scholarly journals Early Assessment of Response to Radiofrequency Ablation With CT Perfusion Imaging in Rabbit VX2 Liver Tumor Model

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiaofei Yue ◽  
Xiangjun Dong ◽  
Mengting Huang ◽  
Hongli Yang ◽  
Kun Qian ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
High Efficiency ◽  
Liver Tumors ◽  
Ct Perfusion ◽  
Early Stage ◽  
Liver Perfusion ◽  
Tumor Model ◽  
Diagnostic Value ◽  
Early Assessment ◽  
Speed Up

ObjectivesTo discriminate viable tumors from benign periablational enhancement (BPE) in early stage after radiofrequency ablation (RFA) is a major confounding problem. The goal of this study is to evaluate quantitative assessment and diagnostic value of CT perfusion between viable tumors and BPE after RFA in the rabbit liver VX2 tumor model, with pathological results as the standard.MethodsTwenty-eight VX2 liver tumors were treated with RFA, on days 1, 3, 7, and 14, seven rabbits were randomly chosen for CT perfusion and performed pathology examinations immediately. The perfusion parameters along with the profile of time-density curves (TDCs) and pseudo-color images of the parameters were observed in both BPE and viable tumors, then compared with the pathology results. The perfusion parameters included blood flow (BF), blood volume (BV), time to peak (TTP), permeability (P), arterial liver perfusion (ALP), portal venous perfusion (PVP) and hepatic perfusion index (HPI).ResultsA total of 26/28 rabbits successfully underwent CT perfusion, while 6/26 lesions were confirmed to be viable tumors. The TDCs of BPE were mainly speed-up platform curves (15/26), while the viable tumors showed mainly speed-up speed-down (3/6) and speed-up platform (2/6) curves. The PVP values were significantly higher, and the HPI values were significantly lower for BPE at all time points than viable tumors (P < 0.05). Both of PVP value and HPI value have high efficiency for the differential diagnosis of the viable tumors and BPE at each time point. These characteristics of CT perfusion parameters were consistent with pathological changes.ConclusionsThe TDCs, PVP and HPI have the potential to indicate BPE and viable tumors effectively early after RFA treatment, the results were highly consistent with pathology. CT perfusion has advantages with great efficacy in monitoring the therapeutic effect early after RFA treatment.

scholarly journals Radiofrequency ablation for hepatocellular carcinoma - analysis of the clinical outcome

2017 ◽  
Vol 145 (9-10) ◽  
pp. 475-480
Author(s):  
Dragan Masulovic ◽  
Danijel Galun ◽  
Ruza Stevic ◽  
Aleksandar Filipovic ◽  
Aleksandar Bogdanovic ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Radiofrequency Ablation ◽  
Clinical Outcome ◽  
Liver Tumors ◽  
Early Stage ◽  
Post Treatment ◽  
Liver Imaging ◽  
Invasive Treatment ◽  
Liver Transaminase ◽  
Liver Specific Contrast Agent

Introduction/Objective. Radiofrequency ablation (RFA) is a minimally invasive treatment modality for primary and metastatic liver tumors. It can be performed percutaneously or as a laparoscopic or open surgical procedure under ultrasound or computerized tomography guidance. The objective of the study was to evaluate the clinical outcome of the initial 16 patients with hepatocellular carcinoma (HCC) managed by percutaneous RFA at a tertiary institution and to assess the efficacy of this procedure in the management of selected patients with HCC. Method. From June 2011 until December 2013, 16 patients with early-stage HCC were managed by percutaneous radiofrequency ablation at the Clinic for Digestive Surgery, Clinical Center of Serbia, Belgrade. All the patients were treated by the same team composed of an interventional radiologist and a liver surgeon. We analyzed the clinical outcome and the biologic effect of this treatment by comparing the pre- and post-treatment levels of alpha-fetoprotein (AFP). Results. Post-treatment values of liver transaminase levels returned to the pre-treatment values from Day 3. Post-treatment hospital stay was two days. Post-procedural complications included mild pain in all patients, skin necrosis at the site of the electrode puncture in five patients, and transient hepatic decompensation in one patient. In all the patients the AFP level correlated with the findings of liver imaging (ultrasound and/or magnetic resonance imaging with liver-specific contrast agent) indicating viability of the treated tumor. Conclusion. RFA is a feasible and effective procedure providing favorable clinical outcome in patients with early-stage HCC.

scholarly journals Influence of interapplicator distance on multibipolar radiofrequency ablation during physiological and interrupted liver perfusion in an in vivo porcine model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
F. G. M. Poch ◽  
C. A. Neizert ◽  
B. Geyer ◽  
O. Gemeinhardt ◽  
L. Bruder ◽  
...  
Keyword(s):  
Blood Flow ◽  
Radiofrequency Ablation ◽  
Hepatic Blood Flow ◽  
Early Stage ◽  
Liver Perfusion ◽  
Strict Adherence ◽  
Ablation Area ◽  
The Impact ◽  
Pringle Manoeuvre

Abstract Radiofrequency ablation (RFA) is a curative treatment option for early stage hepatocellular carcinoma (HCC). Vascular inflow occlusion to the liver (Pringle manoeuvre) and multibipolar RFA (mbRFA) represent possibilities to generate large ablations. This study evaluated the impact of different interapplicator distances and a Pringle manoeuvre on ablation area and geometry of mbRFA. 24 mbRFA were planned in porcine livers in vivo. Test series with continuous blood flow had an interapplicator distance of 20 mm and 15 mm, respectively. For a Pringle manoeuvre, interapplicator distance was predefined at 20 mm. After liver dissection, ablation area and geometry were analysed macroscopically and histologically. Confluent and homogenous ablations could be achieved with a Pringle manoeuvre and an interapplicator distance of 15 mm with sustained hepatic blood flow. Ablation geometry was inhomogeneous with an applicator distance of 20 mm with physiological liver perfusion. A Pringle manoeuvre led to a fourfold increase in ablation area in comparison to sustained hepatic blood flow (p < 0.001). Interapplicator distance affects ablation geometry of mbRFA. Strict adherence to the planned applicator distance is advisable under continuous blood flow. The application of a Pringle manoeuvre should be considered when compliance with the interapplicator distance cannot be guaranteed.

scholarly journals Parametric evaluation of impedance curve in radiofrequency ablation: A quantitative description of the asymmetry and dynamic variation of impedance in bovine ex vivo model

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245145
Author(s):  
Ronei Delfino da Fonseca ◽  
Paulo Roberto Santos ◽  
Melissa Silva Monteiro ◽  
Luciana Alves Fernandes ◽  
Andreia Henrique Campos ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Liver Tumors ◽  
Ex Vivo ◽  
Early Stage ◽  
Quantitative Description ◽  
Maximum Point ◽  
Performance Indices ◽  
Ex Vivo Model ◽  
Ablation Volume ◽  
Impedance Curve

Radiofrequency ablation (RFA) is a treatment for liver tumors with advantages over the traditional treatment of surgical resection. This procedure has the shortest recovery time in early stage tumors. The objective of this study is to parameterize the impedance curve of the RFA procedure in an ex vivo model by defining seven parameters (t1/2, tminimum, tend, Zinitial, Z1/2, Zminimum and Zend). Based on these parameters, three performance indices are defined: one to identify the magnitude of impedance curve asymmetry (δ), one Drop ratio (DR) describing the percentage of impedance decrease until the minimum impedance point is reached, and Ascent Ratio (AR) describing the magnitude of increase in impedance from the minimum impedance point to its maximum point. Fifty ablations were performed in a bovine ex vivo model to measure and evaluate the proposed parameters and performance index. The results show that the groups had an average δ of 29.02%, DR of 22.41%, and AR of 545.33% for RFA without the use of saline or deionized solutions. The saline solution and deionized water-cooled groups indicated the correlation of performance indices δ, DR, and AR with the obtained final ablation volume. Therefore, by controlling these parameters and indices, lower recurrence is achieved.

scholarly journals Liver Damage After Radiofrequency Ablation Combined with Transcatheter Therapy in Treating Rabbit VX2 Liver Tumors

2020 ◽  
Author(s):  
Xu-Hua Duan ◽  
Wen-Hui Wang ◽  
Xinwei Han ◽  
Jian-Zhuang Ren ◽  
Hao Li ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Liver Injury ◽  
Liver Tumors ◽  
Tumor Model ◽  
Arterial Embolization ◽  
Hepatocyte Proliferation ◽  
Control Group ◽  
Tumor Control ◽  
Hepatocellular Necrosis ◽  
Vx2 Tumor

Abstract Background: To evaluate the effect of transcatheter therapies combining with radiofrequency ablation (RFA) treatment on hepatocellular necrosis, apoptosis and proliferation by using the rabbit VX2 tumor model. Methods: Ninety six models were randomly divided into 4 groups: transcatheter arterial chemoembolization group (TACE), radiofrequency ablation group (RFA), TACE+RFA group and transcatheter arterial embolization (TAE) + RFA group. The above groups were further divided into two subgroups, A (15 rabbits) and B (9 rabbits). The subgroup B (control group) was followed up until animal death. Results: The high expression of heat shock protein 70 (HSP70) was observed in the adjacent liver tissue in TACE and TACE+RFA. The highest increase of transaminase levels and serum HSP70 were detected in TACE+RFA group. TAE+RFA group had a low apoptotic rate and more hepatocyte proliferation as compared to TACE and TACE+RFA groups; and it had the longest end-point survival among these groups. Conclusions: The TAE+RFA treatment had a better outcome than RFA, including a better liver tumor control, a less liver injury, and a longer survival than TACE+RFA. Compared to TACE and TACE+RFA procedures, TAE+RFA significantly decreased the liver injury, hepatocellular necrosis, apoptosis and systemic proinflammatory cytokine release caused by anticancer drugs application.

scholarly journals High-throughput microbioreactor provides a capable tool for early stage bioprocess development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mathias Fink ◽  
Monika Cserjan-Puschmann ◽  
Daniela Reinisch ◽  
Gerald Striedner
Keyword(s):  
High Throughput ◽  
Process Development ◽  
Early Stage ◽  
Explanatory Power ◽  
Batch Mode ◽  
E Coli ◽  
Speed Up ◽  
Bioreactor System ◽  
Cell Densities ◽  
Microbial Systems

AbstractTremendous advancements in cell and protein engineering methodologies and bioinformatics have led to a vast increase in bacterial production clones and recombinant protein variants to be screened and evaluated. Consequently, an urgent need exists for efficient high-throughput (HTP) screening approaches to improve the efficiency in early process development as a basis to speed-up all subsequent steps in the course of process design and engineering. In this study, we selected the BioLector micro-bioreactor (µ-bioreactor) system as an HTP cultivation platform to screen E. coli expression clones producing representative protein candidates for biopharmaceutical applications. We evaluated the extent to which generated clones and condition screening results were transferable and comparable to results from fully controlled bioreactor systems operated in fed-batch mode at moderate or high cell densities. Direct comparison of 22 different production clones showed great transferability. We observed the same growth and expression characteristics, and identical clone rankings except one host-Fab-leader combination. This outcome demonstrates the explanatory power of HTP µ-bioreactor data and the suitability of this platform as a screening tool in upstream development of microbial systems. Fast, reliable, and transferable screening data significantly reduce experiments in fully controlled bioreactor systems and accelerate process development at lower cost.

scholarly journals Impulse oscillometry for detection of small airway dysfunction in subjects with chronic respiratory symptoms and preserved pulmonary function

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Liang-Yuan Li ◽  
Tian-Sheng Yan ◽  
Jing Yang ◽  
Yu-Qi Li ◽  
Lin-Xi Fu ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Respiratory Symptoms ◽  
Early Stage ◽  
Roc Curves ◽  
Diagnostic Value ◽  
Small Airway ◽  
Impulse Oscillometry ◽  
Additional Method ◽  
Cutoff Values ◽  
Higher Sensitivity

Abstract Background Subjects with chronic respiratory symptoms and preserved pulmonary function (PPF) may have small airway dysfunction (SAD). As the most common means to detect SAD, spirometry needs good cooperation and its reliability is controversial. Impulse oscillometry (IOS) may complete the deficiency of spirometry and have higher sensitivity. We aimed to explore the diagnostic value of IOS to detect SAD in symptomatic subjects with PPF. Methods The evaluation of symptoms, spirometry and IOS results in 209 subjects with chronic respiratory symptoms and PPF were assessed. ROC curves of IOS to detect SAD were analyzed. Results 209 subjects with chronic respiratory symptoms and PPF were included. Subjects who reported sputum had higher R5–R20 and Fres than those who didn’t. Subjects with dyspnea had higher R5, R5–R20 and AX than those without. CAT and mMRC scores correlated better with IOS parameters than with spirometry. R5, R5–R20, AX and Fres in subjects with SAD (n = 42) significantly increased compared to those without. Cutoff values for IOS parameters to detect SAD were 0.30 kPa/L s for R5, 0.015 kPa/L s for R5–R20, 0.30 kPa/L for AX and 11.23 Hz for Fres. Fres has the largest AUC (0.665, P = 0.001) among these parameters. Compared with spirometry, prevalence of SAD was higher when measured with IOS. R5 could detect the most SAD subjects with a prevalence of 60.77% and a sensitivity of 81% (AUC = 0.659, P = 0.002). Conclusion IOS is more sensitive to detect SAD than spirometry in subjects with chronic respiratory symptoms and PPF, and it correlates better with symptoms. IOS could be an additional method for SAD detection in the early stage of diseases.

scholarly journals Diagnostic Value of Fluorescence Methods, Visual Inspection and Photographic Visual Examination in Initial Caries Lesion: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 9 (3) ◽  
pp. 30
Author(s):  
Mai Thi Giang Thanh ◽  
Ngo Van Toan ◽  
Do Thi Thanh Toan ◽  
Nguyen Phu Thang ◽  
Ngoc Quang Dong ◽  
...  
Keyword(s):  
Systematic Review ◽  
Quality Assessment ◽  
Visual Inspection ◽  
Early Stage ◽  
Meta Analysis ◽  
Diagnostic Value ◽  
Caries Detection ◽  
Permanent Teeth ◽  
Visual Examination ◽  
Initial Caries

This systematic review and meta-analysis aimed to investigate the efficacy of fluorescence-based methods, visual inspections, and photographic visual examinations in initial caries detection. A literature search was undertaken in the PubMed and Cochrane databases. Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines were followed, and eligible articles published from 1 January 2009 to 30 October 2019 were included if they met the following criteria: they (1) assessed the accuracy of methods of detecting initial tooth caries lesions on occlusal, proximal, or smooth surfaces in both primary and permanent teeth (in clinical); (2) used a reference standard; (3) reported data regarding the sample size, prevalence of initial tooth caries, and accuracy of the methods. Data collection and extraction, quality assessment, and data analysis were conducted according to Cochrane standards Quality Assessment of Diagnostic Accuracy Studies-2. Statistical analyses were performed using Review Manager 5.3 and STATA 14.0. A total of 12 eligible articles were included in the meta-analysis. The results showed that the sensitivity and specificity of fluorescence-based methods were 80% and 80%, respectively; visual inspection was measured at 80% and 75%, respectively; photographic visual examination was measured at 67% and 79%, respectively. We found that the visual method and the fluorescence method were reliable for laboratory use to detect early-stage caries with equivalent accuracy.

scholarly journals Perivascular vital cells in the ablation center after multibipolar radiofrequency ablation in an in vivo porcine model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
F. G. M. Poch ◽  
C. A. Neizert ◽  
B. Geyer ◽  
O. Gemeinhardt ◽  
S. M. Niehues ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Early Stage ◽  
Pringle Maneuver ◽  
Vessel Diameter ◽  
Inflow Occlusion ◽  
White Zone ◽  
Cell Vitality ◽  
Internally Cooled ◽  
Hepatic Vessels

AbstractMultibipolar radiofrequency ablation (RFA) is an advanced ablation technique for early stage hepatocellular carcinoma and liver metastases. Vessel cooling in multibipolar RFA has not been systematically investigated. The objective of this study was to evaluate the presence of perivascular vital cells within the ablation zone after multibipolar RFA. Multibipolar RFA were performed in domestic pigs in vivo. Three internally cooled bipolar RFA applicators were used simultaneously. Three experimental settings were planned: (1) inter-applicator-distance: 15 mm; (2) inter-applicator-distance: 20 mm; (3) inter-applicator-distance: 20 mm with hepatic inflow occlusion (Pringle maneuver). A vitality staining was used to analyze liver cell vitality around all vessels in the ablation center with a diameter > 0.5 mm histologically. 771 vessels were identified. No vital tissue was seen around 423 out of 429 vessels (98.6%) situated within the central white zone. Vital cells could be observed around major hepatic vessels situated adjacent to the ablation center. Vessel diameter (> 3.0 mm; p < 0.05) and low vessel-to-ablation-center distance (< 0.2 mm; p < 0.05) were identified as risk factors for incomplete ablation adjacent to hepatic vessels. The vast majority of vessels, which were localized in the clinically relevant white zone, showed no vital perivascular cells, regardless of vessel diameter and vessel type. However, there was a risk of incomplete ablation around major hepatic vessels situated directly within the ablation center. A Pringle maneuver could avoid incomplete ablations.

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