditions. Future research should include comprehensive and modifiable indicators and prioritize well-designed and reported studies for model development.

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

AIMS

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Early Improved Functional Outcomes in Head and Neck Cancer Patients with Primary Tumor Detection

OBJECTIVES

We characterize functional outcomes in head and neck cancer of unknown primary (CUP) based on primary site identification.

METHODS

In this retrospective study, CUP cases were categorized as known primaries (KP) if a tumor was localized after diagnostic workup or persisting unknown primaries (UP). Age, sex, HPV status, diagnostic methods, and treatments regimens were collected. Pretreatment and short-term posttreatment (3-6 months after completion of treatment) weights, PHQ-9, Eating Assessment Tool (EAT-10), and Voice Handicap Index (VHI-10) scores were compared between UP and KP.

RESULTS

Among 67 CUP patients, 35 (52.2%) had identified primaries (91.4% oropharyngeal and 8.6% nasopharyngeal). KP patients were younger (58 vs. 64, p = 0.04) and more likely to be HPV-positive (88.6% vs. 50%, p = 0.002). Overall detection rates were 16.7% for PET/CT, 34.7% for direct laryngoscopy, and 46.6% for transoral robotic oropharyngectomy. Diagnostic workup was not significantly different between groups. Patients with KP received smaller intermediate radiation dose volumes (436.5 vs. 278.9 cc, p = 0.03) and lower doses to the cricopharyngeal muscle (41.6 vs. 24.6 Gy, p = 0.03).Pretreatment weights, PHQ-9, EAT-10, and VHI-10 scores did not differ between groups. However, posttreatment, UP had greater relative weight loss (-14.1% vs. -7.6%, p = 0.032), higher EAT-10 scores (12.5 vs. 3, p = 0.004), and higher PHQ-9 scores (6 vs. 1.4, p = 0.017). Specifically, UP reported more stressful swallowing, difficulty swallowing solids and pills, and swallowing affecting public eating.

CONCLUSION

KP patients experienced less weight loss, depression, and reduced swallowing dysfunction, highlighting an early functional benefit of primary tumor identification likely driven by reduced radiation treatment volumes.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:701-707, 2024.

Radiation-Induced Esophagitis in Non-Small-Cell Lung Cancer Patients: Voxel-Based Analysis and NTCP Modeling

Simple Summary

Radiation-induced esophagitis (RE) is a common dose-limiting complication associated with concurrent chemoradiation therapy for Non-Small-Cell Lung Cancer (NSCLC), and a wide range of esophageal dosimetric parameters have been described as predictive of RE. In this study, we characterize the risk of RE for NSCLC patients enrolled in a prospective trial comparing intensity-modulated RT versus passive scattering proton therapy for locally advanced NSCLC. Dose patterns associated with RE were analyzed by applying voxel-based analysis approaches, and predictive models for RE were finally investigated. Two predictive models for acute RE with good cross-validated predictive performances and discrimination capability were developed (thoracic esophageal model: ROC-AUC = 0.73; whole esophagus model: ROC-AUC = 0.70).

Abstract

The aim of our study is to characterize the risk of radiation-induced esophagitis (RE) in a cohort of Non-Small-Cell Lung Cancer (NSCLC) patients treated with concurrent chemotherapy and photon/proton therapy. For each patient, the RE was graded according to the CTCAE v.3. The esophageal dose-volume histograms (DVHs) were extracted. Voxel-based analyses (VBAs) were performed to assess the spatial patterns of the dose differences between patients with and without RE of grade ≥ 2. Two hierarchical NTCP models were developed by multivariable stepwise logistic regression based on non-dosimetric factors and on the DVH metrics for the whole esophagus and its anatomical subsites identified by the VBA. In the 173 analyzed patients, 76 (44%) developed RE of grade ≥ 2 at a median follow-up time of 31 days. The VBA identified regions of significant association between dose and RE in a region encompassing the thoracic esophagus. We developed two NTCP models, including the RT modality and a dosimetric factor: V_55Gy for the model related to the whole esophagus, and the mean dose for the model designed on the thoracic esophagus. The cross-validated performance showed good predictions for both models (ROC-AUC of 0.70 and 0.73, respectively). The only slight improvement provided by the analysis of the thoracic esophageal subsites might be due to the relevant sparing of cervical and lower thoracic esophagus in the analyzed cohort. Further studies on larger cohorts and a more heterogeneous set of dose distributions are needed to validate these preliminary findings and shed further light on the spatial patterns of RE development.

Factors associated with swallowing dysfunction in patients with head and neck cancer

BACKGROUND

The aim of this prospective cohort study was to investigate swallowing function in relation to personal and clinical factors among patients with head and neck cancer (HNC) from diagnosis up to 2 years after treatment.

METHODS

The 100 mL water swallow test was measured before treatment, and 3, 6, 12, and 24 months after treatment. Linear mixed-effects model analysis was conducted to investigate changes over time and the association with personal (sex, age) and clinical (tumor site, tumor stage, treatment modality) factors.

RESULTS

Among 128 included patients, number of swallows increased from baseline to 3 months after treatment and decreased to baseline again at 6 months after treatment. The number of swallows was associated with age and treatment modality.

CONCLUSIONS

In patients with HNC, swallowing (dys)function changes over time with the worst score 3 months after treatment. A higher age and being treated with surgery are factors associated with swallowing dysfunction over time.

Comparison of functional and survival outcomes in pedicled and microsurgical flap reconstruction for near-total and total glossectomies

Introduction:

Patients with advanced carcinoma tongue end up with near-total/total glossectomy (NTG/TG). We intended to compare functional, oncological, and survival outcomes of patients undergoing pedicled and microsurgical flap reconstruction in NTG/TG patients at our hospital.

Methodology:

A prospective study was conducted for 7 years on 91 patients with carcinoma tongue who underwent NTG/TG at our institute. Patients underwent anterolateral thigh (ALT), free radial artery forearm flap (FRAFF), and pectoralis major myocutaneous (PMMC) flap reconstruction and were followed up for immediate complications and functional outcomes for speech, swallowing, and decannulation after completion of adjuvant treatment and then for survival rates for a period of 60 months and statistically analysed with log rank test and Fisher’s exact test for correlation.

Results:

Ninety-one (42.85%) patients underwent NTG, while 57.14% underwent TG. 85% of patients had >5 mm margin, 14% had ≤ of 5 mm, and none were positive. 57% of patients did not have postoperative complications and 10% underwent re-exploration. During follow-up, 85.7% of patients were able to take orally: 52% soft diet and 32% liquid diet. Multivariate analysis of individual flaps, swallowing, and speech intelligibility values were significant. After 5 years of postadjuvant therapy, there was 76% overall survival, 11% local recurrence and 12% had regional recurrence.

Discussion:

Morbidity and functional outcome depends on the extent of resection. PMMC flaps can be done on lack of expertise. FRAFF has better functional outcomes owing to pliability of flap. ALT and other bulky flaps require expertise and are prone to flap-related complications. Planning of reconstruction should be based on the defect size together with counseling of patients regarding the risk of complications and delay in adjuvant therapy.

Radiotherapy-Induced Digestive Injury: Diagnosis, Treatment and Mechanisms

Radiotherapy is one of the main therapeutic methods for treating cancer. The digestive system consists of the gastrointestinal tract and the accessory organs of digestion (the tongue, salivary glands, pancreas, liver and gallbladder). The digestive system is easily impaired during radiotherapy, especially in thoracic and abdominal radiotherapy. In this review, we introduce the physical classification, basic pathogenesis, clinical characteristics, predictive/diagnostic factors, and possible treatment targets of radiotherapy-induced digestive injury. Radiotherapy-induced digestive injury complies with the dose-volume effect and has a radiation-based organ correlation. Computed tomography (CT), MRI (magnetic resonance imaging), ultrasound (US) and endoscopy can help diagnose and evaluate the radiation-induced lesion level. The latest treatment approaches include improvement in radiotherapy (such as shielding, hydrogel spacers and dose distribution), stem cell transplantation and drug administration. Gut microbiota modulation may become a novel approach to relieving radiogenic gastrointestinal syndrome. Finally, we summarized the possible mechanisms involved in treatment, but they remain varied. Radionuclide-labeled targeting molecules (RLTMs) are promising for more precise radiotherapy. These advances contribute to our understanding of the assessment and treatment of radiation-induced digestive injury.

Identifying Patient-Reported Outcome Measures (PROMs) for Routine Surveillance of Physical and Emotional Symptoms in Head and Neck Cancer Populations: A Systematic Review

The aims of this review were to identify symptoms experienced by head and neck cancer (HNC) patients and their prevalence, as well as to compare symptom coverage identified in HNC specific patient-reported outcome measures (PROMs). Searches of Ovid Medline, Embase, PsychInfo, and CINAHL were conducted to identify studies. The search revealed 4569 unique articles and identified 115 eligible studies. The prevalence of reported symptoms was highly variable among included studies. Variability in sample size, timing of the assessments, and the use of different measures was noted across studies. Content mapping of commonly used PROMs showed variability and poor capture of prevalent symptoms, even though validation studies confirmed satisfactory reliability and validity. This suggests limitations of some of the tools in providing an accurate and comprehensive picture of the patient's symptoms and problems.

Sequential Evaluation of Swallowing Function During Chemoradiotherapy for Head and Neck Cancer

Background

Many studies have addressed chronic dysphagia resulting from chemoradiotherapy for head and neck cancer (HNC) because of its severity, but changes in the swallowing function during chemoradiotherapy has been rarely reported. This study aimed to elucidate the changes in the swallowing function during chemoradiotherapy for HNC.

Methods

From April 2018 to July 2020, 20 patients who underwent definitive or postoperative chemoradiotherapy at our hospital for head and neck squamous cell carcinoma were evaluated by flexible endoscopy with the Hyodo scoring system for swallowing, the Penetration-Aspiration Scale (PAS), and the Functional Outcomes Swallowing Scale (FOSS).

Results

Assessments at the start of treatment, at 40 Gy, and at the end of treatment yielded these mean values: Hyodo score-0.39, 1.22, and 2.56; PAS-1.00, 1.05, and 1.5; FOSS-0.2, 0.55, and 1.1, respectively. The Dunn multiple comparison test was used for analysis to determine significance (P < 0.05). The Hyodo score and FOSS were significantly increased at the end of treatment versus initial evaluation; however, score was maintained at a tolerable level for oral intake. PAS did not show a significant increase.

Conclusion

In conclusion, changes in the swallowing function during chemoradiotherapy for HNC were mild, and swallowing function was maintained at a tolerable level for oral intake.

Radiation-Induced Dyspnea in Lung Cancer Patients Treated with Stereotactic Body Radiation Therapy

Simple Summary

Dyspnea is a common symptomatic side-effect of thoracic radiation therapy. The aim of this study is to build a predictive model of any-grade radiation-induced dyspnea within six months after stereotactic body radiation therapy in patients treated for non-small cell lung cancer. The occurrence of pre-treatment chronic obstructive pulmonary disease and higher relative lungs volume receiving more than 15 Gy as well as heart volume were shown to be risk factors for dyspnea. The obtained results encourage further studies on the topic, which could validate the present organ-based findings and explore the voxel-based landscape of radiation dose sensitivity in the development of dyspnea.

Abstract

In this study, we investigated the prognostic factors for radiation-induced dyspnea after hypo-fractionated radiation therapy (RT) in 106 patients treated with Stereotactic Body RT for Non-Small-Cell Lung Cancer (NSCLC). The median prescription dose was 50 Gy (range: 40–54 Gy), delivered in a median of four fractions (range: 3–12). Dyspnea within six months after SBRT was scored according to CTCAE v.4.0. Biologically Effective Dose (α/β = 3 Gy) volume histograms for lungs and heart were extracted. Dosimetric parameters along with patient-specific and treatment-related factors were analyzed, multivariable logistic regression method with Leave-One-Out (LOO) internal validation applied. Model performance was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC) and calibration plot parameters. Fifty-seven patients (53.8%) out of 106 developed dyspnea of any grade after SBRT (25/57 grade ≥ 2 cases). A three-variable predictive model including patient comorbidity (COPD), heart volume and the relative lungs volume receiving more than 15 Gy was selected. The model displays an encouraging performance given by a training ROC-AUC = 0.71 [95%CI 0.61–0.80] and a LOO-ROC-AUC = 0.64 [95%CI 0.53–0.74]. Further modeling efforts are needed for dyspnea prediction in hypo-fractionated treatments in order to identify patients at high risk for developing lung toxicity more accurately.

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

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

Spatial descriptions of radiotherapy dose: normal tissue complication models and statistical associations

For decades, dose-volume information for segmented anatomy has provided the essential data for correlating radiotherapy dosimetry with treatment-induced complications. Dose-volume information has formed the basis for modelling those associations via normal tissue complication probability (NTCP) models and for driving treatment planning. Limitations to this approach have been identified. Many studies have emerged demonstrating that the incorporation of information describing the spatial nature of the dose distribution, and potentially its correlation with anatomy, can provide more robust associations with toxicity and seed more general NTCP models. Such approaches are culminating in the application of computationally intensive processes such as machine learning and the application of neural networks. The opportunities these approaches have for individualising treatment, predicting toxicity and expanding the solution space for radiation therapy are substantial and have clearly widespread and disruptive potential. Impediments to reaching that potential include issues associated with data collection, model generalisation and validation. This review examines the role of spatial models of complication and summarises relevant published studies. Sources of data for these studies, appropriate statistical methodology frameworks for processing spatial dose information and extracting relevant features are described. Spatial complication modelling is consolidated as a pathway to guiding future developments towards effective, complication-free radiotherapy treatment.

Reliability of the 100 mL water swallow test in patients with head and neck cancer and healthy subjects

Background

Dysphagia may occur in up to 44% of patients with head and neck cancer (HNC) treated with radiation therapy and up to 84% of patients treated with surgery. To test the extent of dysphagia, the 100 mL water swallow test (WST) was developed. In this study, reliability of the 100 mL WST was determined in patients with HNC and healthy subjects.

Methods

Thirty‐three patients and 40 healthy subjects performed the WST twice on the same day. To assess reliability, the intraclass correlation coefficient (ICC_2,1), standard error of measurement, smallest detectable change, and limits of agreement were calculated.

Results

Good to excellent correlations were found for patients with HNC (number of swallows; ICC = 0.923, duration; ICC = 0.893), and excellent correlations for healthy subjects (number of swallows; ICC = 0.950, duration; ICC = 0.916).

Conclusion

The 100 mL WST has a good to excellent reliability in patients with HNC and healthy subjects.

Nutritional outcomes in head and neck cancer patients: is intensive nutritional care worth it?

OBJECTIVE

This study aimed to compare nutritional outcomes before and after implementation of weekly dietetic counseling (intensive nutritional care) in head and neck cancers patients.

METHODS

A retrospective study with all head and neck patients, who received radiotherapy between January 2010 and December 2017 were performed. The main outcome was significant weight loss. Compliance to caloric and protein recommendations were also evaluated.

RESULTS

In all, 472 patients were included. Weight loss was not different between before and after implementation (-6.7%; IQ -10.5/-1.9 vs -5.0%; IQ -9.8/-0.7;p=0.06).There were no significant difference in terms of meeting the recommended intake. Higher baseline body mass index and oral nutritional support predicted significant weight loss.

CONCLUSION

Implementation of intensive nutritional care did not have an impact on weight loss and energy and protein intake in head and neck cancer patients. Further research would be of value to determine the appropriate service-delivery model to achieve optimal patient outcomes.

Radiation-induced neuropathies in head and neck cancer: prevention and treatment modalities

Head and neck cancer (HNC) is the sixth most common human malignancy with a global incidence of 650,000 cases per year. Radiotherapy (RT) is commonly used as an effective therapy to treat tumours as a definitive or adjuvant treatment. Despite the substantial advances in RT contouring and dosage delivery, patients suffer from various radiation-induced complications, among which are toxicities to the nervous tissues in the head and neck area. Radiation-mediated neuropathies manifest as a result of increased oxidative stress-mediated apoptosis, neuroinflammation and altered cellular function in the nervous tissues. Eventually, molecular damage results in the formation of fibrotic tissues leading to susceptible loss of function of numerous neuronal substructures. Neuropathic sequelae following irradiation in the head and neck area include sensorineural hearing loss, alterations in taste and smell functions along with brachial plexopathy, and cranial nerves palsies. Numerous management options are available to relieve radiation-associated neurotoxicities notwithstanding treatment alternatives that remain restricted with limited benefits. In the scope of this review, we discuss the use of variable management and therapeutic modalities to palliate common radiation-induced neuropathies in head and neck cancers.

Generalizability assessment of head and neck cancer NTCP models based on the TRIPOD criteria

This review aimed to provide an overview of the level of maturity of normal tissue complication probability (NTCP) models for head and neck cancer (HNC) patients. A systematic literature review was performed to retrieve NTCP models for HNC toxicities. Patient population characteristics, NTCP model and the predictors, treatment technique and endpoint definition were extracted per article. Models were then scored based on the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) consensus guidelines to evaluate their generalizability. 335 articles on photon and proton therapy of HNC were identified and 52 relevant articles were further analyzed. Eighteen articles on xerostomia and sticky saliva (TRIPOD types 1a-2b: 15; TRIPOD type 3: 1; TRIPOD types 4a: 1 & 4b:1), thirteen articles on dysphagia and tube feeding dependence (TRIPOD types 1a-2b: 7; TRIPOD type 3: 2; TRIPOD types 4a:2 & 4b:2), five articles on oral mucositis (TRIPOD types 1a-2b: 4; TRIPOD type 4b: 1), seven articles on hypothyroidism (TRIPOD types 1a-2b: 4; TRIPOD type 3: 1; TRIPOD types 4a: 1 & 4b:1), four articles on hearing loss and tinnitus (TRIPOD type 1a: 4) and ten articles on esophagitis (TRIPOD types 1a-2b: 9; TRIPOD type 4a: 1) were included. External validation studies of HNC NTCP models are scarce. Moreover, the majority of them were validating a model developed by the same researchers. Only 2 independent external validation studies were found. There is a strong need to publish external validation studies to get more mature NTCP models applicable in clinical practice.

Mixed-beam approach in locally advanced nasopharyngeal carcinoma: IMRT followed by proton therapy boost versus IMRT-only. Evaluation of toxicity and efficacy

Objective: To compare radiation-induced toxicity and dosimetry parameters in patients with locally advanced nasopharyngeal cancer (LANPC) treated with a mixed-beam (MB) approach (IMRT followed by proton therapy boost) with an historic cohort of patients treated with a full course of IMRT-only.Material and methods: Twenty-seven patients with LANPC treated with the MB approach were compared to a similar cohort of 17 patients treated with IMRT-only. The MB approach consisted in a first phase of IMRT up to 54-60 Gy followed by a second phase delivered with a proton therapy boost up to 70-74 Gy (RBE). The total dose for patients treated with IMRT-only was 69.96 Gy. Induction chemotherapy was administrated to 59 and 88% and concurrent chemoradiotherapy to 88 and 100% of the MB and IMRT-only patients, respectively. The worst toxicity occurring during the entire course of treatment (acute toxicity) and early-late toxicity were registered according to the Common Terminology Criteria Adverse Events V4.03.Results: The two cohorts were comparable. Patients treated with MB received a significantly higher median total dose to target volumes (p = .02). Acute grade 3 mucositis was found in 11 and 76% (p = .0002) of patients treated with MB and IMRT-only approach, respectively, while grade 2 xerostomia was found in 7 and 35% (p = .02) of patients treated with MB and IMRT-only, respectively. There was no statistical difference in late toxicity. Local progression-free survival (PFS) and progression-free survival curves were similar between the two cohorts of patients (p = .17 and p = .40, respectively). Local control rate was 96% and 81% for patients treated with MB approach and IMRT-only, respectively.Conclusions: Sequential MB approach for LANPC patients provides a significantly lower acute toxicity profile compared to full course of IMRT. There were no differences in early-late morbidities and disease-related outcomes (censored at two-years) but a longer follow-up is required to achieve conclusive results.

Age-dependent hemato- and nephrotoxicity in patients with head and neck cancer receiving chemoradiotherapy with weekly cisplatin

BACKGROUND AND PURPOSE

In cases of simultaneous chemoradiotherapy (CRT), early recognition of toxic side effects is important, as drug discontinuation may prevent further injury. It appears favorable to undertake further steps to investigate whether patient subgroups behave differently depending on their toxicity profile.

METHODS

We retrospectively analyzed 125 consecutive patients with non-metastasized carcinoma of the head and neck who were treated with CRT (cisplatin 40 mg/m² weekly) in 2013/2014. Patients were planned to receive six cycles of cisplatin. Statistical analyses were performed using the chi² test, t-test, Kaplan-Meier method, and the log-rank test, as appropriate.

RESULTS

Eighty-six patients did not reach the intended sixth cycle (68.8%; 60.0% of whom were ≥60 years, p < 0.05). Acute kidney injury (glomerular filtration rate <60 mL/min/1.73m²) was the most common reason for drug discontinuation (26.7%; 82.6% of whom were ≥60 years; p < 0.01), followed by leukopenia <3/nL (23.3%; 75% of whom were <60 years; p < 0.01) and infection (11.6%). Patients who underwent ≥5 cycles were associated with prolonged overall survival and metastasis-free survival after CRT (p < 0.02; median follow-up 24 months), especially patients <60 years.

CONCLUSION

Acute kidney injury was the most common side effect in patients ≥60 years, whereas leukopenia characteristically occurred significantly more often in younger patients. Discontinuing cisplatin during CRT was associated with a worse outcome, especially in patients <60 years.

Is there a patient population with squamous cell carcinoma of the head and neck region who might benefit from de-intensification of postoperative radiotherapy? : A monocentric retrospective analysis of a previously defined low-risk patient population treated with standard-of-care radiotherapy

PURPOSE

The aim of this retrospective study was to evaluate the clinical outcome of a previously defined low-risk patient population with completely resected (R0) squamous cell carcinoma of the oral cavity, oropharynx, larynx (pT1-3, pN0-pN2b), hypopharynx (pT1-2, pN0-pN1), and the indication for postoperative radio(chemo)therapy.

PATIENTS AND METHODS

According to predefined criteria, 99 patients with head and neck squamous cell carcinoma (SCC) who were treated at our institution from January 1, 2005 to December 31, 2014, were available for analysis. The Kaplan-Meier method was used for calculating survival and incidence rates. For univariate comparative analysis, the log-rank test was used for analyzing prognostic clinicopathologic parameters.

RESULTS

Median follow-up was 67 months. Cumulative overall (OS) and disease-free survival (DFS) were 97.9%/94.7%/88.0% and 96.9%/92.6%/84.7% after 1, 2, and 5 years, respectively. Cumulative incidence of loco-regional recurrence (LRR), distant metastases (DM), and second cancer (SC) were 1.0%/1.0%/4.9%, 0.0%/3.4%/5.8%, and 2.1%/4.2%/13.1%, respectively. In univariate comparative analysis, location of the primary tumor in the oropharynx was a significant predictor for increased OS (p = 0.043) and DFS (p = 0.048).

CONCLUSION

Considering the low disease relapse rates and high rates of therapy-induced late side effects, as well as the increased risk of developing SC, a prospective multicentric trial investigating de-escalation of radiotherapy in this clearly defined low-risk patient population was started and is still recruiting patients (DIREKHT-Trial, NCT02528955).

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

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