Bridging the gap - Establishing a dental-oncology service in a cancer centre.

Dental disease remains the most common non-communicable disease worldwide. It predisposes patients to significant morbidities following bone modifying agents or radiation therapy to the head and neck. Preventative dental regimes effectively reduce the risk of both medication-related osteonecrosis of the jaw (MRONJ) and osteoradionecrosis (ORN) in these patients. Co-ordination of routine dental care as a component of mainstream oncology treatment optimises long term outcomes for oncology patients. This case series offers insights into patient, institutional and social difficulties that challenge the dental-oncology interface. These obstacles and subsequent resolutions experienced whilst establishing a dental-oncology service in a cancer centre highlight the importance of effective multidisciplinary lead care for oncology patients. It reinforces the need for structured, supported dental pathways for these oncology patients.

In reply to the letter to the editor regarding "Clinical outcomes of teeth adjacent to the site of mandibulotomy or mandibulectomy in patients with head and neck cancer: results from a multidisciplinary mono-institutional head and neck tumor board".

This paper aims to reply to Somay et al., regarding their comment to a previous paper from our group, titled "Clinical outcomes of teeth adjacent to the site of mandibulotomy or mandibulectomy in patients with head and neck cancer: results from a multidisciplinary mono-institutional head and neck tumor board".The following concerns were addressed: 1) Within the limits of a case series, mandibulectomy might be considered a risk factor for the loss of tooth vitality as well as mandibulotomy. 2) Root canal therapy before surgery on the teeth adjacent to the surgical site could be an appropriate strategy, although in some cased it may involve teeth which are not destinate to have endodontic complications. 3) Dose-volume data of the included teeth were provided: the impact of radiotherapy (RT) as a confounding factor seems not to be as relevant as Somay et al. have pointed out.

Revolution of Medical Review: The Application of Meta-Analysis and Convolutional Neural Network-Natural Language Processing in Classifying the Literature for Head and Neck Cancer Radiotherapy.

This study explored the application of meta-analysis and convolutional neural network-natural language processing (CNN-NLP) technologies in classifying literature concerning radiotherapy for head and neck cancer. It aims to enhance both the efficiency and accuracy of literature reviews. By integrating statistical analysis with deep learning, this research successfully identified key studies related to the probability of normal tissue complications (NTCP) from a vast corpus of literature. This demonstrates the advantages of these technologies in recognizing professional terminology and extracting relevant information. The findings not only improve the quality of literature reviews but also offer new insights for future research on optimizing medical studies through AI technologies. Despite the challenges related to data quality and model generalization, this work provides clear directions for future research.

This study examines how advanced technologies like meta-analysis and machine learning, specifically through Convolutional Neural Networks and Natural Language Processing (CNN-NLP), can revolutionize the way medical researchers review literature on radiotherapy for head and neck cancer. Typically, reviewing vast amounts of medical studies is time-consuming and complex. This paper showcases a method that combines statistical analysis and AI to streamline the process, enhancing the accuracy and efficiency of identifying crucial research. By applying these technologies, the researchers were able to sift through thousands of articles rapidly, pinpointing the most relevant ones without the extensive manual effort usually required. This approach not only speeds up the review process but also improves the quality of the information extracted, making it easier for medical professionals to keep up with the latest findings and apply them effectively in clinical settings. The findings of this study are promising, demonstrating that integrating AI with traditional review methods can significantly aid in managing the ever-growing body of medical literature, potentially leading to better treatment strategies and outcomes for patients suffering from head and neck cancer. Despite some challenges like data quality and the need for extensive computational resources, the study provides a forward path for using AI to enhance medical research and practice.

Delineation of the "Oropharyngeal Mucosa" and Limiting its Dose in Head and Neck Cancer Patients Spares the Oropharynx Without Compromising Target Coverage.

OBJECTIVES: Radiation-induced oropharyngeal injury is a dose-limiting toxicity in head and neck cancer patients. Delineation of the "oropharyngeal mucosa" and limiting its dose to spare the oropharynx was investigated. METHODS: In this retrospective study, computed tomography imaging from eight patients with previously untreated head and neck cancer was employed. An adaptive contouring brush within the planning software Monaco was used to create an air cavity within the oropharynx, and then the air cavity was expanded uniformly 2 mm to create the "oropharyngeal mucosa". Three plans were independently generated for each patient: Plan1: dose constraint was applied for the oropharynx; Plan2: dose constraints were applied for the oropharynx and the "oropharyngeal mucosa"; Plan3: dose constraint was applied for the "oropharyngeal mucosa". T-tests were used to compare the dosimetry variables. RESULTS: All plans had adequate target coverage and there were no statistical differences among plans. The mean dose, D30%, D45%, D50%, D85%, D90%, D95%, D100%, V25 Gy, V30 Gy, V35 Gy, V40 Gy, and V45 Gy of the oropharynx and "oropharyngeal mucosa" in Plan1 were significantly higher than those in Plan2 and Plan3. There were no significant differences between Plan2 and Plan3. There were no significant differences in the dosimetric parameters of any other organs at risk. CONCLUSION: Delineation of the "oropharyngeal mucosa" and limiting its dose should be an easy and effective method to spare the oropharynx.

Radiation-induced oropharyngeal injury is dose-limiting toxicity in head and neck cancer patients. Delineation of "oropharyngeal mucosa" and limiting its dose should be an easy and effective method to spare the oropharynx.

Tumor volume changes after stereotactic, hypofractionated and conventional radiotherapy in paragangliomas of head and neck.

BACKGROUND: The aim of this study is comparison the effectiveness of stereotactic, hypofractionated and conventional radiotherapy assessed by the tumor volume changes of paraganglioma located in the head and neck region concerning fractional and total doses. METHODS: We analyzed 76 patients after radiotherapy due to paraganglioma who were assigned to 3 groups considering fractional (≤2 Gy, 3-5.5 Gy, ≥6 Gy) and total (≤20 Gy, 21-40 Gy, >40 Gy) doses. The volumes of irradiated tumors were measured and compared based on diagnostic images performed before and after the treatment. RESULTS: The mean tumor volume after the treatment with the lowest fractional dose (≤2 Gy) was decreased by 14.4 cm3. In patients treated with higher fractional doses (>2 Gy), the mean tumor volumes decreased by less than 1 cm3 for hypofractionated and stereotactic radiotherapy. 15.9 cm3 reduction of the mean tumor volume after the treatment with the highest RT total dose (>40 Gy) was stated. In patients treated with total doses ≤20 Gy and 21-40 Gy, the mean tumor volume was stable and reduced by 1.15 cm3, respectively. The analysis demonstrates a statistically significant (p < 0.05) treatment advantage in patients after the lowest fractional and highest total doses. CONCLUSION: The reduction of the tumor's volume was reported after conventional and unconventional radiotherapy. The most significant depletion of the paraganglioma volume was noted after a factional dose ≤2 Gy and a total dose >40 Gy.

Oral mucositis management with photobiomodulation, Bidens pilosa L. (Asteraceae) and Curcuma longa L. (Zingiberaceae), the FITOPROT herbal medicine, and its influence on inflammatory cytokine levels: a randomized clinical trial.

PURPOSE: This randomized clinical trial aimed to compare the effects of a mucoadhesive formula, containing curcuminoids from Curcuma longa L. and glycerinated extract of Bidens pilosa L. (FITOPROT), associated with photobiomodulation (PBM), and of PBM exclusively, on the incidence of oral mucositis (OM)-induced by radiotherapy (RT) in the head and neck region, and the salivary expression of inflammatory cytokines, in patients with head neck cancer. METHODS: Patients were randomly assigned into two intervention groups-FITOPROT + PBM (n = 25) or PBM (n = 27). PBM protocol comprised a wavelength of 660 nm, 25 mW, 0.25 J/point, and daily irradiation from the first until the last day of RT. FITOPROT was gargled twice a day. All patients underwent a preventive oral care program throughout the study. OM degree, salivary concentration of nitrite, and inflammatory (IL-1, TNFα, IL-6, IL-8, and IL-12p70), and anti-inflammatory (IL-10) cytokines were assessed at baseline, and at the 7th, 14th, 21st, and 30th RT sessions. RESULTS: There were no differences in the OM degree between groups, but the RT dose significantly affected the OM. The RT significantly affected the salivary nitrite, TNFα, IL-1ß, and IL-10 concentrations. CONCLUSION: FITOPROT associated with PBM showed limited effects on preventing the incidence of severe OM compared to PBM alone. However, FITOPROT + PBM may be associated with nitrite and cytokine balance, which may contribute to the occurrence of fewer cases of severe OM. TRIAL REGISTRATION: Brazilian Clinical Trials database (ReBEC; RBR-9vddmr), registered UTN code: U1111-1193-2066, registered in August 8th, 2017.

Potential of E-Learning Interventions and Artificial Intelligence-Assisted Contouring Skills in Radiotherapy: The ELAISA Study.

PURPOSE: Most research on artificial intelligence-based auto-contouring as template (AI-assisted contouring) for organs-at-risk (OARs) stem from high-income countries. The effect and safety are, however, likely to depend on local factors. This study aimed to investigate the effects of AI-assisted contouring and teaching on contouring time and contour quality among radiation oncologists (ROs) working in low- and middle-income countries (LMICs). MATERIALS AND METHODS: Ninety-seven ROs were randomly assigned to either manual or AI-assisted contouring of eight OARs for two head-and-neck cancer cases with an in-between teaching session on contouring guidelines. Thereby, the effect of teaching (yes/no) and AI-assisted contouring (yes/no) was quantified. Second, ROs completed short-term and long-term follow-up cases all using AI assistance. Contour quality was quantified with Dice Similarity Coefficient (DSC) between ROs' contours and expert consensus contours. Groups were compared using absolute differences in medians with 95% CIs. RESULTS: AI-assisted contouring without previous teaching increased absolute DSC for optic nerve (by 0.05 [0.01; 0.10]), oral cavity (0.10 [0.06; 0.13]), parotid (0.07 [0.05; 0.12]), spinal cord (0.04 [0.01; 0.06]), and mandible (0.02 [0.01; 0.03]). Contouring time decreased for brain stem (-1.41 [-2.44; -0.25]), mandible (-6.60 [-8.09; -3.35]), optic nerve (-0.19 [-0.47; -0.02]), parotid (-1.80 [-2.66; -0.32]), and thyroid (-1.03 [-2.18; -0.05]). Without AI-assisted contouring, teaching increased DSC for oral cavity (0.05 [0.01; 0.09]) and thyroid (0.04 [0.02; 0.07]), and contouring time increased for mandible (2.36 [-0.51; 5.14]), oral cavity (1.42 [-0.08; 4.14]), and thyroid (1.60 [-0.04; 2.22]). CONCLUSION: The study suggested that AI-assisted contouring is safe and beneficial to ROs working in LMICs. Prospective clinical trials on AI-assisted contouring should, however, be conducted upon clinical implementation to confirm the effects.

T lymphocyte and neutrophil/lymphocyte ratio in patients with radiation-induced oral mucositis after intensity-modulated radiation therapy for head and neck cancer: A retrospective single-center study.

To investigate T lymphocyte, neutrophil/lymphocyte ratio (NLR) and their impact on patients with radiation-induced oral mucositis (RIOM) after intensity-modulated radiotherapy for head and neck cancer. The clinical data of 148 patients diagnosed with head and neck cancer from January 2016 to January 2019 were retrospectively analyzed. Patients were divided into RIOM group (n = 42 cases) and non-RIOM group (n = 106 cases), based on whether they developed RIOM after intensity-modulated radiation therapy. The T lymphocyte and NLR of the 2 groups were analyzed before and after treatment; The correlation between T lymphocyte and NLR in RIOM group was analyzed. We used RTOG grading system to evaluate and scale the RIOM. The relationship between the grade of RIOM, T lymphocyte and NLR in RIOM group was analyzed. After treatment, the proportion of CD3 +, CD4 +, and CD8 + T lymphocytes in the 2 groups after treatment were decreased, and the RIOM group was significantly lower than non-RIOM group, P < .05. NLR in RIOM group was significantly higher than that in non-RIOM group, P < .05. The data of overall survival showed no significant differences between 2 groups (HR = 0.82, 95% CI: 0.43-1.59). Compared with RIOM group, patients in non-RIOM group showed a longer progress-free survival (HR = 0.57, 95% CI: 0.33-0.99). In RIOM group, NLR was negatively correlated with CD3 + (r = -0.433, P = .004), CD4 + (r = -0.644, P < .001) and CD8 + T cells (r = -0.665, P < .001). RIOM was positively correlated with NLR (R = 0.621, P < .001), negatively correlated with CD4 + T cell ratio (r = -0.449, P = .003) and CD8 + T cell ratio (r = -0.307, P = .048), but RIOM did not correlate with CD3 + T cell ratio (r = -0.225, P = .152). For patients with RIOM after intensity-modulated radiotherapy for head and neck cancer, T lymphocyte showed a downward trend, and NLR showed an upward trend. In addition, T lymphocyte and NLR are closely related to the RIOM, indicating that clinicians should be aware of the importance of T lymphocyte and NLR on patients received radiotherapy.

Evaluating an analytical prediction algorithm of positron emitter distributions in patient data for PET monitoring of carbon ion therapy: A simulation study.

In vivo treatment monitoring in ion therapy is one of the key issues for improving the treatment quality assurance procedures. Range verification is one of the most relevant and yet complex task used for in vivo treatment monitoring. In carbon ion therapy, positron emission tomography is the most widely used method. This technique exploits the ß+-activity of positron emitters created by nuclear interactions between the incoming beam and the irradiated tissue. Currently, high computational efforts and time-consuming Monte Carlo simulation platforms are typically used to predict positron emitter distributions. In order to avoid time-consuming simulations, an extended filtering approach was suggested to analytically predict positron emitter profiles from depth dose distributions in carbon ion therapy. The purpose of this work is to investigate such an analytical prediction model in patient anatomies of varying complexity, highlighting its potential and the need of further improvements, especially in highly heterogeneous anatomies where many air cavities are present in the beam path. The accuracy of range verification showed a mean relative error of ∼3% and a deviation between the simulation and the prediction below 2mm for the three patient cases analysed: a brain case and two head and neck cases. Additional investigations demonstrated the region of applicability of the method for cases of patient data. The analytical method enables range verification in carbon ion therapy by replacing computing-intensive Monte Carlo simulations and thus minimize the PET monitoring burden on the clinical workflow.

Deep learning-based statistical robustness evaluation of intensity-modulated proton therapy for head and neck cancer.

Objective. Previous methods for robustness evaluation rely on dose calculation for a number of uncertainty scenarios, which either fails to provide statistical meaning when the number is too small (e.g., ∼8) or becomes unfeasible in daily clinical practice when the number is sufficiently large (e.g., >100). Our proposed deep learning (DL)-based method addressed this issue by avoiding the intermediate dose calculation step and instead directly predicting the percentile dose distribution from the nominal dose distribution using a DL model. In this study, we sought to validate this DL-based statistical robustness evaluation method for efficient and accurate robustness quantification in head and neck (H&N) intensity-modulated proton therapy with diverse beam configurations and multifield optimization.Approach. A dense, dilated 3D U-net was trained to predict the 5th and 95th percentile dose distributions of uncertainty scenarios using the nominal dose and planning CT images. The data set comprised proton therapy plans for 582 H&N cancer patients. Ground truth percentile values were estimated for each patient through 600 dose recalculations, representing randomly sampled uncertainty scenarios. The comprehensive comparisons of different models were conducted for H&N cancer patients, considering those with and without a beam mask and diverse beam configurations, including varying beam angles, couch angles, and beam numbers. The performance of our model trained based on a mixture of patients with H&N and prostate cancer was also assessed in contrast with models trained based on data specific for patients with cancer at either site.Results. The DL-based model's predictions of percentile dose distributions exhibited excellent agreement with the ground truth dose distributions. The average gamma index with 2 mm/2%, consistently exceeded 97% for both 5th and 95th percentile dose volumes. Mean dose-volume histogram error analysis revealed that predictions from the combined training set yielded mean errors and standard deviations that were generally similar to those in the specific patient training data sets.Significance. Our proposed DL-based method for evaluation of the robustness of proton therapy plans provides precise, rapid predictions of percentile dose for a given confidence level regardless of the beam arrangement and cancer site. This versatility positions our model as a valuable tool for evaluating the robustness of proton therapy across various cancer sites.

Soluble urokinase plasminogen activator receptor (suPAR) is a potential biomarker of stage III-IV, grade C periodontitis through the impact of post-radiotherapy on head and neck cancer patients.

BACKGROUND: The urokinase-type plasminogen activator receptor (uPAR) plays an essential function in leukocytes and endothelial homeostasis and, therefore, in the development of chronic periodontitis. METHODS: The study enrolled 150 participants, 50 chronic periodontitis with head and neck cancer post radiotherapy (CP + HNC post-RT) patients, 50 chronic periodontitis (CP) without HNC patients, and 50 healthy controls. Clinical Attachment Loss (CAL), Probing Pocket Depth (PPD), Plaque Index (PI), and Gingival Bleeding Index (GBI) were recorded. An enzyme-linked immunosorbent assay (ELISA) was constructed to quantify serum (suPAR) levels. RESULTS: Stage and grade of periodontitis were stage III-IV, grade C in patients (CP + HNC post-RT), stage I-III, grade A/B in patients (CP without HNC), and absent in (healthy). Chronic periodontitis with HNC post-RT patients presented a significantly higher proportion of suPAR levels (506.7 pg/ml) compared to chronic periodontitis without HNC and healthy controls (423.08 pg/ml and 255.9 pg/ml), respectively. A significant positive correlation was found between serum suPAR levels and CAL, PPD, PI, and GBI in the periodontal disease groups. ROC results of suPAR (AUC = 0.976 for CP + HNC post-RT, AUC = 0.872 for CP without HNC). Hyposalivation appeared in patients (CP + HNC post-RT; 0.15 [0.11-0.23] ml/min, P = 0.001) and (CP without HNC; 0.30 [0.25-0.41] ml/min, P = 0.001), compared to healthy controls; 0.35 [0.28-0.54] ml/min, P = 0.001). CONCLUSION: The study showed a significant elevation in serum suPAR levels in CP + HNC post-RT patients compared to the CP without HNC and control groups. CLINICAL TRIAL REGISTRATION: The study was registered retrospectively; clinicaltrials.gov identifier: NCT06529588. Date of registration: July 31, 2024 https://clinicaltrials.gov/study/NCT06529588 .

Sculpting the tumour microenvironment by combining radiotherapy and ATR inhibition for curative-intent adjuvant immunotherapy.

The combination of radiotherapy/chemoradiotherapy and immune checkpoint blockade can result in poor outcomes in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Here, we show that combining ATR inhibition (ATRi) with radiotherapy (RT) increases the frequency of activated NKG2A+PD-1+ T cells in animal models of HNSCC. Compared with the ATRi/RT treatment regimen alone, the addition of simultaneous NKG2A and PD-L1 blockade to ATRi/RT, in the adjuvant, post-radiotherapy setting induces a robust antitumour response driven by higher infiltration and activation of cytotoxic T cells in the tumour microenvironment. The efficacy of this combination relies on CD40/CD40L costimulation and infiltration of activated, proliferating memory CD8+ and CD4+ T cells with persistent or new T cell receptor (TCR) signalling, respectively. We also observe increased richness in the TCR repertoire and emergence of numerous and large TCR clonotypes that cluster based on antigen specificity in response to NKG2A/PD-L1/ATRi/RT. Collectively, our data point towards potential combination approaches for the treatment of HNSCC.

Study on the sensitizing effect of SM-1 combined with irradiation on head and neck squamous cell carcinoma.

PURPOSE: Head and neck squamous cell carcinoma (HNSCC) is globally prevalent with high recurrence, low survival rate, and poor quality of life for patients. Derived from PAC-1, SM-1 can activate procaspase-3 and induce apoptosis in cancer cells to exert anti-tumor effects. However, the inhibitory effect of SM-1 on HNSCC after combination with radiation are unclear. This study aims to investigate the radiosensitizing effect of SM-1 on HNSCC in vitro and in vivo. METHODS: MTT method was used to detect the effect of SM-1 on the viability of HNSCC cell lines (HONE1, HSC-2, and CAL27). The effects of SM-1 combined with radiation on the survival index of HONE1, HSC-2, and CAL27 cell lines were determined by colony formation assay. Flow cytometry was used to investigate the effects of SM-1 and radiation combination on cell apoptosis and cell cycle, and western blot experiments were performed to detect the expression of apoptosis and cell cycle-related proteins. Finally, a xenograft tumor model of CAL27 was established to evaluate the anti-tumor effect of SM-1 combined with radiation in vivo. RESULTS: In vitro, SM-1 effectively inhibited the activity of HNSCC cell lines HONE1, HSC-2, and CAL27 cells, and synergistically showed anti-proliferation activity during combined irradiation. Meanwhile, anti-tumor effect of SM-1 on HNSCC was higher than that of Debio1143, and the radiosensitivity of cells was greatly increased. Flow cytometry and western blot analysis showed that SM-1 induced G2/M phase arrest of head and neck squamous cell carcinoma cells via inhibiting the expression of CyclinB1 and CDC2. Moreover, SM-1 activated caspase-3 activity and up-regulated the cleaved form of PARP1 to induce cell apoptosis. In vivo, SM-1 combined irradiation showed a good anti-tumor effect. CONCLUSION: SM-1 enhances HNSCC cell radiation sensitivity in vitro and in vivo, supporting its potential as a radiosensitizer for clinical trials in combination with radiotherapy.

Aqueous extracts from Dioscorea sansibarensis Pax show cytotoxic and radiosensitizing potential in 3D growing HPV-negative and HPV-positive human head and neck squamous cell carcinoma models.

Numerous natural substances have anti-cancer properties. Especially indigenous people use aqueous plant extracts for tea or ointments including Dioscorea sansibarensis Pax to treat various diseases. The aim of this study was to evaluate the cytotoxic and radiosensitizing potential of aqueous extracts from Dioscorea sansibarensis Pax collected from Kenya in a panel of HPV-negative and -positive head and neck squamous cell carcinoma (HNSCC) cells grown in three-dimensional laminin-rich extracellular matrix (3D lrECM). The results show cytotoxicity, radiosensitization and increased levels of residual double strand breaks (DBS) by Dioscorea sansibarensis Pax extracts in HPV-negative and -positive HNSCC models in a concentration- and cell model-dependent manner. Application of ROS scavengers indicated an association between ROS-induced DSB and radiosensitization through Dioscorea sansibarensis Pax pretreatment. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) based characterization of Dioscorea sansibarensis Pax identified the main components of the extract including camptothecin. Overall, Dioscorea sansibarensis Pax aqueous extracts alone and in combination with X-ray irradiation showed effective anticancer properties, which are worthy of further mechanistic investigation.

The role of shared decision-making in enhancing patient experience: Insights from a cohort of curative head and neck cancer patients.

INTRODUCTION: Shared decision-making (SDM) is on the NHS policy agenda, and the preferred model for preference-sensitive decisions. This study establishes baseline patient-perceived SDM in a radical head and neck cohort, and explores patients' views on SDM in a large, specialist trust. METHODS: An SDM questionnaire was distributed to all radical head and neck radiotherapy patients (N = 165), June-December 2023. This combined a well-validated instrument for measuring SDM from the patient perspective, SDM-Q-9, with additional questions exploring patient views. Thematic analysis was used to construct and interpret themes. RESULTS: 65/165 (39%) questionnaires were returned. SDM-Q-9 mean standardised score was 78.6 (SD 26.3). There was a moderate ceiling effect (26%). Scores were not sensitive to sex (p = 0.64) or age (ρ = 0.1). Higher levels of SDM were perceived by participants who stated SDM was very important (51/65, 79%) than somewhat or not at all important (82.4 vs. 62.7; p = 0.02; Cohen d = 0.75). Individuals who discussed their personal priorities with the clinician (46/65, 70.8%), were more likely to be very satisfied with their involvement in SDM (89.1% vs. 52.9%). Thematic analysis generated three themes: Control, Desire for Transparency and Understanding, and Doctor as the Expert. CONCLUSION: Patient-perceived SDM levels are high for head and neck patients. Participants who value SDM also perceive higher levels of SDM. Patient satisfaction increases when individuals discuss their personal priorities. The modest response rate and self-selection bias affect the generalisability of the results. Only radiotherapy patients were included; those who chose alternative treatment may perceive different levels of SDM. The moderate ceiling effect may limit the use of SDM-Q-9 to measure impact of future interventions to improve SDM. IMPLICATIONS FOR PRACTICE: SDM-Q-9 should be combined with an objective, observer measure of SDM.

Impact of sarcopenia and obesity on overall survival in patients with head and neck cancer receiving radiotherapy: A longitudinal study.

PURPOSE: To analyze the impact of sarcopenia and obesity on overall survival (OS) in patients with head and neck cancer (HNC) receiving radiotherapy (RT). METHODS: This prospective longitudinal study recruited 494 patients using convenient sampling. Weight and body composition were assessed before RT (T1), and at the end of RT (T2) using bioelectrical impedance analysis (BIA). The appendicular skeletal mass index was used to define sarcopenia, while the body mass index and fat mass index were used to define obesity. Patient OS was followed and described using Kplan-Meier analysis. Cox proportional hazard regression was used to analyze influencing factors of OS. RESULTS: The median follow-up time was 26.2 months (IQR: 18.4-34.4 months). Multivariable models indicated that sarcopenia/obesity type assessed at T1 was not significantly associated with OS. Multivariable models involving body composition at T2 showed that age (P < 0.001), tumor site (P = 0.003), tumor stage (P = 0.024), and sarcopenia/obesity type (P = 0.040) were significantly associated with OS, while sarcopenic patients without obesity at T2 had worse OS. CONCLUSIONS: Patients with sarcopenia and no obesity at the end of RT might have worse OS. Healthcare professionals should enhance HNC patients' management during RT, helping them maintain a certain amount of muscle mass and fat mass to improve their survival.

MitoTam induces ferroptosis and increases radiosensitivity in head and neck cancer cells.

BACKGROUND AND PURPOSE: Radiotherapy (RT) is an integral treatment part for patients with head and neck squamous cell carcinoma (HNSCC), but radioresistance remains a major issue. Here, we use MitoTam, a mitochondrially targeted analogue of tamoxifen, which we aim to stimulate ferroptotic cell death with, and sensitize radioresistant cells to RT. MATERIALS AND METHODS: We assessed viability, reactive oxygen species (ROS) production, disruption of mitochondrial membrane potential, and lipid peroxidation in radiosensitive (UT-SCC-40) and radioresistant (UT-SCC-5) HNSCC cells following MitoTam treatment. To assess ferroptosis specificity, we used the ferroptosis inhibitor ferrostatin-1 (fer-1). Also, total antioxidant capacity and sensitivity to tert-butyl hydroperoxide were evaluated to assess ROS-responses. 53BP1 staining was used to assess radiosensitivity after MitoTam treatment. RESULTS: Our data revealed increased ROS, cell death, disruption of mitochondrial membrane potential, and lipid peroxidation following MitoTam treatment in both cell lines. Adverse effects of MitoTam on cell death, membrane potential and lipid peroxidation were prevented by fer-1, indicating induction of ferroptosis. Radioresistant HNSCC cells were less sensitive to the effects of MitoTam due to intrinsic higher antioxidant capacity. MitoTam treatment prior to RT led to superadditive residual DNA damage expressed by 53BP1 foci compared to RT or MitoTam alone. CONCLUSION: MitoTam induced ferroptosis in HNSCC cells, which could be used to overcome the elevated antioxidant capacity of radioresistant cells and sensitize such cells to RT. Treatment with MitoTam followed by RT could therefore present a promising effective therapy of radioresistant cancers. STATEMENT OF SIGNIFICANCE: Radiotherapy is applied in the treatment of a majority of cancer patients. Radioresistance due to elevated antioxidant levels can be overcome by promoting ferroptotic cell death combining ROS-inducing drug MitoTam with radiotherapy.