Effect of radiotherapy and chemotherapy on the risk of mucositis during intensity-modulated radiation therapy for oropharyngeal cancer

Normal tissue complication probability model for acute oral mucositis in patients with head and neck cancer undergoing carbon ion radiation therapy based on dosimetry, radiomics, and dosiomics

BACKGROUND AND PURPOSE

To develop a normal tissue complication probability (NTCP) model for predicting grade ≥ 2 acute oral mucositis (AOM) in head and neck cancer patients undergoing carbon-ion radiation therapy (CIRT).

METHODS AND MATERIALS

We retrospectively included 178 patients, collecting clinical, dose-volume histogram (DVH), radiomics, and dosiomics data. Patients were randomly divided into training (70%) and test sets (30%). Feature selection involved univariable logistic regression, least absolute shrinkage and selection operator regression, stepwise backward regression, and Spearman's correlation test, with the bootstrap method ensuring reliability. Multivariable models were built on the training set and evaluated using the test set.

RESULTS

The optimal NTCP model incorporated a DVH parameter (V37Gy [relative biological effectiveness, RBE]), radiomics, and dosiomics features, achieving an area under the curve (AUC) of 0.932 in the training set and 0.959 in the test set. This hybrid model outperformed those based on single DVH, radiomics, dosiomics, or clinical data (Bonferroni-adjusted p < 0.001 and ΔAUC > 0 for all comparisons in 1,000 bootstrap validations). Calibration curves showed strong agreement between predictions and outcomes. A 44.0 % AOM risk threshold was proposed, yielding accuracies of 87.1 % in the training set and 90.7 % in the test set.

CONCLUSIONS

We developed the first NTCP model for estimating AOM risk in head and neck cancer patients undergoing CIRT and proposed a risk stratification. This model may assist in clinical decision-making and improve treatment planning for AOM prevention and management by identifying high-risk patients.

A multi-center, multi-organ, multi-omic prediction model for treatment-induced severe oral mucositis in nasopharyngeal carcinoma

PURPOSE

Oral mucositis (OM) is one of the most prevalent and crippling treatment-related toxicities experienced by nasopharyngeal carcinoma (NPC) patients receiving radiotherapy (RT), posing a tremendous adverse impact on quality of life. This multi-center study aimed to develop and externally validate a multi-omic prediction model for severe OM.

METHODS

Four hundred and sixty-four histologically confirmed NPC patients were retrospectively recruited from two public hospitals in Hong Kong. Model development was conducted on one institution (n = 363), and the other was reserved for external validation (n = 101). Severe OM was defined as the occurrence of CTCAE grade 3 or higher OM during RT. Two predictive models were constructed: 1) conventional clinical and DVH features and 2) a multi-omic approach including clinical, radiomic and dosiomic features.

RESULTS

The multi-omic model, consisting of chemotherapy status and radiomic and dosiomic features, outperformed the conventional model in internal and external validation, achieving AUC scores of 0.67 [95% CI: (0.61, 0.73)] and 0.65 [95% CI: (0.53, 0.77)], respectively, compared to the conventional model with 0.63 [95% CI: (0.56, 0.69)] and 0.56 [95% CI: (0.44, 0.67)], respectively. In multivariate analysis, only the multi-omic model signature was significantly correlated with severe OM in external validation (p = 0.017), demonstrating the independent predictive value of the multi-omic approach.

CONCLUSION

A multi-omic model with combined clinical, radiomic and dosiomic features achieved superior pre-treatment prediction of severe OM. Further exploration is warranted to facilitate improved clinical decision-making and enable more effective and personalized care for the prevention and management of OM in NPC patients.

The relevance of dental management prior to radiation therapy with severe oral mucositis in head and neck cancer patients

Background/purpose

Dental management prior to radiotherapy is often time-critical, and there are no studies on whether manipulations such as tooth extraction influence the risk of severe radiation-induced oral mucositis (ROM) during radiotherapy. Therefore, the aim of this study was to describe the relationship between dental management and the incidence of severe ROM.

Materials and methods

A retrospective analysis was conducted on 144 head and neck cancer (HNC) patients who received dental management before radiotherapy at Peking University Cancer Hospital, from January 2016 to December 2017. Demographic characteristics, primary tumor features, cancer treatment characteristics, and severity of oral mucositis during radiotherapy were recorded. Univariate analysis and logistic regression analysis were used to explore factors associated with severe radiation-induced oral mucositis.

Results

The incidence of grade 3 mucositis was 14.5% (22/144); univariate analysis showed that the number of extracted teeth (OR = 1.313; 95%CI = 1.012-1.702; P = 0.040) and patients with primary oral cancer had a higher risk of developing grade 3 mucositis (OR = 3.848; 95% CI = 1.508-9.822; P = 0.005). No statistical correlation was found between pre-radiation therapy prophylaxis, dental restoration, endodontic treatment, and grade 3 mucositis (P > 0.05). Logistic regression analysis showed that the number of extracted teeth (OR = 1.421, 95%CI = 1.071-1.885, P = 0.015) and primary tumor location in the oral cavity (compared with other head and neck cancers) (OR = 5.165, 95%CI = 1.636-16.311, P = 0.005) were significantly associated with grade 3 mucositis.

Conclusion

In HNC patients undergoing radiotherapy, the primary site located in the oral cavity and a higher number of teeth extracted are independent risk factors for the development of severe mucositis.

Artificial intelligence-based predictive model for guidance on treatment strategy selection in oral and maxillofacial surgery

Application of deep learning (DL) and machine learning (ML) is rapidly increasing in the medical field. DL is gaining significance for medical image analysis, particularly, in oral and maxillofacial surgeries. Owing to the ability to accurately identify and categorize both diseased and normal soft- and hard-tissue structures, DL has high application potential in the diagnosis and treatment of tumors and in orthognathic surgeries. Moreover, DL and ML can be used to develop prediction models that can aid surgeons to assess prognosis by analyzing the patient's medical history, imaging data, and surgical records, develop more effective treatment strategies, select appropriate surgical modalities, and evaluate the risk of postoperative complications. Such prediction models can play a crucial role in the selection of treatment strategies for oral and maxillofacial surgeries. Their practical application can improve the utilization of medical staff, increase the treatment accuracy and efficiency, reduce surgical risks, and provide an enhanced treatment experience to patients. However, DL and ML face limitations, such as data drift, unstable model results, and vulnerable social trust. With the advancement of social concepts and technologies, the use of these models in oral and maxillofacial surgery is anticipated to become more comprehensive and extensive.

Efficacy of probiotics in the treatment of oral mucositis in head and neck cancer patients: A systematic review and meta-analysis

OBJECTIVES

To assess the effect of probiotics in oral mucositis induced by chemotherapy or radiotherapy on patients with head and neck cancer (HNC).

METHODS

The PubMed, Embase, Cochrane Library, Clinical trials were screened from January 2010 to April 2024. Randomized clinical trials (RCTs) comparing the efficacy of probiotics in treatment of oral mucositis in HNC were eligible. Outcomes of interest were incidence of oral mucositis and severe oral mucositis. The PROSPERO registration number was 42 022 384 685. The Cochrane risk-of-bias tool (RoB2) was used to assess methodological quality of studies and GRADE criteria (GRADEpro) was applied for rating the certainty of evidence. Meta-analysis was performed by using RevMan 5.4.

RESULTS

A total of eight RCTs comprising 691 patients with HNC were included in this meta-analysis. Probiotics administration significantly reduced the incidence of SOM (RR = 0.60, 95%CI: 0.46-0.78, P = 0.0002). However, it showed no distinct advantage in reducing the overall incidence of oral mucositis (RR = 0.88, 95%CI: 0.76-1.02, P = 0.08). Subgroup analysis found more benefit for reducing SOM in multi-bacterial treated group (RR = 0.35, 95%CI: 0.17-0.73, P = 0.005) than mono-bacterial treated group (RR = 0.69, 95%CI: 0.58-0.82, P < 0.0001). In Addition, probiotics could reduce the incidence of SOM in nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (RR = 0.43, 95%CI: 0.26-0.70, P = 0.0006).

CONCLUSION

Probiotics reduced the incidence of SOM caused by chemotherapy or radiotherapy for HNC. The multi-bacterial combination therapy was more efficacious than the mono-bacterial therapy. Moreover, probiotics also reduced the incidence of SOM in nasopharyngeal carcinoma. However, the advantage of probiotics had not been established in the overall incidence of OM.

Predicting severe radiation-induced oral mucositis in head and neck cancer patients using integrated baseline CT radiomic, dosimetry, and clinical features: A machine learning approach

Purpose

To establish the early prediction models of radiation-induced oral mucositis (RIOM) based on baseline CT-based radiomic features (RFs), dosimetric data, and clinical features by machine learning models for head and neck cancer (HNC) patients.

Methods

In this single-center prospective study, 49 HNCs treated with curative intensity modulated radiotherapy (IMRT) were enrolled. Baseline CT images (i.e., CT simulation), dosimetric, and clinical features were collected. RIOM was assessed using CTCAE v.5.0. RFs were extracted from manually-contoured oral mucosa structures. Minimum-redundancy-maximum-relevance (mRMR) method was applied to select the most informative radiomics, dosimetric, and clinical features. Then, binary prediction models were constructed for predicting acute RIOM based on the top mRMR-ranked radiomics, dosimetric, and clinical features alone or in combination, using random forest classifier algorithm. The predictive performance of models was assessed using the area under the receiver operating curve (AUC), accuracy, weighted-average based sensitivity, precision, and F1-measure.

Results

Among extracted features, the top 10 RFs, the top 5 dose-volume features, and the top 5 clinical features were selected using mRMR method. The model exploiting the integrated features (10-radiomics + 5-dosimetric + 5-clinical) achieved the best prediction with AUC, accuracy, sensitivity, precision, and F1-measure values of 91.7 %, 90.0 %, 83.0 % 100.0 %, and 91.0 %, respectively. The model developed using baseline CT RFs alone provided the best performance compared to dose-volume features or clinical features alone, with an AUC of 87.0 %.

Conclusion

Our results suggest that the integration of baseline CT radiomic features with dosimetric and clinical features showed promising potential to improve the performance of machine learning models in early prediction of RIOM. The ultimate goal is to personalize radiotherapy for HNC patients.

Predictive Factors for Chemoradiation-Induced Oral Mucositis and Dysphagia in Head and Neck Cancer: A Scoping Review

Despite advances in head and neck cancer treatment, virtually all patients experience chemoradiation-induced toxicities. Oral mucositis (OM) and dysphagia are among the most prevalent and have a systemic impact on patients, hampering treatment outcome and harming quality of life. Accurate prediction of severe cases is crucial for improving management strategies and, ultimately, patient outcomes. This scoping review comprehensively maps the reported predictors and critically evaluates the performance, methodology, and reporting of predictive models for these conditions. A total of 174 studies were identified from database searches, with 73 reporting OM predictors, 97 reporting dysphagia predictors, and 4 reporting both OM and dysphagia predictors. These predictors included patient demographics, tumor classification, chemoradiotherapy regimen, radiation dose to organs-at-risk, genetic factors, and results of clinical laboratory tests. Notably, many studies only conducted univariate analysis or focused exclusively on certain predictor types. Among the included studies, numerous predictive models were reported: eight for acute OM, five for acute dysphagia, and nine for late dysphagia. The area under the receiver operating characteristic curve (AUC) ranged between 0.65 and 0.81, 0.60 and 0.82, and 0.70 and 0.85 for acute oral mucositis, acute dysphagia, and late dysphagia predictive models, respectively. Several areas for improvement were identified, including the need for external validation with sufficiently large sample sizes, further standardization of predictor and outcome definitions, and more comprehensive reporting to facilitate reproducibility.

Multimodal Data Integration to Predict Severe Acute Oral Mucositis of Nasopharyngeal Carcinoma Patients Following Radiation Therapy

(1) Background: Acute oral mucositis is the most common side effect for nasopharyngeal carcinoma patients receiving radiotherapy. Improper or delayed intervention to severe AOM could degrade the quality of life or survival for NPC patients. An effective prediction method for severe AOM is needed for the individualized management of NPC patients in the era of personalized medicine. (2) Methods: A total of 242 biopsy-proven NPC patients were retrospectively recruited in this study. Radiomics features were extracted from contrast-enhanced CT (CECT), contrast-enhanced T1-weighted (cT1WI), and T2-weighted (T2WI) images in the primary tumor and tumor-related area. Dosiomics features were extracted from 2D or 3D dose-volume histograms (DVH). Multiple models were established with single and integrated data. The dataset was randomized into training and test sets at a ratio of 7:3 with 10-fold cross-validation. (3) Results: The best-performing model using Gaussian Naive Bayes (GNB) (mean validation AUC = 0.81 ± 0.10) was established with integrated radiomics and dosiomics data. The GNB radiomics and dosiomics models yielded mean validation AUC of 0.6 ± 0.20 and 0.69 ± 0.14, respectively. (4) Conclusions: Integrating radiomics and dosiomics data from the primary tumor area could generate the best-performing model for severe AOM prediction.

Correlation of oral mucosa dose and volume parameters with Grade 3 mucositis, in patients treated with volumetric modulated arc radiotherapy for oropharyngeal cancer?

Background

Oral mucositis is the dose-limiting toxicity of chemoradiation in oropharyngeal cancer patients, which can be minimized by giving constraints to oral mucosa. However, the constraints defined in literature are extrapolated from chemoradiation in head and neck cancers as a whole. This study aims to determine oral mucosa dose-volume parameters that can predict grade ≥ 3 acute oral mucositis in oropharyngeal cancer patients treated with volumetric modulated arc radiotherapy.

Methods

This prospective study was done in 52 patients of locally advanced oropharyngeal cancer treated with Volumetric modulated arc radiotherapy. Dose-volume histogram data were extracted and then acute oral mucosa toxicity was analysed. Receiver operating characteristic analysis and logistic regression were carried out to determine predictive factors for grade ≥ 3 mucositis.

Results

Grade ≥ 3 acute oral mucositis occurred in 57.6% (30/52) patients in the study. V30Gy &gt; 53.35% (P = 0.005) was an independent dosimetric factor related to grade ≥ 3 acute toxicity. In the receiver operating characteristic curve, the area under V30Gy was 0.770 (P = 0.001); the cut-off value of V30 was 46.23% (sensitivity, 0.80; specificity, 0.91).

Conclusions

Dose-volume histogram analysis predicts V30 &gt; 53.35% as independent factors for grade ≥ 3 acute oral mucositis in patients with oropharyngeal cancers treated with Volumetric modulated arc radiotherapy. Studies in future with more patient number can further validate the above results.

Confounding factors in the assessment of oral mucositis in head and neck cancer

Treatment of locally advanced head and neck carcinoma not amenable for surgical resection or resected with high-risk features is usually based on (chemo-)radiation treatment. Oral mucositis represents one of the main side effects of (chemo-)radiation, with an important impact on quality of life and causing approximately 20% of early interruption of treatment, leading to a suboptimal dose administered. Treatment and prevention of oral mucositis have a central role in the therapeutic pathways of head and neck cancer patients but remains quite challenging. Although extensive research is conducted to identify interventions for the management of mucositis, very few interventions had sufficient evidence to generate an international expert consensus. This may be partially explained by confounding factors that could influence the development and assessment of oral mucositis. Little is known about the confounding factors of oral mucositis, which, if not well balanced in an experimental study, could lead to non-solid results. The current paper aims to review the main oral mucositis confounding factors related to head and neck cancer patients.

Precision medicine for risk prediction of oral complications of cancer therapy–The example of oral mucositis in patients receiving radiation therapy for cancers of the head and neck

Oral complications of cancer therapy are common, markedly symptomatic, negatively impact patients' quality of life, and add significantly to the cost of care. Patients' risk of treatment-related toxicities is not uniform; most patients suffer at least one side effect, while others tolerate treatment without any. Understanding those factors which impact risk provides opportunities to customize cancer treatment plans to optimize tumor kill and minimize regimen-related toxicities. Oral mucositis (OM) is an iconic example of a clinically significant and common complication of head and neck radiotherapy. Individuals' OM risk is governed by the cumulative impact of factors related to treatment, the tumor, and the patient. In addition to OM risk prediction, a second opportunity to apply precision medicine will evolve as viable treatment options become available. Patients vary widely in how well or poorly they respond to specific treatments. What works well in one individual, might fail in another. Prospective determination of the likelihood of a patient's response or non-response is based on a range of biological interactions. Coupled with risk determination, the application of precision medicine will allow caregivers, patients, and payers to integrate risk/benefit to optimize the probability that the best treatment is be given to the most appropriate patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Predicting acute severe toxicity for head and neck squamous cell carcinomas by combining dosimetry with a radiosensitivity biomarker: a pilot study

OBJECTIVE

Radiotherapy (RT) against head and neck squamous cell carcinomas (HNSCC) may lead to severe toxicity in 30-40% of patients. The normal tissue complication probability (NTCP) models, based on dosimetric data refined the normal tissue dose/volume tolerance guidelines. In parallel, the radiation-induced nucleoshuttling (RIANS) of the Ataxia-Telangiectasia Mutated protein (pATM) is a predictive approach of individual intrinsic radiosensitivity. Here, we combined NTCP with RADIODTECT©, a blood assay derived from the RIANS model, to predict RT toxicity in HNSCC patients.

METHODS

RADIODTECT© cutoff values (i.e. 57.8 ng/mL for grade⩾2 toxicity and 46 ng/mL for grade⩾3 toxicity) have been previously assessed. Validation was performed on a prospective cohort of 36 HNSCC patients treated with postoperative RT. Toxicity was graded with the Common Terminology Criteria for Adverse Events (CTCAE) scale and two criteria were considered: grade⩾2 oral mucositis (OM2), grade⩾3 mucositis (OM3) and grade⩾2 dysphagia (DY2), grade⩾3 dysphagia (DY3). pATM quantification was assessed in lymphocytes of HNSCC patients. The discrimination power of the pATM assay was evaluated through the Area Under the Receiver Operator Characteristics Curve (AUC-ROC). Two previously described NTCP models were considered, including the dose to the oral cavity and the mean dose to the parotid glands (OM2 and OM3) and the dose to the oral cavity, to the larynx and the volume of pharyngeal constrictor muscles (DY2 and DY3).

RESULTS

Combining NTCP models with RADIODTECT© blood test improved the AUC-ROC. Considering the prediction of mucositis, AUC-ROC^{NTCP+RADIODTECT©}=0.80 was for OM2, and AUC-ROC^{NTCP+RADIODTECT©}=0.78 for OM3. Considering the prediction of acute dysphagia, AUC-ROC^{NTCP+RADIODTECT©}=0.71 for DY2 and for DY3.

CONCLUSIONS

Combining NTCP models with a radiosensitivity biomarker might significantly improve the prediction of toxicities for HNSCC patients.

Pathogenesis and Amelioration of Radiation-Induced Oral Mucositis

OPINION STATEMENT

Oral mucositis (OM) causes significant detriment to patient quality of life. Despite advances in RT, chemotherapy, and surgery for HNC which have led to improved local control and survival, management of certain toxicities such as OM have not kept pace. Numerous strategies have emerged with demonstrable benefit in preventing severe OM. However, ones which are not only effective, but practical and affordable to implement are rare. For example, infusion of growth factors or free radical scavengers, and daily treatment of intra-oral sites with lasers are supported by high-quality evidence but have not become widely adopted. It falls to familiarity of the physician with the available preventative measures and ultimately, patient preference in accepting which strategies for OM amelioration are used. In this review, we present a pathophysiological-based review of prevention techniques available for reducing the incidence and duration of severe OM.

Benefits of immunonutrition in patients with head and neck cancer receiving chemoradiation: A phase II randomized, double-blind study

BACKGROUND & AIMS

The benefits of immunonutrition in patients with head and neck cancer (HNC), especially for those undergoing definitive concurrent chemoradiation (CCRT), remain unclear. We evaluated the benefits of immunonutrition regarding the prevention of severe oral mucositis. Secondary objectives included assessments of other treatment-related toxicities, changes of nutritional and inflammatory marker levels, treatment tolerance, and survival.

METHODS

In total, 110 patients with HNC undergoing definitive CCRT including 3-week cycles of cisplatin were enrolled in our double-blind phase II study. Patients were randomly assigned to receive an immunonutrient formula containing omega-3-fatty acids, arginine, dietary nucleotides, and soluble fiber (n = 55) or an isocaloric isonitrogenous control (n = 55). All patients received the assigned product 5 consecutive days before each chemotherapy session. The proportion of patients with severe oral mucositis was compared between the immunonutrients and control groups.

RESULTS

The rates of nasopharyngeal cancer (NPC) were 67% and 51% in the immunonutrients and control groups, respectively. All patients had 100% compliance to the assigned product. There was no difference of the proportion of patients with grade 3-4 oral mucositis between the two groups (62% vs. 67%, p = 0.690). At the time of analyses, survival tended to be better in the immunonutrients group. The 3-year progression-free survival rates were 69% (95% confidence interval [CI] = 55%-80%) and 44% (95% CI = 30%-57%) in the immunonutrients and control groups, respectively (p = 0.056), whereas the 3-year overall survival rates in these groups were 69% (95% CI = 54%-80%) and 50% (95% CI = 36%-66%; p = 0.065), respectively. In subgroup analyses according to the primary tumor location, the survival benefits were apparently maintained in patients with NPC.

CONCLUSIONS

Although our study did not demonstrate a reduced risk of severe oral mucositis, we found that immunonutrition might improve survival. Larger studies are needed to determine the optimal dose and schedule of immunonutrition to prevent oral mucositis. In addition, randomized phase III trials evaluating the survival benefits of immunonutrition in patients with cancer are required, and NPC might be a primary malignancy of interest.

TRIAL REGISTRATION

ClinicalTrials.gov ID NCT05101889.

The Role of Patient- and Treatment-Related Factors and Early Functional Imaging in Late Radiation-Induced Xerostomia in Oropharyngeal Cancer Patients

Simple Summary

In the present prospective study, we assessed the role of various Magnetic Resonance Imaging biomarkers combined with self-assessed xerostomia questionnaires and patient- and treatment-related factors, in predicting xerostomia at 12 months after chemoradiotherapy for oropharyngeal squamous cell carcinoma. We hypothesized that the integration of pre-treatment imaging biomarkers, which addresses the tissue heterogeneity and individual variations among patients, could improve the accuracy of conventional prediction models that are based only on dose information, ultimately providing a better understanding of the pathophysiological mechanisms underlying radiation induced salivary dysfunction. The implementation of multifactorial models, driven by machine learning algorithms, may improve prediction accuracy of radiation-induced toxicity and tailor individual treatment options for patients.

Abstract

The advent of quantitative imaging in personalized radiotherapy (RT) has offered the opportunity for a better understanding of individual variations in intrinsic radiosensitivity. We aimed to assess the role of magnetic resonance imaging (MRI) biomarkers, patient-related factors, and treatment-related factors in predicting xerostomia 12 months after RT (XER₁₂) in patients affected by oropharyngeal squamous cell carcinoma (OSCC). Patients with locally advanced OSCC underwent diffusion-weighted imaging (DWI) and dynamic-contrast enhanced MRI at baseline; DWI was repeated at the 10th fraction of RT. The Radiation Therapy Oncology Group (RTOG) toxicity scale was used to evaluate salivary gland toxicity. Xerostomia-related questionnaires (XQs) were administered weekly during and after RT. RTOG toxicity ≥ grade 2 at XER₁₂ was considered as endpoint to build prediction models. A Decision Tree classification learner was applied to build the prediction models following a five-fold cross-validation. Of the 89 patients enrolled, 63 were eligible for analysis. Thirty-six (57.1%) and 21 (33.3%) patients developed grade 1 and grade 2 XER₁₂, respectively. Including only baseline variables, the model based on DCE-MRI and V65 (%) (volume of both glands receiving doses ≥ 65 Gy) had a fair accuracy (77%, 95% CI: 66.5–85.4%). The model based on V65 (%) and XQ-Int_mid (integral of acute XQ scores from the start to the middle of RT) reached the best accuracy (81%, 95% CI: 71–88.7%). In conclusion, non-invasive biomarkers from DCE-MRI, in combination with dosimetric variables and self-assessed acute XQ scores during treatment may help predict grade 2 XER₁₂ with a fair to good accuracy.

Is There an Interplay between Oral Microbiome, Head and Neck Carcinoma and Radiation-Induced Oral Mucositis?

Head and neck carcinoma is one of the most common human malignancy types and it ranks as the sixth most common cancer worldwide. Nowadays, a great potential of microbiome research is observed in oncology-investigating the effect of oral microbiome in oncogenesis, occurrence of treatment side effects and response to anticancer therapies. The microbiome is a unique collection of microorganisms and their genetic material, interactions and products residing within the mucous membranes. The aim of this paper is to summarize current research on the oral microbiome and its impact on the development of head and neck cancer and radiation-induced oral mucositis. Human microbiome might determine an oncogenic effect by, among other things, inducing chronic inflammatory response, instigating cellular antiapoptotic signals, modulation of anticancer immunity or influencing xenobiotic metabolism. Influence of oral microbiome on radiation-induced oral mucositis is expressed by the production of additional inflammatory cytokines and facilitates progression and aggravation of mucositis. Exacerbated acute radiation reaction and bacterial superinfections lead to the deterioration of the patient's condition and worsening of the quality of life. Simultaneously, positive effects of probiotics on the course of radiation-induced oral mucositis have been observed. Understanding the impact on the emerging acute radiation reaction on the composition of the microflora can be helpful in developing a multifactorial model to forecast the course of radiation-induced oral mucositis. Investigating these processes will allow us to create optimized and personalized preventive measures and treatment aimed at their formation mechanism. Further studies are needed to better establish the structure of the oral microbiome as well as the dynamics of its changes before and after therapy. It will help to expand the understanding of the biological function of commensal and pathogenic oral microbiota in HNC carcinogenesis and the development of radiation-induced oral mucositis.

An underestimated pitfall of oral candidiasis in head and neck cancer patients undergoing radiotherapy: an observation study

Background

Oral candidiasis is a common problem associated with head and neck radiation therapy (RT) consequences being pain, burning sensation, taste change, and systemic infection. There are difficulties in differentiating between oral candidiasis and radiation induced oral mucositis. We conducted a prospective study to explore the incidence of clinical oral candidiasis and evaluate the accuracy of diagnosis among head and neck cancer (HNC) patients receiving RT or concurrent chemoradiotherapy (CCRT).

Methods

This study included 86 HNC patients who had no clinical signs or symptoms of oral candidiasis. Oral mucosa and tongue swabs were carried out and analyzed three times by fungal cultures at the following time points: (1) before RT, (2) at the time of clinically diagnosed candidiasis or during RT at between the 15th–17th fraction (whichever occurred first), and (3) at the end of RT. The accuracy of clinical oral candidiasis was explored and confirmed by fungal colonization techniques. The incidence and risk factors associated with fungal colonization before and throughout the treatment were analyzed.

Results

The overall incidence of clinical oral candidiasis was 53.5% throughout the course of RT. Confirmation of fungal colonization was found in 39.5%, 65.9%, and 57.7% of cases before RT, during RT, and end of RT, respectively. The accuracy of the diagnosis using only clinical presentation was demonstrated in 60%, 50%, and 52% before RT, during RT, and end of RT, respectively. Logistic regression analysis showed that age, CCRT, and using 2% viscous lidocaine solution were independent risk factors for fungal colonization.

Conclusions

The results of this study demonstrated an underestimation of clinical oral candidiasis before and throughout the course of radiotherapy from using only clinical sign and symptoms. Crucial attention to detail and testing in the oral examination could improve decision making for detection of oral candidiasis in HNC patients receiving RT or CCRT.

Progressive muscle loss is an independent predictor for survival in locally advanced oral cavity cancer: A longitudinal study

BACKGROUND AND PURPOSE

To investigate the association between progressive muscle loss and survival outcomes of patients with advanced-stage oral squamous cell carcinoma (OSCC) undergoing surgery and adjuvant (chemo)radiotherapy.

METHODS

We analyzed the computed tomography (CT) scans of 155 patients with stage III-IVB OSCC at baseline, at simulation CT for radiotherapy, and at 3- and 9-months post-treatment. Skeletal muscle index (SMI) was measured using CT at the C3 vertebral level. The predictors of overall survival (OS) and recurrence-free survival (RFS) were evaluated using Cox regression models.

RESULTS

The median follow-up period was 75.0 months. Fifty-one patients (32.9%) developed recurrence, with the median time from the fourth CT to recurrence being 9.1 months. The SMI progressively decreased from baseline to simulation CT by 1.1% (p = 0.006), to 3 months post-treatment by 5.1% (p < 0.001), and to 9 months post-treatment by 15.6% (p < 0.001) in patients developing recurrence. Patients without recurrence lost SMI at the simulation CT by 0.7% (p = 0.001) and at 3 months post-treatment by 2.1% (p < 0.001); their SMI returned to the baseline level at 9 months post-treatment. SMI changes were weakly correlated with changes in body mass index (BMI) (Spearman ρ, 0.13; p = 0.11). In multivariate analysis, SMI changes (per 5% decrease) were independently associated with significantly worse OS (hazard ratio: 1.88, 95% confidence interval: 1.58-2.23; p < 0.001) and RFS (hazard ratio: 1.89, 95% confidence interval: 1.61-2.20; p < 0.001).

CONCLUSION

Progressive muscle loss was independently associated with worse survival outcomes in patients with stage III-IVB OSCC. Muscle loss might not be detected by changes in BMI.

Radiation Induced Mucositis: What the Radiologist Needs to Know

Radiation induced oral mucositis (RIOM) is a common and debilitating complication of radiation therapy for head and neck cancers. RIOM can lead to oral pain, dysphagia, and reduced oral intake, which can be severe enough to necessitate placement of a feeding tube or utilization of total parenteral nutrition. When severe, RIOM can cause premature termination of radiation therapy and can alter treatment plans leading to suboptimal treatment doses. While patient reporting of RIOM symptoms has been the gold standard of documenting RIOM progression, little has been described in the radiology literature concerning the typical imaging findings of RIOM. Herein, we review the pathophysiology and clinical presentation that underlies the development of RIOM with illustrative cases to highlight the relevant imaging findings related to RIOM for the practicing radiologist.

Predictive Model and Precaution for Oral Mucositis During Chemo-Radiotherapy in Nasopharyngeal Carcinoma Patients

PURPOSE

To explore risk factors for severe acute oral mucositis of nasopharyngeal carcinoma (NPC) patients receiving chemo-radiotherapy, build predictive models and determine preventive measures.

METHODS AND MATERIALS

Two hundred and seventy NPC patients receiving radical chemo-radiotherapy were included. Oral mucosa structure was contoured by oral cavity contour (OCC) and mucosa surface contour (MSC) methods. Oral mucositis during treatment was prospectively evaluated and divided into severe mucositis group (grade ≥ 3) and non-severe mucositis group (grade < 3) according to RTOG Acute Reaction Scoring System. Nineteen clinical features and nineteen dosimetric parameters were included in analysis, least absolute shrinkage and selection operator (LASSO) logistic regression model was used to construct a risk score (RS) system.

RESULTS

Two predictive models were built based on the two delineation methods. MSC based model is more simplified one, it includes body mass index (BMI) classification before radiation, retropharyngeal lymph node (RLN) area irradiation status and MSC V55%, RS = -1.480 + (0.021 × BMI classification before RT) + (0.126 × RLN irradiation) + (0.052 × MSC V55%). The cut-off of MSC based RS is -1.011, with an area under curve (AUC) of 0.737 (95%CI: 0.672-0.801), a specificity of 0.595 and a sensitivity of 0.786. OCC based model involved more variables, RS= -4.805+ (0.152 × BMI classification before RT) + (0.080 × RT Technique) + (0.097 × Concurrent Nimotuzumab) + (0.163 × RLN irradiation) + (0.028 × OCC V15%) + (0.120 × OCC V60%). The cut-off of OCC based RS is -0.950, with an AUC of 0.767 (95%CI: 0.702-0.831), a specificity of 0.602 and a sensitivity of 0.819. Analysis in testing set shown higher AUC of MSC based model than that of OCC based model (AUC: 0.782 vs 0.553). Analysis in entire set shown AUC in these two method-based models were close (AUC: 0.744 vs 0.717).

CONCLUSION

We constructed two risk score predictive models for severe oral mucositis based on clinical features and dosimetric parameters of nasopharyngeal carcinoma patients receiving chemo-radiotherapy. These models might help to discriminate high risk population in clinical practice that susceptible to severe oral mucositis and individualize treatment plan to prevent it.

Oral mucositis: the hidden side of cancer therapy

Inflammation response of epithelial mucosa to chemo- radiotherapy cytotoxic effects leads to mucositis, a painful side effect of antineoplastic treatments. About 40% of the patients treated with chemotherapy develop mucositis; this percentage rises to about 90% for head and neck cancer patients (HNC) treated with both chemo- and radiotherapy. 19% of the latter will be hospitalized and will experience a delay in antineoplastic treatment for high-grade mucositis management, resulting in a reduction of the quality of life, a worse prognosis and an increase in patient management costs. Currently, several interventions and prevention guidelines are available, but their effectiveness is uncertain. This review comprehensively describes mucositis, debating the impact of standard chemo-radiotherapy and targeted therapy on mucositis development and pointing out the limits and the benefits of current mucositis treatment strategies and assessment guidelines. Moreover, the review critically examines the feasibility of the existing biomarkers to predict patient risk of developing oral mucositis and their role in early diagnosis. Despite the expression levels of some proteins involved in the inflammation response, such as TNF-α or IL-1β, partially correlate with mucositis process, their presence does not exclude others mucositis-independent inflammation events. This strongly suggests the need to discover biomarkers that specifically feature mucositis process development. Non-coding RNAs might hold this potential.

[Concurrent chemoradiotherapy for head neck cancers. Should organs at risk dose constraints be revisited ?]

Concurrent chemoradiotherapy improves the outcome of locally advanced head and neck cancers and the current reference chemotherapy is cisplatin. These results are obtained at the cost of increased toxicities. To limit the risk of toxicity, organ at riskdose constraints have been established starting with 2D radiotherapy, then 3D radiotherapy and intensity-modulated radiotherapy. Regarding grade ≥3 acute toxicities, the scientific literature attests that concurrent chemoradiotherapy significantly increases risks of mucositis and dysphagia. Constraints applied to the oral mucosa volume excluding the planning target volume, the pharyngeal constrictor muscles and the larynx limit this adverse impact. Regarding late toxicity, concurrent chemoradiotherapy increases significantly the risk of postoperative neck fibrosis and hearing loss. However, for some organs at risk, concurrent chemotherapy appears to increase late radiation induced effect, even though the results are less marked (brachial plexus, mandible, pharyngeal constrictor muscles, parotid gland). This additional adverse impact of concomitant chemotherapy may be notable only when organs at risk receive less than their usual dose thresholds and this would be vanished when those thresholds are exceeded as seems to be the situation for the parotid glands. Until the availability of more robust data, it seems appropriate to apply the principle of delivering dose to organs at risk as low as reasonably achievable.

A Dosimetric Comparison of Oral Cavity Sparing in the Unilateral Treatment of Early Stage Tonsil Cancer: IMRT, IMPT, and Tongue-Deviating Oral Stents

Introduction

Tongue-deviating oral stents (TDOS) are commonly used during unilateral neck radiation therapy to reduce unnecessary dose to nontarget oral structures. Their benefit in the setting of highly conformal treatment techniques, however, is not defined. The goal of this study was to investigate the potential benefit of TDOS use on dosimetric parameters in unilateral intensity modulated radiation therapy (IMRT) and intensity modulated proton therapy (IMPT).

Methods

A total of 16 patients with T1-2 tonsil cancer treated at a single institution were selected, of which 8 were simulated/treated with a TDOS and 8 without a TDOS. All received definitive unilateral IMRT to a dose of 66 Gy in 30 fx. IMPT plans were generated for each patient for study purposes and optimized according to standard institutional practice.

Results

For IMRT plans, the presence of a TDOS (vs without) was associated with a significantly lower oral mucosa mean dose (31.4 vs 35.3 Gy; P = .020) and V30 (42.7% vs 57.1%; P = .025). For IMPT plans, the presence of TDOS (vs without) was not associated with any improvement in oral mucosa mean dose (18.3 vs 19.9 Gy; P = .274) or V30 (25.0% vs 26.2%; P = .655). IMPT plans without TDOS compared with IMRT plans with TDOS demonstrated reduced oral mucosa mean dose (P < .001) and V30 (P < .001).

Conclusion

The use of a TDOS for the unilateral treatment of well-lateralized tonsil cancers was associated with oral mucosa sparing for IMRT, but not for IMPT. Moreover, mucosa sparing was improved for IMPT plans without a TDOS compared to IMRT plans with a TDOS.

The association between oral candidiasis and severity of chemoradiotherapy-induced dysphagia in head and neck cancer patients: A retrospective cohort study

•

Oral candidiasis (OC) aggravated dysphagia in chemoradiation for HNC.

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OC patients required higher doses of opioids.

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Early diagnosis of chemoradiation-associated OC seems difficult.

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Antifungal prophylaxis may reduce the severity of mucositis and dysphagia.

Background and purpose

Concurrent chemoradiotherapy (CCRT) for head and neck cancer (HNC) is a risk factor for oral candidiasis (OC). As Candida spp. are highly virulent, we conducted a retrospective study to determine whether OC increases the severity of dysphagia related to mucositis in HNC patients.

Patients and methods

We retrospectively analyzed the cases of consecutive patients with carcinomas of the oral cavity, pharynx, and larynx who underwent CCRT containing cisplatin (CDDP) at our hospital. The diagnosis of OC was based on gross mucosal appearance. We performed a multivariate analysis to determine whether OC was associated with the development of grade 3 dysphagia in the Radiation Therapy Oncology Group (RTOG) Acute Toxicity Criteria. The maximum of the daily opioid doses was compared between the patients with and without OC.

Results

We identified 138 HNC patients. OC was observed in 51 patients (37%). By the time of their OC diagnosis, 19 (37%) had already developed grade 3 dysphagia. Among the 30 patients receiving antifungal therapy, 12 (40%) showed clinical deterioration. In the multivariate analysis, OC was independently associated with grade 3 dysphagia (OR 2.75; 95%CI 1.22–6.23; p = 0.015). The patients with OC required significantly higher morphine-equivalent doses of opioids (45 vs. 30 mg/day; p = 0.029).

Conclusion

Candida infection causes refractory dysphagia. It is worth investigating whether antifungal prophylaxis reduces severe dysphagia related to candidiasis.

International Guideline on Dose Prioritization and Acceptance Criteria in Radiation Therapy Planning for Nasopharyngeal Carcinoma

PURPOSE

The treatment of nasopharyngeal carcinoma requires high radiation doses. The balance of the risks of local recurrence owing to inadequate tumor coverage versus the potential damage to the adjacent organs at risk (OARs) is of critical importance. With advancements in technology, high target conformality is possible. Nonetheless, to achieve the best possible dose distribution, optimal setting of dose targets and dose prioritization for tumor volumes and various OARs is fundamental. Radiation doses should always be guided by the As Low As Reasonably Practicable principle. There are marked variations in practice. This study aimed to develop a guideline to serve as a global practical reference.

METHODS AND MATERIALS

A literature search on dose tolerances and normal-tissue complications after treatment for nasopharyngeal carcinoma was conducted. In addition, published guidelines and protocols on dose prioritization and constraints were reviewed. A text document and preliminary set of variants was circulated to a panel of international experts with publications or extensive experience in the field. An anonymized voting process was conducted to rank the proposed variants. A summary of the initial voting and different opinions expressed by members were then recirculated to the whole panel for review and reconsideration. Based on the comments of the panel, a refined second proposal was recirculated to the same panel. The current guideline was based on majority voting after repeated iteration for final agreement.

RESULTS

Variation in opinion among international experts was repeatedly iterated to develop a guideline describing appropriate dose prioritization and constraints. The percentage of final agreement on the recommended parameters and alternative views is shown. The rationale for the recommendations and the limitations of current evidence are discussed.

CONCLUSIONS

Through this comprehensive review of available evidence and interactive exchange of vast experience by international experts, a guideline was developed to provide a practical reference for setting dose prioritization and acceptance criteria for tumor volumes and OARs. The final decision on the treatment prescription should be based on the individual clinical situation and the patient's acceptance of optimal balance of risk.

Modern radiotherapy for head and neck cancer

Radiation therapy (RT) plays a key role in curative-intent treatments for head and neck cancers. Its use is indicated as a sole therapy in early stage tumors or in combination with surgery or concurrent chemotherapy in advanced stages. Recent technologic advances have resulted in both improved oncologic results and expansion of the indications for RT in clinical practice. Despite this, RT administered to the head and neck region is still burdened by a high rate of acute and late side effects. Moreover, about 50% of patients with high-risk disease experience loco-regional recurrence within 3 years of follow-up. Therefore, in recent decades, efforts have been dedicated to optimize the cost/benefit ratio of RT in this subset of patients. The aim of the present review was to highlight modern concepts of RT for head and neck cancers considering both the technological advances that have been achieved and recent knowledge that has informed the biological interaction between radiation and both tumor and healthy tissues.

Tongue surface model can predict radiation tongue mucositis due to intensity-modulated radiation therapy for head and neck cancer

Acute radiation tongue mucositis has a profound effect on talking and eating. We examined whether the dose-volume histogram obtained from the tongue surface model correlates with mucositis severity, and whether it is useful for predicting acute radiation tongue mucositis in patients with head and neck cancer treated with intensity-modulated radiation therapy. Thirty-six patients who received intensity-modulated radiation therapy for head and neck cancer were analysed for acute radiation tongue mucositis according to the Common Terminology Criteria for Adverse Events, version 4.0, as well as the Radiation Therapy Oncology Group scoring systems. The corresponding high-dose locations in anatomical sub-regions in the tongue surface model and the development of high-grade acute radiation tongue mucositis were compared. The mucositis sites coincided with the high-dose anatomical sub-regions in the tongue surface model. There was a clear dose-response relationship between the mean dose to the tongue and the acute radiation tongue mucositis Radiation Therapy Oncology Group grade. According to the dose-volume histogram, patients receiving 16.0-73.0 Gy to the tongue were susceptible to grade 2-3 toxicity. The tongue surface model can predict the site and severity of acute radiation tongue mucositis. In future, radiation treatment plans ccould be optimized using this model.

Intensity modulated radiation therapy and oral mucosa sparing in Head and neck cancer patients: A systematic review on behalf of Italian Association of Radiation Oncology - Head and neck working group

Oral mucositis is a common dose-limiting toxicity during radiotherapy with or without chemotherapy in head and neck cancer patients. This potentially severe complication globally worsens quality of life and negatively impacts local control and survival's outcomes. Several studies have been published on feasibility and/or clinical benefit of intensity modulated radiotherapy (IMRT) mucosa-sparing technique. In 2017, the Italian Association of Radiation Oncology Head and Neck Cancer Working Group organized a study group to perform a systematic review. The aim was to verify if practical indications, including dose-constraints and demonstrated clinical benefit, could be proposed for oral mucosa (OM)-sparing IMRT in order to reduce the incidence of severe acute mucositis. Although dose to OM should be reduced as much as possible without compromising target volumes coverage, it is still tricky to firmly state that OM-sparing procedure should be considered the standard of care, especially due to high subjective variability in OM contour.

Radiomics and Machine Learning for Radiotherapy in Head and Neck Cancers

Introduction: An increasing number of parameters can be considered when making decisions in oncology. Tumor characteristics can also be extracted from imaging through the use of radiomics and add to this wealth of clinical data. Machine learning can encompass these parameters and thus enhance clinical decision as well as radiotherapy workflow. Methods: We performed a description of machine learning applications at each step of treatment by radiotherapy in head and neck cancers. We then performed a systematic review on radiomics and machine learning outcome prediction models in head and neck cancers. Results: Machine Learning has several promising applications in treatment planning with automatic organ at risk delineation improvements and adaptative radiotherapy workflow automation. It may also provide new approaches for Normal Tissue Complication Probability models. Radiomics may provide additional data on tumors for improved machine learning powered predictive models, not only on survival, but also on risk of distant metastasis, in field recurrence, HPV status and extra nodal spread. However, most studies provide preliminary data requiring further validation. Conclusion: Promising perspectives arise from machine learning applications and radiomics based models, yet further data are necessary for their implementation in daily care.

Correlation between plan quality improvements and reduced acute dysphagia and xerostomia in the definitive treatment of oropharyngeal squamous cell carcinoma

BACKGROUND

To evaluate plan quality using volumetric-modulated arc therapy (VMAT) and step-and-shoot intensity-modulated radiation therapy (SS-IMRT) techniques and for patients treated for oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

Treatment plans for patients treated definitively for stages I-IVb, OPSCC between December 2009 and August 2015 were retrospectively reviewed. Dosimetric endpoints of involved organs-at-risk (OARs) were retrieved from clinical plans. Common Terminology Criteria for Adverse Events scores of acute toxicities were compared.

RESULTS

Two-hundred twenty-two patients were identified with 134 and 88 receiving SS-IMRT and VMAT with median follow-up time of 23.0 and 7.9 months, respectively. The dosimetric endpoints of the OARs were significantly improved in VMAT cohort, which translated into significantly lower rates of grade 2 or higher acute dysphagia and xerostomia.

CONCLUSION

Improvements in stages I-IVb, oropharyngeal cancer plan quality are associated with reduced grade ≥ 2 acute dysphagia and xerostomia.

Leukotoxicity after moderately Hypofractionated radiotherapy versus conventionally fractionated dose escalated radiotherapy for localized prostate Cancer: a secondary analysis from a randomized study

Background

To compare WBC counts during treatment of localized prostate cancer with either conventionally fractionated (CF) or moderately hypofractionated (HYPO) radiotherapy.

Methods

Weekly blood test results were extracted from the charts of patients treated within a phase III study comparing HYPO to CF. In order to compare WBC counts at the same nominal dose in both arms and thus to tease out the effect of fractionation, for each recorded WBC value the corresponding cumulative total dose was extracted as well. WBC counts were binned according to percentiles of the delivered dose and three dose levels were identified at median doses of 16, 34.1 and 52 Gy, respectively. A General Linear Model based on mixed design Analysis Of Variance (ANOVA) was used to test variation of WBC counts between the two treatment arms.

Results

Out of 168 randomized patients, 140 (83.3%) had at least one observation for each one of the selected dose levels and were included in the analysis. Mean counts were lower in the CF than the HYPO arm at all selected dose levels, reaching a statistically significant difference at dose level #3 (5397/mm³ vs 6038/mm³ for CF and HYPO, respectively, p = 0.004). The GLM model confirms that the impact of dose on WBC counts is significantly lower in the HYPO arm over the CF one (Greenhouse-Geisser test, p = 0.04). Interestingly, while WBC counts tend to drop throughout all dose levels in the CF arm, this is the case only in the earlier part of treatment in the HYPO arm.

Conclusion

This secondary analysis of a phase III study shows that dose fractionation is correlated to WBC drop during treatment of localized prostate cancer, favoring HYPO over CF.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1223-2) contains supplementary material, which is available to authorized users.

Association between breast cancer chemotherapy, oral health and chronic dental infections: a pilot study

Breast cancer has developed to become the leading type of cancer in females. For this study, 80 women were examined after chemotherapy for breast cancer and compared to 80 healthy age-matched women. This cross-sectional study comprised a dental examination with number of teeth, caries frequency (DMFT) and the presence of periodontal diseases (PSI). With the help of X-rays (OPG), the number of root canal fillings and apical lesions (LEO/LPO) were recorded. Furthermore, the education level, body mass index (BMI), smoking habits and general health conditions were recorded. All women completed questionnaires on oral health-related quality of life (OHIP-G14) and general well-being (HADS-D). To assess the influence of cancer therapy on oral health parameters, appropriate generalized linear models were fitted with disease status as main explanatory variable, adjusting for age and education. For OHIP and HADS, we additionally adjusted for number of missing teeth. The examined 160 women showed a comparable mean age (60.4 years) and an average BMI of 24.6. Cancer patients showed a higher risk for missing teeth (p < 0.001) and more apical lesions (p < 0.0041), particularly those of endodontic origin without root canal fillings (p = 0.0046), than the control women. The general well-being of cancer patients was significantly reduced with a HADS score of 9.4 for women with breast cancer compared to 5.3 for the healthy control. This study suggests that women after breast cancer chemotherapy are inclined to have a poorer oral health status with more missing teeth and apical lesions. Therefore, tightly scheduled dental recall visits should be recommended.

A Quantitative Clinical Decision-Support Strategy Identifying Which Patients With Oropharyngeal Head and Neck Cancer May Benefit the Most From Proton Radiation Therapy

PURPOSE

Developing a quantitative decision-support strategy estimating the impact of normal tissue complications from definitive radiation therapy (RT) for head and neck cancer (HNC). We developed this strategy to identify patients with oropharyngeal HNC who may benefit most from receiving proton RT.

METHODS AND MATERIALS

Recent normal tissue complication probability (NTCP) models for dysphagia, esophagitis, hypothyroidism, xerostomia, and oral mucositis were used to estimate NTCP for 33 patients with oropharyngeal HNC previously treated with photon intensity modulated radiation therapy (IMRT). Comparative proton therapy plans were generated using clinical protocols for HNC RT at a collaborating proton center. Organ-at-risk (OAR) doses from photon and proton RT plans were used to calculate NTCPs; Monte Carlo sampling 10,000 times was used for each patient to account for model parameter uncertainty. The latency and duration of each complication were modeled from calculated NTCP, accounting for age-, sex-, smoking- and p16-specific conditional survival probability. Complications were then assigned quality-adjustment factors based on severity to calculate quality-adjusted life years (QALYs) lost from each complication.

RESULTS

Based on our institutional-delivered photon IMRT doses and the achievable proton therapy doses, the average QALY reduction from all HNC RT complications for photon and proton therapy was 1.52 QALYs versus 1.15 QALYs, with proton therapy sparing 0.37 QALYs on average (composite 95% confidence interval, 0.27-2.53 QALYs). Long-term complications (dysphagia and xerostomia) contributed most to the QALY reduction. The QALYs spared with proton RT varied considerably among patients, ranging from 0.06 to 0.84 QALYs. Younger patients with p16-positive tumors who smoked ≤10 pack-years may benefit most from proton therapy, although this finding should be validated using larger patient series. A sensitivity analysis reducing photon IMRT doses to all OARs by 20% resulted in no overall estimated benefit with proton therapy with -0.02 QALYs spared, although some patients still had an estimated benefit in this scenario, ranging from -0.50 to 0.43 QALYs spared.

CONCLUSIONS

This quantitative decision-support strategy allowed us to identify patients with oropharyngeal cancer who might benefit the most from proton RT, although the estimated benefit of proton therapy ultimately depends on the OAR doses achievable with modern photon IMRT solutions. These results can help radiation oncologists and proton therapy centers optimize resource allocation and improve quality of life for patients with HNC.

Multivariable model for predicting acute oral mucositis during combined IMRT and chemotherapy for locally advanced nasopharyngeal cancer patients

INTRODUCTION/OBJECTIVE

Oral and oropharyngeal mucositis (OM) represents amultifactorialand complexinterplayof patient-, tumor-, and treatment-related factors. We aimed to build a predictive model for acute OM for locally advanced nasopharyngeal carcinoma (NPC) patients by combining clinical and dosimetric factors.

MATERIALS/METHODS

A series of consecutive NPC patients treated curatively with IMRT/VMAT + chemotherapy at 70 Gy (2-2.12 Gy/fr) was considered. For each patient, clinical- tumor- and treatment-related data were retrospectively collected. oral cavity (OC) and parotid glands (PG, considered as a single organ) were selected as organs-at-risk (OARs). Acute OM was assessed according to CTCAE v4.0 at baseline and weekly during RT. Two endpoints were considered: grade ≥3 and mean grade ≥1.5. DVHs were reduced to Equivalent Uniform Dose (EUD). Dosimetric and clinical/treatment features selected via LASSO were inserted into a multivariable logistic model. Goodness of fit was evaluated through Hosmer-Lemeshow test and calibration plot.

RESULTS

Data were collected for 132 patients. G ≥ 3 and mean G ≥ 1.5 OM were reported in 40 patients (30%). Analyses resulted in a 3-variables model for G ≥ 3 OM, including OC EUD with n = 0.05 (OR = 1.02), PG EUD with n = 1 (OR = 1.06), BMI ≥ 30 (OR = 3.8, for obese patients), and a single variable model for mean G ≥ 1.5 OM, i.e. OC EUD with n = 1 (mean dose) (OR = 1.07). Calibration was good in both cases.

CONCLUSION

OC mean dose was found to impact most on OM duration (mean G ≥ 1.5), while G ≥ 3 OM was associated to a synergic effect between PG mean dose and high dose received by small OC volumes, with BMI acting as a dose-modifying factor.

Revisiting the dose constraints for head and neck OARs in the current era of IMRT

Head and neck cancer poses a particular challenge in radiation therapy, whilst being an effective treatment modality it requires very high doses of radiation to provide effective therapy. This is further complicated by the fact that the head and neck region contains a large number of radiosensitive tissues, often resulting in patients experiencing debilitating normal tissue complications. In the era of intensity-modulated radiation therapy (IMRT) treatments can be delivered using non-uniform dose distributions selectively aimed at reducing the dose to critical organs-at-risk while still adequately covering the tumor target. Dose-volume constraints for the different risk organs play a vital role in one's ability to devise the best IMRT treatment plan for a head and neck cancer patient. To this end, it is pivotal to have access to the latest and most relevant dose constraints available and as such the goal of this review is to provide a summary of suggested dose-volume constraints for head and neck cancer RT that have been published after the QUANTEC reports were made available in early 2010.

Feasibility of optimizing intensity-modulated radiation therapy plans based on measured mucosal dose adjacent to dental fillings and toxicity outcomes

We prospectively investigated the feasibility of IMRT treatment plan optimization based on dosimeter measurements of lateral tongue mucosal dose adjacent to the dental fillings and evaluated dose‐toxicity relationship and factors affecting oral mucositis (OM) in head and neck cancer patients. Twenty‐nine head and neck cancer patients with metallic dental fillings who were scheduled to undergo fractionated external beam radiation therapy (RT) ± chemotherapy were enrolled. The lateral tongue dose was measured and if the calculated dose for the entire treatment was ≥35 Gy, a re‐plan was generated to reduce the lateral tongue mucosal dose. OM was graded weekly according to Common Terminology Criteria for Adverse Events version 4.0 and the patients completed the Oral Mucositis Weekly Questionnaire‐Head and Neck Cancer. The result showed that it was not feasible to optimize the IMRT plan based on measured tongue dose in most of the patients who needed re‐plan as re‐planning compromised the target coverage in 60% of these patients. The duration of grade (Gr) 2 OM was correlated with measured lateral tongue dose (P = 0.050). Concurrent cetuximab was significantly associated with faster onset of Gr2 OM than concurrent cisplatin (P = 0.006) and with longer duration of OM (P = 0.041) compared to concurrent cisplatin or IMRT‐alone. The pattern of reported pain over time was significantly different for each treatment type (RT and cetuximab, RT and cisplatin and RT‐alone) and depending on the dose level (P = 0.006). In conclusion, optimizing the IMRT plan based on measured lateral tongue dose was not feasible. Measured lateral tongue dose was significantly correlated with longer duration of OM ≥Gr2, and concurrent cetuximab was associated with earlier onset and longer duration of OM ≥Gr2.

Management of Radiation Toxicity in Head and Neck Cancers

Head and neck cancers account for approximately 3% of all cancers in the United States with 62,000 new cases diagnosed annually. The global incidence is approximately 700,000 new cases a year. There has also been a recent increase in human papilloma virus-related oropharyngeal cancers. External beam radiation therapy (RT) is commonly used as an effective therapy for head and neck (H&N) cancers. This is used as a definitive treatment (alone or in combination with chemotherapy) or as an adjuvant treatment after surgical resection of the tumors. Because of the complex anatomy of the H&N region, several critical structures in and around the area receive radiation treatment. This includes the neural structures (brainstem, spinal cord, and brachial plexus), salivary glands, mucosa, major blood vessels, and swallowing musculature. Careful RT planning is necessary to avoid or mitigate the side effects of treatment. This review discusses some of the major acute and late side effects of RT for H&N cancers and provides evidence-based guidelines for their management. Patient-reported outcomes and quality-of-life implications are also discussed.

Humidification mitigates acute mucosal toxicity during radiotherapy when factoring volumetric parameters. Trans Tasman Radiation Oncology Group (TROG) RadioHUM 07.03 substudy

PURPOSE/OBJECTIVE(S)

To model in a subset of patients from TROG 07.03 managed at a single site the association between domiciliary based humidification use and mucositis symptom burden during radiotherapy (RT) for head and neck cancer (HNC) when factoring in volumetric radiotherapy parameters derived from tumour and normal tissue regions of interest.

MATERIALS/METHODS

From June 2008 through June 2011, 210 patients with HNC receiving RT were randomised to either a control arm or humidification using the Fisher & Paykel Healthcare MR880 humidifier. This subset analysis involves patients recruited from Auckland City Hospital treated with a prescribed dose of ≥70 Gy. Regression models included control variables for Planning Target Volume 70 GY (PTV70Gy); Equivalent Uniform Dose (EUD) MOIST and TSV (surrogates of total mucosal and total swallowing volumes respectively).

RESULTS

The analysis included 39 patients (humidification 20, control 19). There was a significant odds reduction in CTCAE v3.0 functional mucositis score of 0.29 associated with the use of humidification (p<.001). Within the parameters of the model therefore, the risk of a humidification patient being scored as experiencing a one-step increase in functional mucositis was 3.45 times lower (1/0.29) than for control patients. A control patient was 4.17 times more likely to receive an unfavourable nutritional mode score (p<.001). The risk of being admitted to hospital decreased by a factor of 11.11 for humidification patients (p=.013).

CONCLUSION

The results support the hypothesis that humidification can help mitigate mucositis symptom burden. Radiotherapy dosimetric parameters assist in the evaluation of toxicity interventions.

Systematic Review of Normal Tissue Complication Models Relevant to Standard Fractionation Radiation Therapy of the Head and Neck Region Published After the QUANTEC Reports

There has recently been an increasing interest in model-based evaluation and comparison of different treatment options in radiation oncology studies. This is partly driven by the considerable technical advancements in radiation therapy of the last decade, leaving radiation oncologists with a multitude of options to consider. In lieu of randomized trials comparing all of these different treatment options for varying indications, which is unfeasible, treatment evaluations based on normal tissue complication probability (NTCP) models offer a practical alternative. The Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) effort, culminating in a number of reports published in 2010, provided a basis for many of the since-implemented dose-response models and dose-volume constraints and was a key component for model-based treatment evaluations. Given that 7 years have passed since the QUANTEC publications and that patient-reported outcomes have emerged as an important consideration in recent years, an updated summary of the published radiation dose-response literature, which includes a focus on patient-reported quality of life outcomes, is warranted. Here we provide a systematic review of quantitative dose-response models published after January 1, 2010 for endpoints relevant to radiation therapy for head and neck cancer, because these patients are typically at risk for a variety of treatment-induced normal tissue complications.

New Frontiers in the Pathobiology and Treatment of Cancer Regimen-Related Mucosal Injury

Mucositis is a common complication of chemotherapy, radiotherapy and targeted agents. It often affects compliance to anticancer therapies as it frequently causes schedule delays, interruptions or discontinuations of treatment. Moreover, the economic impact related to the management of mucositis is topical and several estimations of additional hospital costs due to this clinical condition have been recently reported. The ability to determine risk factors for mucositis, to early detect its onset, to assess correctly the degree of this toxicity and to plan its multidisciplinary management are all key elements to guarantee the quality of life of patients and to avoid useless dose reduction or interruption of treatment. The pathogenesis of mucositis is multifactorial and it is classily subdivided into oral and gastrointestinal mucositis according to its anatomic presentation. Treatment and patients’ related factors might help in predicting the frequency and the potential degree of symptoms onset. Here we discuss about clinical presentation and pathogenesis of mucositis in relation to different kinds of treatments. Moreover, we focus on therapeutic and prevention strategies, describing past and present management according to international guidelines and the most promising new data about agents potentially able to further improve the treatment of mucositis in the next future.

Normal Tissue Complication Probability (NTCP) Modelling of Severe Acute Mucositis using a Novel Oral Mucosal Surface Organ at Risk

AIMS

A normal tissue complication probability (NTCP) model of severe acute mucositis would be highly useful to guide clinical decision making and inform radiotherapy planning. We aimed to improve upon our previous model by using a novel oral mucosal surface organ at risk (OAR) in place of an oral cavity OAR.

MATERIALS AND METHODS

Predictive models of severe acute mucositis were generated using radiotherapy dose to the oral cavity OAR or mucosal surface OAR and clinical data. Penalised logistic regression and random forest classification (RFC) models were generated for both OARs and compared. Internal validation was carried out with 100-iteration stratified shuffle split cross-validation, using multiple metrics to assess different aspects of model performance. Associations between treatment covariates and severe mucositis were explored using RFC feature importance.

RESULTS

Penalised logistic regression and RFC models using the oral cavity OAR performed at least as well as the models using mucosal surface OAR. Associations between dose metrics and severe mucositis were similar between the mucosal surface and oral cavity models. The volumes of oral cavity or mucosal surface receiving intermediate and high doses were most strongly associated with severe mucositis.

CONCLUSIONS

The simpler oral cavity OAR should be preferred over the mucosal surface OAR for NTCP modelling of severe mucositis. We recommend minimising the volume of mucosa receiving intermediate and high doses, where possible.

A randomised controlled trial of Caphosol mouthwash in management of radiation-induced mucositis in head and neck cancer

PURPOSE

This phase III, non-blinded, parallel-group, randomised controlled study evaluated the efficacy of Caphosol mouthwash in the management of radiation-induced oral mucositis (OM) in patients with head and neck cancer (HNC) undergoing radical (chemo)radiotherapy.

PATIENTS AND METHODS

Eligible patients were randomised at 1:1 to Caphosol plus standard oral care (intervention) or standard oral care alone (control), stratified by radiotherapy technique and use of concomitant chemotherapy. Patients in the intervention arm used Caphosol for 7weeks: 6weeks during and 1-week post-radiotherapy. The primary endpoint was the incidence of severe OM (CTCAE ⩾grade 3) during and up to week 8 post-radiotherapy. Secondary endpoints include pharyngeal mucositis, dysphagia, pain and quality of life.

RESULTS

The intervention (n=108) and control (n=107) arms were well balanced in terms of patient demographics and treatment characteristics. Following exclusion of patients with missing data, 210 patients were available for analysis. The incidence of severe OM did not differ between the intervention and control arms (64.1% versus 65.4%, p=0.839). Similarly, no significant benefit was observed for other secondary endpoints. Overall, compliance with the recommended frequency of Caphosol was low.

CONCLUSION

Caphosol did not reduce the incidence or duration of severe OM during and after radiotherapy in HNC.

Normal tissue complication probability (NTCP) modelling using spatial dose metrics and machine learning methods for severe acute oral mucositis resulting from head and neck radiotherapy

BACKGROUND AND PURPOSE

Severe acute mucositis commonly results from head and neck (chemo)radiotherapy. A predictive model of mucositis could guide clinical decision-making and inform treatment planning. We aimed to generate such a model using spatial dose metrics and machine learning.

MATERIALS AND METHODS

Predictive models of severe acute mucositis were generated using radiotherapy dose (dose-volume and spatial dose metrics) and clinical data. Penalised logistic regression, support vector classification and random forest classification (RFC) models were generated and compared. Internal validation was performed (with 100-iteration cross-validation), using multiple metrics, including area under the receiver operating characteristic curve (AUC) and calibration slope, to assess performance. Associations between covariates and severe mucositis were explored using the models.

RESULTS

The dose-volume-based models (standard) performed equally to those incorporating spatial information. Discrimination was similar between models, but the RFCstandard had the best calibration. The mean AUC and calibration slope for this model were 0.71 (s.d.=0.09) and 3.9 (s.d.=2.2), respectively. The volumes of oral cavity receiving intermediate and high doses were associated with severe mucositis.

CONCLUSIONS

The RFCstandard model performance is modest-to-good, but should be improved, and requires external validation. Reducing the volumes of oral cavity receiving intermediate and high doses may reduce mucositis incidence.

A longitudinal evaluation of improvements in radiotherapy treatment plan quality for head and neck cancer patients

PURPOSE

To investigate changes in head-and-neck cancer (HNC) plan quality following the introduction of new technologies and planning techniques in the last decade.

METHODS AND MATERIALS

Thirty plans were selected from each of four successive periods (P). P1: 7-field static intensity-modulated radiotherapy (IMRT) with parotid gland sparing; P2: dual-arc volumetric-modulated arc therapy (VMAT, similar to P3-P4), including submandibular gland sparing; P3: inclusion of individual swallowing muscles and attempts to further reduce parotid and oral cavity doses through manual interactive optimization; P4: containing the same organs-at-risk (OARs) as P3, but automatically interactively optimized. Plan benchmarking included mean salivary gland/swallowing muscle/oral cavity (Dsal/Dswal/Doc) doses. Differences in mean doses between the periods were analyzed by an ANCOVA, taking geometric differences across periods into account.

RESULTS

Compared to P1, P2 plans improved Dsal by 3.4Gy on average. P3 improved Dsal/Dswal/Doc by 6.9/11.5/7.2Gy over P2, showing that Dswal and Dsal could be improved simultaneously. In P4, Doc/Dswal slightly improved over P3 by 1.7/3.8Gy. Improved OAR sparing in P3/P4 did not come at the cost of increased dose deposition elsewhere and planning target volume (PTV) dose homogeneity was similar.

CONCLUSIONS

New technologies and planning techniques were successfully implemented into routine clinical care and resulting in improved HNC plan quality.

Temporal course and predictive factors of analgesic opioid requirement for chemoradiation-induced oral mucositis in oropharyngeal cancer

BACKGROUND

Oral mucositis (OM)-related pain affects most patients with head and neck cancer during treatments, but its management is not standardized.

METHODS

We retrospectively collected data about the opioid therapy used for OM-induced pain in all patients with oropharyngeal cancer treated with chemoradiotherapy (CRT) between 2009 and 2013. To compare the different opioids, a conversion into oral morphine equivalent daily dose (OMEDD) was performed. The highest OMEDD (h-OMEDD) and the opioids' weekly increase were associated with patient, tumor, or treatment-related characteristics in order to identify predictive factors of opioid consumption.

RESULTS

Ninety-seven percent of patients received opioids. The h-OMEDD was significantly correlated with a higher OM-grade and a lower smoking history. The weekly opioids' increase was higher in patients with lower smoking history and human papillomavirus (HPV) positivity.

CONCLUSION

Opioid therapy remains the mainstay for OM-related pain management during CRT. The role of previous smoking and HPV on opioid use needs further confirmations. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1521-E1527, 2016.