Magnetic resonance imaging staging of nasopharyngeal carcinoma in the head and neck

Deep Learning for Nasopharyngeal Carcinoma Segmentation in Magnetic Resonance Imaging: A Systematic Review and Meta-Analysis

Nasopharyngeal carcinoma is a significant health challenge that is particularly prevalent in Southeast Asia and North Africa. MRI is the preferred diagnostic tool for NPC due to its superior soft tissue contrast. The accurate segmentation of NPC in MRI is crucial for effective treatment planning and prognosis. We conducted a search across PubMed, Embase, and Web of Science from inception up to 20 March 2024, adhering to the PRISMA 2020 guidelines. Eligibility criteria focused on studies utilizing DL for NPC segmentation in adults via MRI. Data extraction and meta-analysis were conducted to evaluate the performance of DL models, primarily measured by Dice scores. We assessed methodological quality using the CLAIM and QUADAS-2 tools, and statistical analysis was performed using random effects models. The analysis incorporated 17 studies, demonstrating a pooled Dice score of 78% for DL models (95% confidence interval: 74% to 83%), indicating a moderate to high segmentation accuracy by DL models. Significant heterogeneity and publication bias were observed among the included studies. Our findings reveal that DL models, particularly convolutional neural networks, offer moderately accurate NPC segmentation in MRI. This advancement holds the potential for enhancing NPC management, necessitating further research toward integration into clinical practice.

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.

Content Analysis of YouTube Videos on Radiographic Anatomy on Dental Panoramic Images

The radiographic anatomy on dental panoramic images is essential knowledge for proper diagnosis and treatment planning purposes. No prior study has examined the content of YouTube videos with regard to radiographic anatomy on panoramic radiography. The objective of this study was to provide a content analysis on these videos. The initial search string was: (panoramic anatomy). An additional search was performed with the search string: (OPG landmarks). By screening the resultant videos and their related videos (recommended by YouTube as a list on the right of the screen), a total of 62 videos were screened. Videos were excluded if they were irrelevant (e.g., focusing on radiographic errors without covering the anatomy), elaborating mainly with drawings without showing the landmarks on panoramic images, duplicate videos, and non-English speaking. Finally, 38 videos were included and analyzed. Most of them showed clear panoramic images and had clear tracing or delineation of the anatomical landmarks. On average, each video described 26 landmarks, including 12.3 from the midfacial region, 8.2 from the mandible, and 5.2 from soft tissue/air space/others. The videos were of good quality in general, with some frequent shortcomings being lack of visual aid with skull and schematic diagrams, and lack of discussion on clinical relevance. The maxillary sinus was the structure mostly involved in wrong information, particularly the wrong delineation of its posterior wall.

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.

Imaging of Oligometastatic Disease

Simple Summary

The imaging of oligometastatic disease (OMD) is challenging as it requires precise loco-regional staging and whole-body assessment. The combination of imaging modalities is often required. The more accurate imaging tool will be selected according to tumor type, the timing with regard to measurement and treatment, metastatic location, and the patient’s individual risk for metastasis. The most commonly used modalities are contrast-enhanced computed tomography (CT), magnetic resonance imaging and metabolic and receptor-specific imaging, particularly, ¹⁸F-fluorodesoxyglucose positron emission tomography/CT, used alone or in combination.

Abstract

Oligometastatic disease (OMD) is an emerging state of disease with limited metastatic tumor burden. It should be distinguished from polymetastatic disease due the potential curative therapeutic options of OMD. Imaging plays a pivotal role in the diagnosis and follow-up of patients with OMD. The imaging tools needed in the case of OMD will differ according to different parameters, which include primary tumor type, timing between measurement and treatment, potential metastatic location and the patient’s individual risk for metastasis. In this article, OMD is defined and the use of different imaging modalities in several oncologic situations are described in order to better understand OMD and its specific implication for radiologists.

Predictive Value of a Combined Model Based on Pre-Treatment and Mid-Treatment MRI-Radiomics for Disease Progression or Death in Locally Advanced Nasopharyngeal Carcinoma

Purpose

A combined model was established based on the MRI-radiomics of pre- and mid-treatment to assess the risk of disease progression or death in locally advanced nasopharyngeal carcinoma.

Materials and Methods

A total of 243 patients were analyzed. We extracted 10,400 radiomics features from the primary nasopharyngeal tumors and largest metastatic lymph nodes on the axial contrast-enhanced T1 weighted and T2 weighted in pre- and mid-treatment MRI, respectively. We used the SMOTE algorithm, center and scale and box-cox, Pearson correlation coefficient, and LASSO regression to construct the pre- and mid-treatment MRI-radiomics prediction model, respectively, and the risk scores named P score and M score were calculated. Finally, univariate and multivariate analyses were used for P score, M score, and clinical data to build the combined model and grouped the patients into two risk levels, namely, high and low.

Result

A combined model of pre- and mid-treatment MRI-radiomics successfully categorized patients into high- and low-risk groups. The log-rank test showed that the high- and low-risk groups had good prognostic performance in PFS (P<0.0001, HR: 19.71, 95% CI: 12.77–30.41), which was better than TNM stage (P=0.004, HR:1.913, 95% CI:1.250–2.926), and also had an excellent predictive effect in LRFS, DMFS, and OS.

Conclusion

Risk grouping of LA-NPC using a combined model of pre- and mid-treatment MRI-radiomics can better predict disease progression or death.

Comparison of new magnetic resonance imaging grading system with conventional endoscopy for the early detection of nasopharyngeal carcinoma

BACKGROUND

Although stratifying individuals with respect to nasopharyngeal carcinoma (NPC) risk with Epstein-Barr virus-based markers is possible, the performance of diagnostic methods for detecting lesions among screen-positive individuals is poorly understood.

METHODS

The authors prospectively evaluated 882 participants aged 30 to 70 years who were enrolled between October 2014 and November 2018 in an ongoing, population-based NPC screening program and had an elevated NPC risk. Participants were offered endoscopy and magnetic resonance imaging (MRI), and lesions were identified either by biopsy at a follow-up endoscopy or further contact and linkage to the local cancer registry through December 31, 2019. The diagnostic performance characteristics of endoscopy and MRI for NPC detection were investigated.

RESULTS

Eighteen of 28 identified NPC cases were detected by both methods, 1 was detected by endoscopy alone, and 9 were detected by MRI alone. MRI had significantly higher sensitivity than endoscopy for NPC detection overall (96.4% vs 67.9%; P_difference = .021) and for early-stage NPC (95.2% vs 57.1%; P = .021). The sensitivity of endoscopy was suggestively lower among participants who had previously been screened in comparison with those undergoing an initial screening (50.0% vs 81.2%; P = .11). The authors observed a higher overall referral rate by MRI versus endoscopy (17.3% vs 9.1%; P < .001). Cases missed by endoscopy had early-stage disease and were more commonly observed for tumors originating from the pharyngeal recess.

CONCLUSIONS

MRI was more sensitive than endoscopy for NPC detection in the context of population screening but required the referral of a higher proportion of screen-positive individuals. The sensitivity of endoscopy was particularly low for individuals who had previously been screened.

Differences in Radiomics Signatures Between Patients with Early and Advanced T-Stage Nasopharyngeal Carcinoma Facilitate Prognostication

BACKGROUND

Accurately predicting the risk of death, recurrence, and metastasis of patients with nasopharyngeal carcinoma (NPC) is potentially important for personalized diagnosis and treatment. Survival outcomes of patients vary greatly in distinct stages of NPC. Prognostic models of stratified patients may aid in prognostication.

PURPOSE

To explore the prognostic performance of MRI-based radiomics signatures in stratified patients with NPC.

STUDY TYPE

Retrospective.

POPULATION

Seven hundred and seventy-eight patients with NPC (T1-2 stage: 298, T3-4 stage: 480; training cohort: 525, validation cohort: 253).

FIELD STRENGTH/SEQUENCE

Fast-spin echo (FSE) axial T1-weighted images, FSE axial T2-weighted images, contrast-enhanced FSE axial T1-weighted images at 1.5 T or 3.0 T.

ASSESSMENT

Radiomics signatures, clinical nomograms, and radiomics nomograms combining the radiomic score (Radscore) and clinical factors for predicting progression-free survival (PFS) were constructed on T1-2 stage patient cohort (A), T3-4 stage patient cohort (B), and the entire dataset (C).

STATISTICAL TESTS

Least absolute shrinkage and selection operator (LASSO) method was applied for radiomics modeling. Harrell's concordance indices (C-index) were employed to evaluate the predictive power of each model.

RESULTS

Among 4,410 MRI-extracted features, we selected 16, 16, and 14 radiomics features most relevant to PFS for Models A, B, and C, respectively. Only 0, 1, and 4 features were found overlapped between models A/B, A/C, and B/C, respectively. Radiomics signatures constructed on T1-2 stage and T3-4 stage patients yielded C-indices of 0.820 (95% confidence interval [CI]: 0.763-0.877) and 0.726 (0.687-0.765), respectively, which were larger than those on the entire validation cohort (0.675 [0.637-0.713]). Radiomics nomograms combining Radscore and clinical factors achieved significantly better performance than clinical nomograms (P < 0.05 for all).

DATA CONCLUSION

The selected radiomics features and prognostic performance of radiomics signatures differed per the type of NPC patients incorporated into the models. Radiomics models based on pre-stratified tumor stages had better prognostic performance than those on unstratified dataset.

LEVEL OF EVIDENCE

4 Technical Efficacy Stage: 5.

Combing MRI Perfusion and 18F-FDG PET/CT Metabolic Biomarkers Helps Predict Survival in Advanced Nasopharyngeal Carcinoma: A Prospective Multimodal Imaging Study

We prospectively investigated the prognostic value of imaging parameters for nasopharyngeal carcinoma (NPC) using dynamic contrast-enhanced MRI (DCE-MRI), diffusion-weighted imaging (DWI), and 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography (¹⁸F-FDG PET)/computed tomography (CT). Patients with stage III-IVb NPC underwent F-FDG PET/CT, DCE-MRI, and DWI before treatment. Kaplan-Meier and Cox-regression analyses were used to assess associations of PET and MRI imaging biomarkers with overall survival (OS) and recurrence-free survival (RFS). We used independent prognosticators to establish prognostic models; model performance was examined using Harrell's concordance index (c-index). Sixty-one patients were available for analysis, as 13 patients died and 20 experienced recurrence. Total lesion glycolysis (TLG) (p = 0.002) from PET/CT and the initial area under the curve (iAUC) (p = 0.036) from DCE-MRI were identified as independent prognosticators of OS; Epstein-Barr virus (EBV) DNA (p = 0.027), the extracellular volume fraction (V_e) (p = 0.027) from DCE-MRI, and TLG/iAUC (p = 0.025) were significant predictors of RFS. The c-indices of the prognostic models incorporating TLG + iAUC in predicting OS and incorporating EBV DNA + V_e + TLG/iAUC in predicting RFS were 0.79 and 0.76, respectively. These were significantly higher than the corresponding c-indices of the TNM staging system (p = 0.047 and 0.025, respectively); they were also higher than those of models with only MRI or PET biomarkers. In conclusion, the combination of pretreatment DCE-MRI and ¹⁸F-FDG PET/CT imaging biomarkers helps survival prediction in advanced NPC. Integrating MRI perfusion with PET metabolism and plasma EBV information may aid clinicians in planning the optimal personalized management strategy.

Convolutional neural network in nasopharyngeal carcinoma: how good is automatic delineation for primary tumor on a non-contrast-enhanced fat-suppressed T2-weighted MRI?

PURPOSE

Convolutional neural networks (CNNs) show potential for delineating cancers on contrast-enhanced MRI (ce-MRI) but there are clinical scenarios in which administration of contrast is not desirable. We investigated performance of the CNN for delineating primary nasopharyngeal carcinoma (NPC) on non-contrast-enhanced images and compared the performance to that on ce-MRI.

MATERIALS AND METHODS

We retrospectively analyzed primary NPC in 195 patients using a well-established CNN, U-Net, for tumor delineation on the non-contrast-enhanced fat-suppressed (fs)-T2W, ce-T1W and ce-fs-T1W images. The CNN-derived delineations were compared to manual delineations to obtain Dice similarity coefficient (DSC) and average surface distance (ASD). The DSC and ASD on fs-T2W were compared to those on ce-MRI. Primary tumor volumes (PTVs) of CNN-derived delineations were compared to that of manual delineations.

RESULTS

The CNN for NPC delineation on fs-T2W images showed similar DSC (0.71 ± 0.09) and ASD (0.21 ± 0.48 cm) to those on ce-T1W images (0.71 ± 0.09 and 0.17 ± 0.19 cm, respectively) (p > 0.05), and lower DSC but similar ASD to ce-fs-T1W images (0.73 ± 0.09, p < 0.001; and 0.17 ± 0.20 cm, p > 0.05). The CNN overestimated PTVs on all sequences (p < 0.001).

CONCLUSION

The CNN showed promise for NPC delineation on fs-T2W images in cases where it is desirable to avoid contrast agent injection. The CNN overestimated PTVs on all sequences.

Exploring MRI based radiomics analysis of intratumoral spatial heterogeneity in locally advanced nasopharyngeal carcinoma treated with intensity modulated radiotherapy

Background

We hypothesized that spatial heterogeneity exists between recurrent and non-recurrent regions within a tumor. The aim of this study was to determine if there is a difference between radiomics features derived from recurrent versus non recurrent regions within the tumor based on pre-treatment MRI.

Methods

A total of 14 T4NxM0 NPC patients with histologically proven “in field” recurrence in the post nasal space following curative intent IMRT were included in this study. Pretreatment MRI were co-registered with MRI at the time of recurrence for the delineation of gross tumor volume at diagnosis(GTV) and at recurrence(GTVr). A total of 7 histogram features and 40 texture features were computed from the recurrent(GTVr) and non-recurrent region(GTV-GTVr). Paired t-tests and Wilcoxon signed-rank tests were carried out on the 47 quantified radiomics features.

Results

A total of 7 features were significantly different between recurrent and non-recurrent regions. Other than the variance from intensity-based histogram, the remaining six significant features were either from the gray-level size zone matrix (GLSZM) or the neighbourhood gray-tone difference matrix (NGTDM).

Conclusions

The radiomic features extracted from pre-treatment MRI can potentially reflect the difference between recurrent and non-recurrent regions within a tumor and has a potential role in pre-treatment identification of intra-tumoral radio-resistance for selective dose escalation.

Paranasal sinus invasion suggested T4 classification of patients of nasopharyngeal carcinoma: A two-center retrospective investigation

BACKGROUND

To investigate the prognostic significance of paranasal sinus invasion in nasopharyngeal carcinoma (NPC) patients.

METHODS

Patients with NPC after intensity-modulated radiotherapy from 2010 to 2013 were identified (n = 1225). Clinical features and magnetic resonance images were analyzed.

RESULTS

Paranasal sinus invasion was identified in 182/1225 patients (14.9%). Multivariate analysis showed that paranasal sinus invasion was an independent factor for overall survival, progression-free survival, distant metastasis-free survival, and local recurrence-free survival (P < .05 for all). T3 NPC patients with paranasal sinus invasion had a poorer prognosis than those without (P < .05), and there was no significant survival difference compared with T4 patients, regardless of involvement of inner structures (P > .05 for all). Upgrading NPC with paranasal sinus invasion to T4 disease achieved better predictive abilities.

CONCLUSIONS

Paranasal sinus invasion is an independent prognostic factor for NPC. It may be appropriate to upgrade the T classification.

Risk of ocular complications following radiation therapy in patients with nasopharyngeal carcinoma

OBJECTIVE

To examine the risk of ocular complications following radiotherapy in patients with nasopharyngeal carcinoma (NPC).

METHODS

We adopted 1:1 propensity score matching and identified an NPC cohort (n = 736) and a comparison cohort (n = 736) that comprised non-NPC head and neck cancer patients who received radiotherapy in the National Health Insurance Research Database from 1997 to 2010. The follow-up period was terminated upon developing ocular complications (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM]360-379) or on December 31, 2010.

RESULTS

After adjusting for the confounding factors of the study, the NPC cohort had a higher adjusted hazard ratio (HR) for developing ocular complications than the comparison cohort (adjusted HR = 2.786, 95% confidence interval [CI] = 1.805-4.112, P < 0.001). The NPC cohort was associated with a significantly higher risk of developing ocular complications compared with the comparison cohort within 12 and after 24 months of follow-up (P < 0.05). The most common associated ocular complications were optic nerve disorder and retinopathy.

CONCLUSIONS

Patients with NPC might be at higher risk of developing ocular complications after radiotherapy than non-NPC head and neck cancer patients in Taiwan. Either further investigation or routine assessments by ophthalmological physician is recommended.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:1270-1277, 2020.

Comparison between the seventh and eighth edition of the AJCC/UICC staging system for nasopharyngeal cancer integrated with pretreatment plasma Epstein–Barr virus DNA level in a non-Chinese population: secondary analysis from a prospective randomized trial

The eighth AJCC/UICC staging for nasopharyngeal cancer had higher prognostic values than the previous edition. Pretreatment plasma EBV DNA integrated into the next edition could further improve the outcome prediction.

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.

The prognostic value of pretreatment tumor apparent diffusion coefficient values in nasopharyngeal carcinoma

Background

Diffusion-weighted MR imaging (DWI) has increasingly contributed to the management of nasopharyngeal carcinoma (NPC) patients. The objective of this paper was to explore the prognostic significance of apparent diffusion coefficient (ADC) values in 93 NPC patients.

Methods

This retrospective study included 93 newly diagnosed NPC patients. Pretreatment ADC values were determined and compared with patients’ age, gender, alcohol intake, smoking, tumor volume, pathological type, tumor stage, and nodal stage. Using the Kaplan-Meier method, overall survival (OS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were calculated and the values compared between the low and high ADC groups. Multivariate analysis of ADC values and other 9 clinical parameters was performed using a Cox proportional hazards model to test the independent significance for OS, LRFS and DMFS.

Results

The mean ADC value for the initial nasopharyngeal tumors was 0.72 × 10⁻³ mm²/s (range: 0.48–0.97 × 10⁻³ mm²/s). There was no significant difference between pretreatment ADCs and patient’ gender, age, smoking, alcohol intake, or tumor stage. A significant difference in the ADCs for different N stages (P = 0.022) and correlation with initial tumor volume (r = −0.26, P = 0.012) were observed. In comparison, the ADC value for undifferentiated carcinoma was lower than that for other 3 pathological types. With a median follow-up period of 50 months, the 3-year and 5-year OS rates were 88.2% and 83.3%, respectively, 3-year and 5-year LRFS rates were 93.5% and 93.3%, respectively, and 3-year and 5-year DMFS rates were 83.9% and 83.3%, respectively. Patients with tumor ADC values ≥0.72 × 10⁻³ mm²/s exhibited longer OS and LRFS periods compared with tumor ADC values <0.72 × 10⁻³ mm²/s, with P values 0.036 and 0.018, respectively. In addition, patients with deaths or recurrences or distant metastasis had significant lower ADC values than those without disease failures. According to a multivariate analysis using the Cox proportional hazard test, ADC values showed a significant correlation with OS (P = 0.0004), LRFS (P = 0.0009), and DMFS (P < 0.0001), respectively.

Conclusions

Pretreatment tumor ADC values supposed to be a noninvasive important prognostic parameter for NPC.

Validation and comparison of the 7th and 8th edition of AJCC staging systems for non-metastatic nasopharyngeal carcinoma, and proposed staging systems from Hong Kong, Guangzhou, and Guangxi

OBJECTIVES

We aimed to validate and compare the 7th and 8th edition of AJCC staging systems for non-metastatic nasopharyngeal carcinoma, and proposed staging systems from Hong Kong, Guangzhou, and Guangxi.

MATERIALS AND METHODS

We retrospectively included 899 patients treated between November 5, 2002 and May 27, 2010. Separation and discrimination of each staging system in overall survival were primarily compared.

RESULTS

Compared with the 7th AJCC, the 8th AJCC and all proposed staging systems well separated across T-classification. T-classification from Guangzhou seemed to perform best in discrimination (C-index 0.6454), followed by the 8th AJCC (0.6451), the 7th AJCC (0.6386), Hong Kong (0.6376) and Guangxi (0.5889). For N-classification, no staging systems improved the weakness of the 7th AJCC in separating N2 and N1, except that suggestion from Guangzhou showed higher potential (P=0.096). Besides, N-classification from Guangzhou had a C-index of 0.6444, larger than that of the 8th AJCC (0.6235), the 7th AJCC (0.6179), Hong Kong (0.6175) and Guangxi (0.6175). Accordingly, stage group of staging system from Guangzhou showed higher discrimination (C-index 0.6839), compared with the 8th AJCC (0.6791), the 7th AJCC (0.6766), Hong Kong (0.6765) and Guangxi (0.6688), despite that stage I and II remained inseparable (P=0.322).

CONCLUSIONS

The 8th AJCC staging system appeared to be better than the 7th AJCC. But the proposed staging system from Guangzhou was more likely to improve the separation and discrimination abilities.

Prognostic factors and failure patterns in non-metastatic nasopharyngeal carcinoma after intensity-modulated radiotherapy

Background

The prognostic values of staging parameters require continual re-assessment amid changes in diagnostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non-metastatic nasopharyngeal carcinoma (NPC) in the intensity-modulated radiotherapy (IMRT) era.

Methods

We reviewed the data from 749 patients with newly diagnosed, biopsy-proven, non-metastatic NPC in our cancer center (South China, an NPC endemic area) between January 2003 and December 2007. All patients underwent magnetic resonance imaging (MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log-rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insignificant explanatory variables.

Results

The 5-year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5-year survival rates were as follows: local relapse-free survival, 94.6%; nodal relapse-free survival, 97.0%; distant metastasis-free survival, 82.6%; disease-free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only significant prognostic factor for local failure (P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho’s location of the cervical lymph nodes were significant prognostic factors for both distant failure and disease failure (all P < 0.05). Intracranial extension had significant prognostic value for distant failure (P = 0.040).

Conclusions

The key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the significant prognostic parameters for local control have also been altered substantially.

Prognostic Value and Grading of MRI-Based T Category in Patients With Nasopharyngeal Carcinoma Without Lymph Node Metastasis Undergoing Intensity-Modulated Radiation Therapy

We investigated the prognostic value and gradation of the T category in N0 nasopharyngeal carcinoma (NPC) patients undergoing magnetic resonance imaging (MRI) and intensity-modulated radiotherapy (IMRT).A total of 749 patients were retrospectively reviewed, and a total of 181 N0 NPC patients were included in this retrospective study. All patients were restaged according to the 7th edition of the American Joint Committee on Cancer staging system. The following endpoints were estimated: overall survival (OS), progression-free survival (PFS), locoregional relapse-free survival (LRFS), and distant metastasis-free survival (DMFS).The 5-year survival rates for T1 to T4 were: OS (97.3%, 100.0%, 86.1%, and 82.8%; P = 0.007), PFS (94.6%, 96.9%, 76.5%, and 76.7%; P = 0.002), LRFS (98.5%, 100.0%, 92.2%, and 86.7%; P < 0.001), and DMFS (97.3%, 96.9%, 85.5%, and 85.7%; P = 0.042), respectively. Pairwise comparisons showed that the OS, PFS, and LRFS rates were significantly poorer in the advanced T categories (T3 and T4) than the early ones (T1 and T2), and no significant differences between T1 and T2, and T3 and T4 were found. In Cox's proportional hazard analysis, T category was found to be an independent prognostic factor only for PFS (P = 0.003). According to the primary tumor extent, we then graded all 181 N0 patients into 3 groups: group 1, early T category (n = 107); group 2, low-risk advanced T category (n = 35); and group 3, high-risk advanced T category (n = 39). The 5-year survival rates for the 3 groups were: OS (98.1%, 94.1%, and 76.3%; P < 0.001), PFS (95.3%, 88.2%, and 66.2%; P < 0.001), LRFS (99.0%, 97.0%, and 83.4%; P < 0.001), and DMFS (97.2%, 91.1%, and 80.4%; P = 0.002). The 5-year OS, PFS, and LRFS rates of group 3 differed significantly from those of groups 1 and 2, and a significant difference was observed in the DMFS rate only between groups 3 and 1. In Cox's proportional hazard analysis, the 3-grade T category was an independent prognostic factor for OS (P = 0.002), PFS (P < 0.001), and LRFS (P = 0.002).The 3-grade T category, using MRI according to the site of invasion, has prognostic value for the outcome of IMRT treatment in N0 NPC, and could aid in developing individualized treatment strategies.

The diagnostic accuracy of ultrasonography versus endoscopy for primary nasopharyngeal carcinoma

Objective

To compare the accuracy of ultrasonography (US) with the current clinical standard of endoscopy for a diagnosis of nasopharyngeal carcinoma (NPC).

Methods

A total of 150 patients suspected of having NPC underwent US and endoscopy. A diagnosis was obtained from an endoscopic biopsy collected from each suspected tumor and was compared with a biopsy obtained from a normal nasopharynx. The diagnostic accuracy of US and endoscopy for NPC was evaluated using receiver operating curve (ROC) analysis performed by MedCalc Software.

Results

The sensitivity, specificity, and accuracy of US versus endoscopy for this cohort were 90.1%, 84.8%, and 87.3% for US, and 88.7%, 97.5%, and 93.3% for endoscopy, respectively. Both US and endoscopy exhibited good diagnostic accuracy for NPC with area under the curve (AUC) values of 0.929 and 0.938, respectively. However, this difference was not significant (Z = 0.36, P = 0.72).

Conclusion

US is a useful tool for the detection of tumors in endoscopically suspicious nasopharynx tissues, and also for the detection of subclinical tumors in endoscopically normal nasopharynx tissues.

Involvement of both cervical lymph nodes and retropharyngeal lymph nodes has prognostic value for N1 patients with nasopharyngeal carcinoma

Background

The N1 definition of 2010 UICC/AJCC staging system for nasopharyngeal carcinoma (NPC) covers quite a large range of nodal pattern. The objective of this research is to investigate prognostic value of lymph nodes related factors including involvement of both cervical lymph nodes (CLNs) and retropharyngeal lymph nodes (RLNs) or not, size and number of cervical lymph nodes (CLNs) in N1 patients with NPC.

Methods

142 newly diagnosed non-metastatic N1 patients with NPC, staged according to the 2010 AJCC staging system for NPC were retrospectively enrolled. All patients had undergone contrast-enhanced magnetic resonance imaging (MRI), and received radiotherapy, with or without chemotherapy as their primary treatment.

Results

The median follow-up was 48 months. The 5-year local recurrence-free survival (LFS), nodal recurrence-free survival (NFS), local-regional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) of the whole group were 82.3%, 83.0%, 81.0%, 82.1%, 75.3% and 89.8%, respectively. In univariate analysis, patients with both CLNs and RLNs involvement showed a significant lower DMFS, PFS and LRFS than the rest patients (p = 0.004 p = 0.003 and p = 0.034, respectively). Neither size nor number of CLNs affected the survival. In multivariate analysis, involvement of both CLNs and RLNs was an independent prognostic factor for DMFS and PFS (p = 0.019, p = 0.019), but there was no enough evidence confirming its prognostic value for LRFS (p = 0.051).

Conclusions

For N1 patients with NPC, involvement of both RLNs and CLNs may be a potentially prognostic factor for distant metastasis and disease progression. The N stage for N1 patients with involvement of both cervical lymph nodes and retropharyngeal lymph nodes might need to be deliberated.

Comparison of TNM staging systems for nasopharyngeal carcinoma, and proposal of a new staging system

BACKGROUND

There are few systematic evaluations regarding the sixth and seventh editions of the UICC/AJCC TNM Staging System (TNM6th, TNM7th) and Chinese 2008 Staging System (TNMc2008) for nasopharyngeal carcinoma (NPC).

METHODS

We classified 2333 patients into intensity-modulated radiotherapy (IMRT) cohort (n=941) and conventional radiotherapy (CRT) cohort (n=1392). Tumour staging defined by TNM6th, TNM7th and TNMc2008 was compared based on Akaike information criterion (AIC) and Harrell's concordance index (c-index).

RESULTS

For T-classification, TNM6th (AIC=2585.367; c-index=0.6390385) had superior prognostic value to TNM7th (AIC=2593.242; c-index=0.6226889) and TNMc2008 (AIC=2593.998; c-index=0.6237146) in the IMRT cohort, whereas TNMc2008 was superior (AIC=5999.054; c-index=0.623547) in the CRT cohort. For N-classification, TNMc2008 had the highest prognostic value in both cohorts (AIC=2577.726, c-index=0.6297874; AIC=5956.339, c-index=0.6533576). Similar results were obtained when patients were stratified by chemotherapy types, age and gender. Using staging models in the IMRT cohort, we failed to identify better stage migrations than TNM6th T-classification and TNMc2008 N-classification. We therefore proposed to combine these categories; resultantly, stage groups of the proposed staging system showed superior prognostic value over TNM6th, TNM7th and TNMc2008.

CONCLUSION

TNM6th T-classification and TNMc2008 N-classification have superior prognostic value in the IMRT era. By combining them with slight modifications, TNM criteria can be unified and its prognostic value be improved.

Surgical management of recurrent nasopharyngeal carcinoma

OBJECTIVES

Nasopharyngeal carcinoma is a unique tumour which is endemic in Southern China including Hong Kong. While the treatment results for primary cancer has been encouraging, management of persistent or recurrent tumours has been challenging. Compared to other surgical approaches, the maxillary swing operation provides spacious access to the bilateral nasopharynx and the ipsilateral parapharyngeal space, allowing resection of tumours with wide margins. In this article, we will present our results in the surgical management of recurrent nasopharyngeal carcinoma.

MATERIALS AND METHODS

Retrospective review.

RESULTS

Over the years, we have performed salvage maxillary swing nasopharyngectomy for 312 patients. Microscopic negative resection margins were achieved in the majority (79.5%) of the patients. The overall local recurrence rate after surgery was 13.1%, the risk of which was significantly higher in patients with previous positive resection margins. The overall 5-year actuarial local tumour control and overall survival was 74% and 62%, respectively, which was significantly higher in patients with clear resection. For small tumours located in the posterior wall, minimally invasive approach can be used, which included the endoscopic resection, or more recently, the transoral robotic (TORS) assisted approach.

CONCLUSION

The result of surgical salvage of recurrent nasopharyngeal carcinoma is promising. Every effort should be made to ensure microscopic clearance of disease as well as to minimize the potential complications of surgery that may adversely affect the subsequent quality of life.

Prognostic scoring system for locoregional control among the patients with nasopharyngeal carcinoma treated by intensity-modulated radiotherapy

The prognostic value of T category for locoregional control in patients with nasopharyngeal carcinoma (NPC) has decreased with the extensive use of intensity-modulated radiotherapy (IMRT). We aimed to develop a prognostic scoring system (PSS) that incorporated tumor extension and clinical characteristics for locoregional control in NPC patients treated with IMRT. The magnetic resonance imaging scans and medical records of 717 patients with nonmetastatic NPC treated with IMRT at Sun Yat-sen University Cancer Center between January 2003 and January 2008 were reviewed. Age, pathologic classification, primary tumor extension, primary gross tumor volume (GTV-p), T and N categories, and baseline lactate dehydrogenase (LDH) level were analyzed. Hierarchical cluster analysis as well as univariate and multivariate analyses were used to develop the PSS. Independent prognostic factors for locoregional relapse included N2–3 stage, GTV-p ≥26.8 mL, and involvement of one or more structures within cluster 3. We calculated a risk score derived from the regression coefficient of each factor and classified patients into four groups: low risk (score 0), intermediate risk (score >0 and ≤1), high risk (score >1 and ≤2), and extremely high risk (score >2). The 5-year locoregional control rates for these groups were 97.4%, 93.6%, 85.2%, and 78.6%, respectively (P < 0.001). We have developed a PSS that can help identify NPC patients who are at high risk for locoregional relapse and can guide individualized treatments for NPC patients.

Imaging appearances for recurrent nasopharyngeal carcinoma and post-salvage nasopharyngectomy

Nasopharyngeal carcinoma (NPC) is a head and neck neoplasm that occurs in endemic numbers among people of southern Chinese descent. External beam radiation to the nasopharyngeal bed and primary draining lymph node echelons is the mainstay of treatment with concurrent cisplatin-based chemotherapy for more advanced disease. Detection of residual and/or recurrent NPC has important clinical implications, as salvage protocols are available. The review aims to increase awareness of the imaging features of NPC recurrences at local and distant sites using computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography (PET). Important changes in imaging seen in patients after nasopharyngectomy are also discussed.

Sonographic findings of nasopharyngeal carcinoma and its involvement in the parapharyngeal space

OBJECTIVES

The purpose of this study was to determine the sonographic performance in pathologically proven cases of nasopharyngeal carcinoma and its involvement in the parapharyngeal space.

METHODS

The study included 58 patients being treated for suspected nasopharyngeal carcinoma detected by routine nasopharyngoscopy who underwent pathologic biopsy. Sonography was performed immediately thereafter with a convex array transducer in both the B-mode and color mode. Forty-five of the 58 patients (90 parapharyngeal spaces) in whom nasopharyngeal carcinoma was proved by both sonography and pathologic biopsy underwent preradiotherapy magnetic resonance imaging (MRI). The sonographic findings were compared to the pathologic findings. The sonographic findings of parapharyngeal space involvement were correlated with the MRI findings.

RESULTS

The normal anatomy of the nasopharynx and parapharyngeal space, nasopharyngeal carcinoma, and its relationship with the parapharyngeal space were well shown on sonography. The sensitivity of sonography for detection of nasopharyngeal carcinoma was 97.8%, and the specificity was 41.7%. The sonographic findings of parapharyngeal space involvement had a high degree of agreement with MRI (κ = 0.757; P < .001).

CONCLUSIONS

These promising initial data indicate that sonography may be a useful tool for diagnosing nasopharyngeal carcinoma and defining the relationship between the tumor and the parapharyngeal space.

Nasopharyngeal carcinoma: correlation of apparent diffusion coefficient value with prognostic parameters

PURPOSE

The aim of this study was to correlate the apparent diffusion coefficient (ADC) value with the prognostic parameters of nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

This was a prospective study conducted on 30 consecutive patients (19 men, 11 women; mean age 61 years) with NPC. Patients underwent diffusion-weighted magnetic resonance (DW-MR) singleshot echoplanar imaging at 1.5 Tesla. NPC ADC value was correlated with pathological tumour type, pathological tumour grade, tumour volume and nodal status.

RESULTS

Mean NPC ADC value was 0.99 ± 0.11 × 10(-3)mm(2)/s. ADC values of well-differentiated and moderately differentiated tumours differed significantly (p=0.005) from those of poorly differentiated and undifferentiated NPC. There was also a significant difference in ADC value among small, medium and large tumour volume (p=0.03). ADC value was also significantly lower (p=0.003) when metastatic cervical lymph nodes were present. ADC value correlated inversely with tumour volume (r=-0.799, p=0.03).

CONCLUSIONS

ADC value can be considered a noninvasive prognostic parameter that correlates well with prognostic parameters of NPC.

MRI and CT of nasopharyngeal carcinoma

OBJECTIVE

This article reviews the MRI and CT of nasopharyngeal carcinoma. Extension of nasopharyngeal tumors, especially into the skull base and the deep facial spaces, is well illustrated on imaging. Assessment of retropharyngeal and cervical lymphadenopathy is important for treatment planning. MRI is commonly used for monitoring patients after therapy.

CONCLUSION

Imaging can detect effect of radiation on surrounding structures. The imaging findings that help to differentiate nasopharyngeal carcinoma from simulating lesions are discussed.

FDG-PET, a Complementary Modality to Computed-Tomography in Radiotherapy Target Volume Delineation for Head and Neck Cancer

OBJECTIVES

The objective of the current review was to use published data to assess the role of ^[18F] fluorodeoxyglucose-positron emission tomography (FDG-PET) as a complementary modality to computed-tomography (CT) in radiotherapy target volume delineation for head and neck cancer (HNC).

METHODS

Studies were identified by searching PubMed electronic databases. Both prospective and retrospective studies were included. Information regarding the role of FDG-PET for radiotherapy target volume delineation for HNC was analyzed.

RESULTS

FDG-PET is a promising tool for improving radiotherapy target volume delineation by defining a metabolically active biological target volume (BTV). The use of novel PET tracers representing properties such as hypoxia, protein synthesis and proliferation remain to be better characterized.

CONCLUSIONS

The role of FDG-PET for radiotherapy target volume delineation for patients with HNC is expanding and should be further evaluated in clinical trials.

Prognostic value of subclassification using MRI in the t4 classification nasopharyngeal carcinoma intensity-modulated radiotherapy treatment

PURPOSE

To subclassify patients with the T4 classification nasopharyngeal carcinoma (NPC), according to the seventh edition of the American Joint Committee on Cancer staging system, using magnetic resonance imaging (MRI), and to evaluate the prognostic value of subclassification after intensity-modulated radiotherapy (IMRT).

METHODS AND MATERIALS

A total of 140 patients who underwent MRI and were subsequently histologically diagnosed with nondisseminated classification T4 NPC received IMRT as their primary treatment and were included in this retrospective study. T4 patients were subclassified into two grades: T4a was defined as a primary nasopharyngeal tumor with involvement of the masticator space only; and T4b was defined as involvement of the intracranial region, cranial nerves, and/or orbit.

RESULTS

The 5-year overall survival (OS) rate and distant metastasis-free survival (DMFS) rate for T4a patients (82.5% and 87.0%, respectively), were significantly higher than for T4b patients (62.6% and 66.8%; p = 0.033 and p = 0.036, respectively). The T4a/b subclassification was an independent prognostic factor for OS (hazard ratio = 2.331, p = 0.032) and DMFS (hazard ratio = 2.602, p = 0.034), and had no significant effect on local relapse-free survival.

CONCLUSIONS

Subclassification of T4 patients, as T4a or T4b, using MRI according to the site of invasion, has prognostic value for the outcomes of IMRT treatment in NPC.

[MRI findings delay the diagnosis of nasopharyngeal carcinoma]

This report concerns a 55-year-old female patient who presented with headache, dry right eye and dry nose on the right side. After 5 months magnetic resonance imaging (MRI) was carried out but no pathological findings were diagnosed. Right-sided facial pain appeared 6 months later and a second MRI was carried out but only fluid retention in the right mastoid was diagnosed. After a further 8 months paresis of the right abducent nerve occurred and a computed tomography (CT) scan of the petrous bone showed extensive destruction of the apex of the petrous pyramid. Subsequently a third MRI revealed a tumor of about 5 cm in diameter in the right pterygopalatine fossa which was also retrospectively visible in the first MRI with a size of approximately 3 cm and in the second MRI with 4 cm in diameter. The histological examination after biopsy resulted in the diagnosis of a nasopharyngeal carcinoma and radiochemotherapy was initiated. The patient died 9 months later. The relatives of the patient applied to the arbitration board for medical liability which requested expert opinions in neuroradiology and otorhinolaryngology. The board came to the conclusion that the claims for damages against the radiologist who had made the three MRIs were well-founded and recommended an extrajudicial settlement.