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At least 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Associations between cadmium levels in blood and urine, blood pressure and hypertension among Canadian adults

Background: Cadmium has been inconsistently related to blood pressure and hypertension. The present study seeks to clarify the relationship between cadmium levels found in blood and urine, blood pressure and hypertension in a large sample of adults. Methods: The study sample included participants ages 20 through 79 from multiple cycles of the Canadian Health Measures Survey (2007 through 2013) with measured blood cadmium (n=10,099) and urinary cadmium (n=6988). Linear regression models examined the association between natural logarithm transformed cadmium levels and blood pressure (separate models for systolic and diastolic blood pressure) after controlling for known covariates. Logistic regression models were used to examine the association between cadmium and hypertension. Models were run separately by sex, smoking status, and body mass index category. Results: Men had higher mean systolic (114.8 vs. 110.8 mmHg, p<0.01) and diastolic (74.0 vs. 69.6 mmHg, p<0.01) blood pressure compared to women. Although, geometric mean blood (0.46 vs. 0.38 µg/L, p<0.01) and creatinine-adjusted standardized urinary cadmium levels (0.48 vs. 0.38 µg/L, p<0.01) were higher among those with hypertension, these differences were no longer significant after adjustment for age, sex and smoking status. In overall regression models, increases in blood cadmium were associated with increased systolic (0.70 mmHg, 95% confidence interval [CI]=0.25–1.16, p<0.01) and diastolic blood pressure (0.74 mmHg, 95% CI=0.30–1.19, p<0.01). The associations between urinary cadmium, blood pressure and hypertension were not significant in overall models. Model stratification revealed significant and negative associations between urinary cadmium and hypertension among current smokers (OR=0.61, 95% CI=0.44–0.85, p<0.01), particularly female current smokers (OR=0.52, 95% CI=0.32–0.85, p=0.01). Conclusion: This study provides evidence of a significant association between cadmium levels, blood pressure and hypertension. However, the significance and direction of this association differs by sex, smoking status, and body mass index category. - Highlights: • Blood and urinary cadmium levels higher among those with hypertension. • Evidence of association between cadmium levels, blood pressure and hypertension. • Significance and direction of association differs by sex, smoking status, and BMI. • Higher urinary cadmium levels lower hypertension risk for current (female) smokers.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Ecological analysis of associations between groundwater quality and hypertension and cardiovascular disease in rural Saskatchewan, Canada using Bayesian hierarchical models and administrative health data

Highlights: • Hardness and magnesium were associated with decreased risk of cardiovascular disease. • Arsenic concentrations were not associated with the risk of cardiovascular disease. • Summarized water health standards were not associated with cardiovascular disease. Associations between groundwater quality and the prevalence of hypertension and ischemic heart disease were investigated in rural areas of the Canadian province of Saskatchewan. The partially ecological study was analyzed using Bayesian hierarchical models to account for spatial variability in risk. Exposure measures and health outcomes were estimated based on previously collected water quality surveillance data from public water supplies and private wells and administrative health data. Water quality exposures for each study region were estimated by applying geostatistical techniques to arsenic concentrations and principal component (PC) scores. The PC scores summarized groups of parameters measuring either health standards or aesthetic objectives described by the province. Generalized linear mixed models with a log link assessed associations between water quality and observed count of health outcomes relative to the expected value. The Bayesian models contained uncorrelated and spatially correlated random effects for each geographic region. Effect estimates were controlled for sex and age by stratification of case and expected case counts, for smoking by inclusion of sex- and age-specific prevalence of chronic obstructive pulmonary disease as a surrogate covariate, and for education and income by use of census data. There was no evidence for associations between groundwater arsenic concentrations in public or private water supplies and increased risk of hypertension or cardiovascular disease. An increase in the second aesthetic objectives PC score from public supplies was associated with a protective effect against ischemic heart disease. This PC value summarized hardness and magnesium Similarly, an increase in the second aesthetic objectives PC in private supplies was associated with decreased prevalence of hypertension. The results of this study are consistent with others demonstrating a relationship between elevated hardness and magnesium concentrations in drinking water and reduced risk of hypertension and cardiovascular disease. Further investigation is warranted with individual exposure history, particularly with respect to the potential beneficial effect of hard water on the prevalence of hypertension and cardiovascular disease.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

System efficiency of packed bed TES with radial flow vs. axial flow – Influence of aspect ratio

Here, this paper compares the net system efficiency, including thermal efficiency and pressure drop effects, of radial versus axial flow packed beds for thermal energy storage. The traditional packed bed system is a cylindrical geometry where fluid flows axially from one end to another. However, issues of thermal stratification and high-pressure drop have led to recent studies on radial flow systems. One potential benefit is the reduced pressure drop in a radial flow system. This paper compares the performance of radial flow and axial flow systems at a range of aspect ratios (AR = H/D bed ) from 0.21 to 1.92 using a numerical model where the storage volume is held constant in all cases. When the radial flow bed is at a low aspect ratio (short/wide), the thermal front is improved but the pressure drop is high. At a high aspect ratio, the velocity is reduced in radial flow, leading to decreased pressure drop but an increased spreads in the thermal front that lowers thermal efficiency. The opposite trends are noted in axial flow. Thermal efficiencies of 83–91 % were noted for radial flow, while they ranged from 85 to 94 % in axial flow. Net efficiencies including pressure drop ranged from 74 to 82 % for radial flow and 80–87 % for axial flow. In both systems, a peak net efficiency was noted between the highest and lowest aspect ratio. While some aspect ratios with radial flow outperform axial flow from a net efficiency perspective, the results show that the highest net efficiency from axial flow is higher than that from radial flow. Overall, this paper highlights the importance of innovative TES designs and their potential to improve energy efficiency.

25 ENERGY STORAGE↗
DOE OSTI2025

Dehumidification energy storage using a stratified liquid desiccant tank

Liquid desiccants can play an important role in reducing dehumidification energy requirements in the built environment. Because they are in a liquid state, the desiccant can be easily stored and then used to dehumidify buildings during peak energy consumption periods. By maintaining stratification between concentrated and diluted desiccant solutions, a single tank can be used to store liquid desiccant for energy storage purposes. Using a stratified tank instead of separate tanks for dilute and concentrated solutions will reduce storage costs and increase energy storage densities for liquid desiccant systems. This paper describes the experimental validation and one-dimensional modeling of a stratified liquid desiccant tank. The stratified tank prototype developed achieved 80 % of the theoretical energy storage density based on an imposed desiccant concentration change. Here, the stratified tank model was able to reasonably reproduce the experimental results. Using this model, the impact of varying operational conditions on the energy density of the stratified liquid desiccant energy storage was evaluated. Depending on the operating conditions, stratified liquid desiccant energy storage using aqueous LiCl up to 40 wt% can achieve energy storage densities in excess of 330 kWh/m 3 .

25 ENERGY STORAGE↗
DOE OSTI2022

Fuel property impacts on gaseous and PM emissions from a multi-mode single-cylinder engine

The U.S. Department of Energy’s Co-Optima initiative has focused on improving fuel economy and vehicle performance while reducing emissions through the simultaneous development of emerging sustainable fuels with beneficial properties and advanced combustion strategies. A major thrust has been the development of advanced compression ignition (ACI) combustion strategies of gasoline range fuels in combination with spark-ignited (SI) combustion in a single engine capable of multi-mode operation to achieve high power density with enhanced part load efficiency. The aim of this study was to further the understanding of how emissions from both ACI and SI strategies operating on the same fuels in the same engine are impacted by different fuel properties. This investigation focused on particulate matter (PM) and gaseous hydrocarbon emissions from 6 different fuels across 3 different combustion modes on the same single-cylinder engine designed for multi-mode operation: SI combustion, partial fuel stratification (PFS), and spark-assisted compression ignition (SACI). In each of these modes, 3 different CA50 phasings were studied such that all 6 fuels could be studied at the same phasings. Three of the six different fuels used were specially formulated in a previous investigation to study the impact of fuel distillation and aromatic content while maintaining the research octane number (RON) and octane sensitivity. Additionally, neat isooctane and two ethanol containing fuels (RD5-87 and Co-Optima E30) were studied. Different fuel and phasing impacts on emissions were observed across the three combustion modes. Fuel properties were found to impact soot PM and particle number more than the CA50 phasing, while the phasing had more impact on NOx emissions. The NOx emissions were reduced in the PFS mode for all fuels compared to SI combustion, but the SACI combustion mode did not reduce NOx emissions. Although PFS produced low soot PM emissions like SI, total PM mass emissions were significantly higher due to large organic carbon (OC) PM mass contribution. Both PFS and SACI had greater particle number emission than SI operation with small nuclei mode particles dominating in PFS compared to large agglomeration particles in SACI.

42 ENGINEERING↗
DOE OSTI2022

An indirect approach to optimize the reaction rates of thermal NO formation for diesel engines

With stringent emission regulations, it has become more important for modern diesel engine manufacturers to accurately predict engine-out nitrogen oxide (NO x ) emissions across a wide range of operating conditions. Thermal NO is the major source of engine-out NO x in modern diesel engines. For thermal NO formation, several earlier studies have recommended the forward and reverse reaction rate coefficients of the rate-limiting reaction (O + N 2 ⇌ NO + N). However, due to deficiencies in sub-models and inadequacies of reduced chemical mechanisms to represent diesel combustion, these recommended values more often than not need to be adjusted in reduced order combustion models to accurately predict engine-out NO x . Hence, in this work a systematic and computationally efficient approach has been proposed to streamline the process of determining the optimum reaction rate coefficients. Here, to develop the optimization approach, four different production diesel engines with different operating conditions in terms of speed, load, and exhaust-gas recirculation have been considered. Numerical simulations have been performed using a detailed zero-dimensional velocity-composition-frequency transported probability density function (0D-VCF-tPDF) model that uses hundreds of notional particles to capture in-cylinder stratification. Four different combinations of hydrocarbon and NO x chemical mechanisms were used to represent chemistry. It was found that for the rate-limiting reaction, the pre-exponent factors (A f1 , A r1 ) and activation energies (E A,f1 , E A,r1 ) of the forward and reverse reaction rates follow a linear band in A f1 - E A,f1 and A r1 - E A,r1 space where predicted engine-out NO x match the measured values closely. By encompassing such bands from different engines and considering constraints on activation energies, a reduced search domain of pre-exponent factors and activation energies was constructed that is expected to be applicable to any diesel engine. Eventually, computationally efficient three-line and one-line search approaches were proposed to determine the optimum values of the pre-exponent factors and activation energies that led to a minimum error between measured and predicted engine-out NO x . Finally, these three-line and one-line NO x optimization approaches were applied to a fifth production diesel engine for which the 0D-VCF-tPDF model showed a very good predictive performance in terms of predicting peak pressure, 50% burn rate, and engine-out NO x when compared to measured and 3D-CFD values.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2020

Sr-Nd-Pb isotope systematics of Australasian tektites: Implications for the nature and composition of target materials and possible volatile loss of Pb

The Australasian tektite (AAT) strewn field is the largest strewn field on the Earth with about ~10–30% coverage, both land and ocean, but a clearly identified source impact crater is absent despite the young age of AAT of ca. 790 ka. A genetic link between the Australasian tektites and their unequivocal parental materials is therefore largely impossible to establish. Nevertheless, the nature of the parental materials and the extent of volatilization can be constrained using the splash form tektites, carrying the chemical signatures of high-temperature processes, and the layered (so-called Muong Nong-type) tektites, which are less chemically homogenized and exceptionally abundant in the AAT field. New high-precision Sr, Nd and Pb isotopic measurements were obtained for a chemically and petrographically well-characterized suite of AAT, which included the Muong Nong-type (MN-AAT) with precisely known field locations in Laos and splash forms (SF-AAT) from different parts of the strewn field. Additionally, optically dark and light zones of the MN-AAT were also separately analyzed. Homogeneous ε Nd values from -11.8 to -11.2, combined with a narrow range of two-stage Nd model ages from 1.67 to 1.72 Ga for the entire AAT suite, point to a well-mixed source, in terms of REE, of the crustal segment from which the sedimentary material for tektites was ultimately derived. The Sr isotopic data largely overlap for SF-AAT and MN-AAT ( 87 Sr/ 86 Sr = 0.71636–0.72021) and indicate Paleozoic to Mesozoic sedimentary parentage. However, late Neogene to early Quaternary re-deposition and formation of a thick silt-sized sedimentary section with vertical stratification is required to comply with 10Be data. Lead isotope systematics documents at least three different components which can perhaps be represented by different mineral phases, such as feldspar, zircon, organic matter adsorbed on young sediments etc., sorted during fluvial transport and final deposition. In addition, the SF-AAT have systematically lower Pb contents than the MN-AAT, and generally show isotopically heavier Pb isotopic ratios. This is theoretically consistent with a preferential volatilization of lighter Pb isotopes during evaporation and considerably larger Pb loss from SF-AAT when compared to MN-AAT. Nevertheless, further experimental work would be necessary to unambiguously distinguish kinetic fractionation from source mixing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Multi-site evaluation of stratified and balanced sampling of soil organic carbon stocks in agricultural fields

Estimating soil organic carbon (SOC) stocks in agricultural fields is essential for environmental and agronomic research, management, and policy. Stratified sampling is a classic strategy for estimating mean soil properties, and has recently been codified in SOC monitoring protocols. However, for the specific task of estimating the SOC stock of an agricultural field, concrete guidance is needed for which covariates to stratify on and how much stratification can improve estimation efficiency. It is also unknown how stratified sampling of SOC stocks compares to modern alternatives, notably doubly balanced sampling. To address these gaps, we collected high-density (average of 7 samples ha -1 ) and deep (average of 75 cm) measurements of SOC stocks at eight commercial fields under maize-soybean production in two US Midwestern states. We combined these measurements with a Bayesian geostatistical model to evaluate stratified and balanced sampling strategies that use a set of readily-available geographic, topographic, spectroscopic, and soil survey data. We examined the number of samples needed to achieve a given level of SOC stock estimation accuracy. While stratified sampling using these variables enables an average sample size reduction of 17% (95% CI, 11% to 23%) compared to simple random sampling, doubly balanced sampling is consistently more efficient, reducing sample sizes by 32% (95% CI, 25% to 37%). The data most important to these efficiency gains are a remotely-sensed SOC index, SSURGO estimates of SOC stocks, and the topographic wetness index. We conclude that in order to meet the urgent challenge of climate change, SOC stocks in agricultural fields could be more efficiently estimated by taking advantage of this readily-available data, especially with doubly balanced sampling.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Constraining the magnitude of the carbon isotope excursion during the Paleocene-Eocene thermal maximum using larger benthic foraminifera

The Paleocene-Eocene thermal maximum (PETM) was an extraordinary pulse of global warming approximately 56 Ma. This warmingevent is associated with an addition of large amounts of 13C-depleted carbon into the atmosphere-ocean system, but the magnitude of the negative carbon isotope excursion (CIE)signaling the PETMand often used to estimate mass of the released carbonis still debated. Here we gauge the CIE magnitude usingsecondary ion mass spectrometry (SIMS) to perform in situ δ 13 C measurements within individual larger benthic foraminifera preserved in a tropical shallow marine limestone section in south Tibet. This SIMS-based δ 13 C record yields a negative CIE (Δ~7‰) comparable in magnitude to that registered by terrestrial records but larger than the ~4‰CIE returned by surface-dwelling planktonic foraminiferain deep-sea records. We therefore posit that the CIE magnitude was~7‰ in the surface ocean, and that theprevious~4‰ estimates for the CIE areattenuated by incomplete preservation and diagenetic overprinting. The large CIE magnitude in the surface ocean (~7‰) and the evidently smaller CIE magnitude registeredby deep-sea benthic foraminifera(~2-3.5‰) arelikely a function of rateand duration of carbon release as well as ocean stratification during the PETM.

58 GEOSCIENCES↗
DOE OSTI2023

Observations of multi-ion physics and kinetic effects in a surrogate to the solar CNO reactions

The ‘CNO process’ occurs in heavier stars with finite metallicity in which hydrogen burning is catalyzed in the presence of 12 C. These reactions are more strongly dependent on temperature than the pp cycle reactions, and thus the CNO cycle dominates only in massive stars. For these types of reactions to be studied at ICF facilities such as OMEGA, an implosion platform using heavier nuclei in the fuel and capable of creating ion temperatures on the order of at least 20 keV is required. A potential route to reach these conditions is to take advantage of kinetic effects in low-convergence shock-driven ‘exploding pusher’ implosions. In this experiment, shots were conducted at the OMEGA laser facility using the surrogate reaction 13 C + D. Its cross section is substantially higher than the actual astrophysical CNO reactions. The yield of this reaction in these implosions was much lower than expected. Finally, physical explanations are discussed, with significant species stratification the likely explanation.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2026

Modeling and Experimental Validation of a Direct-Contact Counter-Flow Fluidized Bed Heat Exchanger for Thermal Energy Storage (TES) Applications

Particle-based thermal energy storage (TES) systems are an emerging energy storage technology. The technological advances have reduced costs, making TES more competitive and reliable in the marketplace but an efficient and reliable operation is heavily dependent on coherent heat transfer between air to particles or vice versa. The particle-based TES technologies provide an intermediate system that can store energy for short (0-10 h), long (10-200 h) and seasonal (> 200 h) timescales. The TES systems store energy by converting electricity to thermal energy; electricity can be directly sourced intermittent generation technologies and/or the grid, helping manage peak loads and other mismatches in supply and demand. The overall efficiency of the TES system depends on the performance of system components (particle storage silos and particle transfer mechanism etc.). The particle heat exchanger is one of the key system components that affects the system efficiency. The pressurized fluidized bed heat exchanger (PFB HX) performance is challenging to predict due to the chaotic behavior of particle and fluid interaction. This research presents a computational study of a novel direct-contact, counter-flow and air-to-particles PFB HX, that contributes in advancing the particle-based long-duration TES technologies. For the current analysis an unsteady Eulerian-Eulerian CFD model was developed and validated against experiments performed at the National Laboratory of the Rockies for two particle sizes (600 ..mu..m and 825 ..mu..m ). Following validation, parametric simulations were conducted to evaluate the effects of interphase drag models (Syamlal-O'Brien and Gidaspow), particle size, bed height and the influence of a frictional-viscosity term on hydrodynamics and heat transfer between the air & particles. The key findings from the analysis are: (1) for the studied operating window Syamlal-O'Brien provides superior agreement with measured gas temperatures (errors generally < 10%) while Gidaspow shows large deviations for the coarse particle case; (2) model predictions are most sensitive in the lower 0.2 m above the air distributor where bubble initiation and local mixing dominate interphase heat transfer; (3) representation of the distributor (number of inlet ports) materially affects predicted local mixing and temperature stratification; and (4) the Eulerian-Eulerian framework reproduces bulk thermal trends but shows regime dependent limitations for coarse particles, motivating mesoscale informed closures for scale-up analysis for future studies. These results provide validated guidance for drag selection and distributor design in particle-based thermal energy storage applications. Collectively, the validated model and parametric results quantify key drivers of PHB-HX performance and provide practical guidance for design and optimization. The results provide confidence in the model predictability and provide a step forward to improve on heat exchange performance. The demonstrated performance and modeling approach support the deployment and further development of this novel PHB-HX concept for robust, particle-based long-duration thermal energy storage systems.

25 ENERGY STORAGE↗
DOE OSTI2023

Logarithmic scaling of higher-order temperature moments in the atmospheric surface layer

A generalized logarithmic law for high-order moments of homogeneous passive scalars is proposed for turbulent boundary layers. This law is analogous to the generalized log law that has been proposed for high-order moments of the turbulent longitudinal velocity and is derived by combining the random sweeping decorrelation hypothesis with a spectral model informed by the attached eddy hypothesis. The proposed theory predicts that the high-order moments of passive scalar fluctuations within the inertial sublayer will vary logarithmically with wall-normal distance (), and is evaluated using high frequency time-series measurements of temperature and streamwise velocity fluctuations obtained in the first meter of the atmospheric surface layer (ASL) under near-neutral thermal stratification. The logarithmic dependence with within the inertial sublayer is observed in both the air temperature and velocity moments, with good agreement to the predictions from the proposed theory. Surprisingly, the proposed theory appears to be as, if not more, valid for transported passive scalars than for the longitudinal velocity.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Developing Science-based fueling protocols for 250-bar hydrogen tanks onboard hydrogen ferries: Experiments and modeling

Combined modeling and experimental studies are reported of the fueling of a large (28 kg capacity) 250-bar Type IV hydrogen tank of the type being deployed on early hydrogen ferries, such as the MV Sea Change. The primary goal was to determine how such tanks can be successfully fueled with hydrogen (state of charge greater than 97%) within 45 minutes without exceeding the 82 °C temperature limit for such tanks. The modeling studies show that a gas injector is needed to avoid thermal stratification during hydrogen fueling which can result in potential hot spots. Empirically, precooling of the hydrogen to 0 °C was found to be needed in some of the cases examined, as ambient conditions greatly affected the need for a precooling to achieve the 45-minute fill time desired by end users. The experimental results afforded a calibration of the engineering model SOFIL for these large 250-bar tanks, which now enables using SOFIL to predict volume-averaged hydrogen fueling temperatures to an accuracy of ±2.7°C for these tanks. The model can therefore be used to evaluate potential scenarios for development of a standardized fueling methodology for ferries utilizing large Type-IV tanks.

08 HYDROGEN↗
DOE OSTI2016

Factors Associated With Early Mortality in Patients Treated With Concurrent Chemoradiation Therapy for Locally Advanced Non-Small Cell Lung Cancer

Purpose: Concurrent chemoradiation therapy (con-CRT) is recommended for fit patients with locally advanced non-small cell lung cancer (LA-NSCLC) but is associated with toxicity, and observed survival continues to be limited. Identifying factors associated with early mortality could improve patient selection and identify strategies to improve prognosis. Methods and Materials: Analysis of a multi-institutional LA-NSCLC database consisting of 1245 patients treated with con-CRT in 13 institutions was performed to identify factors predictive of 180-day survival. Recursive partitioning analysis (RPA) was performed to identify prognostic groups for 180-day survival. Multivariate logistic regression analysis was used to create a clinical nomogram predicting 180-day survival based on important predictors from RPA. Results: Median follow-up was 43.5 months (95% confidence interval [CI]: 40.3-48.8) and 127 patients (10%) died within 180 days of treatment. Median, 180-day, and 1- to 5-year (by yearly increments) actuarial survival rates were 20.9 months, 90%, 71%, 45%, 32%, 27%, and 22% respectively. Multivariate analysis adjusted by region identified gross tumor volume (GTV) (odds ratio [OR] ≥100 cm{sup 3}: 2.61; 95% CI: 1.10-6.20; P=.029) and pulmonary function (forced expiratory volume in 1 second [FEV{sub 1}], defined as the ratio of FEV{sub 1} to forced vital capacity [FVC]) (OR <80%: 2.53; 95% CI: 1.09-5.88; P=.030) as significant predictors of 180-day survival. RPA resulted in a 2-class risk stratification system: low-risk (GTV <100 cm{sup 3} or GTV ≥100 cm{sup 3} and FEV{sub 1} ≥80%) and high-risk (GTV ≥100 cm{sup 3} and FEV{sub 1} <80%). The 180-day survival rates were 93% for low risk and 79% for high risk, with an OR of 4.43 (95% CI: 2.07-9.51; P<.001), adjusted by region. A clinical nomogram predictive of 180-day survival, incorporating FEV{sub 1}, GTV, N stage, and maximum esophagus dose yielded favorable calibration (R{sup 2} = 0.947). Conclusions: This analysis identified several risk factors associated with early mortality and suggests that future research in the optimization of pretreatment pulmonary function and/or functional lung avoidance treatment may alter the therapeutic ratio in this patient population.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Eastern Cooperative Oncology Group and American College of Radiology Imaging Network Randomized Phase 2 Trial of Neoadjuvant Preoperative Paclitaxel/Cisplatin/Radiation Therapy (RT) or Irinotecan/Cisplatin/RT in Esophageal Adenocarcinoma: Long-Term Outcome and Implications for Trial Design

Purpose: Toxicity, pathologic complete response, and long-term outcomes are reported for the neoadjuvant therapies assessed in a randomized phase 2 Eastern Cooperative Oncology Group and American College of Radiology Imaging Network trial for operable esophageal adenocarcinoma, staged as II-IVa by endoscopy/ultrasonography (EUS). Methods and Materials: A total of 86 eligible patients began treatment. For arm A, preoperative chemotherapy was cisplatin, 30 mg/m{sup 2}, and irinotecan, 50 mg/m{sup 2}, on day 1, 8, 22, 29 during 45 Gy radiation therapy (RT), 1.8 Gy per day over 5 weeks. Adjuvant therapy was cisplatin, 30 mg/m{sup 2}, and irinotecan, 65 mg/m{sup 2} day 1, 8 every 21 days for 3 cycles. Arm B therapy was cisplatin, 30 mg/m{sup 2}, and paclitaxel, 50 mg/m{sup 2}, day 1, 8, 15, 22, 29 with RT, followed by adjuvant cisplatin, 75 mg/m{sup 2}, and paclitaxel, 175 mg/m{sup 2}, day 1 every 21 days for 3 cycles. Stratification included EUS stage and performance status. Results: In arm A, median overall survival was 35 months, and 5-, 6-, and 7-year survival rates were 46%, 39%, and 35%, respectively, whereas for arm B, they were 21 months and 27%, 27%, and 23%, respectively. Median progression- or recurrence-free survival (PFS) was 39.8 months with a 3-year PFS of 50% for arm A and 12.4 months (P=.046) with 3-year PFS of 28% for arm B. Eighty percent of the observed incidents of progression occurred within 19 months. Survival did not differ significantly by EUS and performance status strata. Conclusions: Long-term survival was similar for both arms and did not appear superior to results achieved with other standard regimens.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Quality of Life in Women Undergoing Breast Irradiation in a Randomized, Controlled Clinical Trial Evaluating Different Tumor Bed Boost Fractionations

Purpose: To identify differences in breast cancer patient-reported quality of life (QOL) between 2 radiation tumor bed boost dose regimens. Methods and Materials: Four hundred patients with stage 0, I, or II breast cancer who underwent segmental mastectomy with sentinel node biopsy and/or axillary node dissection were treated with either a daily or weekly boost. Patients were treated prone to 40.5 Gy/15 fractions to the whole breast, 5 days per week. Patients were randomized to a concomitant daily boost to the tumor bed of 0.5 Gy, or a weekly boost of 2 Gy on Friday. Patients completed 6 validated QOL survey instruments at baseline, last week of treatment (3 weeks), 45-60 days from the completion of radiation treatment, and at 2-year follow-up. Results: There were no statistically significance differences in responses to the 6 QOL instruments between the daily and weekly radiation boost regimens, even after adjustment for important covariates. However, several changes in responses over time occurred in both arms, including worsening functional status, cosmetic status, and breast-specific pain at the end of treatment as compared with before and 45 to 60 days after the conclusion of treatment. Conclusions: Whole-breast, prone intensity modulated radiation has similar outcomes in QOL measures whether given with a daily or weekly boost. This trial has generated the foundation for a current study of weekly versus daily radiation boost in women with early breast cancer in which 3-dimensional conformal radiation is allowed as a prospective stratification factor.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Survival After Conservative Management Versus External Beam Radiation Therapy in Elderly Patients With Localized Prostate Cancer

Purpose: To compare survival in elderly men with clinically localized prostate cancer (PCa) according to treatment type, defined as radiation therapy (RT) with or without androgen deprivation therapy (ADT) versus conservative management (observation). Methods and Materials: In the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked database, we identified 23,790 patients aged 80 years or more with clinically localized PCa treated with either RT or observation between 1991 and 2009. Competing risks analyses focused on cancer-specific mortality and other-cause mortality, after accounting for confounders. All analyses were repeated after stratification according to grade (well-differentiated vs moderately differentiated vs poorly differentiated disease), race, and United States region, in patients with no comorbidities and in patients with at least 1 comorbidity. Analyses were repeated within most contemporary patients, namely those treated between 2001 and 2009. Results: Radiation therapy was associated with more favorable cancer-specific mortality rates than observation in patients with moderately differentiated disease (hazard ratio [HR] 0.79; 95% confidence interval [CI] 0.66-0.94; P=.009) and in patients with poorly differentiated disease (HR 0.58; 95% CI 0.49-0.69; P<.001). Conversely, the benefit of RT was not observed in well-differentiated disease. The benefit of RT was confirmed in black men (HR 0.54; 95% CI 0.35-0.83; P=.004), across all United States regions (all P≤.004), in the subgroups of the healthiest patients (HR 0.67; 95% CI 0.57-0.78; P<.001), in patients with at least 1 comorbidity (HR 0.69; 95% CI 0.56-0.83; P<.001), and in most contemporary patients (HR 0.55; 95% CI 0.46-0.66; P<.001). Conclusions: Radiation therapy seems to be associated with a reduction in the risk of death from PCa relative to observation in elderly patients with clinically localized PCa, except for those with well-differentiated disease.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Association Between Radiation Necrosis and Tumor Biology After Stereotactic Radiosurgery for Brain Metastasis

Background: The primary dose-limiting toxicity of stereotactic radiosurgery (SRS) is radiation necrosis (RN), which occurs after approximately 5% to 10% of treatments. This adverse event may worsen neurologic deficits, increase the frequency and cost of imaging, and necessitate prolonged treatment with steroids or antiangiogenic agents. Previous investigations have primarily identified lesion size and dosimetric constraints as risk factors for RN in small populations. We hypothesized that disease histology, receptor status, and mutational status are associated with RN. Methods and Materials: All patients presenting with brain metastasis between 1997 and 2015 who underwent SRS and subsequent radiographic follow-up at a single tertiary-care institution were eligible for inclusion. The primary outcome was the cumulative incidence of radiographic RN. Multivariate competing risks regression was used to identify biological risk factors for RN. Results: 1939 patients (5747 lesions) were eligible for inclusion; 285 patients (15%) experienced radiographic RN after the treatment of 427 (7%) lesions. After SRS, the median time to RN was 7.6 months. After multivariate analysis, graded prognostic assessment, renal pathology, lesion diameter, and the heterogeneity index remained independently predictive of RN in the pooled cohort. In subset analyses of individual pathologies, HER2-amplified status (hazard ratio [HR] 2.05, P=.02), BRAF V600+ mutational status (HR 0.33, P=.04), lung adenocarcinoma histology (HR 1.89, P=.04), and ALK rearrangement (HR 6.36, P<.01) were also associated with RN. Conclusions: In the present investigation constituting the largest series of RN, several novel risk factors were identified, including renal histology, lung adenocarcinoma histology, HER2 amplification, and ALK/BRAF mutational status. These risk factors may be used to guide clinical trial design incorporating biological risk stratification or dose escalation. Future studies determining the optimal timing of targeted therapies are warranted to further define the risk of RN.

62 RADIOLOGY AND NUCLEAR MEDICINE↗