Effect Of Volume Reduction Research Articles

Influence of prefabricated vertical drains spacing on FeCl3-vacuum consolidation of a landfill sludge

The spacing of PVDs is an essential factor affecting the consolidation effect of vacuum preloading. For exploring the influence of spacing of PVDs on the impact of sludge drainage consolidation, FeCl3, a commonly used inorganic coagulant, was used to pretreat the sludge. In the experiment a vacuum filtration test was carried out to determine the optimal addition amount of FeCl3, and then the landfill sludge was pretreated according to the FeCl3 optimal addition amount. And two different spacing of PVDs were used to carry out a vacuum preloading contrast test. Then, the drainage and settlement were recorded, and water content and vane shear strength (VSS) were measured after the experiment. Finally, Mercury intrusion porosimetry (MIP) was carried out to explore the pore characteristics of the sludge further. The main conclusions are as follows: After conditioning by FeCl3, the sludge’s flocculent structure was destroyed, the intracellular water was released, and the effect of drainage capacity was significantly improved. After the spacing of PVDs is halved, the average volume reduction ratio and shear strength increases, and the effect of advanced dewatering and volume reduction of sludge improved significantly, leading to a better consolidation effect. In the progress of vacuum drainage consolidation, halving the spacing of PVDs results in large pores transformation into small pores, and the range of drainage consolidation is greatly expanded.

ES12.01 Defining Operability

ES12.01 Defining Operability

Intracranial Pressure and Cerebral Perfusion Pressure in Large Spontaneous Intracranial Hemorrhage and Impact of Minimally Invasive Surgery

Introduction: We investigated the effect of hematoma volume reduction with minimally invasive surgery (MIS) on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in patients with large spontaneous intracerebral hemorrhage (ICH).Methods:Post-hoc analysis of the Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation (MISTIE III) study, a clinical trial with blinded outcome assessments. The primary outcome was the proportion of ICP readings ≥20 and 30 mmHg, and CPP readings <70 and 60 mm Hg. Secondary outcomes included major disability (modified Rankin scale >3) and mortality at 30 and 365 days. We assessed the relationship between proportion of high ICP and low CPP events and MIS using binomial generalized linear models, and outcomes using multiple logistic regression.Results: Of 499 patients enrolled in MISTIE III, 72 patients had guideline based ICP monitors placed, 34 in the MIS group and 38 in control (no surgery) group. Threshold ICP and CPP events ≥20/ <70 mmHg occurred in 31 (43.1%) and 52 (72.2%) patients respectively. On adjusted analyses, proportion of ICP readings ≥20 and 30 mmHg were significantly lower in the MIS group vs. control group [Odds Ratio (OR) 0.27, 95% Confidence Interval [CI] 0.11–0.63 (p = 0.002); OR = 0.18, 0.04–0.75, p = 0.02], respectively. Proportion of CPP readings <70 and 60 mm Hg were also significantly lower in MIS patients [OR 0.31, 95% CI 0.15–0.63 (p = 0.001); OR 0.30, 95% CI 0.11–0.83 (p = 0.02)], respectively. Higher proportions of CPP readings <70 and 60 mm were significantly associated with short term mortality (p = 0.04), and (p = 0.006), respectively. Long term mortality was significantly associated with higher proportion of time with ICP ≥ 20 (p = 0.04), ICP ≥ 30 (p = 0.04), and CPP <70 mmHg (p = 0.01).Conclusion: Our results are consistent with the hypothesis that surgical reduction of ICH volume decreases proportion of high ICP and low CPP events and that these variables are associated with short- and long-term mortality.

Endobronchial Valve (Zephyr) Treatment in Homogeneous Emphysema: One-Year Results from the IMPACT Randomized Clinical Trial

Rationale: The long-term safety and effectiveness of bronchoscopic lung volume reduction with Zephyr endobronchial valves in subjects with severe homogeneous emphysema with little to no collateral ventilation beyond 3 months have yet to be established. Methods: Ninety-three subjects were randomized to either bronchoscopic lung volume reduction with Zephyr valves or standard of care (SoC) (1:1). Zephyr valve subjects were assessed at 3, 6, and 12 months. SoC subjects were assessed at 3 and 6 months; they were then offered crossover to Zephyr valve treatment. Results: The mean group difference (Zephyr valve – SoC) for change in FEV1 from baseline to 6 months was 16.3 ± 22.1% (mean ± SD; p < 0.001). Secondary outcomes showed the mean between-group difference for the six-minute walk distance of +28.3 ± 55.3 m (p = 0.016); St. George’s Respiratory Questionnaire, −7.51 ± 9.56 points (p < 0.001); modified Medical Research Council, −0.42 ± 0.81 points (p = 0.019); BODE index, −0.85 ± 1.39 points (p = 0.006); and residual volume of −430 ± 830 mL (p = 0.011) in favor of the Zephyr valve group. At 6 months, there were significantly more responders based on the minimal clinically important difference for these same measures in the Zephyr valve versus the SoC group. The clinical benefits were persistent at 12 months. The percentage of subjects with respiratory serious adverse events was higher in the Zephyr valve group compared to SoC during the first 30 days post-procedure but not statistically different for the Zephyr valve and SoC groups from 31 days to 6 months, and stable in the Zephyr valve group out to 12 months. There were 2 deaths in the SoC group in the 31-day to 6-month period and none in the Zephyr valve group out to 12 months. Conclusions: Bronchoscopic lung volume reduction with Zephyr valves in subjects with severe homogeneous emphysema and little to no collateral ventilation provides clinically meaningful change from baseline in lung function, quality of life, exercise capacity, dyspnea, and the BODE index at 6 months, with benefits maintained out to 12 months.

Hemodialysis: effects of preload reduction on novel echocardiographic parameters of left ventricular function

Abstract Funding Acknowledgements Type of funding sources: None. Background Echocardiography has been widely used to study cardiac function in patients with end-stage renal disease on hemodialysis (HD), but cardiac function assessment by measuring cardiac dimensions and their rate of change is load dependent, therefore it is influenced by volume depletion. Effects of acute volume reduction on left (LV) and right ventricular (RV) function are still not well understood. Some studies investigated myocardial mechanics after dialysis using speckle tracking echocardiography (STE) but their relative load-dependency makes STE indices unable to account for changes in pre- and afterload. Myocardial work (MW) incorporates both deformation and load into its analysis and is an emerging tool to study LV myocardial function. There are no data about the effects of hemodialysis on LV MW. Purpose This study aimed to evaluate acute changes of novel echocardiographic indices of both LV and RV function after a HD session. Methods Patients with end-stage renal disease undergoing HD were prospectively enrolled. A transthoracic echo, including STE calculation of LV global longitudinal strain (GLS) and free wall RV strain, was performed before and after hemodialysis. Parameters of MW such as global work index (GWI), global constructive work (GCW), global work efficiency (GWE) and global wasted work (GWW) were quantified using a commercially available software package. Results 27 patients were enrolled, mean baseline parameters were: LV end-diastolic volume 136 ± 38 mL, LV ejection fraction (LVEF) 56.9 ± 7.5%, LV GLS -17.1 ± 4.1%, RV free wall strain -26.9 ± 5.6%, GWI 2117 ± 602 mmHg%, GCW 2299 ± 633 mmHg%, GWW 137 ± 88 mmHg, GWE 93 ± 3.6%, systolic arterial pressure 145 ± 26 mmHg and diastolic pressure 80 ± 16mmHg. After hemodialysis we observed a significative reduction in LV GLS (p = 0.04), RV strain (p = 0.002), GWI (p = 0.002, Figure I) and GCW (p = 0.004). No significative changes in LVEF and blood pressure were observed. Comparing patients using a LVEF cut-off of 55% (19 patients with LVEF≥55%, 8 patients &amp;lt;55%) we observed a significative reduction of LV GLS (p = 0.004), GWI (p &amp;lt; 0.001), GCW (p &amp;lt; 0.001) only in patients with LVEF ≥55% while RV strain and LV volume showed a reduction in both groups. We observed no significative differences in extracted volumes between the groups (2.6 vs 2.1 liters,p = 0.3). Patients with normal LVEF showed a significative negative variation (D) of LVEF (-1 vs 3%), GWI (-551 vs 38 mmHg%) and GCW (-522 vs 11 mmHg%). Correlations were found between DGWI and extracted volume (r= 0.46, p = 0.01), basal GWI and both DLVEF (r= 0.39, p = 0.04) and DLV GLS (r= 0,42, p = 0.02), basal LV GLS and DLVEF (r= 0.5, p &amp;lt; 0.01). Conclusions Our preliminary data show that, immediately after the HD session, there is a reduction in biventricular STE-derived systolic parameters. Patients with normal LV systolic function are more sensitive to acute volume changes and entity of volume depletion seems to be correlated with MW reduction. Abstract Figure.

Effect of Bronchoscopic Lung Volume Reduction in Advanced Emphysema on Energy Balance Regulation

Background: Hypermetabolism and muscle wasting frequently occur in patients with severe emphysema. Improving respiratory mechanics by bronchoscopic lung volume reduction (BLVR) might contribute to muscle maintenance by decreasing energy requirements and alleviating eating-related dyspnoea. Objective: The goal was to assess the impact of BLVR on energy balance regulation. Design: Twenty emphysematous subjects participated in a controlled clinical experiment before and 6 months after BLVR. Energy requirements were assessed: basal metabolic rate (BMR) by ventilated hood, total daily energy expenditure (TDEE) by doubly labelled water, whole body fat-free mass (FFM) by deuterium dilution, and physical activity by accelerometry. Oxygen saturation, breathing rate, and heart rate were monitored before, during, and after a standardized meal via pulse oximetry and dyspnoea was rated. Results: Sixteen patients completed follow-up, and among those, 10 patients exceeded the minimal clinically important difference of residual volume (RV) reduction. RV was reduced with median (range) 1,285 mL (−2,430, −540). Before BLVR, 90% of patients was FFM-depleted despite a normal BMI (24.3 ± 4.3 kg/m²). BMR was elevated by 130%. TDEE/BMR was 1.4 ± 0.2 despite a very low median (range) daily step count of 2,188 (739, 7,110). Following BLVR, the components of energy metabolism did not change significantly after intervention compared to before intervention, but BLVR treatment decreased meal-related dyspnoea (4.1 vs. 1.7, p = 0.019). Conclusions: Impaired respiratory mechanics in hyperinflated emphysematous patients did not explain hypermetabolism. Clinical Trial Registry Number: NCT02500004 at www.clinicaltrial.gov.

Lead-free solder SAC 305 Volume Reduction and Cold Slump after Stencil Printing Process

The present work studied on the volume reduction and cold slump effect for lead-free solder. The solder paste SAC305 type 3 was used to study the effect of waiting time on the solder volume and height at room temperature. DEK 265 was used for the printing purpose and KOH YOUNG Aspire 2 was fully utilized for the measurement of solder volume and solder height. The experiment was conducted for 120 minutes with 15 minutes gap between the measurements. Three types of components size (0603, SOT and Tantalum-D) was compared to see the effect on different components sizes. Solder paste volume and height shows a reduction from its initial values after 120 minutes for all three components size. For solder volume, biggest size component, Tantalum-D give lowest volume reduction at 3.55% compared to 0603 (3.68%) and SOT (3.76%). Meanwhile, solder height gives different results where Tantalum-D have the highest height reduction at 2.8% while SOT and 0603 have lower height reduction at 2.17% and 1.84% respectively.

Impacting Factors, Dynamic Process, and Correction of Adsorption Reduction in Shale Reservoir: A Case Study on Shale Samples from the Western Guizhou.

Adsorption reduction occurring during isothermal experiment leads to the failure of telling the true adsorption capacity of shale reservoir. A correct understanding of this will be helpful in improving the accuracy of resource estimation and economic evaluation of shale gas reserves. Six shale samples were collected from the Permian Longtan Formation in the western Guizhou Province, China. Volumetric methane isotherm adsorption experiment and data processing were conducted in this research. The study investigates the effect of free space volume reduction (FSVR), excess adsorption amount conversion (EAAC), and blank test correction (BTC) on adsorption reduction, the understanding of the dynamic process of adsorption reduction, and the evaluation of the way of weakening and correcting this phenomenon. The conclusions are as follows. (1) Adsorption reduction does exist in the shale sample. The adsorption process of methane in the shale sample can be divided into the strong adsorption stage, approximate saturation stage, and adsorption reduction stage. (2) Shale adsorbing methane has a positive effect on the experimental adsorption amount. Comparatively, free space volume, excess adsorption amount, and blank test have negative effects. Adsorption reduction is the result of combined influence of positive and negative effects above. (3) At the first two stages of methane adsorption, the positive effect is greater than the negative effect, resulting in the hidden of adsorption reduction, and the experimental adsorption amount increases with the growth of experimental pressure. While at the adsorption reduction stage, the former effect is smaller than the latter, and their difference increases as the experimental pressure increases. It leads to the occurrence of adsorption reduction, and the phenomenon becomes increasingly obvious. (4) FSVR has the strongest impact on the weakening of adsorption reduction, followed by EAAC and BTC. The adsorption reduction in shale reservoir can be corrected effectively by BTC and EAAC.

Comparison Studying of Concentrated and Traditional Infiltration of Rainfall Runoff in Sponge Cities

Many studies have been conducted on the volume reduction and pollutants purification effect of low impact development (LID). However, the comparison between the concentrated infiltration and traditional infiltration of rainfall runoff has been rarely explored. In this study, the difference between concentrated and traditional infiltration mode in sponge cities is analyzed from water infiltration and pollutant purification. Then the infiltration mechanism and the pollutant adsorption, microbial degradation, plant absorption or accumulation processes are compared thoroughly. At last the future development direction of sponge city is also prospected. The conclusion of this study could provide scientific basis and theoretical support for the rational allocation and popularization of rainfall runoff infiltration measures, and promote the healthy development of sponge cities in China.

Intérêt de la chirurgie de kystes pulmonaires liés à des dépôts de chaînes légères

Light chain deposition disease is a rare anatomo-clinical disorder, which rarely leads to cystic lung destruction. We report the case of a 62years old female patient with a history of a monoclonal gammopathy of unknown significance who developed progressive dyspnea. Thoracic CT-scan demonstrated a diffuse pulmonary cystic disorder with predominance in the right lower lobe. Thoracoscopic surgical resection of that lobe led to a diagnosis of non-amyloid kappa light chain deposits. Surgery also resulted in a lung volume reduction effect with clinical and functional benefits related to improved ventilation of adjacent segments. This report of pulmonary cystic disorder related to a light chain deposition disease highlights the potential clinical and functional benefits observed after lung volume reduction surgery.

Low-Capacitance Modular Multilevel Converter Operating With High Capacitor Voltage Ripples

To provide a reliable approach that can significantly decrease energy storage requirements, this paper proposes a low-capacitance modular multilevel converter (MMC) operating with high capacitor voltage ripples. In the proposed MMC with high ripples (HR-MMC), the dc value of the capacitor voltage is slightly decreased by slightly increasing the number of series-connected submodules in each arm. Therefore, the MMC can operate under a higher capacitor voltage ripple without changing the peak capacitor voltage. Evaluation shows that the cost and volume of the HR-MMC can be reduced due to the reduction of energy storage requirements. The volume reduction effect is particularly obvious. The impacts of the capacitor voltage ripple on the linear modulation region are also analyzed. The obtained active and reactive power diagram shows that the active power and capacitive reactive power ratings are not affected by the high capacitor voltage ripple. The high capacitor voltage ripple only results in a reduction of inductive reactive power rating. The correctness of the theoretical analysis and the feasibility of the HR-MMC were verified through simulations and experiments.

Low Smoking Exposure, the Adolescent Brain, and the Modulating Role of CHRNA5 Polymorphisms

BackgroundStudying the neural consequences of tobacco smoking during adolescence, including those associated with early light use, may help expose the mechanisms that underlie the transition from initial use to nicotine dependence in adulthood. However, only a few studies in adolescents exist, and they include small samples. In addition, the neural mechanism, if one exists, that links nicotinic receptor genes to smoking behavior in adolescents is still unknown. MethodsStructural and diffusion tensor magnetic resonance imaging data were acquired from a large sample of 14-year-old adolescents who completed an extensive battery of neuropsychological, clinical, personality, and drug-use assessments. Additional assessments were conducted at 16 years of age. ResultsExposure to smoking in adolescents, even at low doses, is linked to volume changes in the ventromedial prefrontal cortex and to altered neuronal connectivity in the corpus callosum. The longitudinal analyses strongly suggest that these effects are not preexisting conditions in those who progress to smoking. There was a genetic contribution wherein the volume reduction effects were magnified in smokers who were carriers of the high-risk genotype of the alpha 5 nicotinic receptor subunit gene, rs16969968. ConclusionsThese findings give insight into a mechanism involving genes, brain structure, and connectivity underlying why some adolescents find nicotine especially addictive.

Reducing lung liquid volume increases biventricular outputs and systemic arterial blood flows despite decreased cardiac filling pressures in fetal lambs.

As prior work has shown that reducing lung liquid volume 1) increases pulmonary arterial (PA) blood flow, 2) augments right ventricular (RV) output/power, and 3) decreases left atrial (LA) pressure, we tested the hypothesis that this perturbation has global cardiovascular effects. Ten anesthetized, open-chest fetal lambs (128 ± 2 days gestation, full term = 147 days) were acutely instrumented with 1) LA and right atrial (RA) catheters, 2) aortic and pulmonary trunk catheters, 3) brachiocephalic trunk, aortic isthmus, ductal, and left PA flow probes to obtain left ventricular (LV) and RV outputs and hydraulic power and flow in the descending thoracic aorta, and 4) an endotracheal tube to remove lung liquid. A 17 ± 7 ml/kg reduction of lung liquid volume 1) decreased LA and RA pressures similarly (1.5-1.6 mmHg, P < 0.001), 2) augmented LV and RV outputs (21-24%, P < 0.001) and total power (27-28%, P < 0.005), 3) increased systolic flows in the brachiocephalic trunk (18%, P < 0.001), aortic isthmus (29%, P < 0.005), ductus (12%, P < 0.005), and descending thoracic aorta (16%, P < 0.001), 4) increased mean PA flow via a higher systolic inflow (37%, P < 0.001) and lower diastolic backflow (-16%, P < 0.05), and 5) did not change systemic vascular conductance or arterial compliance but increased both pulmonary vascular conductance and arterial compliance (1.8-fold, P < 0.001). These data suggest that hemodynamic effects of lung liquid volume reduction are not confined to the lungs but extend to all cardiac chambers via rises in LV and RV outputs and power, despite falls in cardiac filling pressures, as well as the systemic circulation, via downstream increases in systolic flows of major central arteries.

A novel storage driven granular post denitrification process: Long-term effects of volume reduction on phosphate recovery

Anoxic granular biomass with enhanced biological phosphorus (P) removal was used in a post-denitrification configuration to concentrate P in wastewater. The study examined the use of anoxic granules to facilitate application of volume reduction to create a P-enriched stream (>100 mg-P/L). The results indicated the importance of maintaining a food to microorganism (F/M) ratio of ∼0.124 g-COD/g-MLSS.d to achieve P and nitrogen (N) removal close to 100%. While granulation required a short settling time and a high-volume exchange ratio, biomass wasting was essential to control the F/M ratio to maintain a suitable microbial diversity and abundance. Diversity and abundance were also impacted by volume reduction, but the effect of this was marginal compared with the effect of decreasing F/M ratio. Furthermore, a decrease in the F/M ratio enhanced sedimentation (SVI5 decreased from 55.5 to 32.0 mL/g-MLSS) but decreased dewaterability (capillary suction time increased from 15.5 s to 19.4 s). Recovery of P as a concentrated liquor had minimal impact on the bacterial diversity.

Compact Storage of Radioactive Cesium in Compressed Pellets of Zeolite Polymer Composite Fibers.

To facilitate the safe storage of radioactive Cs, a zeolite–poly(ethersulfone) composite fiber was fabricated to be a compact storage form of radioactive Cs, and an immobilization was investigated with respect to the effects of volume reduction and stability of the fiber’s adsorbent matrix. Using compressed heat treatment at 100–800 °C for a zeolite polymer composite fiber (ZPCF) containing Cs, the fabrication changed its form from a fiber into a pellet, which decreased the matrix volume to be about one-sixth of its original volume. The Cs leakage behavior of the ZPCF matrix was examined in its compact pellet form for non-radioactive Cs and radioactive Cs when different fabrication conditions were carried out in the immobilization. The elution ratio of non-radioactive Cs from the matrix was minimal, at 0.05%, when the ZPCF was compressed with heat treatment at 300 °C. When using radioactive Cs for the compression at below 300 °C, the pellet form also had no elution of the pollutants from the matrix. When the compressed treatment was at 500 °C, the matrix exhibited elution of radioactive Cs to the outside, meaning that the plastic component was burning and decomposed in the pellet. A comparison of ZPCF and natural zeolite indicated that the compressed heating process for ZPCF was useful in a less-volume-immobilized form of the compact adsorbent for radioactive Cs storage.

Lung volume reduction with endobronchial coils for patients with emphysema.

The lung volume reduction coil treatment is a minimally invasive bronchoscopic treatment option for emphysema patients who suffer from severe hyperinflation. The treatment is aimed at a large group of patients where lung volume reduction surgery and bronchoscopic lung volume reduction using endobronchial valves are no option, or alternatively, can be offered as a bridge to lung transplantation. The nitinol coil exhibits a shape memory effect and is biologically inert. The lung volume reduction coil procedure is performed in two separate treatment sessions, targeting one lobe per session, with the contralateral lobe being treated 4 to 8 weeks after the first session. In one treatment session, around 10 to 14 coils, thereby treating an entire lobe, are being placed. Selecting optimally treated, symptomatic chronic obstructive pulmonary disease (COPD) patients with emphysema and severe hyperinflation, while avoiding significant airway disease such as asthma, chronic bronchitis and bronchiectasis, is key to achieve treatment success. Three randomized clinical trials investigating lung volume reduction coil treatment have been published until now, reporting the results of 452 treated patients up to 12 months after coil treatment. Lung volume reduction coil treatment results in significant improvement of pulmonary function outcomes and quality of life in patients with severe hyperinflation. The most common complications of lung volume reduction coil treatment are: COPD exacerbations, pneumonia, Coil Associated Opacity and an increased risk of pneumothorax. The purpose of this article is to describe the coil technique and review the available literature regarding effect, safety and future perspectives of lung volume reduction with coils for emphysema patients.

Histotripsy for Non-Invasive Ablation of Hepatocellular Carcinoma (HCC) Tumor in a Subcutaneous Xenograft Murine Model.

Histotripsy fractionates tissue through a mechanical, non-invasive ultrasonic ablation process that precisely controls acoustic cavitation while utilizing real-time ultrasound (US) imaging guidance. This study investigates the potential, feasibility and tumor volume reduction effects of histotripsy for liver cancer ablation in a subcutaneous in vivo murine Hepatocellular Carcinoma (HCC) model. Hep3B tumors were generated in the right flanks of 14 NSG and 7 NOD-SCID mice. The mice were grouped as follows: A (acute, NSG with n=9 treatment and n=1 control), B (chronic, NSG with n=2 treatment and n=2 control) and C (chronic NODSCID, with n=6 treatment and n=1 control). Treatment was performed when the tumor diameters reached >5 mm. 1-2 cycle histotripsy pulses at 100 Hz PRF (p- >30 MPa) were delivered using a custom built 1 MHz therapy transducer attached to a motorized positioner, which scanned the transducer focus to traverse the targeted tumor volume, guided by real-time US imaging. Tumor ablation effectiveness was assessed by obtaining T1, T2 and T2* weighted MR images. Post euthanasia, treated tumor, brain, and lung tissue samples were harvested for histology. Histology of acute group A showed fractionation of targeted region with a sharp boundary separating it from untreated tissue. Groups B and C demonstrated effective tumor volume reduction post treatment on MRI as the homogenate and edema were resorbed within 23 weeks. However, as the tumor was subcutaneous, it was not possible to set adequate treatment margin and since the mice were immune-compromised, residual viable tumor cells eventually developed into tumor regrowth at 3-9 weeks after histotripsy. Groups B and C showed no signs of metastasis in the lung and brain. Our study successfully demonstrated the potential of histotripsy for non-invasive HCC ablation in a subcutaneous murine model. Additional work is ongoing to study the response of histotripsy in immune-competent orthotopic liver tumor models.

Abstract No. 495 Non-invasive liver tumor ablation using histotripsy in an in vivo subcutaneous murine hepatocellular carcinoma model

Histotripsy is a non-thermal, non-invasive ultrasound (US) ablation method that fractionates tissue through the precise control of acoustic cavitation guided by real-time US imaging. Histotripsy has the potential to improve treatment consistency and precision compared to thermal-based ablation methods. This study evaluates the feasibility and tumor volume reduction effects of histotripsy for liver cancer ablation in an in vivo murine HCC model. Subcutaneous xenograft tumors were generated by injecting human HCC Hep3B cells into 14 NSG mice (acute group A: treated n = 9, control n = 1 and chronic group B: treated n = 2, control n = 2) and 6 NOD-SCID mice (chronic group C: treated n = 6). Once tumors reached >5 mm, mice were treated by histotripsy using a custom built 1 MHz histotripsy transducer attached to a motorized positioner guided by US imaging system. 1-2 cycle histotripsy pulses at 100 Hz PRF (p- >30 MPa) were applied to the tumor volume. MRI was performed pre- and posttreatment to assess tumor ablation. Group A was sacrificed within 3 days post treatment. Groups B and C were monitored weekly using caliper measurements and MRI for 3 months or until tumors reached ∼1.8 cm. Tumor, brain and lung tissues were harvested for histology. Histotripsy-generated cavitation cloud and the treated region were visible on US imaging enabling real-time feedback. In group A, histopathology showed that the targeted region was completely fractionated into acellular debris with a sharp boundary. In groups B and C, MRI revealed effective tumor volume reduction post treatment as the homogenate and edema were resorbed within 3 weeks. However, as the subcutaneous tumor does not allow sufficient treatment margin, residual viable tumor cells developed into tumor regrowth at 3-9 weeks after treatment. Treated mice in group B survived 2-3 times longer than the control mice and showed no signs of metastasis in the lung and brain. At the time of submission, group C mice are being monitored until study endpoint. This study demonstrates the potential of histotripsy for non-invasive liver tumor ablation. Future work will study the biological response in immune competent orthotopic liver tumor models.

Effect of Radiation Treatment Volume Reduction on Lymphopenia in Patients Receiving Chemoradiotherapy for Glioblastoma

Toevaluate whether reduction in glioblastoma radiation treatment volume can reduce risk of acute severe lymphopenia (ASL). A total of 210 patients with supratentorial/nonmetastatic glioblastoma were treated with radiation therapy (RT) plus temozolomide from 2007 to 2016 and had laboratory data on total lymphocyte counts. Before 2015, 164 patients were treated with standard-field RT (SFRT), and limited-field RT (LFRT) was implemented thereafter for 46 patients to reduce treatment volume. Total lymphocyte counts were evaluated at baseline, during RT, and at approximately week 12 from initiating RT. Acute severe lymphopenia was defined as any total lymphocyte count < 500cells/μL within 3months (by week 12) of initiating RT. Multivariate analysis for overall survival (OS) was performed with Cox regression and with logistic regression for ASL. Propensity score matching was performed to adjust for variability between cohorts. Acute severe lymphopenia, progression-free survival (PFS), and OS were compared using the Kaplan-Meier method. Limited-field RT patients had higher gross tumor volume than SFRT patients yet lower brain dose-volume parameters, including volume receiving 25Gy (V25Gy: 41% vs 53%, respectively, P<.01). Total lymphocyte count at week 12 was significantly higher for LFRT than for SFRT (median: 1100cells/μL vs 900cells/μL, respectively, P=.02). On multivariate analysis, ASL was an independent predictor of OS, and brain V25Gy was an independent predictor of ASL. The ASL rate at 3months was 15.5% for LFRT and 33.8% for SFRT (P=.12). In a propensity-matched comparison of 45 pairs of LFRT and SFRT patients, PFS (median: 5.9 vs 6.2months, respectively, P=.58) and OS (median: 16.2 vs 13.9months, respectively, P=.69) were not significantly different. Limited-field RT is associated with less lymphopenia after RT plus temozolomide and does not adversely affect PFS or OS. Brain V25Gy is confirmed as an important dosimetric predictor for ASL.

Percutaneous laser ablation of benign thyroid nodules: a one year follow-up study.

ABSTRACTObjective To evaluate safety and effectiveness of nodule volume reduction and thyroid function after percutaneous laser ablation treatment in patients with benign nonfunctioning thyroid nodules.Methods Prospective single-center study, from January 2011 to October 2012, which evaluated 30 euthyroid and thyroid antibodies negative patients with benign solitary or dominant nodule with indication of treatment due to compressive symptoms and aesthetic disturbances. The clinical and laboratory (thyroid ultrasound, TSH, FT4, TG, TG-Ab, TPO-Ab and TRAb levels) evaluations were performed before the procedure, and periodically 1 week, 3 months and 6 months after. The ablation technique was performed under local anesthesia and sedation. In each treatment, one to three 21G spinal needle were inserted into the thyroid nodule. The laser fiber was positioned through the needle, which was then withdrawn 10mm to leave the tip in direct contact with the nodule tissue. Patients were treated with a ND: Yag-laser output power of 4W and 1,500 to 2,000J per fiber per treatment. The entire procedure was performed under US guidance.Results Thirty patients, with a total of 31 nodules submitted to laser ablation were evaluated. The median volumetric reduction of the nodule was approximately 60% after 12 months. No statistical significance was observed on thyroid function and antibodies levels. There was a peak on the level of thyroglobulin after the procedure due to tissue destruction (p<0.0001). No adverse effects were observed.Conclusion Percutaneous laser ablation is a promising outpatient minimally invasive treatment of benign thyroid nodule.