MRI and CT of nasopharyngeal carcinoma

Synthetic MRI and diffusion-weighted imaging for differentiating nasopharyngeal lymphoma from nasopharyngeal carcinoma: combination with morphological features

OBJECTIVES

To investigate the feasibility of synthetic MRI (syMRI), diffusion-weighted imaging (DWI), and their combination with morphological features for differentiating nasopharyngeal lymphoma (NPL) from nasopharyngeal carcinoma (NPC).

METHODS

Sixty-nine patients with nasopharyngeal tumours (NPL, n = 22; NPC, n = 47) who underwent syMRI and DWI were retrospectively enrolled between October 2020 and May 2022. syMRI and DWI quantitative parameters (T1, T2, PD, ADC) and morphological features were obtained. Diagnostic performance was assessed by independent sample t-test, chi-square test, logistic regression analysis, receiver operating characteristic curve (ROC), and DeLong test.

RESULTS

NPL has significantly lower T2, PD, and ADC values compared to NPC (all P < .05), whereas no significant difference was found in T1 value between these two entities (P > .05). The morphological features of tumour type, skull-base involvement, Waldeyer ring involvement, and lymph nodes involvement region were significantly different between NPL and NPC (all P < .05). The syMRI (T2 + PD) model has better diagnostic efficacy, with AUC, sensitivity, specificity, and accuracy of 0.875, 77.27%, 89.36%, and 85.51%. Compared with syMRI model, syMRI + Morph (PD + Waldeyer ring involvement + lymph nodes involvement region), syMRI + DWI (T2 + PD + ADC), and syMRI + DWI + Morph (PD + ADC + skull-base involvement + Waldeyer ring involvement) models can further improve the diagnostic efficiency (all P < .05). Furthermore, syMRI + DWI + Morph model has excellent diagnostic performance, with AUC, sensitivity, specificity, and accuracy of 0.986, 95.47%, 97.87%, and 97.10%, respectively.

CONCLUSION

syMRI and DWI quantitative parameters were helpful in discriminating NPL from NPC. syMRI + DWI + Morph model has the excellent diagnostic efficiency in differentiating these two entities.

ADVANCES IN KNOWLEDGE

syMRI + DWI + morphological feature method can differentiate NPL from NPC with excellent diagnostic performance.

Time-Saving 3D MR Imaging Protocols with Millimeter and Submillimeter Isotropic Spatial Resolution for Face and Neck Imaging as Implemented at a Single-Site Major Referral Center

MR imaging has become the routine technique for staging nasopharyngeal carcinoma, evaluating perineural tumor spread, and detecting cartilage invasion in laryngeal carcinoma. However, these protocols traditionally require in the range of 25 to 35 minutes of acquisition time. 3D sequences offer the potential advantage of time savings through the acquisition of 1-mm or submillimeter resolution isotropic data followed by multiplanar reformats that require no further imaging time. We have iteratively optimized vendor product 3D T1-weighted MR imaging sequences for morphologic face and neck imaging, reducing the average acquisition time of our 3T protocols by 9 minutes 57 seconds (40.9%) and of our 1.5T protocols by 9 minutes 5 seconds (37.0%), while simultaneously maintaining or improving spatial resolution. This clinical report describes our experience optimizing and implementing commercially available 3D T1-weighted MR imaging pulse sequence protocols for clinical face and neck MR imaging examinations using illustrative cases. We provide protocol details to allow others to replicate our implementations, and we report challenges we faced along with our solutions.

Diagnosis of skull-base invasion by nasopharyngeal tumors on CT with a deep-learning approach

PURPOSE

To develop a convolutional neural network (CNN) model to diagnose skull-base invasion by nasopharyngeal malignancies in CT images and evaluate the model's diagnostic performance.

MATERIALS AND METHODS

We divided 100 malignant nasopharyngeal tumor lesions into a training (n = 70) and a test (n = 30) dataset. Two head/neck radiologists reviewed CT and MRI images and determined the positive/negative skull-base invasion status of each case (training dataset: 29 invasion-positive and 41 invasion-negative; test dataset: 13 invasion-positive and 17 invasion-negative). Preprocessing involved extracting continuous slices of the nasopharynx and clivus. The preprocessed training dataset was used for transfer learning with Residual Neural Networks 50 to create a diagnostic CNN model, which was then tested on the preprocessed test dataset to determine the invasion status and model performance. Original CT images from the test dataset were reviewed by a radiologist with extensive head/neck imaging experience (senior reader: SR) and another less-experienced radiologist (junior reader: JR). Gradient-weighted class activation maps (Grad-CAMs) were created to visualize the explainability of the invasion status classification.

RESULTS

The CNN model's diagnostic accuracy was 0.973, significantly higher than those of the two radiologists (SR: 0.838; JR: 0.595). Receiver operating characteristic curve analysis gave an area under the curve of 0.953 for the CNN model (versus 0.832 and 0.617 for SR and JR; both p < 0.05). The Grad-CAMs suggested that the invasion-negative cases were present predominantly in bone marrow, while the invasion-positive cases exhibited osteosclerosis and nasopharyngeal masses.

CONCLUSIONS

This CNN technique would be useful for CT-based diagnosis of skull-base invasion by nasopharyngeal malignancies.

Enhancing Nasopharyngeal Carcinoma Survival Prediction: Integrating Pre- and Post-Treatment MRI Radiomics with Clinical Data

Recurrences are frequent in nasopharyngeal carcinoma (NPC) despite high remission rates with treatment, leading to considerable morbidity. This study aimed to develop a prediction model for NPC survival by harnessing both pre- and post-treatment magnetic resonance imaging (MRI) radiomics in conjunction with clinical data, focusing on 3-year progression-free survival (PFS) as the primary outcome. Our comprehensive approach involved retrospective clinical and MRI data collection of 276 eligible NPC patients from three independent hospitals (180 in the training cohort, 46 in the validation cohort, and 50 in the external cohort) who underwent MRI scans twice, once within 2 months prior to treatment and once within 10 months after treatment. From the contrast-enhanced T1-weighted images before and after treatment, 3404 radiomics features were extracted. These features were not only derived from the primary lesion but also from the adjacent lymph nodes surrounding the tumor. We conducted appropriate feature selection pipelines, followed by Cox proportional hazards models for survival analysis. Model evaluation was performed using receiver operating characteristic (ROC) analysis, the Kaplan-Meier method, and nomogram construction. Our study unveiled several crucial predictors of NPC survival, notably highlighting the synergistic combination of pre- and post-treatment data in both clinical and radiomics assessments. Our prediction model demonstrated robust performance, with an accuracy of AUCs of 0.66 (95% CI: 0.536-0.779) in the training cohort, 0.717 (95% CI: 0.536-0.883) in the testing cohort, and 0.827 (95% CI: 0.684-0.948) in validation cohort in prognosticating patient outcomes. Our study presented a novel and effective prediction model for NPC survival, leveraging both pre- and post-treatment clinical data in conjunction with MRI features. Its constructed nomogram provides potentially significant implications for NPC research, offering clinicians a valuable tool for individualized treatment planning and patient counseling.

Magnetic resonance imaging based on radiomics for differentiating T1-category nasopharyngeal carcinoma from nasopharyngeal lymphoid hyperplasia: a multicenter study

PURPOSE

To investigate the role of magnetic resonance imaging (MRI) based on radiomics using T2-weighted imaging fat suppression (T2WI-FS) and contrast enhanced T1-weighted imaging (CE-T1WI) sequences in differentiating T1-category nasopharyngeal carcinoma (NPC) from nasopharyngeal lymphoid hyperplasia (NPH).

MATERIALS AND METHODS

This study enrolled 614 patients (training dataset: n = 390, internal validation dataset: n = 98, and external validation dataset: n = 126) of T1-category NPC and NPH. Three feature selection methods were used, including analysis of variance, recursive feature elimination, and relief. The logistic regression classifier was performed to construct the radiomics signatures of T2WI-FS, CE-T1WI, and T2WI-FS + CE-T1WI to differentiate T1-category NPC from NPH. The performance of the optimal radiomics signature (T2WI-FS + CE-T1WI) was compared with those of three radiologists in the internal and external validation datasets.

RESULTS

Twelve, 15, and 15 radiomics features were selected from T2WI-FS, CE-T1WI, and T2WI-FS + CE-T1WI to develop the three radiomics signatures, respectively. The area under the curve (AUC) values for radiomics signatures of T2WI-FS + CE-T1WI and CE-T1WI were significantly higher than that of T2WI-FS (AUCs = 0.940, 0.935, and 0.905, respectively) for distinguishing T1-category NPC and NPH in the training dataset (Ps all < 0.05). In the internal and external validation datasets, the radiomics signatures based on T2WI-FS + CE-T1WI and CE-T1WI outperformed T2WI-FS with no significant difference (AUCs = 0.938, 0.925, and 0.874 for internal validation dataset and 0.932, 0.918, and 0.882 for external validation dataset; Ps > 0.05). The radiomics signature of T2WI-FS + CE-T1WI significantly performed better than three radiologists in the internal and external validation datasets.

CONCLUSION

The MRI-based radiomics signature is meaningful in differentiating T1-category NPC from NPH and potentially helps clinicians select suitable therapy strategies.

Multimodality radiomics for tumor prognosis in nasopharyngeal carcinoma

BACKGROUND

The prognosis of nasopharyngeal carcinoma (NPC) is challenging due to late-stage identification and frequently undetectable Epstein-Barr virus (EBV) DNA. Incorporating radiomic features, which quantify tumor characteristics from imaging, may enhance prognosis assessment.

PURPOSE

To investigate the predictive power of radiomic features on overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) in NPC.

MATERIALS AND METHODS

A retrospective analysis of 183 NPC patients treated with chemoradiotherapy from 2010 to 2019 was conducted. All patients were followed for at least three years. The pretreatment CT images with contrast medium, MR images (T1W and T2W), as well as gross tumor volume (GTV) contours, were used to extract radiomic features using PyRadiomics v.2.0. Robust and efficient radiomic features were chosen using the intraclass correlation test and univariate Cox proportional hazard regression analysis. They were then combined with clinical data including age, gender, tumor stage, and EBV DNA level for prognostic evaluation using Cox proportional hazard regression models with recursive feature elimination (RFE) and were optimized using 20 repetitions of a five-fold cross-validation scheme.

RESULTS

Integrating radiomics with clinical data significantly enhanced the predictive power, yielding a C-index of 0.788 ± 0.066 to 0.848 ± 0.079 for the combined model versus 0.745 ± 0.082 to 0.766 ± 0.083 for clinical data alone (p<0.05). Multimodality radiomics combined with clinical data offered the highest performance. Despite the absence of EBV DNA, radiomics integration significantly improved survival predictions (C-index ranging from 0.770 ± 0.070 to 0.831 ± 0.083 in combined model versus 0.727 ± 0.084 to 0.734 ± 0.088 in clinical model, p<0.05).

CONCLUSIONS

The combination of multimodality radiomic features from CT and MR images could offer superior predictive performance for OS, PFS, and DMFS compared to relying on conventional clinical data alone.

Radiological features of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: case series and systematic review

PURPOSE

To comprehensively summarize the clinical data and CT/MRI characteristics of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA).

METHODS

Twenty-seven lesions from 25 study articles identified through a systematic review and three lesions from our institution associated with TL-LGNPPA were evaluated.

RESULTS

The mean age of the patients at diagnosis was 35.7 years, and the male-to-female ratio was nearly half. The chief complaint was nasal obstruction, followed by epistaxis. All patients underwent excision. None of the patients had neck nodes or distant metastases. All patients survived with no locoregional/distant recurrence during 3-93 months of follow-up. All lesions were located at the posterior edge of the nasal septum, attached to the nasopharyngeal parietal wall, and showed no laterality. The mean lesion diameter was 1.7 cm. The margins of lesions were well-defined and lobulated, followed by well-defined smooth margins. None of lesions were associated with parapharyngeal space or skull base destruction. All lesions were iso- and low-density on non-contrast CT. Adjacent skull base sclerosis was detected in 63.6% of lesions. High signal intensity on T2-weighted imaging and mostly iso-signal intensity on T1-weighted imaging compared to muscle tissue. Most lesions were heterogeneous and exhibited moderate contrast enhancement. Relatively large lesions (≥1.4 cm) tended to be more lobulated than smooth margins compared to relatively small lesions (<1.4 cm) (p = 0.016).

CONCLUSION

We summarized the clinical and radiological features of TL-LGNPPA to facilitate accurate diagnosis and appropriate management.

Risk stratification of LA-NPC during chemoradiotherapy based on clinical classification and TVRR

PURPOSE

To investigate the correlation between tumor volume reduction rate (TVRR) and prognosis in patients with diverse clinical types of nasopharyngeal carcinoma (NPC) undergoing chemoradiotherapy, thereby aptly categorizing risks and directing the personalized treatment of NPC.

MATERIALS AND METHODS

A total of 605 NPC patients with varying clinical types were enrolled in this study and subsequently segregated into six subgroups based on their clinical types and TVRR. To accentuate the efficacy of grouping, Groups 1-6 underwent clustered analysis of hazard atio (HR) values pertaining to progression-free survival (PFS), forming three risk clusters denoted as low, intermediate, and high. The log-rank test was employed to discern differences, and R 4.1.1 was utilized for cluster analysis.

RESULTS

According to survival rates, we classified the first (G2 and G4), second (G1 and G6), and third (G3 and G5) risk clusters as low-, intermediate-, and high-risk, respectively. When comparing risk stratification with the 8th edition of the TNM staging system, our classification exhibited superior predictive prognostic performance. Subgroup analysis of treatments for each risk cluster revealed that the PFS in the neoadjuvant chemotherapy (NACT) + concurrent chemoradiotherapy (CCRT) group surpassed that of the CCRT group significantly (p < 0.05).

CONCLUSION

The reliance on clinical types and TVRR facilitates risk stratification of NPC during chemoradiotherapy, providing a foundation for physicians to tailor therapeutic strategies. Moreover, the risk cluster delineated for NPC patients during the mid-term of chemoradiotherapy stands as an independent prognostic factor for progression-free survival (PFS), overall survival (OS), distantmetastasis-free survival (DMFS), and local recurrence-free (LRRFS) posttreatment. Additionally, individuals in the high-risk cluster are recommended to undergo adjuvant chemotherapy after CCRT.

CT-based peritumoral radiomics nomogram on prediction of response and survival to induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma

PURPOSE

The study aims to harness the value of radiomics models combining intratumoral and peritumoral features obtained from pretreatment CT to predict treatment response as well as the survival of LA-NPC(locoregionally advanced nasopharyngeal carcinoma) patients receiving multiple types of induction chemotherapies, including immunotherapy and targeted therapy.

METHODS

276 LA-NPC patients (221 in the training and 55 in the testing cohort) were retrospectively enrolled. Various statistical analyses and feature selection techniques were applied to identify the most relevant radiomics features. Multiple machine learning models were trained and compared to build signatures for the intratumoral and each peritumoral region, along with a clinical signature. The performance of each model was evaluated using different metrics. Subsequently, a nomogram model was constructed by combining the best-performing radiomics and clinical models.

RESULTS

In the testing cohort, the nomogram model exhibited an AUC of 0.816, outperforming the other models. The nomogram model's calibration curve showed good agreement between predicted and observed outcomes in both the training and testing sets. When predicting survival, the model's concordance index (C-index) was 0.888 in the training cohort and 0.899 in the testing cohort, indicating its robust predictive ability.

CONCLUSION

In conclusion, the combined nomogram model, incorporating radiomics and clinical features, outperformed other models in predicting treatment response and survival outcomes for LA-NPC patients receiving induction chemotherapies. These findings highlight the potential clinical utility of the model, suggesting its value in individualized treatment planning and decision-making.

Towards system genetics analysis of head and neck squamous cell carcinoma using the mouse model, cellular platform, and clinical human data

Head and neck squamous cell cancer (HNSCC) is a leading global malignancy. Every year, More than 830 000 people are diagnosed with HNSCC globally, with more than 430 000 fatalities. HNSCC is a deadly diverse malignancy with many tumor locations and biological characteristics. It originates from the squamous epithelium of the oral cavity, oropharynx, nasopharynx, larynx, and hypopharynx. The most frequently impacted regions are the tongue and larynx. Previous investigations have demonstrated the critical role of host genetic susceptibility in the progression of HNSCC. Despite the advances in our knowledge, the improved survival rate of HNSCC patients over the last 40 years has been limited. Failure to identify the molecular origins of development of HNSCC and the genetic basis of the disease and its biological heterogeneity impedes the development of new therapeutic methods. These results indicate a need to identify more genetic factors underlying this complex disease, which can be better used in early detection and prevention strategies. The lack of reliable animal models to investigate the underlying molecular processes is one of the most significant barriers to understanding HNSCC tumors. In this report, we explore and discuss potential research prospects utilizing the Collaborative Cross mouse model and crossing it to mice carrying single or double knockout genes (e.g. Smad4 and P53 genes) to identify genetic factors affecting the development of this complex disease using genome-wide association studies, epigenetics, microRNA, long noncoding RNA, lncRNA, histone modifications, methylation, phosphorylation, and proteomics.

Development and implementation of optimized endogenous contrast sequences for delineation in adaptive radiotherapy on a 1.5T MR-linear-accelerator: a prospective R-IDEAL stage 0-2a quantitative/qualitative evaluation of in vivo site-specific quality-assurance using a 3D T2 fat-suppressed platform for head and neck cancer

Purpose

To improve segmentation accuracy in head and neck cancer (HNC) radiotherapy treatment planning for the 1.5T hybrid magnetic resonance imaging/linear accelerator (MR-Linac), three-dimensional (3D), T2-weighted, fat-suppressed magnetic resonance imaging sequences were developed and optimized.

Approach

After initial testing, spectral attenuated inversion recovery (SPAIR) was chosen as the fat suppression technique. Five candidate SPAIR sequences and a nonsuppressed, T2-weighted sequence were acquired for five HNC patients using a 1.5T MR-Linac. MR physicists identified persistent artifacts in two of the SPAIR sequences, so the remaining three SPAIR sequences were further analyzed. The gross primary tumor volume, metastatic lymph nodes, parotid glands, and pterygoid muscles were delineated using five segmentors. A robust image quality analysis platform was developed to objectively score the SPAIR sequences on the basis of qualitative and quantitative metrics.

Results

Sequences were analyzed for the signal-to-noise ratio and the contrast-to-noise ratio and compared with fat and muscle, conspicuity, pairwise distance metrics, and segmentor assessments. In this analysis, the nonsuppressed sequence was inferior to each of the SPAIR sequences for the primary tumor, lymph nodes, and parotid glands, but it was superior for the pterygoid muscles. The SPAIR sequence that received the highest combined score among the analysis categories was recommended to Unity MR-Linac users for HNC radiotherapy treatment planning.

Conclusions

Our study led to two developments: an optimized, 3D, T2-weighted, fat-suppressed sequence that can be disseminated to Unity MR-Linac users and a robust image quality analysis pathway that can be used to objectively score SPAIR sequences and can be customized and generalized to any image quality optimization protocol. Improved segmentation accuracy with the proposed SPAIR sequence will potentially lead to improved treatment outcomes and reduced toxicity for patients by maximizing the target coverage and minimizing the radiation exposure of organs at risk.

Imaging Recommendations for Diagnosis, Staging, and Management of Nasopharynx Carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial carcinoma originating from lining of the nasopharyngeal mucosa usually at the fossa of Rosenmuller (pharyngeal recess). An early detection on endoscopy can be rewarding, however, often difficult as the tumor at the pharyngeal recess is hidden from the endoscopic view. Magnetic resonance imaging and positron emission tomography–computed tomography form the backbone of detection and spread of the carcinoma into local and distant regions. These modalities help further characterize the precise locoregional infiltration and lymph nodal involvement which aids in the planning of the surgery/chemoradiotherapy. They also help in the follow-up evaluation and further management strategies. Many research and treatment groups namely American Joint Committee on Cancer, National Comprehensive Cancer Network, American Society of Clinical Oncology, American College of Radiology, Radiological Society of North America, European Society of Radiology (iGuide), Indian Radiological & Imaging Association/Indian College of Radiology and Imaging, National Cancer Grid, etc. have devised guidelines for the optimal assessment and treatment of NPC. The present document aims at providing a comprehensive review of the clinicoradiological recommendations for the diagnosis and management of NPC based on these guidelines as well as personalized experience of the contributors.

Impairment mechanism of nasal mucosa after radiotherapy for nasopharyngeal carcinoma

The nasal mucosa, which performs the crucial functions of filtering, humidifying and temperature regulation, is one of the most vulnerable areas of nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). Following RT, NPC patients experience a series of pathological changes in the nasal mucosa, ultimately leading to physiological dysfunction of the nasal epithelium. This article systematically reviews the clinical and pathological manifestations of RT-related nasal damage in NPC patients and summarizes the potential mechanism of damage to the human nasal epithelium by RT. Finally, we outline the current mechanistic models of nasal epithelial alterations after RT in NPC patients and provide additional information to extend the in-depth study on the impairment mechanisms of the nasal mucosa resulting from RT. We also describe the relationship between structural and functional alterations in the nasal mucosa after RT to help mitigate and treat this damage and provide insights informing future clinical and fundamental investigations.

Deep Convolutional Neural Network for Nasopharyngeal Carcinoma Discrimination on MRI by Comparison of Hierarchical and Simple Layered Convolutional Neural Networks

Nasopharyngeal carcinoma (NPC) is one of the most common head and neck cancers. Early diagnosis plays a critical role in the treatment of NPC. To aid diagnosis, deep learning methods can provide interpretable clues for identifying NPC from magnetic resonance images (MRI). To identify the optimal models, we compared the discrimination performance of hierarchical and simple layered convolutional neural networks (CNN). Retrospectively, we collected the MRI images of patients and manually built the tailored NPC image dataset. We examined the performance of the representative CNN models including shallow CNN, ResNet50, ResNet101, and EfficientNet-B7. By fine-tuning, shallow CNN, ResNet50, ResNet101, and EfficientNet-B7 achieved the precision of 72.2%, 94.4%, 92.6%, and 88.4%, displaying the superiority of deep hierarchical neural networks. Among the examined models, ResNet50 with pre-trained weights demonstrated the best classification performance over other types of CNN with accuracy, precision, and an F1-score of 0.93, 0.94, and 0.93, respectively. The fine-tuned ResNet50 achieved the highest prediction performance and can be used as a potential tool for aiding the diagnosis of NPC tumors.

Multi-Modal Optical Imaging and Combined Phototherapy of Nasopharyngeal Carcinoma Based on a Nanoplatform

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck with a high incidence rate worldwide, especially in southern China. Phototheranostics in combination with nanoparticles is an integrated strategy for enabling simultaneous diagnosis, real-time monitoring, and administration of precision therapy for nasopharyngeal carcinoma (NPC). It has shown great potential in the field of cancer diagnosis and treatment owing to its unique noninvasive advantages. Many Chinese and international research teams have applied nano-targeted drugs to optical diagnosis and treatment technology to conduct multimodal imaging and collaborative treatment of NPC, which has become a hot research topic. In this review, we aimed to introduce the recent developments in phototheranostics of NPC based on a nanoplatform. This study aimed to elaborate on the applications of nanoplatform-based optical imaging strategies and treatment modalities, including fluorescence imaging, photoacoustic imaging, Raman spectroscopy imaging, photodynamic therapy, and photothermal therapy. This study is expected to provide a scientific basis for further research and development of NPC diagnosis and treatment.

A practical overview of CT and MRI features of developmental, inflammatory, and neoplastic lesions of the sphenoid body and clivus

The sphenoid bone is an unpaired bone that contributes to the formation of the skull base. Despite the enormous progress in transnasal endoscopic visualisation, imaging techniques remain the cornerstones to characterise any pathological condition arising in this area. In the present review, we offer a bird’s-eye view of the developmental, inflammatory, and neoplastic alterations affecting the sphenoid body and clivus, with the aim to propose a practical diagnostic aid for radiologists based on clinico-epidemiological, computed tomography, and magnetic resonance imaging features.

Prognostic value of cervical nodal necrosis on staging imaging of nasopharyngeal carcinoma in era of intensity-modulated radiotherapy: a systematic review and meta-analysis

Purposes

To systematically review and perform meta-analysis to evaluate the prognostic value of cervical nodal necrosis (CNN) on the staging computed tomography/magnetic resonance imaging (MRI) of nasopharyngeal carcinoma (NPC) in era of intensity-modulated radiotherapy.

Methods

Literature search through PubMed, EMBASE, and Cochrane Library was conducted. The hazard ratios (HRs) with 95% confidence intervals (CIs) of CNN for distant metastasis-free survival (DMFS), disease free survival (DFS) and overall survival (OS) were extracted from the eligible studies and meta-analysis was performed to evaluate the pooled HRs with 95%CI.

Results

Nine studies, which investigated the prognostic values of 6 CNN patterns on MRI were included. Six/9 studies were eligible for meta-analysis, which investigated the CNN presence/absence in any nodal group among 4359 patients. The pooled unadjusted HRs showed that the CNN presence predicted poor DMFS (HR =1.89, 95%CI =1.72-2.08), DFS (HR =1.57, 95%CI =1.08-2.26), and OS (HR =1.87, 95%CI =1.69-2.06). The pooled adjusted HRs also showed the consistent results for DMFS (HR =1.34, 95%CI =1.17-1.54), DFS (HR =1.30, 95%CI =1.08-1.56), and OS (HR =1.61, 95%CI =1.27-2.04). Results shown in the other studies analysing different CNN patterns indicated the high grade of CNN predicted poor outcome, but meta-analysis was unable to perform because of the heterogeneity of the analysed CNN patterns.

Conclusion

The CNN observed on the staging MRI is a negative factor for NPC outcome, suggesting that the inclusion of CNN is important in the future survival analysis. However, whether and how should CNN be included in the staging system warrant further evaluation.

Diagnostic Value of MRI Combined with CXCR4 Expression Level in Lymph Node Metastasis Head and Neck Squamous Cell Carcinoma

Objective

To explore the diagnostic value of magnetic resonance imaging (MRI) combined with CXCR4 expression levels in lymph node metastasis of the head and neck squamous cell carcinoma (HNSCC).

Methods

289 patients with HNSCC were divided into lymph node metastasis group (LNM group, n = 171) and non-LNM group (n = 118) according to the pathological examination results. MRI was used to scan the patient's lesions and cervical lymph nodes, and ADC was measured by MRI diffusion weighting imaging. The expression of CXCR4 in tumor tissues was detected by qRT-PCR. Logistic regression was used to analyze the risk factors of HNSCC lymph node metastasis. ROC curve was used to analyze the diagnostic effects of MRI, CXCR4, and MRI combined with CXCR4 on HNSCC lymph node metastasis.

Results

Compared with the non-LNM group, patients in the LNM group had a lower degree of pathological differentiation, and the positive rate of TNM staging and vascular invasion was higher. The signal intensity of T1WI and T2WI were low intensity and high intensity, respectively, and the ADC value was significantly reduced. At the same time, the expression level of CXCR4 in the tumor tissues of the LNM group was also significantly increased. In addition, compared with MRI and CXCR4 used alone, MRI combined with CXCR4 has a higher predictive value.

Conclusion

MRI has a good effect in demonstrating lymph node metastasis. CXCR4 is significantly upregulated in lymph node metastasis tumor tissue. The combination of the two can be used for clinical diagnosis of HNSCC lymph node metastasis.

Radiomics for Diagnosis and Radiotherapy of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor of the head and neck. The primary clinical manifestations are nasal congestion, blood-stained nasal discharge, headache, and hearing loss. It occurs frequently in Southeast Asia, North Africa, and especially in southern China. Radiotherapy is the main treatment, and currently, imaging examinations used for the diagnosis, treatment, and prognosis of NPC include computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET)-CT, and PET-MRI. These methods play an important role in target delineation, radiotherapy planning design, dose evaluation, and outcome prediction. However, the anatomical and metabolic information obtained at the macro level of images may not meet the increasing accuracy required for radiotherapy. As a technology used for mining deep image information, radiomics can provide further information for the diagnosis and treatment of NPC and promote individualized precision radiotherapy in the future. This paper reviews the application of radiomics in the diagnosis and treatment of nasopharyngeal carcinoma.

Artificial Intelligence and Deep Learning of Head and Neck Cancer

Artificial intelligence (AI) algorithms, particularly deep learning, have developed to the point that they can be applied in image recognition tasks. The use of AI in medical imaging can guide radiologists to more accurate image interpretation and diagnosis in radiology. The software will provide data that we cannot extract from the images. The rapid development in computational capabilities supports the wide applications of AI in a range of cancers. Among those are its widespread applications in head and neck cancer.

MR Imaging of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma is endemic in parts of the world such as southern China and Southeast Asia. It is predominantly an undifferentiated carcinoma with a strong genetic basis and a close association with the Epstein-Barr virus. The ability of MR imaging to depict the boundaries of the primary tumor and its relationship with the complex structures of the skull base makes it the technique of choice for imaging of this disease in the head and neck. This article describes the MR imaging findings pertinent to staging and management and a new role of MR imaging in early cancer detection, in addition to a brief discussion of differential diagnoses.

Investigation of Eye Lens Dose Estimate based on AAPM Report 293 in Head Computed Tomography

Background:

Estimation of eye lens dose is important in head computed tomography (CT) examination since the eye lens is a sensitive organ to ionizing radiation.

Objective:

The purpose of this study is to compare estimations of eye lens dose in head CT examinations using local size-specific dose estimate (SSDE) based on size-conversion factors of the American Association of Physicists in Medicine (AAPM) Report No. 293 with those based on size-conversion factors of the AAPM Report No. 220.

Material and Methods:

This experimental study is conducted on a group of patients who had undergone nasopharyngeal CT examination. Due to the longitudinal (z-axis) dose fluctuation, the average global SSDE and average local SSDE (i.e. particular slices where the eyes are located) were investigated. All estimates were compared to the measurement results using thermo-luminescent dosimeters (TLDs). The estimated and measured doses were implemented for 14 patients undergoing nasopharyngeal CT examination.

Results:

It was found that the percentage differences of the volume CT dose index (CTDI_vol), average global SSDE based on AAPM No. 220 (SSDE_o,g), average local SSDE based on AAPM No. 220 (SSDE_o,l), average global SSDE based on AAPM No. 293 (SSDE_n,g) and average local SSDE based on AAPM No. 293 (SSDE_n,l) against the measured TLD doses were 22.5, 21.7, 15.0, 9.3, and 2.1%, respectively. All comparisons between dose estimates and TLD measurements gave p-values less than 0.001, except for SSDE_n,l (p-value = 0.566).

Conclusion:

SSDE based on AAPM Report No. 293 can be used to accurately estimate eye lens radiation doses by performing the calculations on a number of specific slices containing the eyes.

Radiologic Evaluation of the Head and Neck Cancer Patient

CT, PET, ultrasound, and MRI examinations all have roles in the staging and surveillance of cancers in the head and neck. Contrast-enhanced CT is generally the primary examination because of availability, cost, reproducibility, and good overall quality regardless of where performed. PET, ultrasound, and MRI have more specific and nuanced applications. Good interdisciplinary interactions with radiologist consultation can streamline the examination process and reduce the examination burden on patients by limiting the number and maximizing the quality of the examinations and image-guided interventions performed.

Optimal management of oligometastatic nasopharyngeal carcinoma

PURPOSE

Oligometastatic nasopharyngeal carcinoma (NPC) is a distinctive subset of metastatic NPC. Imaging examinations and biomarkers can screen out NPC patients with limited number of sites showing metastasis. Past studies have demonstrated the survival advantages of oligometastatic NPC over multiple metastatic NPC. The treatment strategies of de-novo oligometastatic NPC differ owing to the heterogeneity of this disease. This study aims to systematically review the characteristics and treatments of oligometastatic NPC.

METHODS

PubMed, EMBASE, the Web of Science, and the Cochrane Library were used to search for publications with an emphasis on oligometastatic NPC.

RESULTS

We have presented the current advances on the management of oligometastatic NPC, including the definition, diagnosis, biomarkers, classification, prognosis, subtype, especially systematic therapy, locoregional radiotherapy to the primary tumor, and treatments of the metastatic lesions.

CONCLUSIONS

More well-designed prospective clinical trials that are exclusive for oligometastatic NPC are warranted to determine the best treatment paradigm.

Computer-aided diagnosis and regional segmentation of nasopharyngeal carcinoma based on multi-modality medical images

PURPOSE

Nasopharyngeal carcinoma (NPC) is a category of tumors with high incidence in head-and-neck (H&N) body region, and the diagnosis and treatment planning are usually conducted by radiologists manually, which is tedious, time-consuming and unrepeatable. In this paper, we integrated different stages of this process and proposed a computer-aided framework to realize automatic detection, tumor region and sub-region segmentation, and visualization of NPC, which are usually investigated separately in literatures.

METHODS

Multi-modality images are utilized in the framework. Firstly, NPC is detected by a convolutional neural network (CNN) on computed tomography (CT) scans. Then, NPC area is segmented from magnetic resonance imaging (MRI) images by using a multi-modality MRI fusion network. Thirdly, NPC sub-regions with different metabolic activities are divided on CT images of the same patient via an adaptive threshold algorithm. Finally, 3D surface model of NPC is generated for observing its shape, size, and location in the head region. The proposed method is compared with other algorithms by evaluation on the volumes and shapes of detected NPCs.

RESULTS

Experiments are conducted on CT images of 130 NPC patients and 102 subjects without NPC and MRI images of 149 NPC patients, among which 52 subjects are overlapped with both CT and MRI images. The reference for evaluation is generated by three experienced radiologists. The results demonstrated that our utilized models outperform other strategies with detection accuracy 0.882 and Dice similarity coefficient 0.719 for NPC segmentation. Sub-region division and the 3D visualized models show great acceptability in clinical usage.

CONCLUSION

The remarkable performance indicated the potential of our framework in alleviating workload of radiologist. Furthermore, the combined usage of multi-modality images is able to generate reliable segmentations of NPC area and sub-regions, which provide evidence to judge the heterogeneity among patients and guide the dose painting for radiation therapy.

Effect of Induction Chemotherapy in Nasopharyngeal Carcinoma: An Updated Meta-Analysis

Background

Previous meta-analysis had evaluated the effect of induction chemotherapy in nasopharyngeal carcinoma. But two trials with opposite findings were not included and the long-term result of another trial significantly differed from the preliminary report. This updated meta-analysis was thus warranted.

Methods

Literature search was conducted to identify randomized controlled trials focusing on the additional efficacy of induction chemotherapy in nasopharyngeal carcinoma. Trial-level pooled analysis of hazard ratio (HR) for progression free survival and overall survival and risk ratio (RR) for locoregional control rate and distant control rate were performed.

Results

Twelve trials were eligible. The addition of induction chemotherapy significantly prolonged both progression free survival (HR=0.68, 95% confidence interval [CI] 0.60–0.76, p<0.001) and overall survival (HR=0.67, 95% CI 0.54–0.80, p<0.001), with 5-year absolute benefit of 11.31% and 8.95%, respectively. Locoregional (RR=0.80, 95% CI 0.70–0.92, p=0.002) and distant control (RR=0.70, 95% CI 0.62–0.80) rates were significantly improved as well. The incidence of grade 3–4 adverse events during the concurrent chemoradiotherapy was higher in leukopenia (p=0.028), thrombocytopenia (p<0.001), and fatigue (p=0.038) in the induction chemotherapy group.

Conclusions

This meta-analysis supported that induction chemotherapy could benefit patients with nasopharyngeal carcinoma in progression free survival, overall survival, locoregional, and distant control rate.

Diagnosis of Skull Base Osteomyelitis

Skull base osteomyelitis (SBO) is an infection of the temporal, sphenoid, or occipital bone that can be a challenge to diagnose because of its nonspecific symptoms, long clinical course, and radiologic findings that mimic those of other entities. The authors review this unusual infection on the basis of six proven cases. The diagnosis of SBO should be made according to four points: a high index of clinical suspicion, radiologic evidence of infection, repeated biopsies that are negative for malignancy, and positive results of microbiologic tests. SBO typically manifests clinically in patients with diabetes and recurrent otitis externa; the infection usually extends inferiorly to the compact bone of the infratemporal fossa, affecting the lower cranial nerve foramina. Several image-based techniques should be used to diagnose SBO. CT is the best option for evaluating bone erosion and demineralization, MRI can help delineate the anatomic location and extent of disease, and nuclear imaging is useful for confirming bone infection with high sensitivity. However, the standard diagnostic procedure for SBO is for patients to undergo repeated biopsies to rule out malignancy, with histopathologic signs of infection and detection of microorganisms in the biopsied bone or soft tissue indicating SBO. The ability to diagnose SBO can be increased by identifying patients at risk, recognizing the most important causes and routes of infection, describing the main radiologic findings, and always considering the differential diagnosis. ^©RSNA, 2021.

Nasopharyngeal Carcinoma: A Retrospective Study on Imaging Patterns at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

Background

Nasopharyngeal carcinoma is one of the rare forms of cancer globally which has a high incidence in select geographic and ethnic populations. The current study aims to assess the clinical presentation, imaging patterns and radiology-pathology correlation of nasopharyngeal carcinoma.

Methods

This is a retrospective analysis of 80 patients with newly diagnosed nasopharyngeal carcinoma who came to Tikur Anbessa Specialized Hospital from January 2016 to August 2017. The patients' history, physical examination, abdominopelvic ultrasound, chest x-ray, computed tomography scan and biopsy reports were reviewed from their medical record. Patients who had previous history of treatment for nasopharyngeal carcinoma, those who did not have biopsy and those without imaging were excluded from the study.

Results

This study showed that 61(81.3%) patients had neck swelling as the initial clinical symptom, and the average time of presentation of symptoms was 6(IQR 8) months. On the other hand, 56(70.0%) were diagnosed with non-keratinizing undifferentiated nasopharyngeal carcinoma while 15(3.8%) had keratinizing nasopharyngeal carcinoma. Sixty-nine (86.3%) patients had nodal metastasis; 22.5% had invasion into the paranasal sinuses; 47.5% had T4 with T1, T2 and T3 being 18.8%, 17.5% and 7.5% stage respectively at time of diagnosis. Ninety percent of the cases had a diagnosis of nasopharyngeal carcinoma on imaging, but 10% were given alternative diagnosis.

Conclusion

Non-keratinizing undifferentiated type was the commonest histologic subtype in this study which is also recognized as the commonest one in endemic countries. A significant number did not have a specific histologic WHO type on pathology report which could in turn affect the management and assessment of risk factors.

Comparison of different images in gross target volume delineating on VX2 nasopharyngeal transplantation tumor models

Background: To determine the optimum conditions for diagnosis of nasopharyngeal carcinoma, we established VX2 rabbit model to delineate gross target volume (GTV) in different imaging methods. Methods: The orthotopic nasopharyngeal carcinoma (NPC) was established in sixteen New Zealand rabbits. After 7-days inoculation, the rabbits were examined by CT scanning and then sacrificed for pathological examination. To achieve the best delineation, different GTVs of CT, MRI, ¹⁸F-FDG PET/CT, and ¹⁸F-FLT PET/CT images were correlated with pathological GTV (GTVp). Results: We found 45% and 60% of the maximum standardized uptake value (SUV_max) as the optimal SUV threshold for the target volume of NPC in ¹⁸F-FDG PET/CT and ¹⁸F-FLT PET/CT images, respectively (GTV_FDG45% and GTV_FLT60%). Moreover, the GTV_MRI and GTV_CT were significantly higher than the GTVp (P ≤ 0.05), while the GTV_FDG45% and especially GTV_FLT60% were similar to the GTVp (R = 0.892 and R = 0.902, respectively; P ≤ 0.001). Conclusions: Notably, the results suggested that ¹⁸F-FLT PET/CT could reflect the tumor boundaries more accurately than ¹⁸F-FDG PET/CT, MRI and CT, which makes ¹⁸F-FLT PET-CT more advantageous for the clinical delineation of the target volume in NPC.

[Malignant tumors of the skull base]

Malignant skull base tumors consist of a heterogeneous group of malignancies that can be divided into primary and secondary (metastatic) skull base tumors. In addition, according their anatomical location, they can be further divided into tumors of the anterior, middle, or posterior cranial fossa. Although malignant skull base tumors do not rigorously respect anatomical borders, their anatomical occurrence can potentially be helpful for possible differential diagnosis. This article is focused on the most common malignant tumors of the skull base and their imaging and clinical presentations.

Preliminary clinical results for PET/MR compared with PET/CT in patients with nasopharyngeal carcinoma

The present study aimed to assess the performance of positron emission tomography-magnetic resonance imaging (PET/MR) for the visualization and characterization of lesions. In addition, the present study investigated whether the apparent diffusion coefficient (ADC) and intravoxel incoherent motion parameters exhibited any significant correlation with standardized uptake values (SUV) in patients with nasopharyngeal carcinoma (NPC). A total of 35 patients with NPC underwent whole body PET-computed tomography (CT) and head and neck MR imaging (MRI) scans using the PET/CT-MRI system. Image quality, lesion conspicuity and the diagnostic confidence of PET/CT, T1 weighted (T1w) PET/MR and T2w PET/MR imaging were assessed. The true diffusion coefficient (D), the pseudo-diffusion coefficient or diffusion within the microcirculation (D*), and the perfusion fraction or the contribution of water moving in the capillaries (f), and ADC, were calculated. The correlation between the ADC, D*, D and f values and the SUV were analyzed using Pearson's correlation analysis. Similar image quality was obtained using PET/CT, T1w PET/MR and T2w PET/MR imaging. However, the T1w PET/MR and T2w PET/MR imaging were more effective than PET/CT in analyzing the lesion conspicuity of the primary tumors and lymph nodes. In addition, T2w PET/MR imaging was more efficient than T1w PET/MR imaging in analyzing primary tumors and lymph nodes. Pearson's correlation analysis showed no significant correlation between the SUV and ADC, and D*, D and f values in NPC. The present results suggested that the application of PET/MR is feasible and could serve as a reliable alternative to PET/CT, while SUV and ADC, D*, D and f values were identified as independent biomarkers in NPC.

Management of locally recurrent nasopharyngeal carcinoma

As a consequence of the current excellent loco-regional control rates attained using the generally accepted treatment paradigms involving intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC), only 10-20% of patients will suffer from local and/or nodal recurrence after primary treatment. Early detection of recurrence is important as localized recurrent disease is still potentially salvageable, but this treatment often incurs a high risk of major toxicities. Due to the possibility of radio-resistance of tumors which persist or recur despite adequate prior irradiation and the limited tolerance of adjacent normal tissues to sustain further additional treatment, the management of local failures remains one of the greatest challenges in this disease. Both surgical approaches for radical resection and specialized re-irradiation modalities have been explored. Unfortunately, available data are based on retrospective studies, and the majority of them are based on a small number of patients or relatively short follow-up. In this article, we will review the different salvage treatment options and associated prognostic factors for each of them. We will also propose a treatment algorithm based on the latest available evidence and discuss the future directions of treatment for locally recurrent NPC.

MiR-597 Targeting 14-3-3σ Enhances Cellular Invasion and EMT in Nasopharyngeal Carcinoma Cells

BACKGROUND

Alterations in microRNAs (miRNAs) are related to the occurrence of nasopharyngeal carcinoma (NPC) and play an important role in the molecular mechanism of NPC. Our previous studies show low expression of 14-3-3σ (SFN) is related to the metastasis and differentiation of NPC, but the underlying molecular mechanisms remain unclear.

METHODS

Through bioinformatics analysis, we find miR-597 is the preferred target miRNA of 14-3-3σ. The expression level of 14-3-3σ in NPC cell lines was detected by Western blotting. The expression of miR-597 in NPC cell lines was detected by qRT-PCR. We transfected miR-597 mimic, miR-597 inhibitor and 14-3-3σ siRNA into 6-10B cells and then verified the expression of 14-3-3σ and EMT related proteins, including E-cadherin, N-cadherin and Vimentin by western blotting. The changes of migration and invasion ability of NPC cell lines before and after transfected were determined by wound healing assay and Transwell assay.

RESULTS

miR-597 expression was upregulated in NPC cell lines and repaired in related NPC cell lines, which exhibit a potent tumor-forming effect. After inhibiting the miR-597 expression, its effect on NPC cell line was obviously decreased. Moreover, 14-3-3σ acts as a tumor suppressor gene and its expression in NPC cell lines is negatively correlated with miR-597. Here 14-3-3σ was identified as a downstream target gene of miR-597, and its downregulation by miR-597 drives epithelial-mesenchymal transition (EMT) and promotes the migration and invasion of NPC.

CONCLUSION

Based on these findings, our study will provide theoretical and experimental evidences for molecular targeted therapy of NPC.

CT Evaluation of Squamous Cell Carcinoma of the Nasopharynx

Squamous cell carcinoma is the most common type of neoplasia which affects the mucosa of the upper aero-digestive tract. Nasopharyngeal carcinoma is a unique disease with clinical behavior, epidemiology, and histopathology that is different from that of squamous cell carcinomas of the head and neck. For malignant tumors such as SCC, rapid growth may occur even though there are no previous clinical signs. Enlargement of a cervical lymph node, as the first presenting feature of neoplasia, is not uncommon, particularly with certain “silent” site, such as nasopharynx. Therefore, clinical examination must be complemented by radiological examination for the assessment of size, thickness and depth of the tumor, the degree of bone tissue invasion, and to detect the presence of enlarged lymph nodes. A total of 16 cases of patients were studied using CT, all diagnosed and operated with squamous cancer with localization in the nasopharynx.

Bone Subtraction Iodine Imaging Using Area Detector CT for Evaluation of Skull Base Invasion by Nasopharyngeal Carcinoma

BACKGROUND AND PURPOSE

Conventional CT has generally lower detectability of bone marrow invasion than MR imaging due to lower tissue contrast. The purpose of this study was to compare the diagnostic performance of conventional CT alone or in combination with bone subtraction iodine imaging using area detector CT for the evaluation of skull base invasion in patients with nasopharyngeal carcinoma.

MATERIALS AND METHODS

Forty-four consecutive patients who underwent contrast-enhanced CT using 320-row area detector CT and contrast-enhanced MR imaging for nasopharyngeal carcinoma staging between April 2012 and November 2017 were enrolled in this retrospective study. Bone subtraction iodine images were generated by subtracting pre- and postcontrast volume scans using a high-resolution deformable registration algorithm. Two blinded observers evaluated skull base invasion at multiple sites (sphenoid body, clivus, bilateral base of the pterygoid process, and petrous bone) using conventional CT images alone or in combination with bone subtraction iodine images. Examination of MR and CT images by an experienced neuroradiologist was the reference standard for evaluating sensitivity, specificity, and area under the receiver operating characteristic curve.

RESULTS

Twenty-six patients (59%) showed skull base invasion at 84 sites on the reference standard. Conventional CT plus bone subtraction iodine images showed higher sensitivity (92.9% versus 78.6%, P = .02) and specificity (95.6% versus 86.1%, P = .01) than conventional CT images alone for evaluating skull base invasion. The area under the receiver operating characteristic curve for conventional CT plus bone subtraction iodine (0.98) was significantly larger (P < .001) than the area under the receiver operating characteristic curve for conventional CT alone (0.90).

CONCLUSIONS

Conventional CT plus bone subtraction iodine performs more closely to the accuracy of combining CT and MR imaging compared with conventional CT alone.

Probe-based confocal laser endomicroscopy for diagnosis of nasopharyngeal carcinoma in vivo

OBJECTIVES/HYPOTHESIS

Probe-based confocal laser endomicroscopy (pCLE) is a novel technique allowing real-time evaluation of the histological features of tissues in vivo at the cellular level. This study aimed to evaluate the feasibility of using pCLE in the diagnosis of nasopharyngeal carcinoma (NPC).

STUDY DESIGN

Feasibility study.

METHODS

In this study, the pCLE images of the lesions, as well as the surrounding or contralateral normal mucosa of the lesions, were acquired in vivo from each patient after intravenous injecting of 2.5 mL fluorescein. Biopsy specimens were collected at the imaged sites followed by a histopathological diagnosis by the pathologists, which was used as the gold standard. The pCLE images were compared to histopathological diagnosis of visualized sites by using sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV).

RESULTS

Diagnoses based on pCLE images correlated well with the gold standard diagnoses based on tissue histology. The overall sensitivity, specificity, PPV, and NPV for diagnosis of carcinoma versus nondysplasia were 93.8% (67.7%-99.7%), 90.5% (68.2%-98.3%), 88.2% (62.3%-97.9%), and 95.0% (73.1%-99.7%), respectively, and the four indices for pCLE diagnosis of dysplasia versus nondysplasia were 60.0% (17.0%-92.7%), 80.9% (57.4%-93.7%), 42.9% (11.8%-79.8%), and 89.5% (65.5%-98.2%), respectively. The overall sensitivity for diagnosis of carcinoma versus dysplasia was 93.8% (67.7%-99.7%), specificity was 40% (7.3%-83.0%), PPV was 83.3% (57.7%-95.6%), and the NPV was 66.7% (12.5%-98.2%).

CONCLUSIONS

CLE is a suitable and valid method for otolaryngologists to diagnose of NPC in vivo.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:897-902, 2019.

Predicting chemoradiotherapy response of nasopharyngeal carcinoma using texture features based on intravoxel incoherent motion diffusion-weighted imaging

The aim of the study was to investigative the utility of gray-level co-occurrence matrix (GLCM) texture analysis based on intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) for predicting the early response to chemoradiotherapy for nasopharyngeal carcinoma (NPC).Baseline IVIM-DWI was performed on 81 patients with NPC receiving chemoradiotherapy in a prospective nested case-control study. The patients were categorized into the residue (n = 11) and nonresidue (n = 70) groups, according to whether there was local residual lesion or not at the end of chemoradiotherapy. The pretreatment tumor volume and the values of IVIM-DWI parameters (apparent diffusion coefficient [ADC], D, D, and f) and GLCM features based on IVIM-DWI were compared between the 2 groups. Receiver operating characteristic (ROC) curves in univariate and multivariate logistic regression analysis were generated to determine significant indicator of treatment response.The nonresidue group had lower tumor volume, ADC, D, CorrelatADC, CorrelatD, InvDfMomADC, InvDfMomD and InvDfMomD values, together with higher ContrastD, Contrastf, SumAvergADC, SumAvergD, and SumAvergD values, than the residue group (all P < .05). Based on ROC curve in univariate analysis, the area under the curve (AUC) values for individual GLCM features in the prediction of the treatment response ranged from 0.635 to 0.879, with sensitivities from 54.55% to 100.00% and specificities from 52.86% to 85.71%. Multivariate logistic regression analysis demonstrated D (P = .026), InvDfMomADC (P = .033) and SumAvergD (P = .015) as the independent predictors for identifying NPC without residue, with an AUC value of 0.977, a sensitivity of 90.91% and a specificity of 95.71%.Pretreatment GLCM features based on IVIM-DWI, especially on the diffusion-related maps, may have the potential to predict the early response to chemoradiotherapy for NPC.

Osteoradionecrosis of the Skull Base in Nasopharyngeal Carcinoma: Incidence and Risk Factors

PURPOSE

Nasopharyngeal carcinoma (NPC) is a type of malignancy with a high prevalence in southern China and Southeast Asia. The primary treatment modality is radiation therapy (RT). Osteoradionecrosis (ORN) of the skull base remains one of the most serious complications after RT, affecting survival time and quality of life. Thus far, skull base ORN has been seldom reported and can be difficult to distinguish and easy to misdiagnose. In this retrospective study, we report the incidence of skull base ORN and analyze its associated factors in an attempt to decrease the occurrence of ORN.

METHODS AND MATERIALS

From January 2001 to December 2012, a total of 1348 patients who received diagnoses of NPC received 1 course of RT. Complete medical records were reviewed, and the patients were examined by magnetic resonance imaging and nasopharyngeal endoscopy during follow-up after primary treatment. Patients with other tumors of the head and neck, a history of RT, failure to complete RT, and those lost to follow-up were excluded. Treatment was delivered with external beam RT using standard linear accelerators.

RESULTS

A total of 1348 patients with NPC were enrolled in this study after 1 course of RT; among these patients, 14 received diagnoses of skull base ORN. The incidence of skull base ORN was 1.04%. The average latency interval from the completion of RT to the diagnosis of skull base ORN was 45.57 months. Skull base ORN after 1 course of RT was associated with the T stage; total radiation dose to the nasopharynx, including the skull base in the radiation field; and anemia.

CONCLUSIONS

The occurrence of skull base ORN was associated with primary tumors with advanced T stages, high doses of nasopharynx RT, and radiation fields that included the skull base. These factors may be used as predictors for the incidence of skull base ORN.

Paranasal Sinus Invasion in Nasopharyngeal Carcinoma after Intensity-Modulated Radiotherapy

PURPOSE

The aim of this study is to evaluate the prognostic significance of paranasal sinus invasion for nasopharyngeal carcinoma (NPC) and its suitable position in the T classification.

Materials and Methods

The magnetic resonance imaging (MRI) scans of 695 patients with previously untreated, biopsy-proven, non-metastatic NPC that was treated with intensity-modulated radiotherapy (IMRT) were reviewed retrospectively.

RESULTS

The incidence of paranasal sinus invasion was 39.4% (274 of 695 patients). Multivariate analysis showed that paranasal sinus invasion was an independent negative prognostic factor for local failure-free survival (LFFS) (p < 0.05). According to the eighth American Joint Committee on Cancer (AJCC) staging system, 275 patients were classified as T3 classification. Of these, 78 patients (28.4%) developed paranasal sinus invasion (T3b) and 197 (71.6%) didn't (T3a). The estimated 5-year LFFS and overall survival (OS) rates for the patients with T3b and T3a classification were 88.6% versus 95.0% (p=0.047), and 84.5% versus 93.3% (p=0.183), respectively. The estimated 5-year LFFS and OS rates for the patientswith T4 classificationwere 89.5% and 83.2%,whichwere similarwith the outcomes of patients with T3b classification.

CONCLUSION

MRI-determined paranasal sinus invasion is an independent prognostic factor of NPC treated by IMRT. Paranasal sinus invasion is recommended to classify as T4 classification in the 8th AJCC staging system for NPC.