31 research outputs found

    The impact of positron emission tomography on primary tumour delineation and dosimetric outcome in intensity modulated radiotherapy of early T-stage nasopharyngeal carcinoma

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    Background: In intensity modulated radiotherapy (IMRT) of nasopharyngeal carcinoma (NPC), accurate delineation of the gross tumour volume (GTV) is important. Image registration of CT and MRI has been routinely used in treatment planning. With recent development of positron emission tomography (PET), the aims of this study were to evaluate the impact of PET on GTV delineation and dosimetric outcome in IMRT of early stage NPC patients.Methods: Twenty NPC patients with T1 or T2 disease treated by IMRT were recruited. For each patient, 2 sets of NP GTVs were delineated separately, in which one set was performed using CT and MRI registration only (GTVCM), while the other set was carried out using PET, CT and MRI information (GTVCMP). A 9-field IMRT plan was computed based on the target volumes generated from CT and MRI (PTVCM). To assess the geometric difference between the GTVCM and GTVCMP, GTV volumes and DICE similarity coefficient (DSC), which measured the geometrical similarity between the two GTVs, were recorded. To evaluate the dosimetric impact, the Dmax, Dmin, Dmean and D95 of PTVs were obtained from their dose volume histograms generated by the treatment planning system.Results: The overall mean volume of GTVCMP was greater than GTVCM by 4.4 %, in which GTVCMP was slightly greater in the T1 group but lower in the T2 group. The mean DSC of the whole group was 0.79 ± 0.05. Similar mean DSC values were also obtained from the T1 and T2 groups separately. The dosimetric parameters of PTVCM fulfilled the planning requirements. When applying this plan to the PTVCMP, the average Dmin (56.9 Gy) and D95 (68.6 Gy) of PTVCMP failed to meet the dose requirements and demonstrated significant differences from the PTVCM (p = 0.001 and 0.016 respectively), whereas the doses to GTVCMP did not show significant difference with the GTVCM.Conclusion: In IMRT of early stage NPC, PET was an important imaging modality in radiotherapy planning so as to avoid underdosing the PTV, although its effect on GTV delineation was not significant. It was recommended that PET images should be included in the treatment planning of NPC patients.Department of Health Technology and Informatic

    International Classification of Functioning, Disability, and Health-based rehabilitation program promotes activity and participation of post-stroke patients

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    BackgroundThe International Classification of Functioning, Disability, and Health (ICF) model has been applied in post-stroke rehabilitation, yet limited studies explored its clinical application on enhancing patients’ Activity and Participation (ICF-A&P) level.PurposeThis study gathered evidence of the effects of an ICF-based post-stroke rehabilitation program (ICF-PSRP) in enhancing community reintegration in terms of ICF-A&P of post-stroke patients.MethodsFifty-two post-stroke patients completed an 8 to 12 weeks multidisciplinary ICF-PSRP after setting personal treatment goals in an outpatient community rehabilitation center. Intake and pre-discharge assessments were administered for primary outcomes of Body function (ICF-BF; e.g., muscle strength) and ICF-A&P (e.g., mobility), and secondary outcomes of perceived improvements in ability (e.g., goal attainment and quality of life).ResultsThere were significantly higher levels in the ICF-BF and ICF-A&P domains, except cognitive function under the ICF-BF. Improvements in the primary outcomes predicted corresponding secondary outcomes. Firstly, expressive and receptive functions (ICP-BF) were mediated by the everyday language (ICF-A&P) which predicted patients’ satisfaction with the language-related quality of life. Secondly, upper extremity function (ICP-BF) was mediated by the lower extremity mobility (ICF-A&P) predicting work and productivity-related quality of life. Content analyses showed that combined ICF-BF and ICF-A&P contents throughout the ICF-PSRP contributed to the positive treatment effects.ConclusionThe ICF-PSRP was effective in promoting body function, and activity and participation levels of post-stroke patients. Positive treatment effects are characterized by goal-setting process, cross-domain content design, and community-setting delivery.Clinical trial registration: https://clinicaltrials.gov/study/NCT05941078?id=NCT05941078&rank=1, identifier NCT05941078

    A Genome-Wide Screen for Promoter Methylation in Lung Cancer Identifies Novel Methylation Markers for Multiple Malignancies

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    BACKGROUND: Promoter hypermethylation coupled with loss of heterozygosity at the same locus results in loss of gene function in many tumor cells. The “rules” governing which genes are methylated during the pathogenesis of individual cancers, how specific methylation profiles are initially established, or what determines tumor type-specific methylation are unknown. However, DNA methylation markers that are highly specific and sensitive for common tumors would be useful for the early detection of cancer, and those required for the malignant phenotype would identify pathways important as therapeutic targets. METHODS AND FINDINGS: In an effort to identify new cancer-specific methylation markers, we employed a high-throughput global expression profiling approach in lung cancer cells. We identified 132 genes that have 5′ CpG islands, are induced from undetectable levels by 5-aza-2′-deoxycytidine in multiple non-small cell lung cancer cell lines, and are expressed in immortalized human bronchial epithelial cells. As expected, these genes were also expressed in normal lung, but often not in companion primary lung cancers. Methylation analysis of a subset (45/132) of these promoter regions in primary lung cancer (n = 20) and adjacent nonmalignant tissue (n = 20) showed that 31 genes had acquired methylation in the tumors, but did not show methylation in normal lung or peripheral blood cells. We studied the eight most frequently and specifically methylated genes from our lung cancer dataset in breast cancer (n = 37), colon cancer (n = 24), and prostate cancer (n = 24) along with counterpart nonmalignant tissues. We found that seven loci were frequently methylated in both breast and lung cancers, with four showing extensive methylation in all four epithelial tumors. CONCLUSIONS: By using a systematic biological screen we identified multiple genes that are methylated with high penetrance in primary lung, breast, colon, and prostate cancers. The cross-tumor methylation pattern we observed for these novel markers suggests that we have identified a partial promoter hypermethylation signature for these common malignancies. These data suggest that while tumors in different tissues vary substantially with respect to gene expression, there may be commonalities in their promoter methylation profiles that represent targets for early detection screening or therapeutic intervention

    Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation

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    OBJECTIVES: Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with Vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet) METHODS: We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use. RESULTS: A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (aHR 2.74, 95% confidence interval 1.76 - 4.26) and ischemic stroke (aHR 1.29, 95% confidence interval 1.04 - 1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleeds burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2-4 microbleeds (25 vs 12 per 1,000 patient-years) and ≥11 microbleeds (94 vs 48 per 1,000 patient-years). INTERPRETATION: Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. This article is protected by copyright. All rights reserved

    Isokinetic Quadriceps and Hamstring Muscle Strength After Anterior Cruciate Ligament Reconstruction: Comparison Between Single-bundle and Double-bundle Reconstruction

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    Introduction: Clinical studies have not yet proven whether single-bundle (SB) or double-bundle (DB) anterior cruciate ligament (ACL) reconstruction is superior. Nonetheless, quadriceps and hamstring muscle deficit is common after ACL reconstruction and it may affect the final outcome. The purpose of this study was to compare the isokinetic quadriceps and hamstring muscle strength after SB-ACL and DB-ACL reconstruction. Materials and methods: We recruited 40 patients with ACL reconstruction (20 SB and 20 DB) by the same team of surgeons from 2006 to 2009. Demographic data of both groups were comparable. Lower extremity concentric isokinetic peak extension and flexion torques were assessed at angular velocities of 60°/second, 180°/second, and 300°/second preoperatively and at least 1 year postoperatively. Clinical evaluation was performed, including anterior stability with an arthrometer (model KT-1000), Lysholm score, Tegner activity score, single leg hop test, and International Knee Documentation Committee score. Data were analysed statistically. Results: The isokinetic quadriceps and hamstring peak torque values in both the SB and DB groups did not show any significant difference. The maximum displacement upon KT-1000 arthrometer measurement appeared lower in the DB group but the difference was not significant. The side-to-side percentage deficits in quadriceps and hamstring peak torque at postoperative assessment were comparable in both groups. Conclusion: Isokinetic quadriceps and hamstring muscle strength after SB-ACL or DB-ACL reconstruction was comparable

    Magnetic Resonance Imaging Assessment of the Femoral Tunnel Position in Medial Patellofemoral Ligament Reconstruction

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    Background/Purpose: Correct femoral tunnel position in medial patellofemoral ligament (MPFL) reconstruction is essential to maintain proper biomechanics of the patellofemoral joint throughout the range of movement. Several techniques have been described for MPFL reconstruction, however, there are few reports describing the accuracy of femoral tunnel positioning assessed postoperatively. Methods: Ten patients having recurrent patellar dislocation with MPFL reconstruction performed in our centre from 2009 to 2013 were analysed. Femoral tunnel position was guided by intraoperative X-ray with landmarks described by Schottle et al, 2007. Postoperative magnetic resonance imaging (MRI) was performed on both knees, and femoral tunnel was assessed with reference to the femoral origin of the MPFL in the nonoperated side. Results: All cases showed an intact MPFL graft, with the majority demonstrating satisfactory femoral tunnel position based on postoperative MRI. Conclusion: MPFL reconstruction with anatomic positioning of the femoral tunnel guided by intraoperative X-ray showed satisfactory accuracy in postoperative MRI results, indicating that a well-positioned MPFL graft results in better clinical outcomes

    The Correlation Between the Noise and Vibration Induced by a Bridge Movement Joint

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    This study addresses the research on the noise and vibration correlation of a bridge movement joint. The aim of this research is to assess the noise induced by the vibration of a bridge movement joint without lane closure during the operation period. There are two methods of developing the correlation between the tyre/joint noise and vibration: (i) Direct Sound and Vibration Measurement Method, (ii) Acoustic-Box-in-Vehicle Method. The first one is the measurements of the vibration change at a bridge movement joint and roadside noise change induced when a control vehicle is passing it (this one requires lane closure). The correlation between the vibration change and roadside noise change is plotted according the measurement data. The second one is the measurements of the structure-borne noise change in an acoustic box installed into the control vehicle and roadside noise change induced. Similarly, the correlation between the structure-borne noise change and roadside noise induced is plotted. It is found that the two correlations are linear and similar to each other, even though the roadside noise is nonlinearly increasing against the control vehicle speed
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