Ophthalmic manifestations of nasopharyngeal carcinoma (NPC): A systematic review of reported cases with and without prior history of nasopharyngeal carcinoma

ABSTRACT Purpose: We aimed to study reported cases of nasopharyngeal carcinoma presenting with ophthalmic manifestations with and without a prior diagnosis of nasopharyngeal carcinoma. Methods: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A literature search was conducted using the MEDLINE database in PubMed and Google Scholar. We included patients with a previous diagnosis of nasopharyngeal carcinoma in Group I and those without a prior diagnosis of nasopharyngeal carcinoma in Group II. Data included demographics, clinical presentation, history of nasopharyngeal carcinoma, treatment, histopathological description, World Health Organization classification, and outcome. Results: Fifty-eight patients (26 in Group I and 32 in Group II) were included. The male-to-female ratio was 3:1. The mean age of the patients (53.3 ± 11.7 years and 54.8 ± 16.2 years, respectively) and gender did not differ significantly between the two groups. The most common ocular presentations were diplopia and proptosis in the first group (each in 34.6%), whereas visual disturbance was most common in the second group (46.9%). Treatment options and World Health Organization grading were comparable. The outcome in 38 patients (after a comparable follow-up period) was significantly better in group II (p=0.003). There was no statistically significant difference in the outcome of 23 patients in correlation with World Health Organization grades II versus III irrespective of group (p=0.094). Conclusions: The demographics of patients with nasopharyngeal carcinoma presenting with ophthalmic manifestations were similar between the two study groups, with a wide age range and male predominance. Patients presenting initially to ophthalmologists with no history of nasopharyngeal carcinoma have a more favorable outcome. World Health Organization grading may have less value as a prognostic indicator.

Nasopharyngeal carcinoma derived exosomes regulate the proliferation and migration of nasopharyngeal carcinoma cells by mediating the miR-99a-5p BAZ2A axis

Abstract Objectives Nasopharyngeal Carcinoma (NPC) is a common malignant tumor of nasopharyngeal mucosal epithelium in clinical practice. Radiotherapy and chemotherapy are the main treatment methods at present, but the therapeutic effect is still unsatisfactory. Studies have shown that exosomes and microRNAs (miRNAs) play an important role in the development of cancer. Therefore, this study aimed to investigate the effects of NPC derived exosomes on NPC and their molecular mechanisms. Methods Serum was collected from healthy subjects, Epstein-Barr Virus (EBV) infected patients and NPC patients (n = 9 group) and exosomes were extracted separately. High-throughput sequencing of exosomes was performed to screen differentially expressed miRNAs. The function of the screened miRNA was identified by treating NPC cells with exosomes. The target gene of miRNA was identified using the dual-luciferase assay. Real-Time quantitative Polymerase Chain Reaction (RT-qPCR) was used to determine the levels of miR-99a-5p and Bromodomain Adjacent Tozinc finger domain protein 2A (BAZ2A). Cell Counting Kit-8 assay, flow cytometry, and wound healing assay were utilized to detect cell viability, cell cycle and apoptosis, and migration ability. The protein levels were evaluated by Western blot. Results MiR-99a-5p was identified as the most significant differentially expressed miRNA in exosomes (p< 0.05). The proliferation and migration of NPC cells were extremely facilitated by exosomes, accompanied by the suppressed apoptosis, upregulated BAZ2A, Monocyte Chemotactic Protein-1 (MCP1), and Vascular Endothelial Growth Factor A (VEGFA), and downregulation of Interleukin (IL)-1β and Nuclear Transcription Factor-κB (NF-κB) (p< 0.05). BAZ2A was a target gene of miR-99a-5p. Furthermore, the regulatory effect of exosomes on the proliferation, migration, and apoptosis was significantly abolished by overexpression of miR-99a-5p or downregulation of BAZ2A (p< 0.05). Conclusion NPC derived exosomes facilitated the proliferation and migration of NPC through regulating the miR-99a-5p/BAZ2A axis.

miR-186 regulates epithelial-mesenchymal transformation to promote nasopharyngeal carcinoma metastasis by targeting ZEB1

Abstract Objectives Nasopharyngeal carcinoma (NPC) is an aggressive epithelial cancer. The expression of miR-186 is decreased in a variety of malignancies and can promote the invasion and metastasis of cancer cells. This study aimed to explore the role and possible mechanism of miR-186 in the metastasis and epithelial-mesenchymal transformation (EMT) of NPC. Methods The expression of miR-186 in NPC tissues and cells was detected by RT-PCR. Then, miR-186 mimic was used to transfect NPC cell lines C666-1 and CNE-2, and cell activity, invasion and migration were detected by CCK8, transwell and scratch assay, respectively. The expression of EMT-related proteins was analyzed by western blotting analysis. The binding relationship between miR-186 and target gene Zinc Finger E-Box Binding Homeobox 1 (ZEB1) was confirmed by double luciferase assay. Results The expression of miR-186 in NPC was significantly decreased, and transfection of miR-186 mimic could significantly inhibit the cell activity, invasion, and migration, and regulate the protein expressions of E-cadherin, N-cadherin and vimentin in C666-1 and CNE-2 cells. Further experiments confirmed that miR-186 could directly target ZEB1 and negatively regulate its expression. In addition, ZEB1 has been confirmed to be highly expressed in NPC, and inhibition of ZEB1 could inhibit the activity, invasion, metastasis and EMT of NPC cells. And co-transfection of miR-186 mimic and si-ZEB1 could further inhibit the proliferation and metastasis of NPC. Conclusion miR-186 may inhibit the proliferation, metastasis and EMT of NPC by targeting ZEB1, and the miR-186/ZEB1 axis plays an important role in NPC.

Hsa_circ_0013561 promotes progression of nasopharyngeal carcinoma by activating JAK2/STAT3 signaling pathway

Abstract Objective Nasopharyngeal Carcinoma (NPC) is a malignancy of epithelium of epithelium of the nasopharynx, with the highest incidence of otolaryngeal malignancies. A growing number of studies confirm that Circular RNA (circRNA) plays an important role in tumor development, including Hsa_circ_0013561. This study aims to elucidate the process and mechanism of NPC regulation hsa_circ_0013561. Methods In this study, circRNA expression nodes and subcellular localization in NPC tissues were analyzed by fluorescence in situ hybridization. The expression of hsa_circ_0013561 in NPC cells was further clarified by RT-qPCR. At the same time, the lentivirus vector interfered by hsa_circ_0013561 was constructed and transfected. The cell proliferation was detected by CCK-8 method, EdU assay and plate cloning assay. The cell cycle and apoptosis were detected by flow cytometry, and the cell migration ability was detected by wound healing assay and Transwell assay. Western blotting examined the expression of apoptosis, Epithelial-Mesenchymal Transition (EMT)-associated proteins, and Janus Kinase/Signal Transductor and Activator of Transcription (JAK/STAT) signaling pathway-related proteins. Results The results showed that the expression of hsa_circ_0013561 in NPC samples was significantly upregulated and hsa_circ_0013561 localized in the cytoplasm. After down-regulating hsa_circ_0013561 expression, it significantly inhibited the proliferation and metastasis ability of NPC, inhibited EMT progression, and promoted apoptosis. Further studies showed that interference hsa_circ_0013561 significantly inhibited JAK2/STAT3 signaling pathway activation and induced the expression of apoptosis-related proteins. Conclusion In summary, we found that hsa_circ_0013561 is a pro-tumor circRNA in NPC, which can reduce the activation of JAK2/STAT3 pathway by knocking down hsa_circ_0013561, thereby slowing down the malignant progression of NPC. Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence Level 4.

Study of Three Potential Diagnostic Biomarkers in Nasopharyngeal Carcinoma Samples from Guilan, North of Iran

Abstract Introduction Finding biomarkers for highly lethal cancers is a priority. Objective The current study was designed to understand the clinical significance of vascular endothelial growth factor (VEGF), latent membrane protein 1 (LMP1), and tumor necrosis factor-α (TNF-α) expression as the biomarkers, and evaluate their correlation with each other, in nasopharyngeal carcinoma (NPC) in the province of Guilan, North of Iran. Methods Gene expression was evaluated in 25 formalin-fixed paraffin-embedded (FFPE) blocks from cases of confirmed NPC and 20 FFPE samples of non-NPC by quantifying messenger ribonucleic acid (mRNA) and protein levels, using real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC) methods, respectively. Furthermore, the correlations among the protein levels of different genes, along with the patients' demographic characteristics were assessed. Results Our findings on mRNA and protein levels demonstrated that the expression of the LMP1 gene in the NPC group was significantly elevated compared with that of the non-NPC group. In addition, the protein levels in the NPC group indicated a positive and significant correlation between LMP1 and VEGF expression. It was noted that both protein and mRNA levels showed no significant differences in the expression of TNF-α and VEGF genes between the NPC and control groups. Furthermore, there was no significant relationship between the expression of these proteins and the demographic characteristics of NPC patients. Conclusion Overall, a significant increase in LMP1 expression was observed in NPC patients, which may serve as a diagnostic biomarker for NPC. Also, LMP1 might be involved in NPC progression by inducing VEGF gene expression.

Treatment outcomes of alternating chemoradiotherapy for nasopharyngeal carcinoma: a single-center safety and efficacy study

Abstract Objective To evaluate the efficacy and safety of Alternating Chemoradiotherapy (ACRT) using cisplatin and 5-Fluorouracil (5-FU) in patients with nasopharyngeal carcinoma. Methods This was a retrospective study in which patients' clinical records were reviewed to identify patients with a new diagnosis of nasopharyngeal carcinoma at our institution between January 2005 and January 2019. Thirty-seven eligible patients were identified; of these, the clinical details of 27 patients treated with ACRT were evaluated. Patient outcomes, including overall survival and progression-free survival, and adverse events were assessed. Results Of these initial 37 patients, 1, 10, 13, 10, and 3 were staged as I, II, III, IVA, and IVB, respectively, as defined by the 8th edition of the TNM classification system. Twenty-seven patients received ACRT comprising sequential administration of chemotherapy, radiotherapy (wide field), chemotherapy, radiotherapy (shrinking field), and chemotherapy. The 5-year overall survival and progression-free survival rates were 83.7% and 88.9%, respectively. Treatment compliance was 93%, which is comparable to that of previous reports. Conclusion ACRT using cisplating and 5-fluorouracil was well tolerated with acceptable efficacy. Level of Evidence IVa

Changes in brain gray matter volume in nasopharyngeal carcinoma patients after radiotherapy in long-term follow-up

Abstract Objectives The aim of this study was to examine the changes in gray matter in nasopharyngeal carcinoma patients with normal hearing (Group 1) and nasopharyngeal carcinoma patients with hearing loss (Group 2) after radiotherapy using voxel-based morphological analysis and to analyze the relationship with the radiation doses of the temporal lobe. Methods 21 patients in Group 1, 14 patients in Group 2, and 21 healthy volunteers were selected. All participants underwent an otologic examination and three-dimensional magnetization preparatory rapid acquisition gradient echo sequence scan. The correlation between the variation of whole brain gray matter volume and the doses of the temporal lobe was analyzed by Data Processing & Analysis for Brain Imaging software. Results Compared with the normal control group, the brain areas with reduced gray matter volume in nasopharyngeal carcinoma patients after radiotherapy were mainly in the left posterior cerebellar lobe (T = −8.797), left insular lobe (T = −7.96), and the right insular lobe (T = −6.632). Compared to Group 1, the brain areas of Group 2 patients with reduced gray matter volume were mainly in the left superior temporal gyrus (T = −2.366), left olfactory bulb (T = −2.52), left Rolandic operculum (T = −2.431), and right olfactory bulb (T = −3.100). Compared with Group 1, the brain areas of Group 2 patients with increased gray matter volume were mainly in the left calcarine sulcus (T = 3.425) and right calcarine sulcus (T = 3.169). There were no correlations between the changes of brain gray matter volume and the radiation doses of the temporal lobe in both Group 1 and Group 2. Conclusions The radiotherapy may cause the changes of brain areas associated with cognitive function in nasopharyngeal carcinoma in a long-term follow-up. At the same time, nasopharyngeal carcinoma patients with the radiation-induced hearing loss had abnormal gray matter volumes in the auditory center and other sensory centers. Our findings might provide new understanding into the pathogenesis of radiation-induced brain damage in normal-appearing brain tissue. Yet this exploratory study should be taken with caution.

The effect of primary tumor volume on the prognosis of nasopharyngeal carcinoma in era of volumetric modulated arc therapy: a propensity score matched cohort study

Abstract Objective The role of Primary Tumor Volume (PTV) in Nasopharyngeal Carcinoma (NPC) treated with Volumetric Modulated Arc Therapy (VMAT) is still unclear. The aim of this study was to access the effect of PTV in prognosis prediction of nasopharyngeal carcinoma in era of VMAT. Methods Between January 20 and November 2011, 498 consecutive NPC patients with stage I-IVA disease who received VMAT at a single center were retrospectively analyzed. Receiver Operating Characteristic (ROC) was performed to access the cut-off point of PTV. Univariate Kaplan-Meier and multivariate Cox regression analyses were used to evaluate prognostic value for PTV. The Propensity Score Matching (PSM) was used to adjust baseline potential confounders. Results The 5-year Locol-Regional Failure-Free (L-FFR), Distant Failure-Free Survival (D-FFR), Disease-Free Survival (DFS) and Overall Survival (OS) were 90.6%, 83.7%, 71.5% and 79.3%, respectively. Before PSM, the 5-year L-FFR, D-FFR, DFS, OS rates for NPC patients with PTV ≤ 38 mL vs. PTV > 38 mL were 94.1% vs. 90.4% (p= 0.063), 87.9% vs. 76.3% (p< 0.001), 78.5% vs. 58.5% (p< 0.001) and 86.3% vs. 66.7% (p< 0.001) respectively. Multivariate analysis showed PTV was an independent prognostic factor for D-FFS (p= 0.034), DFS (p= 0.002) and OS (p= 0.001). PTV classified was still an independent prognostic factor for OS after PSM (HR = 2.034, p= 0.025. Conclusions PTV had a substantial impact on the prognosis of NPC patients treated with VMAT before and after PSM simultaneously. PTV > 38 mL may be considered as an indicator of the clinical stage of nasopharyngeal carcinoma. Level of evidence III.

Virus de Epstein-Barr: más que una mononucleosis infecciosa / Epstein-Barr virus: more than infectious mononucleosis

El virus de Epstein-Barr (VEB) fue el primer virus asociado a neoplasias en humanos. Infecta el 95 % de la población mundial, y aunque usualmente es asintomático, puede causar mononucleosis infecciosa y se relaciona con más de 200.000 casos de neoplasias al año. De igual forma, se asocia con esclerosis múltiple y otras enfermedades autoinmunes. A pesar de ser catalogado como un virus oncogénico, solo un pequeño porcentaje de los individuos infectados desarrollan neoplasias asociadas a VEB. Su persistencia involucra la capacidad de alternar entre una serie de programas de latencia, y de reactivarse cuando tiene la necesidad de colonizar nuevas células B de memoria, con el fin de sostener una infección de por vida y poder transmitirse a nuevos hospederos. En esta revisión se presentan las generalidades del VEB, además de su asociación con varios tipos de neoplasias, como son el carcinoma nasofaríngeo, el carcinoma gástrico, el linfoma de Hodgkin y el linfoma de Burkitt, y la esclerosis múltiple. Adicionalmente, se describen los mecanismos fisiopatológicos de las diferentes entidades, algunos de ellos no completamente dilucidados

Epstein-Barr virus (EBV) was the first virus associated with human cancer. It infects 95% of the world's population, and although it is usually asymptomatic, it causes infectious mononucleosis. It is related to more than 200,000 cases of cancer per year, and is also associated with multiple sclerosis and other autoimmune diseases. Despite being classified as an oncogenic virus, only a small percentage of infected individuals develop EBV-associated cancer. Its persistence involves the ability to alternate between a series of latency programs, and the ability to reactivate itself when it needs to colonize new memory B cells, in order to sustain a lifelong infection and be able to transmit to new hosts. In this review, the general characteristics of EBV are presented, in addition to its association with various types of cancers, such as nasopharyngeal carcinoma, gastric carcinoma, Hodgkin's lymphoma and Burkitt's lymphoma, and multiple sclerosis. Additionally, the pathophysiological mechanisms of the different entities are described, some of them not completely elucidated yet

Preclinical study of LMP1-RNAi-based anti-tumor therapy in EBV-positive nasopharyngeal carcinoma

RNA interference (RNAi) treatment has been proven to be an important therapeutic approach in cancer based on downregulation of target-oncogenes, but its clinical efficacy still needs further investigation. LMP1 is usually presented by Epstein-Barr virus (EBV)-positive tumor cells like EBV-associated nasopharyngeal carcinoma (NPC) and acts as an oncogene in tumorigenesis. However, the mechanism of LMP1 as a proto-oncogene in nasopharyngeal carcinoma is still unclear. Two sequence-specific shRNAs 1 and 2 were designed to target the different nucleotide loci of EBV latent antigen LMP1 gene and a series of in vivo and in vitro experiments were performed to investigate the therapeutic effect of sequence-specific shRNAs targeting LMP1 and its related molecular mechanisms in EBV-positive NPC. LMP1-shRNA2 generated a truncated LMP1 mRNA and protein, whereas LMP1-shRNA1 completely blocked LMP1 mRNA and protein expression. Both LMP1-shRNAs inhibited the proliferation and migration of NPC cells overexpressing LMP1 (NPC-LMP1) as well as the NPC-associated myeloid-derived suppressor cell (MDSC) expansion in vitro. However, LMP1-shRNA2 maintained the immunogenicity of NPC-LMP1 cells, which provoked MHC-class I-dependent T cell recognition. LMP1-shRNAs inhibited tumor growth in nude mice but did not reach statistical significance compared to control groups, while the LDH nanoparticle loaded LMP1-shRNAs and the antigen-specific T cells induced by NPC-LMP1 cells treated with LMP1-shRNA2 significantly reduced tumor growth in vivo. LMP1-RNAi-based anti-tumor therapy could be a new hope for the clinical efficacy of RNAi treatment of tumors like NPC.

Prognostic significance of circulating tumor cell measurement in the peripheral blood of patients with nasopharyngeal carcinoma

Abstract Objective: Nasopharyngeal Carcinoma (NPC) is lethal cancer. Typically, relapse and metastasis are the outcomes of most patients. Against this backdrop, this study aimed to investigate the correlation between Circulating Tumor Cell (CTC) profiles and clinicopathological features in patients with NPC. Patients and methods: A total of 119 blood samples from 79 patients were collected from patients with NPC during treatment. CanPatrol™ CTC enrichment and RNA In Situ Hybridization (RNA-ISH) were used to characterize CTCs, including epithelial, Mesenchymal (MCTCs), and epithelial/mesenchymal mixed types according to their surface markers. Results: The number of CTCs and MCTCs in the pre-treatment group was significantly higher than that in the post-treatment group (p < 0.05). The total number of CTCs and MCTCs cell numbers was significant correlation with Tumor-Node-Metastasis (TNM) staging (p < 0.05), Progression-Free Survival (PFS), and Overall Survival (OS). The PFS of patients with > 7 CTCs or > 5 MCTCs per 5 mL blood was significantly shorter PFS than those patients with ≤ 7 CTCs or ≤ 5 MCTCs (p < 0.05). Patients treated with targeted therapy combined with chemoradiother-apy had poorer PFS and OS rates than those treated with chemoradiotherapy (p < 0.05). The Kaplan-Meier survival analysis also demonstrated that patients with changes in CTC > 4 were strongly associated with PFS and OS rates (p < 0.05). Conclusion: CTC and MCTC number detection in patients with NPC is a useful biomarker for predicting patient progress. Patients with more than 7 CTCs or 5 MCTCs in 5 mL of blood had shorter PFS and OS rates. CTC and MCTC count changes were also significantly associated with the patient's therapy.

Advances on Clinical Application of Adaptive Radiotherapy in Treatment of Nasopharyngeal Carcinoma / 肿瘤防治研究

Radiotherapy is the first treatment choice for nasopharyngeal carcinoma. With the rapid development of image-guided radiotherapy, adaptive radiotherapy (ART) has become widely available in clinical practice. ART may be implemented to monitor the anatomical or physiological variations of patients using dynamic imaging technology and feedback information during the treatment course, including geometric changes (size, shape, and position) of tumor and normal organs. ART also allows the modification of the treatment plan to accurately deliver the maximize dose to target and minimize normal tissue explosion. This review discusses the physics basis of ART and its state-of-art application and potential pitfalls.

Research Progress on Correlation of Glucose Metabolism Mechanism with Invasion and Metastasis of Nasopharyngeal Carcinoma Cells / 肿瘤防治研究

Metastasis is the main cause of cancer-related death. Growing evidence has shown that changes in glucose metabolism in nasopharyngeal carcinoma cells affect the invasion and metastasis of nasopharyngeal carcinoma through many pathways. This review summarizes the molecular mechanism underlying abnormal glucose metabolism in nasopharyngeal carcinoma cells and analyzes its relationship with the invasion and metastasis of nasopharyngeal carcinoma, including aerobic glycolysis, aerobic oxidation, and pentose phosphate pathway. The aim is to provide novel approaches using the relationships among glucose metabolism, invasion, and metastasis in the targeted therapy of nasopharyngeal carcinoma.

Prognostic Value of Hematological Indicators in Children and Adolescents with Nasopharyngeal Carcinoma / 肿瘤防治研究

Objective To explore the prognostic value of pretreatment hematological indicators in children and adolescents with nasopharyngeal carcinoma. Methods We performed a retrospective analysis on the medical records of 79 children and adolescents (≤20 years old) with nasopharyngeal carcinoma. Before treatment, all patients underwent hematological tests, and patients received intensity-modulated radiotherapy alone or intensity-modulated radiotherapy combined with chemotherapy, targeted, and other comprehensive treatment modes. The follow-up endpoints were overall survival (OS) and progression-free survival (PFS). Results Age≤14 years, no concurrent chemotherapy, pretreatment hematological indicators (high NLR, high PLR, high LDH, and high LAR) were associated with poor OS and PFS in children and adolescents with nasopharyngeal carcinoma (all P < 0.05). No concurrent chemotherapy and high LAR before treatment were independent adverse prognostic factors for OS in children and adolescents with nasopharyngeal carcinoma. Conclusion High NLR, high PLR, high LDH, and high LAR of pretreatment hematological indicators are associated with poor OS and PFS. Meanwhile, high LAR before treatment is an independent adverse prognostic factor for OS in children and adolescents with nasopharyngeal carcinoma.

Effect of Shengmai Yin on Epithelial-Mesenchymal Transition of Nasopharyngeal Carcinoma Radioresistant Cells / 中国结合医学杂志

OBJECTIVE@#To investigate the mechanism by which Chinese medicine Shengmai Yin (SMY) reverses epithelial-mesenchymal transition (EMT) through lipocalin-2 (LCN2) in nasopharyngeal carcinoma (NPC) cells CNE-2R.@*METHODS@#Morphological changes in EMT in CNE-2R cells were observed under a microscope, and the expressions of EMT markers were detected using quantitative real-time PCR (RT-qPCR) and Western blot assays. Through the Gene Expression Omnibus dataset and text mining, LCN2 was found to be highly related to radiation resistance and EMT in NPC. The expressions of LCN2 and EMT markers following SMY treatment (50 and 100 µ g/mL) were detected by RT-qPCR and Western blot assays in vitro. Cell proliferation, migration, and invasion abilities were measured using colony formation, wound healing, and transwell invasion assays, respectively. The inhibitory effect of SMY in vivo was determined by observing a zebrafish xenograft model with a fluorescent label.@*RESULTS@#The CNE-2R cells showed EMT transition and high expression of LCN2, and the use of SMY (5, 10 and 20 µ g/mL) reduced the expression of LCN2 and reversed the EMT in the CNE-2R cells. Compared to that of the CNE-2R group, the proliferation, migration, and invasion abilities of SMY high-concentration group were weakened (P<0.05). Moreover, SMY mediated tumor growth and metastasis in a dose-dependent manner in a zebrafish xenograft model, which was consistent with the in vitro results.@*CONCLUSIONS@#SMY can reverse the EMT process of CNE-2R cells, which may be related to its inhibition of LCN2 expression. Therefore, LCN2 may be a potential diagnostic marker and therapeutic target in patients with NPC.

Dose reconstruction of volumetric modulated arc therapy for nasopharyngeal carcinoma based on log files and CBCT / 中华放射肿瘤学杂志

Objective:To reconstruct the dose of nasopharyngeal carcinoma and verify the results of the whole-process radiotherapy plan based on log files and cone beam CT (CBCT).Methods:A total of 15 patients with nasopharyngeal carcinoma who received volumetric modulated arc therapy (VMAT) with Halcyon accelerator in the Cancer Center of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from February to September 2022 were retrospectively selected. Log files and CBCT for all fractionated radiotherapy were recorded. The errors of monitor unit (MU), gantry angle, and multi-leaf collimator (MLC) leaf position per control point were analyzed. The adaptive CT (aCT) were generated according to CBCT and planned CT (pCT) using a commercial software Velocity TM, and the similarities among aCT, pCT and CBCT were analyzed. The original plan was modified from the log files and imported into the treatment planning system to calculate the delivered dose on the corresponding fractionated aCT to reconstruct the fractionated dose. And all the reconstructed doses were mapped back to pCT to obtain the cumulative dose. Theγpass ratios with criteria of 2 mm/2% and 2 mm/3% and the dose differences between the planned dose and the cumulative dose in the planning target volume (PTV) and organs at risk (OAR) were compared. Results:The root mean square (RMS) and the 95th percentile of the errors of MU, gantry angle and MLC leaf position errors were within an acceptable range. The aCT generated by Velocity TM had the anatomical structure of CBCT and the resolution, contrast, noise characteristics of pCT, which could be directly used for dose calculation. Compared with the planned dose, the changes of V 70 Gy of nasopharyngeal primary tumor (PTV nx), V 68 Gy of cervical glands (PTV nd) and V 60 Gy of planning target volume (PTV1) were -0.88%±1.91%, -2.99%±2.99% and -0.63%±0.93%, respectively, and V 40 Gy of parotid gland was increased to 2.65%±2.63%. Cumulative dose showed different degrees of PTV dose decrease ( P<0.05) and parotid dose was increased ( P<0.05). The γ pass ratio (2 mm/3%) between the cumulative dose and planned dose was 97.3%±2.7% and >95.0% in 86.7% of patients. Conclusions:Based on the log files and CBCT, the whole-process dose reconstruction of nasopharyngeal carcinoma patients can be carried out. According to the results of dose reconstruction, the radiotherapy effect of the target area and OAR can be quantitatively evaluated. In the case of high dose coverage and conformity of the original plan, the reconstruction results show that the cumulative dose coverage of the target area is decreased, whereas that of the parotid gland is increased.

The feasibility of individualized primary CTV for lateralized nasopharyngeal carcinoma / 中华放射肿瘤学杂志

Objective:To investigate the feasibility of individualized primary clinical target volume (CTV) delineation in intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC).Methods:Clinical data of 87 consecutive patients newly diagnosed with lateralized NPC in Jiangsu Cancer Hospital between October 2016 and February 2018 were retrospectively analyzed. Lateralized NPC is defined as tumor invasion not exceeding the contralateral wall. According to the tumor spread, the primary CTV was optimized as follows: CTV2 only covered the medial part of the contralateral pterygopalatine fossa, whereas the contralateral foramen oval was not included; on the level of parapharyngeal space, the contralateral side of CTV only covered the posterior lateral lymph nodes, whereas the contralateral internal jugular vein was not regularly covered. Failure patterns and 5-year survival [local control rate (LCR), progression-free survival (PFS) and overall survival (OS)] were evaluated by Kaplan-Meier method. Paired t-test and rank-sum test were used to analyze the dose variation in the optimized region and adverse reactions. Results:The median follow-up time was 59.5 months. The 5-year LCR, PFS, and OS were 98.9%, 86.5% and 92.1%, respectively. There was no local recurrence in the optimized area of CTV. Dosimetric comparison results showed that the doses of parotid gland, temporal lobe, cochlea and middle ear on the contralateral side were reduced by 13.45%, 9.14%, 38.83%, and 29.36%, respectively. Four cases (4.6%) developed grade 3 hearing loss, all on the ipsilateral side. The optimized scheme significantly alleviated the hearing loss on the contralateral side compared to that on the ipsilateral side ( P<0.001). Other grade 3 late adverse reactions included cranial nerve injury, subcutaneous fibrosis in the neck and visual impairment, with 1 case each. Conclusion:Individualized primary CTV for lateralized NPC is feasible and safe, with obvious dosimetric advantages and reduced adverse reaction rate, which is worthy of clinical promotion.

Correlation between monitor units and pass rate of plan dose verification in VMAT plan for different cancers / 中华放射肿瘤学杂志

Objective:To analyze the correlation between the monitor units and pass rate of plan dose verification in the volumetric intensity modulated arc therapy (VMAT) plan.Methods:VMAT plans for 20 patients with nasopharyngeal carcinoma (NPC) and 30 patients with cervical cancer who underwent radiotherapy at Liuzhou Workers' Hospital from January to October 2020 were retrospectively chosen. The Detector 1500 array and Octavius 4D phantom from German PTW company were used for dose measurement. The pass rates of dose verification of relevant plans were analyzed under the conditions of 3%/2 mm and 2%/2 mm. The correlation between the monitor units and pass rate of plan dose verification in VMAT plans was assessed by Pearson's bivariate correlation analysis.Results:Under the condition of 3%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.873 ( P<0.001), -0.800 ( P<0.001), -0.781 ( P<0.001), -0.493 ( P=0.006) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Under the condition of 2%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.842 ( P<0.001), -0.770 ( P<0.001), -0.748 ( P<0.001) and -0.531 ( P=0.003) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Conclusion:Significant negative correlation can be observed between the monitor units and plan dose verification pass rate in VMAT plan.

Expression profiling of cell-derived exosomal lncRNAs resistant to concurrent chemoradiotherapy in nasopharyngeal carcinoma / 中华放射肿瘤学杂志

Objective:To screen the key exosomal long non-coding RNAs (lncRNAs) molecules that cause nasopharyngeal carcinoma cells to develop chemoradiotherapy resistance.Methods:In vitro, a model of concurrent chemoradiotherapy for human nasopharyngeal carcinoma cells was constructed, and the continuous shock method of high-dose concurrent chemoradiotherapy was used to induce the establishment of chemoradiotherapy-resistant nasopharyngeal carcinoma cell lines, and its resistance formation was verified. Exosomes produced by chemoradiotherapy-resistant cell lines and respective mother cell lines for nasopharyngeal carcinoma were extracted and identified. Finally, biochip technology was used to detect the differential expression levels of exosomal lncRNAs. Results:After 10 repeated treatments of concurrent chemoradiotherapy, CNE-1 CRR and CNE-2 CRR were successfully obtained. Compared with the mother cell lines, CNE-1 CRR and CNE-2 CRR had a tendency to transform from epithelial to interstitial morphology, and the number of cell clones was higher, and the values of average lethal dose (D 0), quasi-threshould dose (D q), survival fraction after 2 Gy irradiation (SF 2) and cell survival rate were higher. Nasopharyngeal carcinoma cells were detected by PCR chip of exosomal lncRNAs. Compared with their respective mother cell lines, 18 lncRNAs in CNE-1 CRR exosomes were significantly up-regulated and 31 lncRNAs were significantly down-regulated, and 15 lncRNAs were significantly up-regulated and 38 lncRNAs were significantly down-regulated in CNE-2 CRR exosomes. CNE-1 CRR also had similar expression profiles to CNE-2 CRR. Conclusion:There are significantly up-regulated and down-regulated lncRNAs in the exosomes of CNE-1 CRR and CNE-2 CRR.

Dose volume histogram prediction method for organ at risk in VMAT planning of nasopharyngeal carcinoma based on equivalent uniform dose / 中华放射肿瘤学杂志

Objective:To evaluate the practicability of dose volume histogram (DVH) prediction model for organ at risk (OAR) of radiotherapy plan by minimizing the cost function based on equivalent uniform dose (EUD).Methods:A total of 66 nasopharyngeal carcinoma (NPC) patients received volume rotational intensity modulated arc therapy (VMAT) at Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences from 2020 to 2021 were retrospectively selected for this study. Among them, 50 patients were used to train the recurrent neutral network (RNN) model and the remaining 16 cases were used to test the model. DVH prediction model was constructed based on RNN. A three-dimensional equal-weighted 9-field conformal plan was designed for each patient. For each OAR, the DVHs of individual fields were acquired as the model input, and the DVH of VMAT plan was regarded as the expected output. The prediction error obtained by minimizing EUD-based cost function was employed to train the model. The prediction accuracy was characterized by the mean and standard deviation between predicted and true values. The plan was re-optimized for the test cases based on the DVH prediction results, and the consistency and variability of the EUD and DVH parameters of interest (e.g., maximum dose for serial organs such as the spinal cord) were compared between the re-optimized plan and the original plan of OAR by the Wilcoxon paired test and box line plots.Results:The neural network obtained by training the cost function based on EUD was able to obtain better DVH prediction results. The new plan guided by the predicted DVH was in good agreement with the original plan: in most cases, the D 98% in the planning target volume (PTV) was greater than 95% of the prescribed dose for both plans, and there was no significant difference in the maximum dose and EUD in the brainstem, spinal cord and lens (all P>0.05). Compared with the original plan, the average reduction of optic chiasm, optic nerves and eyes in the new plans reached more than 1.56 Gy for the maximum doses and more than 1.22 Gy for EUD, and the average increment of temporal lobes reached 0.60 Gy for the maximum dose and 0.30 Gy for EUD. Conclusion:The EUD-based loss function improves the accuracy of DVH prediction, ensuring appropriate dose targets for treatment plan optimization and better consistency in the plan quality.