Radiotherapy For Nasopharyngeal Carcinoma Research Articles

Assessment of Prophylactic Internal Carotid Artery Management in Postradiation Nasopharyngeal Necrosis Patients.

Postradiation nasopharyngeal necrosis (PRNN) frequently develops after second-course radiotherapy for nasopharyngeal carcinoma (NPC). PRNN can lead to internal carotid artery (ICA) massive hemorrhage due to ICA rupture, resulting in sudden death. This study aims to explore the pretreatment of the ICA to prevent fatal massive hemorrhage in PRNN patients. Retrospective cohort study. Sun Yat-sen University Cancer Center. Patients diagnosed with NPC and PRNN from January 2010 to September 2022 were included. The Cox proportional hazards regression analysis was performed to analyze risk factors for massive hemorrhage and survival. A nomogram was developed to integrate prognostic models and perform parameter calibration. Two hundred and fifty-fourPRNN patients were included in this study. Prophylactic ICA occlusion significantly reduced the risk of ICA hemorrhage compared to no prophylactic ICA occlusion (3.6% vs40.6%, P < .001). Surgical repair on necrosis significantly prevented hemorrhage and improved survival. The nomogram, incorporating the above 2 factors and the nearest distance from necrosis to ICA ≤ 3 mm, exhibited excellent discriminative ability for hemorrhage. We identified 3 high-risk factors that indicate the need for prophylactic ICA management in PRNN patients: (1) exposure of ICA by rhinoscopy; (2) signs of ICA erosion on MRA scanning; (3) the depth of soft tissue coverage surrounding the ICA wall within the necrotic cavity is less than 3 mm on magnetic resonance imaging. We have identified 3 high-risk factors for PRNN patients that necessitate prophylactic ICA management. These findings are expected to contribute to improving the quality of life and overall survival of PRNN patients.

Effect of Nutritional Intervention on the Management of Radiotherapy and Chemotherapy for Nasopharyngeal Carcinoma

Objective To investigate the application of nutritional intervention in the management of radiotherapy and chemotherapy for nasopharyngeal carcinoma. Methods There were 60 patients with nasopharyngeal carcinoma who were treated with chemoradiotherapy in our department from June 2020 to August 2022, including 30 subjects from the control group and 30 cases from the intervention group. Results (1) In 2002, the 3-week and 24-week NRS scores for radiotherapy and chemotherapy in the control group were higher than those in the intervention group (2.36 ± 0.85 and 1.86 ± 0.57, p = 0.014; 2.76 ± 0.77 and 2.43 ± 0.77, p = 0.023), and the difference was statistically significant (p < 0.05) (Table 2). (2) The weight of patients in the two groups after 3 wk and 24 wk of radiotherapy and chemotherapy were compared, and we found that the weights of the control group were lower than those of the intervention group (66.13 ± 5.53 and 69.03 ± 5.22, p = 0.037; 61.03 ± 5.83 and 64.93 ± 6.85, p = 0.044), and again, the difference was statistically significant (p < 0.05) (Table 3). At week 10 of chemoradiotherapy, the control group lost ≥10% of their weight in the intervention group, and severe malnutrition occurred. The control group lost ≥5% of their weight at 24 wk of chemoradiotherapy and developed malnutrition. (3) The quality of life (measured by the SF-36 scale score) after 24 wk between the two groups was compared, and the control group was lower than the intervention group in all aspects, and this difference was statistically significant (p < 0.05) (Table 4). Conclusion Nutritional intervention is used in the whole management of radiotherapy and chemotherapy for nasopharyngeal carcinoma to improve patient nutritional status and quality of life.

Retracted: Application of Artificial Intelligence in Radiotherapy of Nasopharyngeal Carcinoma with Magnetic Resonance Imaging

Retracted: Application of Artificial Intelligence in Radiotherapy of Nasopharyngeal Carcinoma with Magnetic Resonance Imaging

A Neural Network-based Method for Predicting Dose to Organs at Risk in Intensity-modulated Radiotherapy for Nasopharyngeal Carcinoma

ObjectiveA neural network method was used to establish a dose prediction model for organs at risk (OARs) during intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). Materials and methodsIn total, 103 patients with NPC were randomly selected for IMRT. Suborgans were automatically generated for OARs using ring structures based on distance to the target using a MATLAB program and the corresponding volume of each suborgan was determined. The correlation between the volume of each suborgan and the dose to each OAR was analysed and neural network prediction models of the OAR dose were established using the MATLAB Neural Net Fitting application. The R-value and mean square error in the regression analysis were used to evaluate the prediction model. ResultsThe OAR dose was related to the volume of the corresponding sub-OAR. The average R-values for the normalised mean dose (Dnmean) to parallel organs and serial organs and the normalised maximum dose (Dn0) to serial organs in the training set were 0.880, 0.927 and 0.905, respectively. The mean square error for each OAR in the prediction model was low (ranging from 1.72 × 10−4 to 7.06 × 10−3). ConclusionThe neural network-based model for predicting OAR dose during IMRT for NPC is simple, reliable and worth further investigation and application.

A comprehensive predictive model for radiation-induced brain injury in risk stratification and personalized radiotherapy of nasopharyngeal carcinoma

Background and purposeRadiation-induced brain injury (RBI) is a severe radiotoxicity for nasopharyngeal carcinoma (NPC) patients, greatly affecting their long-term life quality and survival. We aim to establish a comprehensive predictive model including clinical factors and newly developed genetic variants to improve the precision of RBI risk stratification. Materials and methodsBy performing a large registry-based retrospective study with magnetic resonance imaging follow-up on RBI development, we conducted a genome-wide association study and developed a polygenic risk score (PRS) for RBI in 1189 NPC patients who underwent intensity-modulated radiotherapy. We proposed a tolerance dose scheme for temporal lobe radiation based on the risk predicted by PRS. Additionally, we established a nomogram by combining PRS and clinical factors for RBI risk prediction. ResultsThe 38-SNP PRS could effectively identify high-risk individuals of RBI (P = 1.42 × 10−34). Based on genetic risk calculation, the recommended tolerance doses of temporal lobes should be 57.6 Gy for individuals in the top 10 % PRS subgroup and 68.1 Gy for individuals in the bottom 50 % PRS. Notably, individuals with high genetic risk (PRS > P50) and receiving high radiation dose in the temporal lobes (D0.5CC > 65 Gy) had an approximate 50-fold risk over individuals with low PRS and receiving low radiation dose (HR = 50.09, 95 %CI = 24.27–103.35), showing an additive joint effect (Pinteraction < 0.001). By combining PRS with clinical factors including age, tumor stage, and radiation dose of temporal lobes, the predictive accuracy was significantly improved with C-index increased from 0.78 to 0.85 (P = 1.63 × 10−2). ConclusionsThe PRS, together with clinical factors, could improve RBI risk stratification and implies personalized radiotherapy.

Exploring the pharmacological mechanisms of Biyan Qingdu Granula in the treatment after nasopharyngeal carcinoma radiotherapy based on UPLC/Q-TOF MS, network pharmacology and molecular docking

BackgroundBiyan Qingdu Granula (BYQD) is a traditional Chinese medicine (TCM) formula commonly used for post-radiotherapy treatment of nasopharyngeal carcinoma (NPC). Despite its extensive use, the underlying pharmacological mechanisms have yet to be fully elucidated. MethodsUPLC/Q-TOF MS was used to comprehensively analyze the chemical composition of BYQD. Additionally, an everted gut sac model, coupled with UPLC/Q-TOF MS, was used to screen and identify the active ingredients. Subsequently, we conducted a network pharmacological analysis to delve into the potential mechanisms of these active ingredients. Molecular docking experiments were also performed to assess the interactions between active ingredients and potential core targets. ResultsThe findings revealed the identification of 62 identical ingredients upon comparing the sample solution and intestinal absorbed solution of BYQD. We constructed a protein-protein interaction (PPI) network, which led to the identification of five core targets, namely, TP53, STAT3, MAPK1, SRC and AKT1. Through the construction of a drug-active ingredient-intersection target network, we identified Quercetin, Luteolin, Eupatilin, Magnoflorine, Acacetin and other compound as potential active ingredients. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis suggested that pathways in cancer, PI3K-Akt signaling pathway, lipid and atherosclerosis, proteoglycans in cancer, and the MAPK signaling pathway might play the key roles in the treatment of NPC after radiotherapy using BYQD. Molecular docking results corroborated strong binding activity between the putative core targets and the corresponding key active ingredients. ConclusionThis study provides a preliminary revelation of the active ingredients and potential pharmacological mechanisms of BYQD in the post-radiotherapy treatment of NPC. These findings establish a vital theoretical basis and serve as a scientific reference for the future investigating the pharmacological mechanisms and clinical application of BYQD.

Effects of cognitive behavioral and psychological intervention on social adaptation, psychological resilience and level of hope in patients with nasopharyngeal carcinoma in radiotherapy.

To evaluate the effects of cognitive behavioral and psychological intervention(CBPI) on social adaptation, psychological resilience, and the level of hope in patients with nasopharyngeal carcinoma(NPC) in radiotherapy. This is application research. Eighty patients undergoing radiotherapy for NPC at Affiliated Hospital of Hebei University from November 20, 2020 to November 15, 2022 were randomized into control and study groups at a 1:1 ratio. While the control group was provided with standard specialized nursing care, the study group was offered CBPI in addition to the exact nursing care. Differences in quality of life, psychological resilience, level of hope, emotional state, and patient satisfaction between the groups were compared and analyzed before and after treatment. After an intervention, significantly improved physical, mental, and social functions and material living conditions were observed in the study group compared with the control group (all p< 0.05). Although both groups scored higher on the selected psychological resilience scale following the intervention, the study group showed better results as compared to control group in adaptability, tenacity, control, and goal orientation (all p< 0.05). While both groups had elevated scores of temporality and future, interconnectedness, and positive readiness and expectancy at the end of the intervention, the improvements were more pronounced in the study group (all p< 0.05). CBPI supports radiotherapy for NPC by improving patients' quality of life, confidence in treatment, the hope of recovery, psychological resilience, anxiety, depression, and patient satisfaction. Therefore, this treatment strategy is worthy of wide application in clinical settings.

Characteristics of Tongue Pressure Measured by Novel Multisite Flexible Sensors in Nasopharyngeal Carcinoma Patients With Dysphagia

ObjectiveTo explore characteristics of tongue pressure changes in nasopharyngeal carcinoma (NPC) patients with dysphagia after radiotherapy using a novel system with multisite flexible sensors. DesignProspective observational study. SettingInpatient rehabilitation centers and community dwellings. ParticipantsNineteen patients with dysphagia after radiotherapy for NPC and 19 healthy participants were recruited for this study (N=38). InterventionNot applicable. Main Outcome MeasuresA new 9-site (3 × 3) flexible tongue pressure sensor was used to measure tongue-to-palate pressure across different parts of the tongue. The oral tongue was divided into 3 parts: anterior tongue region (TAR), central tongue region (TCR), and posterior tongue region (TPR); 3 sensors were placed on each part. The mean tongue pressure and endurance time at the 3 sites in the TAR, TCR, and TPR were analyzed. The ratios of the mean TAR, TCR, and TPR values were calculated. ResultsPressures of TAR, TCR, and TPR in NPC patients with dysphagia were significantly lower than those in healthy participants (P<.05). The pressure in TPR decreased most significantly, followed by that in TCR. The endurance times of TAR and TCR were longer than those of healthy participants (P<.05). The endurance time of TPR was not significantly different between the patients and healthy participants (P>.05). Ratios of pressure between TAR and TCR and TAR and TPR in patients were lower than that in healthy participants (P<.05). There was no significant difference in the TCR to TPR pressure ratio between patients and healthy participants (P>.05). ConclusionsTongue pressure significantly decreased in NPC patients with dysphagia, and the drop in pressure was most pronounced in the TPR area. The results of our study indicate that we should pay attention to the pressure training of the TPR during treatments. The endurance time of the TAR and TCR increased significantly, which may be due to bolus transport compensation. Therefore, clinical rehabilitation strategies should aim to increase the endurance time training in NPC patients after radiotherapy to help increase the effectiveness of the swallowing process in patients.

Targeting RPA promotes autophagic flux and the antitumor response to radiation in nasopharyngeal carcinoma

BackgroundAutophagy is involved in nasopharyngeal carcinoma (NPC) radioresistance. Replication protein A 1 (RPA1) and RPA3, substrates of the RPA complex, are potential therapeutic targets for reversing NPC radioresistance. Nevertheless, the role of RPA in autophagy is not adequately understood. This investigation was performed to reveal the cytotoxic mechanism of a pharmacologic RPA inhibitor (RPAi) in NPC cells and the underlying mechanism by which RPAi-mediated autophagy regulates NPC radiosensitivity.Methods and resultsWe characterized a potent RPAi (HAMNO) that was substantially correlated with radiosensitivity enhancement and proliferative inhibition of in vivo and in NPC cell lines in vitro. We show that the RPAi induced autophagy at multiple levels by inducing autophagic flux, AMPK/mTOR pathway activation, and autophagy-related gene transcription by decreasing glycolytic function. We hypothesized that RPA inhibition impaired glycolysis and increased NPC dependence on autophagy. We further demonstrated that combining autophagy inhibition with chloroquine (CQ) treatment or genetic inhibition of the autophagy regulator ATG5 and RPAi treatment was more effective than either approach alone in enhancing the antitumor response of NPC to radiation.ConclusionsOur study suggests that HAMNO is a potent RPAi that enhances radiosensitivity and induces autophagy in NPC cell lines by decreasing glycolytic function and activating autophagy-related genes. We suggest a novel treatment strategy in which pharmacological inhibitors that simultaneously disrupt RPA and autophagic processes improve NPC responsiveness to radiation.

Quality of life and swallowing outcomes after early proactive swallowing rehabilitation by either transcutaneous neuromuscular electrical stimulation or exercise-based swallowing training in patients with nasopharyngeal carcinoma after radiotherapy.

Exercise-based swallowing training (EBST) and transcutaneous neuromuscular electrical stimulation (TNMES) are common modalities used to treat late dysphagia after radiotherapy for nasopharyngeal carcinoma (NPC). We aimed to investigate and compare the efficacies of EBST and TNMES as proactive treatments administered early after radiotherapy. Patients with early post-radiotherapy NPC (n = 120) underwent either TNMES or EBST. Flexible endoscopic evaluation of swallowing (FEES), quality of life (QOL), and swallowing function questionnaires were completed before the intervention as well as immediately, 6, and 12 months after the intervention. Outcome measures included the scores for the swallowing function score (SFS), penetration and aspiration scale (PAS), dynamic imaging grade of swallowing toxicity (DIGEST), functional oral intake scale (FOIS), swallowing performance status scale (SPSS), pharyngeal motor impairment (PMI), pharyngeal function impairment (PFI), and functional assessment after cancer therapy-nasopharyngeal (FACT-NP) questionnaire. Three months after radiotherapy, 31 and 34 patients underwent TNMES and EBST, respectively, and completed swallowing assessments at all four assessment timepoints. All patients showed post-radiotherapy impairments in the SFS, PAS, DIGEST, PMI, and PFI. Compared with the EBST group, the TNMES group showed significant improvements in the PFI and PMI scores, with small-to-medium effect sizes. Additionally, compared with the EBST group, the TNMES group demonstrated a trend toward slightly better improvements in the PAS, DIGEST, FOIS, and SPSS scores immediately and 6 months after the intervention. The SFS scores improved from baseline in both groups; however, the TNMES group showed an earlier improvement. Finally, the TNMES group showed better QOL according to the FACT-NP than the EBST group. Proactive TMNES and EBST are safe and feasible modalities for improving swallowing in patients with NPC when administered early after radiotherapy. Although TNMES showed better results than EBST, these results should be interpreted with caution given the study limitations. 1B.

Nutritional intervention for the prognosis of nasopharyngeal carcinoma chemoradiotherapy patients: A meta-analysis.

To conduct a meta-analysis to investigate the effects of different nutritional interventions on various serum nutritional indicators and patients' prognosis during radiotherapy for nasopharyngeal carcinoma, to assess treatment safety and efficacy. A systematic literature search, mainly randomized controlled trials (RCTs), on the effects of nutritional support on patients undergoing radiotherapy for nasopharyngeal carcinoma was conducted between January 2010 and August 2022 using databases such as China National Knowledge Infrastructure, Wanfang Database, Web of Science, PubMed, Cochrane Library, and Embase. Risk of bias was assessed using the Cochrane Rob2 scale. The meta-analysis was performed using Stata 17.0 software, and the heterogeneity between studies was assessed using the I2 test, and funnel plots were used to qualitatively assess publication bias. Overall, 10 RCTs with a total sample size of 879 cases were identified. The meta-analysis results showed that body mass index (BMI) (odds ratio = 0.026, 95% confidence interval[1]: -0.348 to 0.401, P > .05), albumin (standardized mean difference [SMD] = 0.13, 95% CI: -0.127 to 0.387, P > .05), and total protein levels were not significantly different between the nasopharyngeal cancer (NPC) radiotherapy group with nutritional support group (SMD = -0.262, 95% CI: -1.062 to 0.537, P > .05) and the control group; pre-albumin (SMD = 0.256, 95% CI: 0.022-0.491, P = .032), hemoglobin (SMD = 0.436, 95% CI: 0.26-0.612, P < .000), and lymphocyte count (SMD = 1.125, 95% CI: 0.868-1.381, P < .000) were significantly higher in the nutritional intervention group than in the control group. Compared with conventional diets, nutritional interventions can improve serum nutritional parameters, nutritional status, treatment tolerance, and prognosis of patients undergoing radiotherapy for nasopharyngeal carcinoma.

Clinical course of longer than five years after definitive radiotherapy for nasopharyngeal carcinoma.

This study aimed to reveal the long-term outcomes and late toxicities (> 5years) after definitive intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC). Data from 43 patients (median age, 55years; range, 17-72years) with NPC who underwent definitive IMRT between 2001 and 2018 were analyzed. All patients were alive and disease-free 5years after IMRT. A total dose of 70 (range, 66-70) Gy was delivered in 35 (33-35) fractions with concurrent cisplatin chemotherapy. The median follow-up duration was 119 (range, 61.5-242.1) months. Three patients developed locoregional failure at 79, 92, and 149months after IMRT, respectively. Of these, 2 patients died of disease progression at 136 and 153months after IMRT. One patient died of aspiration pneumonia 141months after IMRT, despite salvage of the recurrent tumor by re-irradiation. In addition, one patient died of aspiration pneumonia 62months after the IMRT. Thus, the 10-year overall survival, progression-free survival, and locoregional control rates were 98%, 92%, and 94%, respectively. Grade ≥ 2 and ≥ 3 late toxicities were observed in 28 (65%) and 9 (21%) patients, respectively. Nine second primary cancers, including five tongue cancers and two external auditory canal carcinomas, were observed in seven (16%) patients. Late recurrences, severe late toxicities, and second primary cancers were observed > 5years after IMRT. A long-term follow-up of > 5years is needed in patients with NPC.

Deep Learning-Based Synthesis of Contrast-Enhanced MRI for Automated Delineation of Primary Gross Tumor Volume in Radiotherapy of Nasopharyngeal Carcinoma.

Contrast-enhanced MRIs are necessary to delineate the primary gross tumor volume (GTVp) in radiotherapy of nasopharyngeal carcinoma (NPC). However, using contrast agents to scan contrast-enhanced MRIs is not applicable to some patients due to metal implants or their allergy, and it increases the treatment cost of patients. To address these problems, this work aims at synthesizing contrast-enhance MRIs from unenhanced MRIs by implementing generative adversarial network (GAN). In this work, 324 MRI datasets of patients with NPC were retrospectively collected between September 2016 and September 2017 from a single institute. MRI examinations were performed with un-enhanced T1-weighted (T1) and T2-weighted (T2) sequences, and contrast-enhanced T1-weighted (T1C) and fat-suppressed T1-weighted (T1FSC) sequences. We designed and developed a modified pix2pix network to synthesize T1C (sT1C) and T1FSC (sT1FSC) from real T1. The end of the generator in this network was assembled with multiple heads (the classification head and gradient head) to learn more representation information and features from real images, the discriminator in this network distinguished whether the synthesized image is real and fake and supervised that the generator outputs more realistic synthesized image. We verified the performance of the synthesized images for automated delineation of GTVp. In an independent testing set of 11 patients, the synthesized sT1C and sT1FSC were inputted into the segmentation deep learning network along with their corresponding T1 and T2 sequences to generate GTVp contours. Delineation performance of the synthesized images and real images for automated delineation were evaluated by dice similarity coefficient (DSC), and average surface distance (ASD), using human expert contours as the ground truth. In automated contouring of GTVp for NPC, the segmentation deep learning network using one or two synthesized MRIs showed equivalent performance when compared with the automated contours which generated from four real MRI sequences. Mean DSCs between automated contours by sT1C-replaced or sT1C and sT1FSC-replaced network and ground truth contours were 0.726 ± 0.143 and 0.711 ± 0.157, respectively, slightly inferior to that of contours generated from four real MRI sequences (0.740 ± 0.154, both P >0.05). In terms of mean ASD, there was also no significant difference between automated contours generated from synthesized images and real images (3.056 ± 4.216 mm and 3.537 ± 4.793 mm vs. 3.124 ± 4.637 mm; both P > 0.05). We proposed an MRI-synthesis method based on GAN and the synthesized contrast-enhanced MRIs performed equivalent as the real contrast-enhanced MRIs in the automated delineation of gross tumor volume for radiotherapy of NPC.

Definitive radiotherapy for nasopharyngeal carcinoma in Japan: analysis of cases in the National Head and Neck Cancer Registry from 2011 to 2014.

This study aimed to analyze the nationwide prognosis of patients with nasopharyngeal carcinoma who underwent definitive radiotherapy in Japan, utilizing the National Head and Neck Cancer Registry data. A total of 741 patients diagnosed with primary nasopharyngeal carcinoma were screened from 2011 to 2014. The inclusion criteria were histologically proven nasopharyngeal squamous cell carcinoma, receiving definitive radiotherapy, and no distant metastases. Patients with unclear prognoses or unknown staging were excluded. The primary endpoint was 5-year overall survival, and secondary endpoints were 5-year progression-free survival and survival by stage. A total of 457 patients met the inclusion criteria. The median age was 60years, and 80% were male. The proportions of patients with performance status 0, 1, 2 and 3 were 69, 10, 1 and 1%, respectively. Chemoradiotherapy was administered to 84.7%. Radiotherapy modalities were recorded only for 29 patients (three received intensity-modulated radiotherapy and 26 received two/three-dimensional radiotherapy). Of those included, 7.4, 24.7, 35.7, 24.5 and 7.7% had Stage I, II, III, IVA and IVB disease, respectively. The 5-year overall survival was 72.5% for all patients: 82.6, 86.6, 76.0, 51.4 and 66.5% for Stage I, II, III, IVA and IVB disease, respectively. The 5-year progression-free survival was 58.6%: 75.6, 66.8, 61.5, 43.7 and 46.5% for Stage I, II, III, IVA and IVB disease, respectively. This nationwide survey demonstrated favorable prognoses and provided valuable foundational data for similar future surveys to monitor the penetration of appropriate treatment and changes in clinical structures based on new evidence.

Prediction of Anatomical Presentation during Radiotherapy of Nasopharyngeal Carcinoma Using GAN-LSTM for Plan Adaption Decision

During treatment, patients frequently undergo anatomical changes that might result in dose degradation. Adaptive radiation therapy (ART) is now available to overcome this problem. However, this method is time-consuming, and the lack of criteria to trigger replanning prevents its widespread use. To overcome these obstacles, anatomical presentation models are necessary. In this study, we developed a novel deep-learning method to make a series of predictions for the remaining treatment course. Total 230 nasopharyngeal carcinoma patients who received radiotherapy in 33 fractions were enrolled. The data included cone-beam computed tomography (CBCT) and planning CT images. CBCT image quality was improved to CT level using an in-house software. A generative adversarial network-long short-term memory network model was proposed, with the generation abilities of the former network and forecasting abilities of the latter. To predict the anatomical presentation for 3-6 weeks, we trained four models. The planning CT and CBCT acquired earlier were used as the input. Physicians segmented the gross target volume (GTVnx) and parotid glands on prediction and real CBCT (ground truth). Contours, dosimetry parameters, and plan adaptation decision were used to evaluate the models. The table shows the overall performance of the test set (18 cases). The anatomical changes were predicted over the treatment course with a dice similarity coefficient (DSC) of 0.96, 0.90 and 0.92 and mean distance to agreement (MDA, in mm) of 0.37, 0.70, and 0.60 for GTVnx, left parotid, and right parotid, respectively. Bland-Altman analysis revealed that dosimetry parameters did not show significant difference between prediction and ground truth. The prescription coverage (%) of GTVnx, V30 of the left parotid, and V30 of the right parotid had mean absolute biases of 0.09, 1.09, and 0.27, respectively. At week 6, there were two cases that required plan adaptation, and the model effectively triggered replanning one week in advance. We developed a framework that predicts the anatomical changes occurring in future fractions. Establishing such a framework provides a proactive approach to ART and saves clinical time by anticipating and preparing for treatment strategies in advance.

Automated Contouring of Cervical Lymph Nodes and Clinical Target Volumes for Nasopharyngeal Carcinoma Based on Deep Learning and Experience Constraints

Application of artificial intelligence (AI) for automated contouring of tumor volumes and organs at risk (OARs) for radiotherapy of nasopharyngeal carcinoma (NPC) leads to improved contouring accuracy and efficiency. However, few studies have involved the automated contouring of gross tumor volume of cervical lymph nodes (GTVn) and clinical target volumes (CTVs). In this work, we proposed an AI automated contouring tool for GTVn and CTVs for radiotherapy of NPC on the plain scans of planning compute tomography (CT). In this retrospective study, plain scan datasets of planning CT covering the nasopharynx and neck from 139 patients with NPC between March 2022 and December 2022 were collected and divided into training, validation, and testing cohorts of 95, 24, and 20 patients, respectively. Ground truth contours of primary gross tumor volume (GTVp), GTVn (divided into GTVn_L in left neck and GTVn_R in right neck), CTVs (including high risk CTV1 contains GTVp and low risk CTV2 contains GTVp and cervical nodal levels) and OARs were delineated and were defined by consensus of two experts. We first proposed a three-dimensional (3D) U-net using GTVp and OARs as experience constrains to guide the automated delineation of GTVn and CTVs. The average Dice similarity coefficient (DSC) and average surface distance (ASD) were used to quantify the performance of the AI tool. Next, five prospective patients were enrolled for clinical evaluation of our AI tool. DSC between automated contours and radiation oncologist-revised contours and time consuming of the revision were record. Clinical characteristics of 139 retrospective and 5 prospective patients are list in Table 1. In the independent testing set of 20 patients, our AI tool showed high performance in GTVn and CTVs contouring when compared with the ground truth contours. The mean DSC were 0.73 ± 0.07, 0.74 ± 0.05, 0.93 ± 0.03, and 0.88 ± 0.03, and the mean ASD were 1.01 ± 0.43 mm, 1.14 ± 0.61 mm, 0.51 ± 0.13 mm, 1.17 ± 0.43 mm for GTVn_L, GTVn_R, CTV1 and CTV2, respectively. In the five prospective patients, mean DSC were 0.74 ± 0.07, 0.74 ± 0.10, 0.95 ± 0.01 and 0.89 ± 0.04, respectively. The median time consuming for GTVn and CTVs revision was 2minutes and 10 seconds (range, 1 minutes to 3 minutes). The proposed AI tool integrating clinical experience as constrains showed high accuracy for contouring GTVn and CTVs of NPC. With the assistance of AI contours, contouring efficiency could be probably increased, which is promising in online adaptive radiotherapy of NPC.

All-in-One Online Radiotherapy for Nasopharyngeal Carcinoma: Preliminary Results of Treatment Time, Contouring Accuracy, Treatment Plan Quality and Patient Compliance

To explore the feasibility of Fan-beam CT (FBCT)-based all in one (AIO) online workflow for nasopharyngeal carcinoma (NPC) in radical radiotherapy setting, and to preliminarily describe the timing of different steps in the process, contouring accuracy of regions of interest (ROIs), target coverage, organs at risk (OARs) dose and patient compliance. From March 16, 2022 to January 04, 2023, 25 NPC patients (22/25 diagnosed as phase III/IV disease according to 8th edition of the AJCC/UICC staging system) consecutively treated with AIO radiotherapy were prospectively enrolled. All patients received mask fixation and MRI simulation scan in advance. Primary gross tumor volume (GTVp) of nasopharynx was automatically delineated by AI and edited manually on MRI images. AIO online workflow started with an integrated KV-level CT in a CT-integrated linear accelerator. After that GTVp was registrated to CT images and other ROIs was contoured automatically and then modified manually as needed. Subsequently automatic treatment plan was calculated and optimized until the dose of target and OARs was evaluated satisfactory by physicians and physicists. Finally, treatment was delivered using volumetric modulated arc treatment (VMAT), with prescribed dose of 6996 cGy/ 33 fractions to the GTVp. Twenty-four patients (24/25, 96%) completed the AIO radiotherapy workflow successfully, with average treatment time of 28.3 min (range: 19.9-42.4 min). the AI-assisted ROIs automatically contouring took 1.55 min in average (range: 1.32-1.77 min), with an average DICE of 97.7% compared with modified contouring, and the average DICE was 95.7% for clinical tumor volume 1 (CTV1), 88.6% for CTV2, 73.6% for GTVn (cervical lymph node), 99.3% for 30 OARs. The automatic treatment plan averagely needed 3.5 min, and the pass rate of radiotherapy planning was 91.7% (22/24). The target coverage for PTVs for GTVp, CTV1, and CTV2 was 99.3%, 99.8%, 98.0% respectively. As for the dose of OARs, the average Dmax of brainstem was 5,583cGy; the Dmax of spinal cord was 3,467cGy; the Dmean of parotid was 3,285 cGy. The average monitor units of all patients was 643 MU and the delivery took 2.93 min. Patient compliance with respect to AIO workflow and total treatment time was excellent. The AIO online radiotherapy was promising for NPC patients, with clinically acceptable AI assisted ROIs contouring and treatment planning, as well as favorable patient compliance to the AIO online workflow.

First Implementation of Full-Workflow Automation for Online Adaptive Radiotherapy of Nasopharyngeal Carcinoma

The aim of this work is to established the technical characteristics and implementation procedures of an artificial intelligence (AI)-powered radiotherapy workflow that enables full-process automation for online adaptive radiotherapy (ART); and evaluate its feasibility and performance implemented for ART of nasopharyngeal carcinoma (NPC). This single center, prospective study has been approved by the ethical committee of the institution. The online ART workflow was developed based on a CT-integrated linear accelerator. During the course of radiotherapy, the patient underwent daily pre-treatment fan-beam CT (FBCT) scan. Then the FBCT was automatically registered to the original planning CT and used to assess the need for the patient to implement ART according to radiation oncologist's discretionary. The online ART workflow incorporates critical radiotherapy procedures from re-simulation, auto-segmentation by integrating image fusion and deep learning method, auto-replanning, beam delivery, and in vivo quality assurance (QA) into one scheme, while the patient is on the treatment couch during the whole process. From 2th April 2022 to 5th January 2023, 20 patients with newly-diagnosed, non-metastatic NPC were enrolled in this study. Only one-time online ART was performed for each patient, because that the appropriate timing for triggering online ART was explored in parallel with this study. According to radiation oncologists' discretionary, the median fraction for performing online ART was at 21 fractions (interquartile range, 19-24 fractions). All patients were well tolerated and successfully completed the treatment. For tumor targets contouring, minor revisions were required for automated contours of the primary gross tumor volume (GTVp) and clinical target volumes (CTVs, including CTV1 and CTV2), with the mean DSC between before and after revision of 0.91±0.042, 0.94 ± 0.042 and 0.91 ± 0.061, respectively; and much more revisions for the automated contours of cervical lymph nodes GTV (GTVn), with the mean DSC of 0.74 ± 0.28. The automated contours of normal tissues were clinically acceptable with little modifications. Median time consuming for auto-segmentation and revision was 9.5 minutes (min). For treatment planning, 18 automated plans (90%) were passed at their first auto-optimization and two plans (10%) were passed after further optimization of the dose coverage of CTVs by physicist; and the median time consuming for auto-planning was 6.2 min. Time consuming for other procedures were as follows: re-simulation, 2.3 min; plan evaluation, 3.3 min; beam delivery, 4.6 min; and the duration of the entire process was 25.9 min, range from 19.4 min to 32.5 min. We successfully established an AI-powered online ART workflow for adaptive radiotherapy of NPC, and confirmed that current auto-segmentation and auto-replanning methods are powered enough to support the clinical application of its online ART.

OCT-A evaluation of the retinal and choroidal structures of patients with a history of radiotherapy due to nasopharyngeal carcinoma

BackgroundTo perform the optical coherence tomography angiography (OCT-A) evaluation of the microvascular structures of the retina and choroidal tissue in asymptomatic patients who received radiotherapy for nasopharyngeal carcinoma and to compare the results to those of healthy individuals. MethodsOphthalmological examinations were performed in all asymptomatic patients without vascular or systemic diseases, or fundus findings who had received radiotherapy at least two years earlier. Then, OCT-A scans were obtained. Foveal, parafoveal, and whole retinal thicknesses, vessel densities in the superficial and deep capillary plexuses, subfoveal choroidal thickness, the non-flow area in the superficial capillary plexus, and the choriocapillaris flow area were measured and compared to the values of the healthy control group. ResultsThe radiotherapy group had significantly lower deep capillary plexus vascular density and subfoveal choroidal thickness values and significantly higher choriocapillaris flow area values compared to the control group. ConclusionsWe consider that OCT-A is useful in the early diagnosis of radiation retinopathy that may develop during follow-up in patients with nasopharyngeal carcinoma who have received radiotherapy.

Wearing individualized 3D printed oral stent to protect normal tissues in patients with nasopharyngeal carcinoma during radiotherapy.

To demonstrate a new individualized 3D printed oral stent in radiotherapy of nasopharyngeal carcinoma (NPC) patients and carry out a comparative analysis combining with clinical case. Thirty NPC patients treated in our institution from September 2021 to October 2022 were prospectively enrolled. An individualized 3D printed oral stent was designed for each patient, and one set of computed tomography (CT) slices were obtained with /without wearing the oral stent, respectively. After delineation of target volumes and organs at risk (OARs) on the two CT slices, we finished two treatment plans by using the same target objectives, critical constraints and plan setup for each patient. Finally, the dose distribution and other dosimetric parameters of target volumes and OARs between the two plans were compared. Tongue volume and tongue length outside of mouth was 10.4±2.5cm3 and 2.8±0.6cm, respectively, distance between dorsal surface of oral tongue and plate increased from 0.3±0.3cm to 2.2±0.5cm by wearing the oral stent. For the target volume, there was no significant difference. However, Dmax of tongue, tongue tip and periglottis decreased significantly from 6352.6±259.9cGy to 5994.9±478.9cGy, 3499.8±250.6cGy to 3357.7±158.0cGy and 6345.5±171.0cGy to 6133.4±263.3cGy, respectively (p=0.000); Dmean of tongue, tongue tip and periglottis decreased significantly from 3714.7±204.2cGy to 3169.7±200.9cGy, 3060.8±216.2cGy to 2509.6±196.7cGy and 3853.3±224.9cGy to 3079.3±222.0cGy, respectively (p=0.000). The individualized 3D printed oral stent can reduce the dose of oral tissues and organs, so as to reduce the oral adverse reactions and improve the compliance of patients and the quality of their life. The technique can be used in radiotherapy of NPC patients.