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Mammalian target of rapamycin (mTOR) is one of the most commonly activated pathways in human cancers, including lung cancer. Targeting mTOR with molecule inhibitors is considered as a useful therapeutic strategy. However, the results obtained from the clinical trials with the inhibitors so far have not met the original expectations, largely because of the drug resistance. Thus, combined or multiple drug therapy can bring about more favorable clinical outcomes. Here, we found that activation of ERK pathway was responsible for rapamycin drug resistance in non-small-cell lung cancer (NSCLC) cells. Accordingly, rapamycin-resistant NSCLC cells were more sensitive to ERK inhibitor (ERKi), trametinib, and in turn, trametinib-resistant NSCLC cells were also susceptible to rapamycin. Combining rapamycin with trametinib led to a potent synergistic antitumor efficacy, which induced G1-phase cycle arrest and apoptosis. In addition, rapamycin synergized with another ERKi, MEK162, and in turn, trametinib synergized with other mTORi, Torin1 and OSI-027. Mechanistically, rapamycin in combination with trametinib resulted in a greater decrease of phosphorylation of AKT, ERK, mTOR and 4EBP1. In xenograft mouse model, co-administration of rapamycin and trametinib caused a substantial suppression in tumor growth without obvious drug toxicity. Overall, our study identifies a reasonable combined strategy for treatment of NSCLC.

Energy storage dielectric capacitors based on a physical charge-displacement mechanism have attracted much attention due to their high power density and fast charge–discharge characteristics. How to improve the energy storage capacity of dielectric materials has become an important emerging research topic. Here, antiferroelectric PbZrO3 films were prepared by chemical solution deposition on Pt/Ti/SiO2/Si substrates and crystallized by microwave radiation. The effects of microwave radiation on the antiferroelectric properties and energy storage performance were investigated. In contrast to ordinary heating, microwave radiation can crystallize the amorphous PbZrO3 films into the perovskite phase at 750 °C in only 180 seconds. The PbZrO3 films have a highly (100)-preferred orientation and dense microstructure, which is beneficial to enhance the stability of antiferroelectric phase and the electric breakdown strength. The PbZrO3 films show a recoverable energy storage density of 14.8 J cm−3 at 740 kV cm−1, which is approximately 40% higher than that of the PbZrO3 films crystallized by ordinary heating. The results reveal that microwave radiation is an effective method to improve energy storage performance of antiferroelectric films.

In recent years, antiferroelectric materials have been attracting considerable attention as energy storage capacitors due to their potential applications in pulsed power systems. In this work, antiferroelectric Pb0.88Ca0.12ZrO3 (PCZ) thin films were prepared via chemical solution deposition and annealed using rapid thermal annealing. The microstructures of PCZ thin films were controlled via annealing temperature, and the effects of microstructures on electric properties and energy storage performance were systematically studied. Our results indicate that PCZ thin films annealed at 550 °C crystallized into a nanocrystalline structure of the pyrochlore phase, while also displaying the highest recoverable energy density and efficiency (91.3 J/cm3 and 85.3%). We attribute the ultrahigh energy storage properties mainly to dramatic improvements in the electric breakdown strength caused by the dense nanocrystalline structure. The findings reported herein help to elucidate the relationship between energy storage performance and thin-film microstructure, thereby providing an effective way for improving the energy storage performance of antiferroelectric thin films.

In this work, antiferroelectric Pb1-xCaxZrO3 (PCZ) thin films with different concentrations of Ca2+ were prepared by chemical solution deposition, and the effects of Ca2+ concentration on the antiferroelectric properties and energy storage performance were investigated. The results show that the optimal Ca2+ concentration in the PCZ thin films is x = 0.12 for electric properties and energy storage performance. The recoverable energy storage density and energy storage efficiency is 50.2 J/cm3 and 83.1 % at 2800 kV/cm, which is 261 % and 44.8 % higher than those of the PbZrO3 (PZ) films. These effects are attributed to the enhancement of stability of antiferroelectric phase, diffuseness in the field-induced phase transition and electric breakdown strength by Ca2+-doping in the PZ films. Our results demonstrate that doping an appropriate amount of Ca2+ ions in antiferroelectric thin films is an effective way to improve their energy storage performance.

Objectives: To try another non-invasive method to evaluate the relationship between Magnetic Resonance (MR) elastic value and pathological grade of Hepatocellular Carcinoma (HCC) using Magnetic Resonance Elastography (MRE). Methods: Forty-seven HCC patients underwent MR Imaging (MRI), elastography in the upper abdomen. The elastic value of the lesion area was measured, and that of the normal liver tissue was measured adjacent to the lesion area at the same level. The Mann-Whitney U test was used to compare the difference in elasticity between the lesion area and normal area, and the difference between the low and middle-high differentiation groups. The Receiver Operating Characteristic Curve (ROC) of the lesion area and normal area in the complete case group and different differentiation groups were used to determine the diagnostic cut-off value to distinguish the lesion area from the normal area in each group. Results: (1) There was a significant difference in elasticity between the normal area and HCC area (p

Energy storage dielectric capacitors based on a physical charge-displacement mechanism have attracted much attention due to their high power density and fast charge-discharge characteristics. How to improve the energy storage capacity of dielectric materials has become an important emerging research topic. Here, antiferroelectric PbZrO

In recent years, antiferroelectric materials have been attracting considerable attention as energy storage capacitors due to their potential applications in pulsed power systems. In this work, antiferroelectric Pb

Nasopharyngeal Carcinoma (NPC) has distinct TNM stages whose properties and influences on prognosis are not fully understood ...

Lead zirconate titanate Pb(Zr0.2Ti0.8)O3 (PZT) thin films were deposited on Nb-doped SrTiO3 (NSTO) substrates by a sol-gel method and then crystallized by microwave irradiation. The effects of microwave irradiation on the electrical properties of PZT films were investigated in comparison with conventional annealing. The PZT films crystallized by microwave irradiation at 550 °C for only 10 min exhibited better electrical properties than those obtained by conventional heating at 550 °C for 45 min. The theoretical analysis based on the Schottky emission model reveals that microwave irradiation can increase the concentration of oxygen vacancies at the PZT/NSTO interface, thus reducing the effective built-in potential and depletion layer width at the PZT/NSTO interface to make PZT films exhibit better ferroelectric properties.

Rho guanine nucleotide exchange factors (RhoGEFs) are proteins that activate Rho GTPases in response to extracellular stimuli and regulate various biologic processes. ARHGEF19, one of RhoGEFs, was reported to activate RhoA in the Wnt-PCP pathway controlling convergent extension in Xenopus gastrulation. The goal of our study was to identify the role and molecular mechanisms of ARHGEF19 in the tumorigenesis of non-small cell lung cancer (NSCLC). ARHGEF19 expression was significantly elevated in NSCLC tissues, and ARHGEF19 levels were significantly associated with lymph node status, distant metastasis and TNM stage; Patients with high ARHGEF19 levels had poor overall survival (OS) and progression-free survival (PFS). Our investigations revealed that ARHGEF19 overexpression promoted the cell proliferation, invasion and metastasis of lung cancer cells, whereas knockdown of this gene inhibited these processes. Mechanistically, ARHGEF19 activated the mitogen-activated protein kinase (MAPK) pathway in a RhoA-independent manner: ARHGEF19 interacted with BRAF and facilitated the phosphorylation of its downstream kinase MEK1/2; both the Dbl homology (DH) and Pleckstrin homology (PH) domains of ARHGEF19 were indispensable for the phosphorylation of MEK1/2. Furthermore, downregulation of miR-29b was likely responsible for the increased expression of ARHGEF19 in lung cancer tissues and, consequently, the abnormal activation of MAPK signaling. These findings suggest that ARHGEF19 upregulation, due to the low expression of miR-29 in NSCLC tissues, may play a crucial role in NSCLC tumorigenesis by activating MAPK signaling. ARHGEF19 could serve as a negative prognostic marker as well as a therapeutic target for NSCLC patients.

In this study, Pb(Zr0.52Ti0.48)O3/LaNiO3/Pb(Zr0.52Ti0.48)O3 (PZT/LNO/PZT) composite films with different LNO thicknesses were prepared by a sol-gel method. The influences of LNO interlayer on crystalline structure, microstructure and electrical properties of PZT/LNO/PZT composite films were studied. The results show that the perovskite grains of the upper PZT layer grow along the epitaxy of the LNO interlayer when the LNO layer is inserted into the composite films. Due to the in-plane compressive strain effect in the upper PZT layer and the reduced leakage current caused by the accumulated space charges at the PZT/LNO interface, an obvious enhancement of electrical properties is observed in PZT/LNO/PZT composite films. The PZT/LNO/PZT composite film with the 140-nm-thick-LNO layer possesses the best remnant polarization and dielectric constant, which are 43.3 μC cm−2 and 1841, respectively. The preparation of ferroelectric composite film with a ferroelectric/metallic oxide/ferroelectric structure provides a promising way for improving the electrical properties of ferroelectric materials.

The dynamic simulation of cucumber growth and development in sunlight greenhouse can provide technical support for the intelligent management of cucumber production. According to the cucumber response characteristics to light and temperature, the cucumber development module based on the algorithm of clock model was established by using data from four-stage experiment with 'Jinyou 35' as experiment variety in two years. Based on the relationship between the leaf growth and key meteorological factors (temperature and radiation), leaf area index (LAI) module was established with the accumulated product of thermal effectiveness and photosynthetically active radiation (TEP) as independent variables. The simulation module of cucumber dry matter production was established by taking into consideration the double integral of LAI and daily length in photosynthesis per unit leaf area as well as the respiratory expenditure of different organs. Combined with water content of organs, fresh weight simulation module of cucumber organs was constructed. The whole cucumber development and growth simulation model in greenhouse was built based on each sub-module. The model parameters were calibrated and determined. The results showed that root mean square error (RMSE) of simulated values and observed values of four deve-lopment stages (from transplanting date to stretch tendril, to initial flowering, to early harvested and to uprooting), was 3.9-10.5 d. The normalized root mean square error (nRMSE) was 6.5%-28.6%. The coincidence index (D) was 0.79-0.97. The relationship between LAI and TEP was the regression of 'S' type curve. The RMSE of simulated and observed LAI values was 0.19. The nRMSE was 17.2%. The D value was 0.90. The RMSE of dry weight of root, stem, leaf, flower and fruit of the simulated values and observed values were 0.39-8.94 g·m实现日光温室黄瓜生长发育动态模拟预测,可为日光温室黄瓜智慧生产管理提供技术支撑.本研究依据黄瓜生长发育的光温反应特性,以‘津优35’为试验品种,利用2年4茬分期播种试验观测数据建立基于钟模型的温室黄瓜发育模拟模型.依据温室黄瓜叶片生长与关键气象因子(温度和辐射)的关系,以辐热积(TEP)为自变量构建了黄瓜叶面积指数(LAI)模拟模型;依据单位叶面积光合作用对叶面积指数和日长的二重积分,结合黄瓜不同器官的呼吸消耗,构建了黄瓜干重生产分配模拟模型,结合器官含水量,构建了黄瓜器官鲜重模拟模块.基于各子模块构建了温室黄瓜生长发育模拟模型,确定了模型品种参数并进行检验.结果表明: 日光温室黄瓜移栽期-伸蔓期、移栽期-初花期、移栽期-采收初期和移栽期-拉秧期的模拟值与观测值的均方根误差(RMSE)在3.9～10.5 d,归一化均方根标准误差(nRMSE)在6.5%～28.6%,符合度指数(

Rho guanine nucleotide exchange factors (RhoGEFs) are proteins that activate Rho GTPases in response to extracellular stimuli and regulate various biologic processes. ARHGEF19, one of RhoGEFs, was reported to activate RhoA in the Wnt-PCP pathway controlling convergent extension in Xenopus gastrulation. The goal of our study was to identify the role and molecular mechanisms of ARHGEF19 in the tumorigenesis of non-small cell lung cancer (NSCLC). ARHGEF19 expression was significantly elevated in NSCLC tissues, and ARHGEF19 levels were significantly associated with lymph node status, distant metastasis and TNM stage; Patients with high ARHGEF19 levels had poor overall survival (OS) and progression-free survival (PFS). Our investigations revealed that ARHGEF19 overexpression promoted the cell proliferation, invasion and metastasis of lung cancer cells, whereas knockdown of this gene inhibited these processes. Mechanistically, ARHGEF19 activated the mitogen-activated protein kinase (MAPK) pathway in a RhoA-independent manner: ARHGEF19 interacted with BRAF and facilitated the phosphorylation of its downstream kinase MEK1/2; both the Dbl homology (DH) and Pleckstrin homology (PH) domains of ARHGEF19 were indispensable for the phosphorylation of MEK1/2. Furthermore, downregulation of miR-29b was likely responsible for the increased expression of ARHGEF19 in lung cancer tissues and, consequently, the abnormal activation of MAPK signaling. These findings suggest that ARHGEF19 upregulation, due to the low expression of miR-29 in NSCLC tissues, may play a crucial role in NSCLC tumorigenesis by activating MAPK signaling. ARHGEF19 could serve as a negative prognostic marker as well as a therapeutic target for NSCLC patients.

Concurrent/adjuvant cisplatin-based chemoradiotherapy is regarded as the standard of treatment for locoregionally advanced nasopharyngeal carcinoma (NPC). However, patients who do not respond to cisplatin suffer, rather than benefit, from chemotherapy treatment. The goal of this study was to identify molecules involved in cisplatin resistance and to clarify their molecular mechanisms, which would help in the discovery of potential therapeutic targets and in developing a personalized and precise treatment approach for NPC patients. We previously generated a cisplatin-sensitive NPC cell line, S16, from CNE2 cells and found that eIF3a, ASNS and MMP19 are upregulated in S16 cells, which contributes to their cisplatin sensitivity. In this study, we found that BST2 is downregulated in cisplatin-sensitive S16 cells compared with CNE2 cells. Knockdown of BST2 in NPC cells sensitized their response to cisplatin and promoted cisplatin-induced apoptosis, whereas exogenous overexpression of BST2 increased their cisplatin resistance and inhibited cisplatin-induced apoptosis. Further investigation demonstrated that BST2-mediated cisplatin resistance depended on the activation of the NF-κB signaling pathway and consequent upregulation of anti-apoptotic genes, such as Bcl-XL and livin. Moreover, an analysis of clinical data revealed that a high BST2 level might serve as an independent indicator of poor prognosis in patients with locally advanced NPC treated with platinum-based chemoradiotherapy. These findings suggest that BST2 likely mediates platinum resistance in NPC, offering guidance for personalized and precise treatment strategies for patients with NPC.

To evaluate patterns of skull base invasion and its possible impact on tumor (T)-staging in nasopharyngeal carcinoma (NPC) using magnetic resonance imaging (MRI).838 consecutive newly diagnosed by biopsy proven and untreated patients with NPC underwent MRI. The skull-base invasion of NPC was classified according to their incidence from proximal sites to more distant sites surrounding the nasopharynx as: high (≥35%), medium (≥5-35%), and low (5%) groups. A retrospective analysis of data consisting of a 5-year follow-up was carried out. The skull base invasion was related to their tumor (T) staging and prognosis at the 5-year follow-up after treatment with definitive radiation therapy. In addition, a survival health-related quality of life (QOL), overall survival (OS), local relapse-free survival (LRFS) and distant metastasis-free survival (DMFS) were also assessed among the three groups.The total incidence of skull-base invasion was 65.51% (549/838). The differences in T-stage distribution, and the total survival health-related QOL, among the three groups were statistically significant (χ(2)=160.45, p0.005; χ(2)=38.43, p0.005, respectively). The differences between any two of the three groups were also significant, except when the medium grade was compared to the low grade. Significant differences were observed with regard to 5-year OS (83.2%, 74.7%, 59.2%, p=0.000) and DMFS (95.0%, 88.0%, 88.0%, p=0.016); no significant difference was observed in LRFS (95.3%, 95.6%, 91.23%, p=0.450).The results indicate that medium and low group displayed similar findings of skull base invasion, and survival status. We, therefore, propose that patients in these two groups be grouped under T4 in the TNM classification that might have a bearing in implementing optimum treatment.

Purpose: To evaluate the use of signal intensity index (SII) of skull-base invasion in nasopharyngeal carcinoma (NPC) using magnetic resonance imaging (MRI), select a best cut-off SII value to predict the outcome of NPC. Materials and Methods: One hundred and twenty-two NPC patients (92 men, 30 women) with skull-base invasion were included. All patients underwent MRI, signal intensities on T1-weighted imaging (T1WI) were measured for each invaded site and its contralateral normal counterpart. The SIIs were calculated, receiver operating characteristic curves were constructed. The optimal cut-off values were extracted. The overall survival (OS) rates of 5-year follow-up were performed. Results: Sensitivities for differentiating skull-base invasion from normal contralateral anatomy were 98.9%, 88.5% and 70.0%, and specificities were 98.9%, 96.0% and 74.4%, respectively. There were three cut-off values for differentiating invasion from normal anatomy of skull-base, 49%, 98%, and 60%. Significant difference in OS rates (84.2% vs. 57.1%, p=0.007) was seen for SII threshold values > 60% and those ≤ 60%. Conclusions: The SII might be a useful means of differentiating invasion from normal tissue at the skull-base in NPC. The cut-off value of quantitative SII at the skull-base may aid in monitoring the response to treatment of NPC patients.

The criteria for the diagnosis of metastatic retropharyngeal lymph nodes (RLNs) have not yet been resolved and are not included in the current edition of the American Joint Committee on Cancer (AJCC) staging system (seventh edition) for the staging of nasopharyngeal carcinoma (NPC). The aim of this study was to use MRI to identify an RLN size criterion that can accurately predict prognosis in patients with NPC.Eight hundred seventeen patients with newly diagnosed localized NPC were identified. All of the patients underwent MRI before treatment with definitive radiation therapy. All the MRI studies and medical records were reviewed retrospectively. Overall survival (OS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS) were assessed using SPSS software (version 17.0).RLN size cutoffs of ≥ 5 mm and of ≥ 6 mm were used. There was no significant difference in OS (p = 0.216), DMFS (p = 0.081), or LRFS (p = 0.067) in patients with RLNs ≥ 5 mm and in those with RLNs5 mm. When 6 mm was used as a size cutoff, significant differences in OS (p = 0.000) and DMFS (p = 0.001) were identified; there was no significant difference observed for LRFS (p = 0.380).A minimum axial RLN diameter of 6 mm was a more accurate prognostic predictor in NPC patients with RLN metastases than 5 mm.

This article summarizes the clinical characteristics and imaging features of common gastrointestinal (GI) neoplasms in terms of conventional radiological imaging methods. Barium studies are readily available for displaying primary malignancies and are minimally or not at all invasive. A neoplasm may be manifested as various imaging findings, including mucosal disruption, soft mass, ulcer, submucosal invasion and lumen stenosis on barium studies. Benign tumors typically appear as smoothly marginated intramural masses. Malignant neoplasms most often appear as irregular infiltrative lesions on barium examination. Tumor extension to adjacent GI segments may be indistinct on barium images. Cross-sectional images such as computed tomography and magnetic resonance imaging may provide more accurate details of the adjacent organ invasion, omental or peritoneal spread.

The aim of the study was to analyze the nuclear magnetic resonance image (MRI) findings for invasion of paranasal sinuses in patients with nasopharyngeal carcinoma (NPC) and to improve the understanding of its MRI diagnosis.The MRI data of 182 patients with nasopharyngeal carcinoma and paranasal sinus invasion were retrospectively analyzed.One hundred and eighty-two patients developed paranasal sinus invasion, of which, the incidence of sphenoid sinus invasion was highest. The MRI findings of paranasal sinus invasion of patients with NPC were as follows: 100%, 95.6% and 56.6% patients revealed damage of sinus wall, uneven thickening of mucosa, masses of the sinus cavity connected with the primary tumor of nasopharynx, and all the lesions presented iso- or slightly hypo-intense signal on T1WI and iso- or slightly hyper-intense signal on T2WI and significantly heterogeneous enhancement after contrast administration, which were consistent with the primary tumor of the nasopharynx regarding to the signal intensity and reinforcement schedule. 77.5% patients presented massive sinus cavity effusion. T2-weighted images are excellent in differentiating high signal intensity thickened mucosa or retained secretions from relatively lower signal intensity tumor. In contrast-enhanced MRI, tumor with solid enhancement can be differentiated from thickened mucosa related to inflammation with a thin superficial enhancement. 96.5% and 94.7% patients with maxillary sinus invasion and ethmoid sinus invasion were detected with the contrast enhanced axial T1-weighted MR imaging respectively, which were higher than those with the non-enhanced axial T1 and T2 imaging (88.4% and 77.9% for maxillary sinus invasion; 65.8% and 73.7% for ethmoid sinus invasion), the differences were statistically significant (P0.05 for all comparison). All patients with sphenoid sinus invasion were detected with the contrast enhanced sagittal T1-weighted MR imaging.Multiplanner MR scan and enhanced scan can improve the diagnosis of invasion of paranasal sinuses in patients with NPC. The MRI findings of patients with NPC with paranasal sinus invasion include sinus wall damage; unevenly thickening mucous membrane of sinuses; tumors in sinus cavity connective with the primary tumor of nasopharynx , or with massive sinus cavity effusion. The T2-weighted sequence and contrast enhanced sequence are conducive to differential diagnosis of inflammatory changes from neoplastic tissues. The enhanced axial T1-weighted section and the enhanced sagittal T1-weighted section are most helpful to detection of maxillary sinus, ethmoid sinus invasion and sphenoid sinus invasion, respectively.

The nasopharynx is situated just below the base of the skull. Nasopharyngeal carcinoma (NPC) has a great tendency to invade adjacent regions fairly early. Due to its deep and hidden anatomical location, the infiltrating ability of the tumour, and the non-specific nature of the symptoms, it is not diagnosed until it reaches an advanced stage. So, NPC may present with base of the skull erosion and/or cranial nerve involvement. Magnetic resonance imaging (MRI) could provide useful information about the position and quality of NPC because of its ideal soft tissue contrast and multi-planar imaging capacity. With gadolinium contrast and fat suppression sequences, it has greater sensitivity over clinical examination in detecting the base of the skull with bone erosion and/or perineural invasion. MRI is the choice of imaging modality for evaluating tumour extension. The aims of this article were to review the imaging studies of skull-base invasion and its impact on tumour staging and prognosis.

Purpose Tuberculosis is uncommon in the nasopharynx. The purpose of this study was to investigate the CT and MRI features of 36 cases of tuberculosis in this area. Materials and methods CT (n = 15) and MRI (n = 21) scans from 36 patients with histologically proved tuberculosis of the nasopharynx were reviewed by two experienced radiologists, paying particular attention to the lesions’ distribution, location, extent, size, internal architecture, pattern, and degree of enhancement, and cervical lymphadenopathy. Results Twenty-nine patients exhibited a polypoid mass pattern and seven had diffuse mucosal thickening. The roof of the nasopharynx was involved in all cases. The mean size of the lesions was 11.4 mm. Striped pattern was detected in 19 cases. Adjacent muscle invasion or bone destruction was not detected. Heterogeneous enhancement was detected in all patients, and necrosis in the nasopharyngeal lesions was detected in 16 cases. Poor, moderate, and marked enhancement was detected in one, 27, and eight cases, respectively. Thirty-four patients had involvement of the cervical lymph nodes. Twenty-two and 28 cases were associated with bilateral lymphadenopathy or necrosis, respectively. The retropharyngeal lymph node was the most commonly involved site (94.1%). Conclusion The presence of necrosis and striped pattern in nasopharyngeal lesions, site predilection, no invasion of regional structures, and central necrosis with peripheral rim enhancement of cervical lymphadenopathy may suggest the diagnosis of nasopharyngeal tuberculosis.

To evaluate the distributions of primary nasopharyngeal carcinoma (NPC) and the patterns of skull base involvement in NPC patients using magnetic resonance imaging (MRI).After the approval of institutional review board and informed consent, 838 consecutive newly-diagnosed and untreated NPC patients were examined by MRI. Their MR images were reviewed by two independent radiologists.Among all cases, the incidence rates of superior side and post-superior side involvement were 98.57% (826/838) and 98.21% (823/838) respectively. The differences were not significant between these two sides (P0.05). Lateral side erosion was demonstrated in 784 (93.56%) cases. Posterior side was involved in 391 (46.66%) cases. The total incidence rate of skull base involvement was 65.51% (549/838). According to the anatomic site, the pathways of skull base involvement were classified into 5 spreading routes: anterior; superior; super-lateral; super-anterior and super-posterior. According to the incidence rates and the results of chi-square test, the anatomic sites around the nasopharynx were classified into three groups of risk grades: high-risk (≥ 35%), medium-risk (≥ 5% - 35%) and low-risk (5%).Skull base involvement of NPC spreads stepwise from proximal site to more distal sites. The area of skull base involvement in NPC is classified into high-grade, medium-grade and lower-grade groups respectively. The high and medium-grade groups are related with T3 stage while the lower-grade group T4 stage. Thus T3 stage should be subdivided into T3a and T3b. These schemes may be useful in a more accurate NPC staging and a delineation of clinical target volume for radiotherapy in NPC patients.

To determine the appropriate radiologic criteria of metastatic retropharyngeal lymph nodes (RLNs) in patients with nasopharyngeal carcinoma (NPC).After institutional review board approval and informed consent, 303 consecutive NPC patients treated with definitive radiation therapy were examined after completion of therapy. RLNs were classified as metastatic on the basis of the results of magnetic resonance (MR) imaging follow-up.The receiver operating characteristic curve and area under the curve were determined to assess the accuracy of different size criteria in the diagnosis of RLN metastasis.Initial MR images revealed 523 RLNs in 265 patients. Two hundred sixty-four (50.5%) RLNs positive for malignant involvement were confirmed in 177 patients. The remaining 259 (49.5%) nodes were classified as negative for benign process at follow-up. The minimal axial diameter was found to be more accurate than the maximal axial diameter for assessing metastatic RLNs. The most accurate size criterion of metastatic RLNs was a minimal axial diameter of 6 mm or larger, resulting in an accuracy of 87.5% (457 of 522). Central necrosis or groups of two or more of RLNs had a 100% specificity for diagnosis of RLN metastases.The radiologic criteria that should be used for assessment of RLN metastases in NPC patients are nodes with a minimal axial diameter 6 mm or larger, any node with central necrosis, groups of two or more RLNs, or any medial RLN; these criteria may be useful in tumor staging and treatment planning.

To assess the value of white matter fiber tractography based on magnetic resonance diffusion-tensor imaging (MR-DTI), a new noninvasive technique that helps estimate the structural connectivity of the brain, in understanding the anatomy of the white matter fiber tract.Six consecutive volunteers received MR-DTI examination using a GE 1.5T Sign CV/I whole-body MR system and version 2.0 Functool software for image processing. The protocol included T1WI for localization and single-shot echo-planner diffusion tensor imaging of the entire brain in axial, sagittal, and /or coronal sections.White matter fiber tracts imaged by MR-DTI were consistent with known white matter fiber anatomy. The major fiber tracts were well observed in all the cases. The tracts visualized included the corpus callosum, anterior commissure, uncinate fasciculus superior and inferior longitudinal fascicules, inferior occipito-frontal fasciculus, internal capsule and corona radiate.A set of detailed white matter fiber anatomy maps of the normal brain is obtained by means of single-shot echo-planner diffusion tensor imaging at high resolution. This technique allows rapid visualization of the white matter tracts in vivo, and provides a new reliable means for studying fiber connectivity in the brain.

Background To evaluate the prognostic significance of paranasal sinus invasion for patients with NPC and to provide empirical proofs for the T-staging category of paranasal sinus invasion according to the AJCC staging system for nasopharyngeal carcinoma. Methods The clinical records and imaging studies of 770 consecutive patients with newly diagnosed, untreated, and nondisseminated NPC were reviewed retrospectively. The overall survival, distant metastasis-free survival, and local relapse-free survival of these patients were analyzed using the Kaplan-Meier method, and the differences were compared using the log-rank test. Results The incidence of paranasal sinus invasion was 23.6%, with the rate of incidence of sphenoid sinus invasion being the highest. By multivariate analysis, paranasal sinus invasion was shown to be an independent prognostic factor for overall survival, distant metastasis-free survival, and local relapse-free survival (p