N95 respirator decontamination: a study in reusability

The coronavirus disease 2019 (COVID-19) pandemic had caused a severe depletion of the worldwide supply of N95 respirators. The development of methods to effectively decontaminate N95 respirators while maintaining their integrity is crucial for respirator regeneration and reuse. In this study, we systematically evaluated five respirator decontamination methods using vaporized hydrogen peroxide (VHP) or ultraviolet (254 nm wavelength, UVC) radiation. Through testing the bioburden, filtration, fluid resistance, and fit (shape) of the decontaminated respirators, we found that the decontamination methods using BioQuell VHP, custom VHP container, Steris VHP, and Sterrad VHP effectively inactivated Cardiovirus (3-log10 reduction) and bacteria (6-log10 reduction) without compromising the respirator integrity after 2-15 cycles. Hope UVC system was capable of inactivating Cardiovirus (3-log10 reduction) but exhibited relatively poorer bactericidal activity. These methods are capable of decontaminating 10-1000 respirators per batch with varied decontamination times (10-200 min). Our findings show that N95 respirators treated by the previously mentioned decontamination methods are safe and effective for reuse by industry, laboratories, and hospitals.

[Analysis on factors associated with the place of death among individuals with cardiovascular diseases in China, 2018]

Objective: To understand the distribution patterns of the place of death (PoD) among individuals with cardiovascular disease (CVD) in the provinces of China in 2018. Relationships between CVD deaths in healthcare/medical institutions and individual demographics, social-economic status (SES), the underlying cause of death, and local cultural factors were also explored. Methods: Using data from the National Cause-of-death Reporting System, we examined potential, influential factors of CVD deaths in healthcare/medical institutions through multilevel logistic regression. Results: In 2018, there were 853 832 CVD deaths in disease surveillance points in the country, with 661 625 (77.49%) home deaths and 156 441 (18.32%) occurring in healthcare and medical institutions. Factors including sex, age, nationality, marital status, education level, occupation, the underlying cause of death, criterion for diagnosis, and urban/rural residency, were significantly influential on CVD deaths in healthcare/medical institutions. Meanwhile, spatial variations were shown at factors the subnational level, with 45.39% related to factors at the individual level. Conclusion: Home was the dominant place for CVD deaths in the country, with substantial spatial variations in PoD between provinces. The probability of dying in healthcare/medical settings was comparatively higher among CVD patients with superior socioeconomic status and who lived in urban areas. Adequate information should be collected and included in further studies on exploring influential factors of PoD. Since both social factors, individual preferences, and acute and chronic CVD deaths are critical, it is necessary to enhance treatment capacity. A booming approach incorporating home/hospice care with on-site medical services might also improve the quality of end-of-life care among CVD patients in China.

[Analysis on all-cause mortality rate and life expectancy in China, 2005-2018]

Objective: To understand the geographical variations and temporal trends of all-cause mortality rate and life expectancy in China at national and subnational levels during 2005-2018. Methods: Using data from National Cause-of-death Reporting System, China National Maternal and Child Health Surveillance System, Under-reporting Surveys, and related social determinants covariates, we estimated all-cause mortality rate and life expectancy at national and subnational levels in China during 2005-2018. We depicted the geographical variations and temporal trends between provinces on mortality rate and life expectancy. We then decomposed changes in national and subnational deaths into three explanatory components: change due to age-specific mortality rate, change due to the population structure by age, and change due to growth of the total population. Results: In 2018, it was estimated that there were 10 482 297 total deaths (95%CI: 9 723 233-11 466 875 deaths) in China, with 6 113 926 men (95%CI: 5 773 158-6 572 407 men) and 4 368 241 women (95%CI: 3 950 075-4 894 468 women). The all-cause mortality rate was 755.54 per 100 000 (95%CI: 701.49 per 100 000-825.78 per 100 000), with 861.78 per 100 000 (95%CI: 813.75 per 100 000-926.40 per 100 000) in men and 642.73 per 100 000 (95%CI: 581.20 per 100 000-720.15 per 100 000) in women, while age-standardized all-cause mortality rate was 652.27 per 100 000 (95%CI: 599.22 per 100 000-721.71 per 100 000), with 806.38 per 100 000 (95%CI: 755.10 per 100 000-874.31 per 100 000) in men and 503.37 per 100 000 (95%CI: 450.50 per 100 000-572.01 per 100 000) in women. In 2018, it was estimated that the life expectancy in the whole country was 77.15 years old (95%CI: 75.92-78.11 years old), with 74.81 (95%CI: 73.57-75.76) in men and 79.87 (95%CI: 78.61-80.91) in women. Developed areas as Shanghai, Beijing, Jiangsu, and Zhejiang owned comparatively higher life expectancy, while undeveloped areas like Tibet, Guizhou, Xinjiang, and Qinghai showed lower levels. During 2005-2018, there was a 29.87% increase in total deaths at the national level, with 27.74% in men and 31.29% in women. Changes due to age-specific mortality rate, the population structure by age, and the growth of the total population constituted -35.74%, 7.34%, and 58.28% of the total increase, respectively. Conclusions: From 2005 to 2018, the all-cause mortality rate increased while the age-standardized mortality rate decreased substantially among Chinese residents. Change due to population structure by age was the dominant driver. An upward trend of life expectancy was observed in all provinces, with marked differences between the provinces.

[Influences of using different spatial weight matrices in analyzing spatial autocorrelation of cardiovascular diseases mortality in China]

Objective: To explore the potential influences and applicability of different spatial weight matrices used in analyzing spatial autocorrelation of cardiovascular disease (CVD) mortality in China. Methods: Using data from the National Cause-of-death Reporting System, we used adjacency-based Rook and Queen contiguity and distance-based K nearest neighbors/distance threshold. We then conducted global and local spatial autocorrelation analysis of CVD mortality at the county level in China, 2018. Results: All four categories and 26 types of spatial weight matrices had detected significant global and local spatial autocorrelation of CVD mortality in China. Global Moran's I statistics reached its peak when using first-order Rook (0.406), first-order Queen (0.406), K nearest neighbors including five spatial units (0.409), and distance threshold with 100 kilometers (0.358). Meanwhile, apparent local spatial autocorrelation was found in CVD mortality. Substantial disparities were observed when detecting "High-High clusters", "Low-Low clusters", "High-Low clusters" and "Low-High clusters" of CVD mortality spatial distribution by using different weight matrices. Conclusions: Using different spatial weight matrices in analyzing the spatial autocorrelation of CVD mortality, we could understand the spatial distribution characteristics of CVD mortality in-depth at the county level in China. In this way, adequate supports could also be provided on CVD premature death control and rational medical resource allocation regionally.

Phageome-based vaccination and human innate immune modulation could be a useful strategy to control human Coronavirus infections

Human Coronavirus (CoV) infections, including SARS-COV, MERS-COV, and SARS-CoV-2, usually cause fatal lower and upper respiratory tract infections due to exacerbated expression of pro-inflammatory cytokines and chemokines. We aim to summarize different aspects, such as CoV immune evasion mechanisms and host innate immune response to these infections, and their role in pathogenesis. We have also elaborated the up-to-date findings on different vaccine development strategies and progress against CoVs in both humans and non-human models. Most importantly, we have described the Phageome-human immune interaction, its therapeutic usage as anti-viral, anti-inflammatory agent, and implications for multiple vaccine development systems. The data suggest that endogenous phages might play a vital role in eliminating the infection and regulating the body's immune system. Considering the innate-immune-induced pathogenesis against CoVs and the therapeutic aptitude of phageome, we propose that the prophylactic administration of phages and phage-based vaccines could be a useful strategy to control the emerging CoV infections.

[Disease burden of breast cancer in women in China, 1990-2017]

Objective: To analyze the trend of the incidence, mortality and disease burden of breast cancer in women in China during 1990-2017. Methods: Based on the estimation of data in China from the Global Burden of Disease 2017 (GBD2017), the incidence,mortality, disability- adjusted life years (DALY), years of life lost (YLL), and years lived with disability (YLD) on breast cancer for women in China during 1990-2017 were standardized by the world standard population used for GBD2017. The GBD study applied the attributable burden formula to estimate the attributable deaths by five risk factors of breast cancer, including alcohol use, high body mass index (BMI), high fasting plasma glucose, low physical activity and tobacco smoking. The incidence, mortality, attributable deaths and the disease burden due to breast cancer in women in China were analyzed. Results: In 2017, a total of 357.6 thousand female breast cancer cases, including 84.8 thousand deaths, were reported in China, with the age-standardized incidence rate of 35.62/100 000, which increased by 286.18%, 114.14% and 88.77% respectively compared with 1990. The age-standardized mortality rate decreased from 8.57/100 000 in 1990 to 7.84 /100 000 in 2007, then increased to 8.71 /100 000 in 2015, and then decreased to 8.47/100 000 in 2017. The mortality of breast cancer increased with age in 1990 and 2017. From 1990 to 2017, the trend of standardized DALY rate and standardized YLL rate were the same as that of standardized mortality, while the standardized YLD rate and the proportion of YLD in DALY increased year by year. In 2017, the standardized DALY rate, standardized YLL rate and standardized YLD rate of breast cancer were 253.00/100 000, 228.96/100 000, and 24.05/100 000, respectively. Compared with 1990, the change rates were -6.88% and -11.73% and 95.85% respectively. The proportion of breast cancer deaths attributable to high BMI increased significantly by 165.76%, from 5.49% in 1990 to 14.59% in 2017. The proportion of breast cancer deaths attributable to alcohol use and high fasting blood glucose increased; and the proportion of breast cancer deaths attributed to low physical activity and smoking remained stable. In 2017, the three provinces with the highest age-standardized mortality rate of female breast cancer were Hongkong (9.93/100 000), Guangxi (9.52/100 000) and Liaoning (9.49/100 000). Compared with 1990, the age-standardized mortality of 19 provinces decreased, and Beijing (-27.17%), Macao (-26.06%) and Jilin (-23.89%) had the fastest decrease. The two provinces with the highest growth rates were Hebei (28.85%) and Henan (24.34%). Conclusions: The disease burden of female breast cancer in China increased during 1990-2017. Therefore it is necessary to strengthen the prevention and treatment of breast cancer.

Transcriptome analysis reveals the effect of high-grain pelleted and non-pelleted diets on ruminal epithelium of Hu-lamb

High-grain non-pelleted (HG) and high-grain pelleted (HP) diets are becoming prevalent for ruminant feeding in intensive farms. However, rare information is about their effect on sheep and the comparison between these two kinds of diets. The current study investigated how HG and HP diets affected the transcriptome profiles of rumen epithelium in Hu-lamb. Fifteen male Hu-lambs were assigned randomly to three groups (n = 5 for each group). Lambs in the control (CON), HG, and HP groups were fed with low-grain non-pelleted diet (30% grain), HG diet (70% grain), and HP diet (70% grain), respectively, for 42 days. All these lambs were slaughtered to collect ruminal epithelium samples for transcriptome analysis. Results showed both HG and HP diets obviously changed the transcriptome profiles, and 192, 319, and three differentially expressed genes (DEGs) were identified for CON_HG, CON_HP, and HG_HP comparisons, respectively. Clusters of orthologous group functional classification of CON_HG and CON_HP DEG datasets both showed the enrichments of DEGs in pathways involved in protein biogenesis and modification as well as energy production and conversion. Kyoto encyclopedia of genes and genomes pathway analysis of CON_HG and CON_HP DEG datasets both displayed the enrichments of DEGs in ribosome and oxidative phosphorylation. Almost all these DEGs involved in translation and ribosomal structure and biogenesis as well as oxidative phosphorylation were downregulated in the HG and HP groups compared to the CON group. Furthermore, CON_HP comparison demonstrated more DEGs related to these two pathways than CON_HG comparison. In conclusion, both HG and HP diets inhibited energy production and conversion as well as protein synthesis and modification in ruminal epithelium. HP diet showed lower growth benefits, induced severer rumen acidosis, and more seriously inhibited energy production and protein synthesis as compared to HG diet.

Ageing, hypertension and aortic valve stenosis - Understanding the series circuit using cardiac magnetic resonance and applanation tonometry

BACKGROUND

Aortic stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload, but rather, functions as a series circuit, with important contributions from both the valve and vasculature. Patients with AS are typically elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizeable, and yet, quantifying this to-date has been difficult to determine. We compared measurement of aortic pressure, flow and global LV load using a cardiac magnetic resonance (CMR)/applanation tonometry (AT) technique to uncouple ventriculo-arterial (VA) interactions.

METHODS

20 healthy elderly patients and 20 with AS underwent a CMR/AT protocol. CMR provided LV volume and aortic flow simultaneously with AT pressure acquisition. Aortic pressure was derived by transformation of the AT waveform. Systemic vascular resistance (SVR) and global LV load were determined as the relationship of pressure to flow in the frequency domain. Values from both cohorts were compared.

RESULTS

AS patients were older (p ​< ​0.01) albeit with no significant difference in brachial or central aortic pressure. SVR (14228 vs 19906 ​dyne ​s.cm-3; p ​= ​0.02) and load (740 vs 946 ​dyne ​s.cm-3; p ​= ​0.02) were higher in patients with AS, whilst aortic peak flow velocity was lower (38 vs 58 ​cm/s; p ​< ​0.01).

CONCLUSIONS

Quantification of aortic pressure, flow velocity and global LV load using a simultaneous CMR/AT technique is able to demonstrate the progressive effects of hypertension and aortic stiffening with advanced age and valvular stenosis. This technique may help to better identify future patients at risk of VA coupling mismatch after correction of AS.

Asymptotically Corrected Person Fit Statistics for Multidimensional Constructs with Simple Structure and Mixed Item Types

Person fit statistics are frequently used to detect aberrant behavior when assuming an item response model generated the data. A common statistic, [Formula: see text], has been shown in previous studies to perform well under a myriad of conditions. However, it is well-known that [Formula: see text] does not follow a standard normal distribution when using an estimated latent trait. As a result, corrections of [Formula: see text], called [Formula: see text], have been proposed in the literature for specific item response models. We propose a more general correction that is applicable to many types of data, namely survey or tests with multiple item types and underlying latent constructs, which subsumes previous work done by others. In addition, we provide corrections for multiple estimators of [Formula: see text], the latent trait, including MLE, MAP and WLE. We provide analytical derivations that justifies our proposed correction, as well as simulation studies to examine the performance of the proposed correction with finite test lengths. An applied example is also provided to demonstrate proof of concept. We conclude with recommendations for practitioners when the asymptotic correction works well under different conditions and also future directions.

Tepotinib hydrochloride for the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most devastating cancers with high mortality worldwide. By inhibiting the activity of specific molecular targets in the cancer cells, tyrosine kinase inhibitors (TKIs) have become a standard treatment in combating NSCLC. Tepotinib hydrochloride is an orally bioavailable, mesenchymal-epithelial transition (MET) TKI developed mainly for selected NSCLC patients with METex14 skipping mutations. Tepotinib demonstrated durable clinical response in phase II clinical trials, which led to its approval for use in Japan and breakthrough therapy designation and accelerated approval in the U.S. These progresses highlighted tepotinib as a promising candidate for NSCLC patients. This review summarizes the pharmacological profile of tepotinib, preclinical studies and landmark clinical trials of tepotinib. In addition, we share our perspectives on the future direction of tepotinib as a novel anticancer drug.

Acceleration of Brain TOF-MRA with Compressed Sensitivity Encoding: A Multicenter Clinical Study

BACKGROUND AND PURPOSE

The clinical practice of three-dimensional TOF-MRA, despite its capability in brain artery assessment, has been hampered by the relatively long scan time, while recent developments in fast imaging techniques with random undersampling has shed light on an improved balance between image quality and imaging speed. Our aim was to evaluate the effectiveness of TOF-MRA accelerated by compressed sensitivity encoding and to identify the optimal acceleration factors for routine clinical use.

MATERIALS AND METHODS

One hundred subjects, enrolled at 5 centers, underwent 8 brain TOF-MRA sequences: 5 sequences using compressed sensitivity encoding with acceleration factors of 2, 4, 6, 8, and 10 (CS2, CS4, CS6, CS8, and CS10), 2 using sensitivity encoding with factors of 2 and 4 (SF2 and SF4), and 1 without acceleration as a reference sequence (RS). Five large arteries, 6 medium arteries, and 6 small arteries were evaluated quantitatively (reconstructed signal intensity, structural similarity, contrast ratio) and qualitatively (scores on arteries, artifacts, overall image quality, and diagnostic confidence for aneurysm and stenosis). Comparisons were performed among the 8 sequences.

RESULTS

The quantitative measurements showed that the reconstructed signal intensities of the assessed arteries and the structural similarity consistently decreased as the compressed sensitivity encoding acceleration factor increased, and no significant difference was found for the contrast ratios in pair-wise comparisons among SF2, CS2, and CS4. Qualitative evaluations showed no significant difference in pair-wise comparisons among RS, SF2, and CS2 (P > .05). The visualization of all the assessed arteries was acceptable for CS2 and CS4, while 2 small arteries in images of CS6 were not reliably displayed, and the visualization of large arteries was acceptable in images of CS8 and CS10.

CONCLUSIONS

CS4 is recommended for routine brain TOF-MRA with balanced image quality and acquisition time; CS6, for examinations when small arteries are not evaluated; and CS10, for fast visualization of large arteries.

Fibulin-5 protects the extracellular matrix of chondrocytes by inhibiting the Wnt/β-catenin signaling pathway and relieves osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is a common disease in the elderly and seriously affects the quality of life of patients. The purpose of this study was to explore the protective effect of Fibulin-5 on articular chondrocytes and its mechanism of action.

PATIENTS AND METHODS

Articular cartilage tissues from patients with OA and normal people were selected and tested for differences in Fibulin-5 expression. In addition, human chondrocytes were cultured, and the effects of Fibulin-5 on the extracellular matrix (ECM) of chondrocytes and the level of inflammation were examined by means of cell transfection and cytokine intervention. SKL2001, an agonist of the Wnt/β-catenin signaling pathway, was used to validate the mechanism of action of Fibulin-5 to protect chondrocytes.

RESULTS

Fibulin-5 was lowly expressed in the cartilage tissue of patients with OA. Overexpression of Fibulin-5 significantly increased the expressions of ECM collagen II and aggrecan in chondrocytes, while decreasing the expressions of MMP-3 and MMP-13. In addition, Fibulin-5 reduced IL-1β-induced inflammation of chondrocytes, as well as expressions of IL-6, IL-8, and TNF-α. Overexpression of Fibulin-5 also reduced the activity of Wnt/β-catenin signaling pathway, and activation of Wnt/β-catenin signaling pathway attenuated the protective effects of Fibulin-5 on the ECM of chondrocytes.

CONCLUSIONS

Fibulin-5 can protect the ECM of chondrocytes and reduce the inflammatory response of chondrocytes by inhibiting the Wnt/β-catenin signaling pathway.

Characterisation of symptomatic intracranial plaque without substantial stenosis using high-resolution vessel wall MRI

AIM

To characterise symptomatic intracranial plaque without substantial stenosis using three-dimensional (3D) high-resolution contrast-enhanced black-blood magnetic resonance imaging (BBMRI) and to determine plaque features associated with recent cerebrovascular events.

MATERIALS AND METHODS

The institutional review board approved this retrospective study. The case notes from patients with evidence of intracranial atherosclerosis in a large intracranial artery with preceding BBMRI were reviewed retrospectively. Symptomatic and asymptomatic plaques with substantial luminal stenosis (<50%) were matched by plaque location and patient age. All MRI images were de-identified and interpreted by two neuroradiologists who were blinded to the history of symptoms. Qualitative analyses including the presence of intraplaque haemorrhage (IPH), eccentricity, surface irregularity, and grade of plaque enhancement were recorded. Quantitative analyses including normal wall index and degree of contrast enhancement were calculated. Multivariate regression analysis was performed to identify the association with cerebrovascular ischaemic events.

RESULTS

A total of 38 pairs of symptomatic and asymptomatic plaques from 74 patients were analysed. Compared to asymptomatic plaques, symptomatic plaques demonstrated higher degree of contrast enhancement (29.77 ± 19.23 versus 18.21 ± 12.18%, p=0.039) and presence of IPH (26% versus 8%, p=0.032). No significant differences were detected regarding eccentricity, surface irregularity, and normal wall index. Events were associated with contrast enhancement (OR, 1.212; 95% confidence interval [CI], 1.086-1.352) after controlling for age, sex, cardiovascular risk factors, and stenosis degree. IPH was not associated with events.

CONCLUSION

Contrast enhancement in the intracranial plaque without substantial stenosis is associated with previous events, and may serve as the vulnerable feature, thereby stratifying stroke risk not achievable by luminal stenosis.

MiR-188 inhibits proliferation and promotes apoptosis of lung adenocarcinoma cells by targeting SIX1 to negatively regulate ERK signaling pathway

OBJECTIVE

To explore the effects of micro ribonucleic acid (miR)-188 on proliferation and apoptosis of lung adenocarcinoma (LUAD) cells, and its potential mechanism.

MATERIALS AND METHODS

The expression level of miR-188 in LUAD cell lines was detected via quantitative Real Time-Polymerase Chain Reaction (PCR). The effects of miR-188 overexpression on proliferation and apoptosis of A549 cells were detected using methyl thiazolyl tetrazolium (MTT) assay, colony formation assay, and flow cytometry. The potential targets for miR-188 were predicted using the TargetScan Human database, and the interaction between miR-188 and target gene was determined through Dual-Luciferase reporter assay. Moreover, the associations of miR-188 and sine oculis homeobox homolog 1 (SIX1) with the extracellular signal-regulated kinase (ERK) pathway were detected via Western blotting.

RESULTS

The expression of miR-188 significantly declined in LUAD cell lines (p<0.05). The overexpression of miR-188 significantly reduced the proliferation rate of A549 cells and increased the percentage of apoptotic A549 cells (p<0.05). Similarly, it was found in colony formation assay that the overexpression of miR-188 inhibited the colony formation ability of A549 cells most significantly (p<0.05). SIX1 was a direct target for miR-188, and its mRNA and protein expressions were downregulated by the overexpression of miR-188. The remarkable downregulation of phosphorylated ERK was observed in A549 cells overexpressing miR-188, while the decline in phosphorylated ERK was reversed in A549 cells overexpressing miR-188 and SIX1.

CONCLUSIONS

The expression of miR-188 is downregulated in LUAD cell lines. The overexpression of miR-188 inhibits proliferation and promotes apoptosis of LUAD cells, whose functional mechanism may be related to its regulation on the ERK signaling pathway by targeting SIX1.

MiR-19 enhances pancreatic cancer progression by targeting PTEN through PI3K/AKT signaling pathway

OBJECTIVE

Abnormal expression of micro ribonucleic acids (miRNAs) has become an important marker of cancer. However, the exact molecular mechanisms of miRNAs were not very clear. Here, we decided to investigate the miR-19 effect and molecular mechanism on pancreatic cancer, which was blank until now.

PATIENTS AND METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was applied for testing miR-19 and gene of phosphate and tensin homolog deleted on chromosome ten (PTEN) expression. Western blot was used for detecting the protein expression. Methyl thiazolyl tetrazolium (MTT) assay and transwell assay were carried out to measure cell proliferation, invasion, and migration.

RESULTS

We showed that miR-19 expression was increased in cancerous tissues and was associated with the survival of patients, tumor node metastasis (TNM) stage, tumor size, and lymph node metastasis. MiR-19 mimic enhanced cell proliferation, invasion, and migration, while suppressing miR-19 cell progression was suppressed. With the help of TargetScanHuman and luciferase reporter assay, we verified PTEN as a specific target of miR-19. Moreover, PTEN expression was reduced by miR-19 mimic and was increased by miR-19 inhibitor. We next found that PTEN was elevated in cancerous tissues and its expression was negatively correlated with miR-19 expression. Furthermore, miR-19 regulated cell progression via activating phosphatidylinositol 3-hydroxy kinase/protein kinase B (PI3K/AKT) signaling pathway.

CONCLUSIONS

We demonstrated that miR-19 facilitated cell progression through modulating PI3K/AKT signaling pathway by targeting PTEN, which provided a potential therapeutic target for pancreatic cancer patients.

[Assessment of setup errors of IGRT combined with a six degrees of freedom bed for patients with primary rectal cancer]

Objective: To investigate the effect of six degree of freedom (6-DOF) bed combined with cone beam computed tomography (CBCT) in the on-line correction of setup errors in patients with primary rectal cancer. Methods: The clinicopathological data of 17 patients with primary rectal cancer in Department of Radiotherapy, Third Hospital of Peking University from July 2013 to January 2014 were collected. There were 14 males and 3 females, a median age of 65 years. The difference of CBCT and 6-DOF bed combined with CBCT online correction of patients with positioning error were retrospectively analyzed. Results: Before position correction, the first CBCT verification of setup errors in the three translation directions including X (left and right), Y (in and out) and Z (up and down) directions were (0.06±0.25) cm, (0.13±0.40) cm and (-0.28±0.31) cm, respectively. The setup errors of RX (rotation pitch), RY(rolling) and RZ (left and right rotation) directions were (0.62±1.15)°, (-0.19±0.99)°, and (-0.34 ± 0.84)°, respectively . After correction of IGRT combined with six freedom of bed, the setup errors of translation X, Y and Z were (0.01±0.09) cm, (-0.01±0.05) cm and (-0.03±0.08) cm, respectively, and the setup errors of rotation RX, RY and RZ directions were (-0.16±0.40)°, (0.36±0.31)°and (-0.01±0.25)°, respectively. There were significant differences in translation direction (X, Y and Z direction) and rotation direction (Rx, RY and RZ) before and after 6-DOF bed combined with CBCT correction (all P<0.05). In the translation direction, the higher frequency range of Z-direction error value was 0.20-0.79 cm. In the rotation direction, the frequency range of error in Rx direction was 0.20°-2.99°. There was no significant difference between bone mode and gray scale model registration (P>0.05). With the progress of radiotherapy, the setup errors of X, Z, Rx, RY and RZ directions increased except Y direction. Conclusions: In radiotherapy, six freedom bed combined with CBCT is helpful to correct the setup errors of patients with primary rectal cancer. Six freedom bed may be used to correct the setup errors of patients with primary rectal cancer online. Image-guided radiation therapy (IGRT) is recommended for bone pattern registration in patients with rectal cancer.