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Objective:To investigate the synchronized feature patterns of local field potentials in the hippocampus (HPC) and prefrontal cortex (PFC) during working memory based on time-varying spectral coherence so as to support the study of information processing mechanisms in working memory.Methods:The local field potentials (LFPs) signals of the ventral hippocampus (vHPC) and medial prefrontal cortex (mPFC) were collected from six SD rats during the performance of a spatial working memory task in the Y-maze, and the time-frequency distributions of vHPC and mPFC LFPs were calculated by applying the short-time Fourier transform (STFT) to determine the characteristic frequency bands of the working memory and then to investigate the synchronized patterns of vHPC and mPFC LFPs based on the coherent of the time-varying frequency spectrum. Finally, support vector machines were applied to explore the feasibility of applying spectral coherence values to predict working memory.Results:When rats performed working memory tasks correctly, the energy of the theta band (4 - 12 Hz) of the HPC and PFC increased (all P < 0.01), and the spectral coherence value of the theta band of the HPC-PFC increased ( P < 0.05). Support vector machine training and prediction using the average peak spectral coherence and the difference between the peak and the onset when correctly and incorrectly executing the working memory as features resulted in 89% accuracy, 90% precision, 88% recall, and 88% F1 scores, all of which were statistically significant differences compared to the results of the randomly disrupted labeled data rearranging (all P < 0.05). Conclusions:Synchronized synergy in the HPC-PFC theta band is one of the potential mechanisms for correctly performing information processing in working memory.
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Radiotherapy plays an important role in the treatment of advanced esophageal cancer. Under the premise of effective systemic treatment, selecting patients who may benefit from local radiotherapy can effectively relieve symptoms and improve quality of life, and it is expected to prolong the survival time of patients. Moreover, immunotherapy plays an increasingly significant role in advanced esophageal cancer, and the efficacy of radiotherapy combined with immunotherapy is promising.
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Objective:To compare the efficacy and adverse events of salvage radiotherapy and other treatments for recurrent esophageal cancer after chemoradiotherapy in this Meta-analysis.Methods:Databases including PubMed, Embase, Cochrane Library, CNKI and Wanfang data were searched from the inception to April 2020 to collect the clinical trials which comparatively analyzed the efficacy and safety between radiotherapy and other treatments for recurrent esophageal cancer after chemoradiotherapy. Meta-analysis was performed using RevMan 5.1 software. RR and 95% CI were used to describe the differences among different groups. Results:According to the inclusion and exclusion criteria, a total of 11 clinical trials involving 842 patients were included. Meta-analysis showed that the overall survival in the salvage radiotherapy group was significantly lower than that in the salvage esophagectomy group ( RR=0.40, 95% CI: 0.27-0.61, P<0.001), whereas significantly higher than that in the chemotherapy group ( RR=2.91, 95% CI: 1.43-5.95, P=0.003). There was no significant difference in the treatment-related mortality between the salvage radiotherapy and salvage esophagectomy groups ( RR=0.53, 95% CI: 0.14-1.98, P=0.350), but the incidence was significantly higher in the salvage esophagectomy group (1.7%-11.4% vs. 1.9%-2.8%). Conclusion:Salvage radiotherapy is an effective treatment for recurrent esophageal cancer after chemoradiotherapy, which can be regarded as one choice for clinical patients.
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Objective: To analyze the clinicopathological features of small cell lung cancer transformed from lung adenocarcinoma. Methods: We retrospectively analyzed the clinical and pathological characteristics and follow-up data of seven patients who had been diagnosed with small cell lung cancer transformed from lung adenocarcinoma following treatment from January 2014 to December 2018 at the Fourth Hospital of Hebei Medical University. Results: The latest follow-up had been performed on June 1, 2020. The median time of small cell lung cancer transformation from lung adenocarcinoma following treatment was 31 months; the median time of tyrosine kinase inhibitor (TKI) application before transformation is 14 months. Three patients had transformation at the same site as the original. Seven patients had higher levels of neuron-specific enolase (NSE) before transformation. Before the transformation, disease progression mostly occurred at multiple sites, and the lung, bone, brain, pleura, and lymph nodes were commonly affected. In all cases, immunohistochemical indicators after transformation showed that thyriod transcription factor-1 (TTF-1) was positive; Napsin A was negative; Syn, CD56, and AE1/AE3 were positive; Ki67 expression was high; and PD-L1 expression was negative. Genetic testing after transformation showed that six patients had maintained the original mutant EGFR gene. Treatments after transformation were mainly comprehensive, based on chemotherapy. The median progression-free survival time after transformation was 6 months, and median survival time after transformation for five patients who died was 10 months. Conclusions: Once lung adenocarcinoma undergoes transformation to small cell lung cancer, the disease progresses rapidly, and survival time is short. Patients with lung adenocarcinoma due to EGFR E19 mutation who undergo EGFR-TKI therapy are more prone to small cell lung cancer transformation, and the time to transformation generally exceeds 2 years. The sites of disease progression before transformation are often multiple, and NSE is increased. After transformation, patients generally maintain the original EGFR mutation.
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Objective Because of statistical noise in Monte Carlo dose calculations,the effective point doses may not be accurately calculated.A user-defined sphere volume was adopted to substitute the effective point to take sphere sampling around the effective point,which minimize the random errors and improve the accuracy of statistical dose.Methods Direct dose measurements were performed at 0°and 90° using a 0.125 cm3 Semiflex ionization chamber (IC) 31010 isocentrically placed in the center of a homogeneous Cylindric sliced RW3 phantom (PTW,Germany).In the scanned CT phantom series,the sensitive volume length of the IC (6.5 mm) was delineated and the isocenter was defined as the simulated effective point.All beams were simulated in the treatment planning system (TPS) in accordance to the measured model.The grid spacing was calculated by 2 mm voxels and the relative standard deviation should be ≤ 0.5％.The statistical and measured doses were statistically compared among three IC models with different electron densities (ED;esophageal lumen ED =0.210 g/cm3 for model A,air ED =0.001 g/cm3 for model B and the default CT scanned ED for model C) at different sampling sphere radius (2.5,2.0,1.5 and 1.0 mm) to evaluate the effect of Monte Carlo.calculation uncertainty upon the dose accuracy.Results In the Monaco TPS,the statistical value was in the highest accordance with the measured value with an absolute average deviation of 0.49％ when the IC was set as esophageal lumen ED =0.210 g/cm3 and the sampling sphere radius was 1.5 mm.When the IC was set as air ED=0.001 g/cm3 and default CT scanned ED,and,the recommended statistical sampling sphere radius was 2.5 mm,the absolute average deviations were 0.61％ and 0.70％.Conclusion In the Monaco TPS,the calculation model with an ED of 0.210 g/cm3 and a sampling radius of 1.5 mm is recommended for the ionization chamber 31010 to substitute the effective point dose measurement to decrease the random stochastic errors of Monte Carlo.
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Objective To evaluate the clinical efficacy and analyze relevant prognostic factors of simultaneous integrated boost intensity-modulated radiation therapy ( SIB-IMRT ) for esophageal squamous cell carcinoma. Methods A total of 101 patients diagnosed with esophageal squamous cell carcinoma received SIB-IMRT from 2009 to 2015. The prescribed dose of PTV was 5040 cGy/28 times ( 180 cGy/time) and the dose for planning gross tumor volume (PGTV) was 6020 cGy/28 times (215 cGy/time) or 6160 cGy/28 times ( 220 cGy/time) simultaneously. The total treatment time was 5. 5 weeks ( once a day, 5 times a week).The adverse events, mode of treatment failure,l-,3-and 5-year local control (LC) and overall survival ( OS) rates were observed. Results The quantity of patients who completed the 1-,3-and 5-year follow-up was 101, 84 and 45, respectively. The 1-,3-and 5-year LC rates were 81. 6％,70. 4％ and 68. 4％, respectively. The 1-, 3-and 5-year OS rates were 72. 3％, 49. 4％ and 45. 2％, respectively. The median survival time was 36 months. Univariate and multivariate analyses showed that clinical staging ( stageⅠ/Ⅱ/Ⅲ) and tumor response ( complete remission/ partial remission/no remission ) were the prognostic factors of OS (P=0. 016,0. 000,0. 005,0. 000).There were no significant differences in the LC and OS between the two groups of 215 cGy and 220 cGy (P=0. 283,0. 951).The incidence rates of grade 1,2,3 acute pneumonitis were 10. 9％(11/101),2. 0％(2/101) and 2. 0％(2/101), respectively. The incidence rates of grade 1, 2, 3 acute esophagitis were 63. 4％( 64/101 ) , 10. 9％( 11/101 ) and 4. 0％( 4/101 ) , respectively. No acute esophageal perforation or hemorrhage occurred. Five patients experienced late pneumonitis ( two died) . One case developed late lemostenosis, two cases developed esophageal perforation and hemorrhage, and two patients experienced esophageal hemorrhage. The patients treated with a fractionated dose of 220 cGy had a higher incidence rate of acute pneumonitis and upper gastrointestinal adverse reactions than those receiving 215 cGy ( P= 0. 062, 0. 024 ) . The local failure and recurrence accounted for 62. 5％ of all treatment-related failures. Conclusions SIB-IMRT yields high long-term clinical efficacy and tolerable adverse events in the treatment of esophageal squamous cell carcinoma. Compared with the dose of 215 cGy, the fractionated dose of 220 cGy fails to improve LC and OS rates, whereas enhances the risk of adverse events. The clinical staging and short-term clinical efficacy are the prognostic factors of survival rate.
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Objective To analyze and compare the outcomes of esophageal carcinoma treated with simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) and late course boost intensity-modulated radiation therapy (LCB-IMRT).Methods We retrospectively analyzed 128 patients with esophageal squamous cell carcinoma who were treated with SIB-IMRT or LCB-IMRT at the fifth department of radiation oncology in our hospital,from January 2009 to August 2015.Propensity score matching analysis was used to balance the variables differences in the two groups.Survival,failure patterns and toxicities were observed and compared between the two groups.Results one hundred and eleven patients were finally included after propensity scores matching.The 1-,3-and 5-year local control rates and survival rates were 83.6％ vs.81.7％,70.8％ vs.46.3％ and 66.0％ vs.38.2％ in the whole group,respectively.The 1-,3-and 5-year local control rates of SIB-IMRT and LCB-IMRT group were 81.6％ vs.88.0％,72.3％ vs.67.6％ and68.5％ vs.60.8％,respectively (P＞0.05).The 1-,3-and 5-year survival rates of SIB-IMRT and LCB-IMRT group were 81.3％ vs.82.4％,51.7％ vs.36.7％ and 45.8％ vs.26.7％,respectively (P ＞ 0.05).There was no statistical difference between the two group in ≥ grade 3 toxicities (P ＞ 0.05).There were 40 (36.0％) patients result in treatment failure in all.The treatment failure rates in SIB-IMRT and LCB-IMRT group were 33.8％ (26/77) vs.41.2％ (14/34),respectively (P ＞ 0.05).The local failure accounted for 65.0％ (26/40) of all treatment-related failures.Conclusions The toxicities of esophageal squamous cell carcinoma treated with SIB-IMRT and LCB-IMRT have no significant differences and were well tolerated.There were no significant differences in local control rates and survival rates between the two groups.However,SIB-IMRT had better trend than LCB-IMRT.Given SIB-IMRT's convenient manipulation,it could be a better choice in the treatment of advanced esophageal carcinoma.
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Objective To investigate the therapeutic effects,adverse effects,and patterns of failure of elective irradiation of lymphatic drainage area (extended-field) and involved-field irradiation in three-dimensional radiotherapy (3DRT) in patients with esophageal cancer via a Meta-analysis.Methods The databases Wanfang Data,CNKI,VIP,CBM,PubMed,Embase,and Cochrane Library were searched to collect the controlled clinical trials on extended-field irradiation and involved-field irradiation in 3DRT in patients with esophageal cancer.Stata 11.0 was used for data analysis.The odds ratio (OR) with 95％ confidence interval was used to describe the differences between two groups.Results According to the inclusion and exclusion criteria,a total of 12 controlled clinical trials involving 1 095 patients with esophageal cancer were included in this meta-analysis.The results of the meta-analysis showed that compared with the involved-field irradiation group,the extended-field irradiation group had a significantly reduced rate of out-field failure in patients with esophageal cancer who received 3DRT (OR=3.727,P=0.007),but showed significantly higher rates of grade ≥ 3 acute radiation pneumonitis and radiation esophagitis (acute radiation pneumonitis:OR =0.348,P =0.001;radiation esophagitis:OR =0.385,P =0.000).The two groups had similar 1-,2-,and 3-year local control rate and overall survival rate (local control rate:OR=0.966/0.946/0.732,P=0.837/0.781/0.098;overall survival rate:OR=0.952/1.149/0.768,P=0.756/0.422/0.120),as well as a similar distant metastasis rate (OR=0.986,P=0.937).Conclusions Compared with involved-field irradiation,extended-field irradiation can reduce the rate of out-field failure in patients with esophageal cancer who receive 3DRT.However,it does not have significant advantages in local control rate and overall survival rate and has an increased incidence rate of adverse effects.
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Objective To construct the uniform electron density couch model (model A ED =0.25) and two components non uniform electron density couch model (model B FD =0.5and foam core=0.1) in the Monaco treatment planning system for the iBEAM(R) evo Extension 415,and to compare which model can better quantify the treatment couch influence on radiation dose.Methods Phantom was positioned in the center of the couch,the attenuation of the couch was evaluated with 6 MV for a field size of 10 cm× 10 cm.Dose measurements of couch attenuation were performed at gantry angles from 180.0° to 122.8°,using a 0.125cc semiflex ionization chamber (PTW),isocentrically placed in the center of a homogeneous cylindrical phantom.Each experimental setup was first measured on the linear accelerator and then reproduced in the TPS.By adjusting the relative-to water electron density (ED) values of the couch,the measured attenuation was replicated.The model accuracies of the model A and model B were evaluated by comparing the measured and calculated results at the minimum computational grid (2 mm) and maximum computing grid (5 mm),respectively.Results The maximum measured and calculated percentage deviation for the central phantom position was 4.01％.The couch model was included in the TPS with a uniform ED of 0.25 or a 2 component model with a fiber ED=0.5 and foam core ED=0.1.For model A and B under 2 and 5 mm voxel grid size,the mean absorbed dose with couch was reduced to 0.61％,0.84％,0.71％ and 0.92％from 2.8％ without couch.Conclusions Model A has a good agreement between measured and calculated dose distributions for all different voxel grid sizes and gantry angles.It can accurately describes the dose perturbations due to the presence of the couch and should therefore be used during treatment planning.
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Objective To evaluate the efficacy of salvage radiotherapy for supraclavicular lymph node metastasis ( SLNM) after initial treatment in patients with esophageal cancer. Methods A total of 117 patients with SLNM after radical resection for esophageal cancer were enrolled as subjects from 2006 to 2012. All patients received three?dimensional radiotherapy with 1. 8?2. 0 Gy per cycle, 5 cycles a week. The survival rates were calculated using the Kaplan?Meier method and analyzed using the log?rank test. The Cox model was used for multivariate analysis. Results The follow?up rate was 100%. In all the patients, the 1?and 3?year overall survival (OS) rates were 38. 5% and 14. 1%, respectively. The 1?and 3?year OS rates were significantly higher in patients treated with salvage radiotherapy or radiochemotherapy ( n=100) than in patients without any salvage treatment (n=17)(42% vs. 18%,P=0. 008;17% vs. 0%, P=0. 008). The patients treated with radiochemotherapy ( n=32) had significantly higher 1?and 3?year OS rates than those treated with radiotherapy alone (n=68)(59% vs. 34%, 36% vs. 11%, P=0. 002) or without any salvage treatment (n=17)(59% vs. 18%, 36% vs. 0%, P=0. 002). Patients without visceral metastasis (n=80) had significantly higher 1?and 3?year OS rates than those with visceral metastasis ( n=37) ( 44% vs. 27%, P=0. 002;22% vs. 0%,P=0. 002) . Patients with supraclavicular doses of ≥60 Gy in salvage radiotherapy ( n=75) had significantly higher 1?and 3?year OS rates than those with supraclavicular doses of<60 Gy in salvage radiotherapy ( n=25) ( 75% vs. 25%,P=0. 000;24% vs. 8%,P=0. 000) . The multivariate analysis using the Cox model showed that supraclavicular doses of ≥60 Gy, mediastinal metastasis, visceral metastasis, and salvage treatment method were independent factors for survival ( P=0. 001,0. 015,0. 009, 0. 025) . Conclusions Salvage radiotherapy can improve the survival of patients with SLNM in esophageal cancer. Salvage radiotherapy or radiochemotherapy is highly recommended for patients with SLNM alone. A radiation dose of ≥60 Gy in salvage radiotherapy improves survival in patients.
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Objective Toinvestigatetheentropyoflocalfieldpotentials(LFPs)recordedinratmedialprefrontal cortex during a Y-maze working memory (WM) task, to provide computing support for neural coding mechanism.Methods Sixteen-channel LFPs were recorded from SD rats while they performed a Y-maze WM task.The data came from 4 rats, 20 trials (10 correct trials and 10 incorrect trials) per rat provided by laboratory of neurobiology in medicine,Tianjin Medical University.Original LFPs were preprocessed to remove 50 Hz power line noise and baseline drift.Multi-taper Fourier transform was applied to calculate spatial distributions of LFPs and band pass filter were used to extract characteristic signal.The entroy coding of 16 channel LFPs was as follows: the physiological window was set to be 500 ms, the step length of physiological window was set to be 125 ms, windows were added to LFPs data, and then LFPs entropy of each sliding window was computed and averaged to get the trend of multichannel entropy values duringthe WM task.Results The power of θ band (4-12 Hz) in LFPs increased.The averaged entropy value ofmultichannel θ band LFPs in correct trials was 0.939±-0.020, which were larger than those in the resting state, 0.795±0.031 (P＜0.05).Those during wrong WM task had no significant difference, which didn't encode the WM task.Conclusions The principal frequency band related to WM is the θ band and LFPs entropy encodes the WM effectively.
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Objective Comparing the dosimetric characteristics of volumetric modulated arc therapy (VMAT) and constant dose rate intensity modulated arc therapy (IMAT) in esophagus cancer to evaluate the performance of the two different arc therapy delivery techniques.Methods 22 cases of esophageal cancer patients were selected for the planning comparison study.All plans were done for IMAT and VMAT treatment plans on Oncentra 4.1 treatment planning system,prescription dose of 2 Gy in total 30 fractions.Planning objectives for PTV were at least 95％ reached the prescription dose and V110 no more than 10％.The maximum dose of spinalcord below 45 Gy and double lung dose V20 ≤ 28％,V30 ≤ 18％ were constrained.Plans were evaluated based on the ability to meet the dose volume histogram.The dose homogeneity index (HI),radiation conformity index (CI),radiation delivery time,monitor units and γ pass rate were also compared.SPSS 19.0 software paired ttest analysis was carried out on the two sets of data.Results The results showed that the IMAT plans in terms of the PTV's CI (t =3.35,P=0.003),D2(t =-2.27,P=0.034) lung's V30(t =-2.46,P=0.023) were better than that of VMAT group.But the VMAT plans spinal's V40 (t =2.37,P =0.027),lung's V5 (t =2.43,P =0.024) were superior to that of IMAT plans.There were no significant differences between IMAT and VMAT plans in the average dose of PTV,CTV,GTV,heart,spinal cord,double lung and the γpass rate.Conclusion IMAT presents a slight improvement in the OAR sparing in high dose with shorter treatment time when compared to VMAT.While in terms of delivered MU and tissue of low dose irradiated area is higher than that of in VMAT.These two treatment methods all can meet the clinical demand,which should be selected according to the actual situation of the patient.
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Objective To analyze neural activity of in rat prefrontal cortex with the use of nonnegative matrix factorization with sparseness constrains (NMFs) as a methodology and to study how to express neural ensemble with higher precision during working memory task.Methods Experiment data were obtained from neural population activity in the period 5 s before and after the working memory event.From the zero point,the neuronal firing times were binned in windows of 200 ms with 50 ms overlapping.The normalized neuronal bin-count matrix is decomposed by NMFs into mixing matrix and source component matrix with sparseness constraints.Meaningful components were extracted to reconstruct the input by an inverse of NMFs transform.Results By analyzing the ten groups of data from 2 rats,with the numbers of the sparse sources of 10 and 15 respectively,explicit neural ensembles with the feature components were obtained in the sparse reconstructed activity.Comparing to rate coding,the spatiotemporal location of neural ensemble was more precisely detected.Conclusion The working memory information is encoded with neural ensemble activity.NMFs could find the sparse firing pattern robustly in neuron population activity.NMFs removes much redundancy and demonstrate the possibility to express neural ensemble with higher precision compared with rate coding,which would be helpful to infer correlations between cortical firing pattern and working memory event.
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Objective To investigate how the independent components(ICs)energies of multichannel local field potentials(LFPs) code event base on the analysis of ICA of the cortical LFPs of rats. Methods Taking the event point as the zero point, 15-channel LFPs between the span of ±500ms recorded from the prefrontal cortex of rats were decomposed into 15 ICs. The energies of the ICs were computed in a 50-ms window. By sliding the window with step of 25 ms, a dynamic distribution mapping of the 15 ICs' energies was established. ICs with distinctly increased energies during the span of ±200 ms, which indicating that these ICs energies coded event,were selected as the targets. The corresponding channels of these ICs were determined consequently via the inverse transformation of ICA. Results Considering each trail of the repetitious analysis for the same segment of data, the spatial localization of the dominate function region(s) turned out to be relatively stable in spite of the uncertainty of the number and sequence of the target IC(s) due to the ambiguities of the decomposition of ICA.Meanwhile, the analysis results of a series of data segments showed satisfactory correspondence between data segments and dominate function regions. Conclusion The ICs' energies of multichannel LFPs are able to code events in working memories; It is valid for ICA to identify the coding patterns of multichannel LFPs to events; ICA is capable to localize the dominate function regions of event coding with satisfactory robustness.