[Simulation model of tumor-treating fields].

Tumor-treating fields (TTFields) is a novel treatment modality for malignant solid tumors, often employing electric field simulations to analyze the distribution of electric fields on the tumor under different parameters of TTFields. Due to the present difficulties and high costs associated with reproducing or implementing the simulation model construction techniques, this study used readily available open-source software tools to construct a highly accurate, easily implementable finite element simulation model for TTFields. The accuracy of the model is at a level of 1 mm 3. Using this simulation model, the study carried out analyses of different factors, such as tissue electrical parameters and electrode configurations. The results show that factors influncing the distribution of the internal electric field of the tumor include changes in scalp and skull conductivity (with a maximum variation of 21.0% in the treatment field of the tumor), changes in tumor conductivity (with a maximum variation of 157.8% in the treatment field of the tumor), and different electrode positions and combinations (with a maximum variation of 74.2% in the treatment field of the tumor). In summary, the results of this study validate the feasibility and effectiveness of the proposed modeling method, which can provide an important reference for future simulation analyses of TTFields and clinical applications.

40 Hz light flickering promotes sleep through cortical adenosine signaling.

Flickering light stimulation has emerged as a promising non-invasive neuromodulation strategy to alleviate neuropsychiatric disorders. However, the lack of a neurochemical underpinning has hampered its therapeutic development. Here, we demonstrate that light flickering triggered an immediate and sustained increase (up to 3 h after flickering) in extracellular adenosine levels in the primary visual cortex (V1) and other brain regions, as a function of light frequency and intensity, with maximal effects observed at 40 Hz frequency and 4000 lux. We uncovered cortical (glutamatergic and GABAergic) neurons, rather than astrocytes, as the cellular source, the intracellular adenosine generation from AMPK-associated energy metabolism pathways (but not SAM-transmethylation or salvage purine pathways), and adenosine efflux mediated by equilibrative nucleoside transporter-2 (ENT2) as the molecular pathway responsible for extracellular adenosine generation. Importantly, 40 Hz (but not 20 and 80 Hz) light flickering for 30 min enhanced non-rapid eye movement (non-REM) and REM sleep for 2-3 h in mice. This somnogenic effect was abolished by ablation of V1 (but not superior colliculus) neurons and by genetic deletion of the gene encoding ENT2 (but not ENT1), but recaptured by chemogenetic inhibition of V1 neurons and by focal infusion of adenosine into V1 in a dose-dependent manner. Lastly, 40 Hz light flickering for 30 min also promoted sleep in children with insomnia by decreasing sleep onset latency, increasing total sleep time, and reducing waking after sleep onset. Collectively, our findings establish the ENT2-mediated adenosine signaling in V1 as the neurochemical basis for 40 Hz flickering-induced sleep and unravel a novel and non-invasive treatment for insomnia, a condition that affects 20% of the world population.

A Dual-Branch Framework With Prior Knowledge for Precise Segmentation of Lung Nodules in Challenging CT Scans.

Lung cancer is one of the deadliest cancers globally, and early diagnosis is crucial for patient survival. Pulmonary nodules are the main manifestation of early lung cancer, usually assessed using CT scans. Nowadays, computer-aided diagnostic systems are widely used to assist physicians in disease diagnosis. The accurate segmentation of pulmonary nodules is affected by internal heterogeneity and external data factors. In order to overcome the segmentation challenges of subtle, mixed, adhesion-type, benign, and uncertain categories of nodules, a new mixed manual feature network that enhances sensitivity and accuracy is proposed. This method integrates feature information through a dual-branch network framework and multi-dimensional fusion module. By training and validating with multiple data sources and different data qualities, our method demonstrates leading performance on the LUNA16, Multi-thickness Slice Image dataset, LIDC, and UniToChest, with Dice similarity coefficients reaching 86.89%, 75.72%, 84.12%, and 80.74% respectively, surpassing most current methods for pulmonary nodule segmentation. Our method further improved the accuracy, reliability, and stability of lung nodule segmentation tasks even on challenging CT scans.

Research Progress on the Mechanism of Anti-Tumor Immune Response Induced by TTFields.

Tumor treating fields (TTFields), a biophysical therapy technology that uses alternating electric fields to inhibit tumor proliferation, has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of newly diagnosed or recurrent glioblastomas (GBM) and malignant pleural mesotheliomas (MPM). Clinical trials have confirmed that TTFields are effective in slowing the tumor growth and prolonging patient survival. In recent years, many researchers have found that TTFields can induce anti-tumor immune responses, and their main mechanisms include upregulating the infiltration ratio and function of immune cells, inducing the immunogenic cell death of tumor cells, modulating immune-related signaling pathways, and upregulating the expression of immune checkpoints. Treatment regimens combining TTFields with tumor immunotherapy are emerging as a promising therapeutic approach in clinical practice. Given the increasing number of recently published studies on this topic, we provide an updated review of the mechanisms and clinical implications of TTFields in inducing anti-tumor immune responses. This review not only has important reference value for an in-depth study of the anticancer mechanism of TTFields but also provides insights into the future clinical application of TTFields.

Deep neural network pulmonary nodule segmentation methods for CT images: Literature review and experimental comparisons.

Automatic and accurate segmentation of pulmonary nodules in CT images can help physicians perform more accurate quantitative analysis, diagnose diseases, and improve patient survival. In recent years, with the development of deep learning technology, pulmonary nodule segmentation methods based on deep neural networks have gradually replaced traditional segmentation methods. This paper reviews the recent pulmonary nodule segmentation algorithms based on deep neural networks. First, the heterogeneity of pulmonary nodules, the interpretability of segmentation results, and external environmental factors are discussed, and then the open-source 2D and 3D models in medical segmentation tasks in recent years are applied to the Lung Image Database Consortium and Image Database Resource Initiative (LIDC) and Lung Nodule Analysis 16 (Luna16) datasets for comparison, and the visual diagnostic features marked by radiologists are evaluated one by one. According to the analysis of the experimental data, the following conclusions are drawn: (1) In the pulmonary nodule segmentation task, the performance of the 2D segmentation models DSC is generally better than that of the 3D segmentation models. (2) 'Subtlety', 'Sphericity', 'Margin', 'Texture', and 'Size' have more influence on pulmonary nodule segmentation, while 'Lobulation', 'Spiculation', and 'Benign and Malignant' features have less influence on pulmonary nodule segmentation. (3) Higher accuracy in pulmonary nodule segmentation can be achieved based on better-quality CT images. (4) Good contextual information acquisition and attention mechanism design positively affect pulmonary nodule segmentation.

Clinical application of enhanced recovery after surgery concept in laparoscopic treatment of pediatric acute appendicitis.

BACKGROUND: This study assesses whether enhanced recovery after surgery (ERAS) is beneficial in treating acute appendicitis in pediatrics by laparoscopic techniques. METHOD: The children with acute appendicitis (n = 116) were divided into the ERAS group (n = 54) and the control group (n = 62). Then the preoperative data, intraoperative observation indexes, and postoperative data were analyzed. RESULTS: There was no significant difference in preoperative data and intraoperative observation indexes between the two groups. C-reactive protein (CRP) and white blood cell (WBC) in the ERAS group were significantly lower than those in the control group 3 days after the operation. Moreover, no significant difference in the visual analog score (VAS) between the two groups 3 days after the operation, but the other postoperative observation indexes in the ERAS group were significantly better than those in the control group. Nausea and vomiting in the ERAS group were significantly lower than those in the control group, with no significant difference in other complications between the two groups. CONCLUSION: ERAS could improve children's comfort, reduce some postoperative complications, reduce hospitalization expenses, and speed up recovery from acute appendicitis treated by laparoscopy. Therefore, it has clinical application value.

Therapeutic Effect of Biomimetic Scaffold Loaded with Human Amniotic Epithelial Cell-Derived Neural-like Cells for Spinal Cord Injury.

Spinal cord injury (SCI) results in devastating consequences for the motor and sensory function of patients due to neuronal loss and disrupted neural circuits, confronting poor prognosis and lack of effective therapies. A new therapeutic strategy is urgently required. Here, human amniotic epithelial cells (hAEC), featured with immunocompatibility, non-tumorgenicity and no ethical issues, were induced into neural-like cells by a compound cocktail, as evidenced with morphological change and the expression of neural cell markers. Interestingly, the hAEC-neural-like cells maintain the characteristic of low immunogenicity as hAEC. Aiming at SCI treatment in vivo, we constructed a 3D-printed GelMA hydrogel biomimetic spinal cord scaffold with micro-channels, in which hAEC-neural-like cells were well-induced and grown. In a rat full transection SCI model, hAEC-neural-like cell scaffolds that were implanted in the lesion demonstrated significant therapeutic effects; the neural circuit and hindlimb locomotion were partly recovered compared to little affection in the SCI rats receiving an empty scaffold or a sham implantation operation. Thus, the establishment of hAEC-neural-like cell biomimetic scaffolds may provide a safe and effective treatment strategy for SCI.

Validation of Computational Simulation for Tumor-treating Fields with Homogeneous Phantom.

Tumor-treating Fields (TTFields) is a promising cancer therapy technique in clinical application. Computational simulation of TTFields has been used to predict the electric field (EF) distribution in the human body and to optimize the treatment parameters. However, there are only a few studies to validate the accuracy of the simulation model. Here we propose a measurement platform with technical details for validating the simulation model of TTFields. We further constructed homogeneous agar phantoms with different conductivity for voltage measurement. With the measured voltages from six equidistance recording points in the cylinder phantom, we calculated the EF intensity in the phantoms at different frequencies. Comparing the measured values with the simulated values obtained from two types of source simulation, we found that the current source simulation model of TTFields is a reliable method for evaluating the EF intensity distribution.

Nerve growth factor regulates liver cancer cell polarity and motility.

Nerve growth factor (NGF), a prototypical neurotrophic factor essential for neuronal cell proliferation and survival, has been implicated as a marker of tumor progression, as well as a potential target for novel therapeutic approaches in cancer. To investigate the functional potential of NGF in liver cancer in the present study, a stable NGF­overexpressing HepG2 cell line was generated. The scratch­wound assay was used to investigate cell motility and polarity. Western blotting was performed to evaluate the expression levels of epithelial­mesenchymal transition (EMT)­related proteins, including E­cadherin, N­cadherin and vimentin. Moreover, immunofluorescence was performed to investigate the arrangement of the actin cytoskeleton. Cell anoikis resistance was examined using a suspension culture model and cell apoptosis was examined via flow cytometry. The present results indicated that NGF overexpression in HepG2 cells disrupted HepG2 cell polarity and promoted cell motility. Furthermore, NGF overexpression induced EMT and actin cytoskeleton rearrangement in HepG2 cells, as well as enhanced anoikis resistance and prevented cellular apoptosis. Notably, a tropomyosin receptor kinase A receptor inhibitor blocked NGF­induced cell motility and apoptosis. Therefore, it was suggested that NGF serves a critical role in the invasion and metastasis of liver cancer. The use of NGF as a biomarker or potential new target could lead to the development of novel factors for diagnosis or for improving therapeutic strategies in liver cancer.

Ultrathin Transition Metal Chalcogenide Nanosheets Synthesized via Topotactic Transformation for Effective Cancer Theranostics.

Ultrathin transition metal chalcogenide (TMC) nanosheets with ultrahigh photothermal conversion efficiency (η) and excellent stability are strongly desired in the application of photothermal therapy (PTT). However, the current synthetic methods of ultrathin TMC nanosheets have issues in obtaining uniform morphology, good dispersion, and satisfactory PTT behavior. Herein, ultrathin nanosheets of CoFe-selenide (CFS) with a finely controlled structure were prepared via a topological structural transformation process from an ultrathin CoFe-layered double hydroxide (LDH) precursor, followed by surface modification with poly(ethylene glycol) (PEG). The as-prepared CFS-PEG nanosheets inherit the ultrathin morphology of CoFe-LDH and exhibit an outstanding photothermal performance with a η of 74.5%, which is the first rank level of reported two-dimensional (2D) TMC nanosheet materials. The CFS-PEG nanosheets possess a satisfactory photoacoustic (PA) imaging capability with an ultralow detection limit (5 ppm) and simultaneously superior T2 magnetic resonance imaging (MRI) performance with a large transverse MR relaxivity value (r2) of 347.7 mM-1 s-1. Moreover, in vitro and in vivo assays verify superior anticancer activity with a dramatic photoinduced cancer cell apoptosis and tumor ablation. Therefore, a successful paradigm is provided for rational design and preparation of ultrathin TMC nanosheets in this work, holding enormous potential in cancer theranostics.

Adenosine A2A receptor blockade improves neuroprosthetic learning by volitional control of population calcium signal in M1 cortical neurons.

Volitional control is at the core of brain-machine interfaces (BMI) adaptation and neuroprosthetic-driven learning to restore motor function for disabled patients, but neuroplasticity changes and neuromodulation underlying volitional control of neuroprosthetic learning are largely unexplored. To better study volitional control at annotated neural population, we have developed an operant neuroprosthetic task with closed-loop feedback system by volitional conditioning of population calcium signal in the M1 cortex using fiber photometry recording. Importantly, volitional conditioning of the population calcium signal in M1 neurons did not improve within-session adaptation, but specifically enhanced across-session neuroprosthetic skill learning with reduced time-to-target and the time to complete 50 successful trials. With brain-behavior causality of the neuroprosthetic paradigm, we revealed that proficiency of neuroprosthetic learning by volitional conditioning of calcium signal was associated with the stable representational (plasticity) mapping in M1 neurons with the reduced calcium peak. Furthermore, pharmacological blockade of adenosine A2A receptors facilitated volitional conditioning of neuroprosthetic learning and converted an ineffective volitional conditioning protocol to be the effective for neuroprosthetic learning. These findings may help to harness neuroplasticity for better volitional control of neuroprosthetic training and suggest a novel pharmacological strategy to improve neuroprosthetic learning in BMI adaptation by targeting striatal A2A receptors.

Bioresorbable Electrode Array for Electrophysiological and Pressure Signal Recording in the Brain.

Medical implantation of an electrocorticography (ECoG) recording system for brain monitoring is an effective clinical tool for seizure focus location and brain disease diagnosis. Planar and flexible ECoG electrodes can minimize the risks of infection and serious inflammatory response, and their good shape adaptability allows the device to fit complex cortex shape and structure to record brain signals with high spatial and temporal resolution. However, these ECoG electrodes require an additional surgery to remove the implant, which imposes potential medical risks. Here, a novel flexible and bioresorbable ECoG device integrated with an intracortical pressure sensor for monitoring swelling of the cortex during operation is reported. The ECoG device is fabricated with poly(l-lactide) and polycaprolactone composite and transient metal molybdenum. In vivo tests on rats show that the ECoG system can record the dynamic changes in brain signals for the different epilepsy stages with high resolution, while the malleable pressure sensor shows a linear relationship between the pressure and resistance in in vitro tests. In vitro degradation experiments show that the ECoG system can work stably for about five days before loss of efficacy, and the whole ECoG system degrades completely in a phosphate buffer solution in about 100 days.

A bottom-up synthesis of rare-earth-hydrotalcite monolayer nanosheets toward multimode imaging and synergetic therapy.

Recently, ultrathin two-dimensional (2D) nanomaterials have attracted considerable research interest in biomedical applications, owing to their intriguing quantum size and surface effects. In this work, a one-step "bottom-up" method is developed to prepare rare-earth (Gd3+ and Yb3+) co-doped layered double hydroxide (LDH) monolayer nanosheets, with a precisely controlled composition and uniform morphology. Due to the successful introduction of Gd3+ and Yb3+ into the LDH host layer, the Gd&Yb-LDH monolayer nanosheets exhibit excellent magnetic resonance (MR)/X-ray computed tomography (CT) dual-mode imaging functionality. Moreover, the Gd&Yb-LDH monolayer nanosheets achieve an ultrahigh loading of a chemotherapeutic drug (SN38) with a loading content (LC) of 925%, which is a one order of magnitude enhancement compared with previously reported delivery systems of hydrophobic drugs. Interestingly, by further combination with indocyanine green (ICG), in vivo tri-mode imaging, including CT, MR and near infrared fluorescence (NIRF) imaging, is achieved, which enables a noninvasive visualization of cancer cell distribution with deep spatial resolution and high sensitivity. In addition, in vitro and in vivo therapeutic evaluations demonstrate an extremely high tri-mode synergetic anticancer activity and superior biocompatibility of SN38&ICG/Gd&Yb-LDH. Therefore, this work demonstrates a paradigm for the synthesis of novel multifunctional 2D monolayer materials via a facile "bottom-up" route, which shows promising applications in cancer synergetic theranostics.

Effects of depression on heart rate variability in elderly patients with stable coronary artery disease.

BACKGROUND: Depression is an independent risk factor in coronary artery disease (CAD). Our objective was to evaluate the impact of depression on heart rate variability (HRV) in patients with stable CAD. METHODS: This study included patients with a stable CAD who admitted to our hospital in the geriatric medical center from August 2016 to December 2016. All patients agreed to participate in the study and sign informed consent. The study group included 90 CAD patients with a diagnosis of depression and 99 CAD patients without depression. All study population underwent a 24-hour Holter recording for HRV. The depression was assessed by 5-Item Geriatric Depression. RESULTS: There was a linear correlation between age and HRV. There were no significant differences in heart rate variability between male and female patients, married and unmarried/widowed, smoking and nonsmoking, drinking and nondrinking groups. Multiple linear regression analysis showed that there were correlations between depression and HRV. ß-blockers were associated with SDNN, SDANN, SDNN index, and RMSSD in HRV. CONCLUSION: Depression is an important risk factor for heart rate variability in elderly patients with CAD. Clinicians should pay attention for evaluation of depressive patients with CAD.

An ultrathin photosensitizer for simultaneous fluorescence imaging and photodynamic therapy.

An ultrathin photosensitizer was prepared by immobilization of chlorin e6 (Ce6) and carbon dots (CDs) onto layered double hydroxide (LDH) nanosheets, which exhibited excellent fluorescence imaging and photodynamic therapy performance toward cancer theranostics.

Hybrid PET/MRI-based delineation of gross tumor volume in head and neck cancer and tumor parameter analysis.

OBJECTIVES: Accurate target delineation allows an increase in radiation dose to the target tumor while reducing damage to the surrounding normal tissue. However, there is currently no standard for evaluating volumes measured by different imaging modalities. The aim of this study is to evaluate the feasibility of contouring gross tumor volume (GTV) by PET/MRI in head and neck cancer, and to define an adaptive threshold level (aTL) for delineating the biological target volume (BTV). PATIENTS AND METHODS: Eighteen head and neck cancer patients underwent time of flight PET/MRI before chemoradiotherapy. Different GTVs of primary tumors and metastatic lymph nodes were manually contoured on MRI (GTVMRI), PET (GTVVIS), and fused PET/MRI (GTVFUS). An MRI-based GTV contour was substituted for the pathologic GTV. The percentile threshold boundary of the maximum standardized uptake value (SUVmax) for the BTV was determined when the volume of BTV approached that of GTVMRI. RESULTS: All GTVs were highly correlated (all Pearson's r>0.85, all P<0.001). Tumor diameter strongly correlated with GTVs (r=0.7-0.8 for all lesions and primary tumor; r=0.8-0.9 for lymph node metastases). aTL and SUVmax were moderately correlated for all lesions (r=-0.692, P<0.001) and were strongly correlated for primary tumors (r=-0.866, P<0.001). CONCLUSION: Delineating GTV on hybrid PET/MRIs is feasible, and aTL, the threshold boundary of BTV, was correlated inversely with the SUVmax.

PET/MRI with diagnostic MR sequences vs PET/CT in the detection of abdominal and pelvic cancer.

OBJECTIVE: Integrated positron emission tomography/magnetic resonance imaging (PET/MRI) scanners provide combined MR-based anatomic and metabolic image information. The aim of this study was to evaluate qualitative and quantitative diagnostic performance of PET/MR with (18)fluoro-2-deoxyglucose ((18)F-FDG) using a diagnostic MR sequence in patients with abdominal and pelvic tumors, compared to positron emission tomography/computed tomography (PET/CT). MATERIALS AND METHODS: Forty five patients underwent a single-injection ((18)F-FDG), dual-imaging protocol including whole-body PET/CT and subsequent regional PET/MR hybrid imaging. A regional PET/MR scan followed the PET/CT. Images from both modalities were analyzed using a 3-point scale for PET/CT and PET/MR image quality, image alignment, and lesion visibility on PET images. PET-CT/PET-MR functional and anatomical correlation was analyzed. RESULTS: A total of 66 lesions were studied, from which 63 were identified using PET/CT and 59 were identified using PET/MR. The (18)F-FDG PET images had good diagnostic quality (P<0.001); alignment was found to be excellent in PET/MR data as well as PET/CT data (P=0.102), and there was no difference in lesion visibility (P=0.18). The average rating score regarding anatomical correlation for PET-positive lesions was 2.75 for combined MR sequence images and 2.04 for CT, with a significant difference (P=0.317), Standard uptake value (SUV) for focal lesions had excellent correlation (SUVmax/mean: R=0.948/0.948); furthermore, the SUVmean of background organs combined, bone marrow and the muscle tissue showed good correlation (R=0.329/0.398/0.298). No correlations were found in the liver and spleen. CONCLUSIONS: PET/MR with diagnostic MR sequence was able to detect abdominal and pelvic lesions and had good image quality compared to PET/CT. SUVmax and SUVmean values in focal lesions, and the SUVmean of background organs generally correlated well in abdominal and pelvic oncology patients examined using PET/CT and PET/MRI.

Accuracy of PET/MR image coregistration of cervical lesions.

PURPOSE: This study aimed to evaluate the accuracy of sequential whole-body PET/MR image coregistration of cervical lesions. MATERIALS AND METHODS: Twenty-five patients with cervical carcinomas underwent fluorine-18 fluorodeoxyglucose PET/MR before radiotherapy. MR-volumes of interest (VOIs), PET-VOIs, and apparent diffusion coefficient (ADC)-VOIs were outlined manually on T2-weighted MR images, PET images, and ADC maps. The difference between the lesion centers on PET and MR was determined by calculating the distance of the respective geometric center of gravity. In addition, the tumor volume contour differences were assessed using the dice similarity coefficient for PET and ADC. Results were analyzed by mean±SD and a two-sample t-test. RESULTS: The mean values of the center of gravity mismatch were relatively higher with lesions between PET and ADC (5.79±1.70 mm) than that between PET and MR-T2 (5.22±1.97 mm; P=0.304). Tumor location overlap difference between MR-T2 and PET images (0.64±0.13) was larger than that between ADC and PET (0.56±0.14; P=0.054). The average differences between the centers of lesions on PET and T2-weighted images were 6.25±1.91, 5.24±2.17, and 4.30±1.30 mm for MR-VOI less than 14, 14-62, and at least 62 ml. The average differences between the center of lesions on PET and ADC were 5.97±1.48, 5.43±1.40, and 5.78±2.75 mm, respectively. Image registration tended to be slightly less accurate in the smaller lesions than in the larger lesions (P>0.05). The average overlaps were 0.51±0.13, 0.63±0.10, and 0.76±0.03 between the T2-weighted image and PET, respectively. The average overlaps were 0.44±0.14, 0.58±0.11, and 0.66±0.04 between the ADC and PET, respectively. Larger tumors had a higher degree of overlap compared with small tumors (P<0.05). CONCLUSION: Image coregistration of cervical lesions is usually accurate in sequential whole-body PET/MR. The accuracy of image registration between MR-T2 and PET was larger than that between ADC and PET. Image registration tended to be more accurate in the larger lesions.

[Effects of Exogenous Nerve Growth Factor on Late Reperfusion after Myocardial Infarction].

This study demonstrates that nerve growth factor (NGF) plays a protective role in myocardial infarction and early reperfusion by reducing the myocardial cell apoptosis and by improving ventricular remodeling and seeks to assess the effects and mechanisms of NGF on late reperfusion after myocardial infarction. The models of late reperfusion were established by ligating the left main coronary artery and then cutting the suture 2 hours after coronary artery ligation. The rats in NGF treatment group were injected 10 µL Ad-NGF (by constructing the adenovirus vector Ad-NGF containing NGF gene) at four locations around infarction. The rats in adenoviral vector (Adv) group were injected 10 µL adenoviral cector as the NGF group. The late reperfusion group and the sham group were given normal saline as above, and the sham group underwent thracotomy without coronary ligation. On the 3rd, 7th, 14th and 28th day after operation, we investigated the role of NGF on late reperfusion by recording cardiac structure and function with echocardiography, by examining the expression of NGF and VIII factor with immunohistochemical method, and by evaluating the myocardial cell apoptosis with terminal dUTP nick end-labeling method (TUNEL). We found that the NGF group had higher expression of NGF protein (P < 0.01) and lower apoptosis index (AI) (P < 0.01 or P < 0.05) compared to the late reperfusion group and Adv group on all time points. The NGF group had remarkably higher level of neovascularization compared to the late reperfusion group on the 14th day (P < 0.01) and the 28th day (P < 0.05). The NGF group also had higher LVEF and FS levels compared to the late reperfusion group on the 14th day (P = 0.006, P = 0.006) and on the 28th day (P = 0.000, P = 0.000). Whereas the NGF group had lower LVEDD, LVESD (P = 0.038, P = 0.000) and lower LVEDV, LVESV (P = 0.001, P = 0.000) on the 28th day compared to late reperfusion group. In this experiment, the NGF gene carried by adenovirus vector had been transfected and obviously increased the expression of NGF protein in NGF group. NGF may help postpone the myocardial remodeling and improve the heart function by promoting the myocardial neovascularization and inhibiting myocardial apoptosis.

Defining PET tumor volume in cervical cancer with hybrid PET/MRI: a comparative study.

OBJECTIVE: The aim of the study was to determine the standardized uptake value (SUV) threshold on gross tumor volume from PET images (PET-GTV) that generates the maximal spatial overlap with MRI-defined GTV (MR-GTV) in locally advanced cervical cancer with the aid of hybrid PET/MRI. MATERIALS AND METHODS: Twenty-seven patients with cervical carcinomas underwent F-FDG PET/MRI before radiotherapy. MR-GTV was manually outlined on T2-weighted MRI. PET-GTVs were contoured on PET images using visual inspection (PETvis-GTV), 2.5 SUV (PET2.5-GTV) and 40% SUVmax threshold (PET40-GTV), and compared with MR-GTV. All PET data were reviewed again. The PET-GTV was determined, with the SUVmax threshold defined as the value at which the Dice similarity coefficient (DSC) between PET-GTV and MR-GTV was maximal (PETdsc-GTV). Results were analyzed by Pearson's analysis, the t-test, and one-way analysis of variance. RESULTS: The mean PETvis-GTV, PET40-GTV, and PET2.5-GTV were significantly different from the mean MR-GTV. The average DSCs were 0.64, 0.65, and 0.68 for PETvis-GTV, PET40-GTV, and PET2.5-GTV with MR-GTV, respectively. The mean threshold of PETdsc-GTV was 29.4% SUVmax, with a maximal DSC value of 0.72 in all patients. PET-GTVs as defined by thresholds of 25 and 30% of SUVmax were not statistically different from the MR-GTV. The mean thresholds of PETdsc-GTV were 43.3±8.8, 27.9±5.8, and 22.2±2.6% for MR-GTV<14, 14-62, and ≥62 cm, respectively. CONCLUSION: PETvis-GTV, PET2.5-GTV, and PET40-GTV do not appear to be suitable for target volume delineation in locally advanced cervical cancer. The PETdsc-GTV may increase the accuracy in target volume delineation. Furthermore, a high level of tumor overlap existed between MR-GTV and PETdsc-GTV in hybrid PET/MRI.