bluuebunny/crossref_metadata_2025_split huggingface dataset:
SU‐C‐19A‐06: A Robust and Affordable Table Indexing Approach for Total Lymphoid Irradiation Treatment
Authors: Yu S , Fahimian B , Kenyon M , Hsu A 
Published: July 2014

Purpose:Total lymphoid irradiation (TLI) is conventionally delivered through the dosimetric matching of mantle, spleen, and pelvis fields, necessitating multiple isocenters delivered through a combination of couch shifts and sliding of patients relative to the couch rendering the technique susceptible to shifting errors. To address this challenge, a novel technique for the couch indexing of TLI treatments is developed and evaluated through a multi‐patient pilot trial.Methods:An immobilization device was designed consisting of a movable indexed slide board with an Exact Lok‐Bar drilled into it. A Timo headrests were used fixate the head of the patient relative to the slide board. For the Varian Exact Couch™, the immobilization board was connected to the H3 notch to avoid the metal infrastructure of the couch for the delivery of the mantle and spleen fields. For tall patients the required shift for the pelvis isocenter reaches the shifting limit and the board was slid from H3 to H4 (a fixed distance of 14 cm). A total 22 patients were stratified in two groups of 11, one consisting of the conventional setup, and one group with the proposed immobilization technique.Results:The standard deviations (SD) of the couch positions in lateral, longitudinal, and vertical directions for 10 fractions for each patient in both groups were calculated. In the non‐indexed group, the positioning SD ranged from 0.9 to 4.7 cm. Using our device, the positioning SD was reduced to a range of 0.2 to 0.9 cm, with the longitudinal direction showing the largest improvement.Conclusion:Matched field TLI remains error prone to geometrical misses. The feasibility of full indexing TLI treatments was validated and shown to result in a significant reduction of positioning errors.
SU‐C‐BRE‐01: 3D Conformal Micro Irradiation Results of Four Treatment Sites for Preclinical Small Animal and Clinical Treatment Plans
Authors: Price S , Yaddanapudi S , Rangaraj D , Izaguirre E 
Published: July 2014

Purpose:Small animal irradiation can provide preclinical insights necessary for clinical advancement. In order to provide clinically relevant data, these small animal irradiations must be designed such that the treatment methods and results are comparable to clinical protocols, regardless of variations in treatment size and modality.Methods:Small animal treatments for four treatment sites (brain, liver, lung and spine) were investigated, accounting for change in treatment energy and target size. Up to five orthovoltage (300kVp) beams were used in the preclinical treatments, using circular, square, and conformal tungsten apertures, based on the treatment site. Treatments were delivered using the image guided micro irradiator (microIGRT). The plans were delivered to a mouse sized phantom and dose measurements in axial and coronal planes were performed using radiochromic film. The results of the clinical and preclinical protocols were characterized in terms of conformality number, CTV coverage, dose nonuniformity ratio, and organ at risk sparing.Results:Preclinical small animal treatment conformality was within 1–16% of clinical results for all treatment sites. The volume of the CTV receiving 100% of the prescription dose was typically within 10% of clinical values. The dose non‐uniformity was consistently higher for preclinical treatments compared to clinical treatments, indicating hot spots in the target. The ratios of the mean dose in the target to the mean dose in an organ at risk were comparable if not better for preclinical versus clinical treatments. Finally, QUANTEC dose constraints were applied and the recommended morbidity limits were satisfied in each small animal treatment site.Conclusion:We have shown that for four treatment sites, preclinical 3D conformal small animal treatments can be clinically comparable if clinical protocols are followed. Using clinical protocols as the standard, preclinical irradiation methods can be altered and iteratively improved to achieve a clinically relevant irradiation model.
SU‐C‐BRE‐07: Sensitivity Analysis of the Threshold Energy for the Creation of Strand Breaks and of Single and Double Strand Break Clustering Conditions
Authors: Pater P 
Published: July 2014

Purpose:To analyse the sensitivity of the creation of strand breaks (SB) to the threshold energy (Eth) and thresholding method and to quantify the impact of clustering conditions on single strand break (SSB) and double strand break (DSB) yields.Methods:Monte Carlo simulations using Geant4‐DNA were conducted for electron tracks of 280 eV to 220 keV in a geometrical DNA model composed of nucleosomes of 396 phospho‐diester groups (PDGs) each. A strand break was created inside a PDG when the sum of all energy deposits (method 1) or energy transfers (method 2) was higher than Eth or when at least one interaction deposited (method 3) or transferred (method 4) an energy higher than Eth. SBs were then clustered into SSBs and DSBs using clustering scoring criteria from the literature and compared to our own.Results:The total number of SBs decreases as Eth is increased. In addition, thresholding on the energy transfers (methods 2 and 4) produces a higher SB count than when thresholding on energy deposits (methods 1 and 3). Method 2 produces a step‐like function and should be avoided when attempting to optimize Eth. When SBs are grouped into damage patterns, clustering conditions can underestimated SSBs by up to 18 % and DSBs can be overestimated by up to 12 % compared to our own implementation.Conclusion:We show that two often underreported simulation parameters have a non‐negligible effect on overall DNA damage yields. First more SBs are counted when using energy transfers to the PDG rather than energy deposits. Also, SBs grouped according to different clustering conditions can influence reported SSB and DSB by as much as 20%. Careful handling of these parameters is required when trying to compare DNA damage yields from different authors.Research funding from the governments of Canada and Quebec. PP acknowledges partial support by the CREATE Medical Physics Research Training Network grant of the Natural Sciences and Engineering Research Council (Grant number: 432290)
SU‐C‐BRD‐01: A Statistical Modeling Method for Quality Control of Intensity‐ Modulated Radiation Therapy Planning
Authors: Gao S , Meyer R , Shi L , D' Souza W , Zhang H 
Published: July 2014

Purpose:To apply a statistical modeling approach, threshold modeling (TM), for quality control of intensity‐modulated radiation therapy (IMRT) treatment plans.Methods:A quantitative measure, which was the weighted sum of violations of dose/dose‐volume constraints, was first developed to represent the quality of each IMRT plan. Threshold modeling approach, which is is an extension of extreme value theory in statistics and is an effect way to model extreme values, was then applied to analyze the quality of the plans summarized by our quantitative measures. Our approach modeled the plans generated by planners as a series of independent and identically distributed random variables and described the behaviors of them if the plan quality was controlled below certain threshold. We tested our approach with five locally advanced head and neck cancer patients retrospectively. Two statistics were incorporated for numerical analysis: probability of quality improvement (PQI) of the plans and expected amount of improvement on the quantitative measure (EQI).Results:After clinical planners generated 15 plans for each patient, we applied our approach to obtain the PQI and EQI as if planners would generate additional 15 plans. For two of the patients, the PQI was significantly higher than the other three (0.17 and 0.18 comparing to 0.08, 0.01 and 0.01). The actual percentage of the additional 15 plans that outperformed the best of initial 15 plans was 20% and 27% comparing to 11%, 0% and 0%. EQI for the two potential patients were 34.5 and 32.9 and the rest of three patients were 9.9, 1.4 and 6.6. The actual improvements obtained were 28.3 and 20.5 comparing to 6.2, 0 and 0.Conclusion:TM is capable of reliably identifying the potential quality improvement of IMRT plans. It provides clinicians an effective tool to assess the trade‐off between extra planning effort and achievable plan quality.This work was supported in part by NIH/NCI grant CA130814.
SU‐C‐BRD‐03: Analysis of Accelerator Generated Text Logs for Preemptive Maintenance
Authors: Able CM , Baydush AH , Nguyen C , Gersh J , Ndlovu A , Rebo I , Booth J , Perez M , Sintay B , Munley MT 
Published: July 2014

Purpose:To develop a model to analyze medical accelerator generated parameter and performance data that will provide an early warning of performance degradation and impending component failure.Methods:A robust 6 MV VMAT quality assurance treatment delivery was used to test the constancy of accelerator performance. The generated text log files were decoded and analyzed using statistical process control (SPC) methodology. The text file data is a single snapshot of energy specific and overall systems parameters. A total of 36 system parameters were monitored which include RF generation, electron gun control, energy control, beam uniformity control, DC voltage generation, and cooling systems. The parameters were analyzed using Individual and Moving Range (I/MR) charts. The chart limits were calculated using a hybrid technique that included the use of the standard 3σ limits and the parameter/system specification. Synthetic errors/changes were introduced to determine the initial effectiveness of I/MR charts in detecting relevant changes in operating parameters. The magnitude of the synthetic errors/changes was based on: the value of 1 standard deviation from the mean operating parameter of 483 TB systems, a small fraction (≤ 5%) of the operating range, or a fraction of the minor fault deviation.Results:There were 34 parameters in which synthetic errors were introduced. There were 2 parameters (radial position steering coil, and positive 24V DC) in which the errors did not exceed the limit of the I/MR chart. The I chart limit was exceeded for all of the remaining parameters (94.2%). The MR chart limit was exceeded in 29 of the 32 parameters (85.3%) in which the I chart limit was exceeded.Conclusion:Statistical process control I/MR evaluation of text log file parameters may be effective in providing an early warning of performance degradation or component failure for digital medical accelerator systems.Research is Supported by Varian Medical Systems, Inc.
SU‐C‐BRD‐06: Results From a 5 Patient in Vivo Rectal Wall Dosimetry Study Using Plastic Scintillation Detectors
Authors: Wootton L , Kudchadker R , Lee A , Beddar S 
Published: July 2014

Purpose:To evaluate the performance characteristics of plastic scintillation detectors (PSDs) in an in vivo environment for external beam radiation, and to establish the usefulness and ease of implementation of a PSD based in vivo dosimetry system for routine clinical use.Methods:A five patient IRB approved in vivo dosimetry study was performed. Five patients with prostate cancer were enrolled and PSDs were used to monitor rectal wall dose and verify the delivered dose for approximately two fractions each week over the course of their treatment (approximately fourteen fractions), resulting in a total of 142 in vivo measurements. A set of two PSDs was fabricated for each patient. At each monitored fraction the PSDs were attached to the anterior surface of an endorectal balloon used to immobilize the patient's prostate during treatment. A CT scan was acquired with a CTon‐ rails linear accelerator to localize the detectors and to calculate the dose expected to be delivered to the detectors. Each PSD acquired data in 10 second intervals for the duration of the treatment. The deviation between expected and measured cumulative dose was calculated for each detector for each fraction, and averaged over each patient and the patient population as a whole.Results:The average difference between expected dose and measured dose ranged from ‐3.3% to 3.3% for individual patients, with standard deviations between 5.6% and 7.1% for four of the patients. The average difference for the entire population was ‐0.4% with a standard deviation of 2.8%. The detectors were well tolerated by the patients and the system did not interrupt the clinical workflow.Conclusion:PSDs perform well as in vivo dosimeters, exhibiting good accuracy and precision. This, combined with the practicability of using such a system, positions the PSD as a strong candidate for clinical in vivo dosimetry in the future.This work supported in part by the National Cancer Institute through an R01 grant (CA120198‐01A2) and by the American Legion Auxiliary through the American Auxiliary Fellowship in Cancer Research.
Complete Genome Sequences of Two Porcine Circovirus Type 2 Field Isolates Bearing an Unusual Sequence Duplication in the
rep
Gene
Authors: Willems Hermann , Hofmeister Regina , Reiner Gerald 
Published: July 2014

ABSTRACT

Porcine circovirus type 2 (PCV-2) is the etiologic agent of porcine circovirus-associated disease (PCVAD). PCV-2 is classified into three genotypes. Here, we present the complete genomic sequences of two PCV-2 isolates (KM and H026) with an unusual sequence duplication in the
rep
gene coding for viral replicase proteins.
Draft Whole-Genome Sequences of Nine Non-O157 Shiga Toxin-Producing Escherichia coli Strains
Authors: Lindsey Rebecca L. , Trees Eija , Sammons Scott , Loparev Vladimir , Frace Mike , Strockbine Nancy , Sabol Ashley L. , Sowers Evan , Stripling Devon , Martin Haley , Knipe Kristen , Rowe Lori , Gerner-Smidt Peter 
Published: July 2014

ABSTRACT

Shiga toxin-producing
Escherichia coli
(STEC) is an important food-borne pathogen. Here, we report the draft whole-genome sequences of nine STEC strains isolated from clinical cases in the United States. This is the first report of such information for STEC of serotypes O69, H11, O145:H25, O118:H16, O91:H21, O146:H21, O45:H2, O128:H2, and O121:H19.
Complete Genome Sequence of the
Streptococcus
sp. Strain VT 162, Isolated from the Saliva of Pediatric Oncohematology Patients
Authors: Vecherkovskaya Maria F. , Tetz George V. , Tetz Victor V. 
Published: July 2014

ABSTRACT

Streptococcus
sp. strain VT 162 was isolated from the saliva of pediatric oncohematology patients. Its full genome is 2,045,418 bp. The availability of this genome will provide insights into the composition of microbial flora among pediatric oncohematology patients and the host interaction and pathogenicity of this species.
Automated Measurement of Volumetric Mammographic Density: A Tool for Widespread Breast Cancer Risk Assessment
Authors: Brand Judith S. , Czene Kamila , Shepherd John A. , Leifland Karin , Heddson Boel , Sundbom Ann , Eriksson Mikael , Li Jingmei , Humphreys Keith , Hall Per 
Published: July 2014

Abstract
Introduction: Mammographic density is a strong risk factor for breast cancer and an important determinant of screening sensitivity, but its clinical utility is hampered due to the lack of objective and automated measures. We evaluated the performance of a fully automated volumetric method (Volpara).
Methods: A prospective cohort study included 41,102 women attending mammography screening, of whom 206 were diagnosed with breast cancer after a median follow-up of 15.2 months. Percent and absolute dense volumes were estimated from raw digital mammograms. Genotyping was performed in a subset of the cohort (N = 2,122). We examined the agreement by side and view and compared density distributions across different mammography systems. We also studied associations with established density determinants and breast cancer risk.
Results: The method showed good agreement by side and view, and distributions of percent and absolute dense volume were similar across mammography systems. Volumetric density was positively associated with nulliparity, age at first birth, hormone use, benign breast disease, and family history of breast cancer, and negatively with age and postmenopausal status. Associations were also observed with rs10995190 in the ZNF365 gene (P &lt; 1.0 × 10−6) and breast cancer risk [HR for the highest vs. lowest quartile, 2.93; 95% confidence interval, 1.73–4.96 and 1.63 (1.10–2.42) for percent and absolute dense volume, respectively].
Conclusions: In a high-throughput setting, Volpara performs well and in accordance with the behavior of established density measures.
Impact: Automated measurement of volumetric mammographic density is a promising tool for widespread breast cancer risk assessment. Cancer Epidemiol Biomarkers Prev; 23(9); 1764–72. ©2014 AACR.
Metabolic Health Reduces Risk of Obesity-Related Cancer in Framingham Study Adults
Authors: Moore Lynn L. , Chadid Susan , Singer Martha R. , Kreger Bernard E. , Denis Gerald V. 
Published: July 2014

Abstract
Background: It is unknown whether the risk for obesity-related cancers differs between metabolically unhealthy and healthy overweight/obese adults.
Methods: Data on body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and random blood glucose in Framingham Heart Study adults (n = 3,763) ages 55 to 69 years were used to estimate risks of obesity-related cancers (n = 385), including postmenopausal breast, female reproductive, colon, liver, gallbladder, pancreas, and kidney cancers, as well as esophageal adenocarcinomas. Multivariable-adjusted Cox proportional hazards models were used to estimate risk for obesity-related cancers associated with body fat and metabolic health (as defined by glucose levels) among subjects in three risk groups (vs. referent group with normal weight/normal glucose): normal weight/elevated glucose, overweight/normal glucose, and overweight/elevated glucose.
Results: Overweight adults [BMI ≥ 25 or WHtR ≥ 0.51 (men) and ≥0.57 (women)] with elevated glucose (≥125 mg/dL) had a statistically significant 2-fold increased risk of developing obesity-related cancer, whereas overweight adults with normal glucose had a 50% increased risk. Normal-weight adults with elevated glucose had no excess cancer risk. The effects of BMI and WHtR were independent of one another. Finally, overweight women with elevated blood glucose had a 2.6-fold increased risk [95% confidence interval (CI), 1.4–4.9] of female reproductive (cervical, endometrial, uterine cancers) and postmenopausal breast cancers, whereas overweight women with normal glucose levels had only a 70% increased risk (95% CI, 1.1–2.5).
Conclusion: These results suggest that cancer risk may be lower among metabolically healthy overweight/obese older adults than among overweight/obese adults with metabolic dysfunction.
Impact: Metabolic dysfunction and obesity act synergistically to increase cancer risk. Cancer Epidemiol Biomarkers Prev; 23(10); 2057–65. ©2014 AACR.
Retinal Vasculopathy Is Reduced by Dietary Salt Restriction
Authors: Deliyanti Devy , Armani Roksana , Casely David , Figgett William A. , Agrotis Alex , Wilkinson-Berka Jennifer L. 
Published: July 2014

Objective—
Neovascularization and vaso-obliteration are vision-threatening events that develop by interactions between retinal vascular and glial cells. A high-salt diet is causal in cardiovascular and renal disease, which is linked to modulation of the renin–angiotensin–aldosterone system. However, it is not known whether dietary salt influences retinal vasculopathy and if the renin–angiotensin–aldosterone system is involved. We examined whether a low-salt (LS) diet influenced vascular and glial cell injury and the renin–angiotensin–aldosterone system in ischemic retinopathy.

Approach and Results—
Pregnant Sprague Dawley rats were fed LS (0.03% NaCl) or normal salt (0.3% NaCl) diets, and ischemic retinopathy was induced in the offspring. An LS diet reduced retinal neovascularization and vaso-obliteration, the mRNA and protein levels of the angiogenic factors, vascular endothelial growth factor, and erythropoietin. Microglia, which influence vascular remodeling in ischemic retinopathy, were reduced by LS as was tumor necrosis factor-α. Macroglial Müller cells maintain the integrity of the blood–retinal barrier, and in ischemic retinopathy, LS reduced their gliosis and also vascular leakage. In retina, LS reduced mineralocorticoid receptor, angiotensin type 1 receptor, and renin mRNA levels, whereas, as expected, plasma levels of aldosterone and renin were increased. The aldosterone/mineralocorticoid receptor–sensitive epithelial sodium channel alpha (ENaCα), which is expressed in Müller cells, was increased in ischemic retinopathy and reduced by LS. In cultured Müller cells, high salt increased ENaCα, which was prevented by mineralocorticoid receptor and angiotensin type 1 receptor blockade. Conversely, LS reduced ENaCα, angiotensin type 1 receptor, and mineralocorticoid receptor expression.

Conclusions—
An LS diet reduced retinal vasculopathy, by modulating glial cell function and the retinal renin–angiotensin–aldosterone system.
Haploinsufficiency of the Insulin-Like Growth Factor-1 Receptor Enhances Endothelial Repair and Favorably Modifies Angiogenic Progenitor Cell Phenotype
Authors: Yuldasheva Nadira Y. , Rashid Sheikh Tawqeer , Haywood Natalie J. , Cordell Paul , Mughal Romana , Viswambharan Hema , Imrie Helen , Sukumar Piruthivi , Cubbon Richard M. , Aziz Amir , Gage Matthew , Mbonye Kamatamu Amanda , Smith Jessica , Galloway Stacey , Skromna Anna , Scott D. Julian A. , Kearney Mark T. , Wheatcroft Stephen B. 
Published: July 2014

Objectives—
Defective endothelial regeneration predisposes to adverse arterial remodeling and is thought to contribute to cardiovascular disease in type 2 diabetes mellitus. We recently demonstrated that the type 1 insulin-like growth factor receptor (IGF1R) is a negative regulator of insulin sensitivity and nitric oxide bioavailability. In this report, we examined partial deletion of the IGF1R as a potential strategy to enhance endothelial repair.

Approach and Results—

We assessed endothelial regeneration after wire injury in mice and abundance and function of angiogenic progenitor cells in mice with haploinsufficiency of the IGF1R (IGF1R
+/−
). Endothelial regeneration after arterial injury was accelerated in IGF1R
+/−
mice. Although the yield of angiogenic progenitor cells was lower in IGF1R
+/−
mice, these angiogenic progenitor cells displayed enhanced adhesion, increased secretion of insulin-like growth factor-1, and enhanced angiogenic capacity. To examine the relevance of IGF1R manipulation to cell-based therapy, we transfused IGF1R
+/−
bone marrow–derived CD117
+
cells into wild-type mice. IGF1R
+/−
cells accelerated endothelial regeneration after arterial injury compared with wild-type cells and did not alter atherosclerotic lesion formation.

Conclusions—

Haploinsufficiency of the IGF1R is associated with accelerated endothelial regeneration in vivo and enhanced tube forming and adhesive potential of angiogenic progenitor cells in vitro. Partial deletion of IGF1R in transfused bone marrow–derived CD117
+
cells enhanced their capacity to promote endothelial regeneration without altering atherosclerosis. Our data suggest that manipulation of the IGF1R could be exploited as novel therapeutic approach to enhance repair of the arterial wall after injury.