bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of dose calculation resolution on dose accuracy for radiation therapy treatments of the lung. Part I. A Monte Carlo model of the lung
Authors: Babcock Kerry , Sidhu Narinder 
Published: January 2010

Purpose: The purpose of this work was to create an anatomically detailed EGSnrc Monte Carlo based model of the right lung. The resulting model, called BRANCH, includes an accurate representation of the right bronchial, arterial, and venous branching networks down to a scale of 0.1 mm. The model may be varied to represent lung shape and density at any phase of the respiration cycle.Methods: Polynomial surfaces were used to approximate the anatomic boundaries that define the right lung surface at several phases of the respiration cycle. A branching network algorithm was used to generate the bronchial, arterial, and venous trees within the anatomic boundaries. The branching networks were modeled as a series of bifurcating cylinders connected by spherical junctions. The validity of the BRANCH dose calculation was verified using an all‐water version of the model.Results: The geometric dimensions of the BRANCH model corresponded well with published data. The bronchial tree model contained 27 798 branches ranging from 0.02 to 0.54 cm in diameter. The arterial tree model had 27 957 branches ranging from 0.02 to 1.2 cm in diameter. The venous model tree had 26 347 branches ranging from 0.02 to 0.34 cm in diameter. A gamma analysis indicated that the all‐water BRANCH Monte Carlo code produced dose distributions that agreed within 0.1 cm and 0.5% to conventional DOSXYZnrc results.Conclusions: The BRANCH model is a useful tool for performing detailed dosimetric studies within a realistic representation of the lung.
An intraoperative 3D ultrasound system for tumor margin determination in breast cancer surgery
Authors: DeJean Paul , Brackstone Muriel , Fenster Aaron 
Published: January 2010

Purpose:The purpose of this study was to analyze the clinical utility of a portable three‐dimensional ultrasound (3DUS) system to be used for surgical guidance of lumpectomy surgeries. In 11%–60% of lumpectomy surgeries, a second surgery is required to fully resect the tumor. Previous studies have used 3DUS as a guidance tool with the hope of more accuracy in resecting the entire tumor during the first surgery. However, they utilized larger systems, which are not easily integrated into the operating room.Methods:The portable 3DUS scanning system we developed consisted of a motorized “tilt” scanner coupled to a Terason t3000 portable ultrasound machine (Terason Ultrasound, Burlington, MA). The 3DUS system was evaluated by measuring agar “tumor” phantoms of known volumes and acquiring and segmenting images from nine patients undergoing lumpectomy.Results:Experiments on simulated agar tumor phantoms have shown that our device could be used to measure objects with smooth, well‐defined boundaries of known volume with an error of 3%. It was possible to view and segment estimated tumor margins from the clinical images in three dimensions. Correspondence between measurements obtained in the laboratory and the operating room varied with tumor geometry and the degree of spiculation in the ultrasound image. The measured values obtained by the system did not correspond closely with those obtained using histology. However, a more accurate histological measurement using 3D histology may provide a better basis for comparison.Conclusions:The results of imaging simulated agar tumor phantoms indicate the system's consistency in measuring objects of known volume and geometry. The system could be used for segmenting the approximate boundary of lumpectomy patients’ breast tumors relative to inserted guide wires. The potential advantages of this system are a reduction in the number of re‐excision surgeries required and a reduction in the operative time with the patient under anesthesia.
Stereotactic targeting and dose verification for age‐related macular degeneration
Authors: Gertner Michael , Chell Erik , Pan Kuang‐Hung , Hansen Steve , Kaiser Peter K. , Moshfeghi Darius M. 
Published: January 2010

Purpose:Validation of the targeting and dose delivery of the IRay™ low voltage age‐related macular degeneration treatment system.Methods:Ten human cadaver eyes were obtained for this study and mounted in the IRay™ system. Using gel and vacuum, an I‐Guide™ immobilization device was coupled to the eyes and radiochromic film was affixed to the posterior aspect of the globes. Three narrow x‐ray beams were delivered through the pars plana to overlap on the predicted nominal fovea. A needle was placed through the center of the film's beam spot and into the eye to register the film and the inner retina. The process was performed three times for each of the ten eyes (30 simulated treatments; 90 individual beams). The globes were dissected to assess the targeting accuracy by measuring the distances from the needles to the fovea. The dose to the fovea was calculated from the radiochromic film.Results:X‐ray targeting on the retina averaged from the fovea. Repeated treatments on the same eye showed a reproducibility of . The optic nerve was safely avoided, with the 90% isodose edge of the beam spot between 0.4 and 2.6 mm from the edge of the optic disk. Measured dose matched that prescribed.Conclusions:This study provides confidence that the IRay™, with an average accuracy of 0.6 mm and a precision of 0.4 mm, can reliably treat most AMD lesions centered on the fovea. With the exception of motion, all sources of error are included.
Time‐efficient patient‐specific quantification of regional carotid artery fluid dynamics and spatial correlation with plaque burden
Authors: LaDisa John F. , Bowers Mark , Harmann Leanne , Prost Robert , Doppalapudi Anil Vamsi , Mohyuddin Tayyab , Zaidat Osama , Migrino Raymond Q. 
Published: January 2010

Purpose:Low wall shear stress (WSS) and high oscillatory shear index (OSI) influence plaque formation, yet little is known about their role in progression/regression of established plaques because of lack of practical means to calculate them in individual patients. Our aim was to use computational fluid dynamics (CFD) models of patients with carotid plaque undergoing statin treatment to calculate WSS and OSI in a time‐efficient manner, and determine their relationship to plaque thickness (PT), plaque composition (PC), and regression.Methods:Eight patients (, one female) underwent multicontrast 3 T MRI at baseline and six‐month post statin treatment. PT and PC were measured in carotid segments (common–CC, bifurcation–B, internal–IC) and circumferentially in nonoverlapping 60° angles and correlated with CFD models created from MRI, ultrasound, and blood pressure.Results:PT was highest in B ( versus CC: , IC: , ). Circumferentially, plaque was greatest opposite the flow divider , where the lowest WSS and highest OSI were observed. In B and IC, PT was inversely related to WSS ( and −0.37, ) and directly related to OSI ( and 0.52, ). The total plaque volume changed from to at six months . Baseline WSS, but not OSI, correlated with changes in PT, necrotic tissue, and hemorrhage in B and IC, but not CC. CFD modeling took per patient.Conclusions:PT and PC correspond to adverse WSS and OSI in B and IC, and WSS is modestly but significantly related to changes in PT after short‐term statin treatment. Regional hemodynamics from CFD can feasibly augment routine clinical imaging for comprehensive plaque evaluation.
Simultaneous navigation of multiple Pareto surfaces, with an application to multicriteria IMRT planning with multiple beam angle configurations
Authors: Craft David , Monz Michael 
Published: January 2010

Purpose:To introduce a method to simultaneously explore a collection of Pareto surfaces. The method will allow radiotherapy treatment planners to interactively explore treatment plans for different beam angle configurations as well as different treatment modalities.Methods:The authors assume a convex optimization setting and represent the Pareto surface for each modality or given beam set by a set of discrete points on the surface. Weighted averages of these discrete points produce a continuous representation of each Pareto surface. The authors calculate a set of Pareto surfaces and use linear programming to navigate across the individual surfaces, allowing switches between surfaces. The switches are organized such that the plan profits in the requested way, while trying to keep the change in dose as small as possible.Results:The system is demonstrated on a phantom pancreas IMRT case using 100 different five beam configurations and a multicriteria formulation with six objectives. The system has intuitive behavior and is easy to control. Also, because the underlying linear programs are small, the system is fast enough to offer real‐time exploration for the Pareto surfaces of the given beam configurations.Conclusions:The system presented offers a sound starting point for building clinical systems for multicriteria exploration of different modalities and offers a controllable way to explore hundreds of beam angle configurations in IMRT planning, allowing the users to focus their attention on the dose distribution and treatment planning objectives instead of spending excessive time on the technicalities of delivery.
A photon spectrometric dose‐rate constant determination for the Advantage™ Pd‐103 brachytherapy source
Authors: Chen Zhe Jay , Bongiorni Paul , Nath Ravinder 
Published: January 2010

Purpose:Although several dosimetric characterizations using Monte Carlo simulation and thermoluminescent dosimetry (TLD) have been reported for the new Advantage™ Pd‐103 source (IsoAid, LLC, Port Richey, FL), no AAPM consensus value has been established for the dosimetric parameters of the source. The aim of this work was to perform an additional dose‐rate constant determination using a recently established photon spectrometry technique (PST) that is independent of the published TLD and Monte Carlo techniques.Methods:Three Model IAPD‐103A Advantage™ Pd‐103 sources were used in this study. The relative photon energy spectrum emitted by each source along the transverse axis was measured using a high‐resolution germanium spectrometer designed for low‐energy photons. For each source, the dose‐rate constant was determined from its emitted energy spectrum. The PST‐determined dose‐rate constant was then compared to those determined by TLD and Monte Carlo techniques. A likely consensus value was estimated as the arithmetic mean of the average values determined by each of three different techniques.Results:The average value for the three Advantage™ sources was found to be . Intersource variation in was less than 0.01%. The was within 2% of the reported values determined by PTRAN, EGSnrc, and MCNP5 codes. It was 3.4% lower than the reported . A likely consensus value was estimated to be , similar to the AAPM consensus values recommended currently for the Theragenics (Buford, GA) Model 200 , the NASI (Chatsworth, CA) Model MED3633 , and the Best Medical (Springfield, VA) Model 2335 sources.Conclusions:An independent determination has been performed for the Advantage™ Pd‐103 source. The obtained in this work provides additional information needed for establishing a more accurate consensus value for the Advantage™ Pd‐103 source.
Organ doses to adult patients for chest CT
Authors: Huda Walter , Sterzik Alexander , Tipnis Sameer , Schoepf U. Joseph 
Published: January 2010

Purpose:The goal of this study was to estimate organ doses for chest CT examinations using volume computed tomography dose index data as well as accounting for patient weight.Methods:A CT dosimetry spreadsheet (ImPACT CT patient dosimetry calculator) was used to compute organ doses for a 70 kg patient undergoing chest CT examinations, as well as volume computed tomography dose index in a body CT dosimetry phantom at the same CT technique factors. Ratios of organ dose to were generated as a function of anatomical location in the chest for the breasts, lungs, stomach, red bone marrow, liver, thyroid, liver, and thymus. Values of were obtained for x‐ray tube voltages ranging from 80 to 140 kV for 1, 4, 16, and 64 slice CT scanners from two vendors. For constant CT techniques, we computed ratios of dose in water phantoms of differing diameter. By modeling patients of different weights as equivalent water cylinders of different diameters, we generated factors that permit the estimation of the organ doses in patients weighing between 50 and 100 kg who undergo chest CT examinations relative to the corresponding organ doses received by a 70 kg adult.Results:For a 32 cm long CT scan encompassing the complete lungs, values of ranged from 1.7 (thymus) to 0.3 (stomach). Organs that are directly in the x‐ray beam, and are completely irradiated, generally had values well above 1 (i.e., breast, lung, heart, and thymus). Organs that are not completely irradiated in a total chest CT scan generally had values that are less than 1 (e.g., red bone marrow, liver, and stomach). Increasing the x‐ray tube voltage from 80 to 140 kV resulted in modest increases in for the heart (9%) and thymus (8%), but resulted in larger increases for the breast (19%) and red bone marrow (21%). Adult patient chests have been modeled by water cylinders with diameters between for a 50 kg patient and for a 100 kg patient. At constant x‐ray techniques, a 50 kg patient is expected to have doses that are higher than those in a 70 kg adult, whereas a 100 kg patient will have doses that are lower.Conclusions:We describe a practical method to use CTDI data provided by commercial CT scanners to obtain patient and examination specific estimates of organ dose for chest CT examinations.
Dose Response of Attenuated
Bordetella pertussis
BPZE1-Induced Protection in Mice
Authors: Mielcarek Nathalie , Debrie Anne-Sophie , Mahieux Severine , Locht Camille 
Published: January 2010

ABSTRACT

Despite the availability of efficacious vaccines, the incidence of whooping cough is still high in many countries and is even increasing in countries with high vaccine coverage. Most severe and life-threatening pertussis cases occur in infants who are too young to be sufficiently protected by current vaccine regimens. As a potential solution to this problem, we have developed an attenuated live
Bordetella pertussis
vaccine strain, named BPZE1. Here, we show that after a single administration, BPZE1 induces dose-dependent protection against challenge with virulent
B. pertussis
in low-dose and in high-dose intranasal mouse lung colonization models. In addition, we observed BPZE1 dose-dependent antibody titers to
B. pertussis
antigens, as well as cell-mediated immunity, evidenced by the amounts of gamma interferon (IFN-γ) released from spleen cells upon stimulation with
B. pertussis
antigens. These two parameters may perhaps be used as readouts in clinical trials in humans that are currently being planned.
Development of a Bead Immunoassay To Measure Vi Polysaccharide-Specific Serum IgG after Vaccination with the
Salmonella enterica
Serovar Typhi Vi Polysaccharide
Authors: Staats Herman F. , Kirwan Shaun M. , Whisnant Carol C. , Stephenson James L. , Wagener Diane K. , Majumder Partha P. 
Published: January 2010

ABSTRACT

Vi polysaccharide from
Salmonella enterica
serotype Typhi is used as one of the available vaccines to prevent typhoid fever. Measurement of Vi-specific serum antibodies after vaccination with Vi polysaccharide by enzyme-linked immunosorbent assay (ELISA) may be complicated due to poor binding of the Vi polysaccharide to ELISA plates resulting in poor reproducibility of measured antibody responses. We chemically conjugated Vi polysaccharide to fluorescent beads and performed studies to determine if a bead-based immunoassay provided a reproducible method to measure vaccine-induced anti-Vi serum IgG antibodies. Compared to ELISA, the Vi bead immunoassay had a lower background and therefore a greater signal-to-noise ratio. The Vi bead immunoassay was used to evaluate serum anti-Vi IgG in 996 subjects from the city of Kolkata, India, before and after vaccination. Due to the location being one where
Salmonella
serotype Typhi is endemic, approximately 45% of the subjects had protective levels of anti-Vi serum IgG (i.e., 1 μg/ml anti-Vi IgG) before vaccination, and nearly 98% of the subjects had protective levels of anti-Vi serum IgG after vaccination. Our results demonstrate that a bead-based immunoassay provides an effective, reproducible method to measure serum anti-Vi IgG responses before and after vaccination with the Vi polysaccharide vaccine.
An Oral versus Intranasal Prime/Boost Regimen Using Attenuated Human Rotavirus or VP2 and VP6 Virus-Like Particles with Immunostimulating Complexes Influences Protection and Antibody-Secreting Cell Responses to Rotavirus in a Neonatal Gnotobiotic Pig Model
Authors: Azevedo Marli S. P. , Gonzalez Ana Maria , Yuan Lijuan , Jeong Kwang-il , Iosef Cristiana , Van Nguyen Trang , Lovgren-Bengtsson Karin , Morein Bror , Saif Linda J. 
Published: January 2010

ABSTRACTWe determined the impact of mucosal prime/boost regimens and vaccine type (attenuated Wa human rotavirus [AttHRV] or nonreplicating Wa 2/6 rotavirus-like particles [VLP]) on protection and antibody-secreting cell (ASC) responses to HRV in a neonatal gnotobiotic pig disease model. Comparisons of delivery routes for AttHRV and evaluation of nonreplicating VLP vaccines are important as alternative vaccine approaches to overcome risks associated with live oral vaccines. Groups of neonatal gnotobiotic pigs were vaccinated using combinations of oral (PO) and intranasal (IN) inoculation routes as follows: (i) 3 oral doses of AttHRV (AttHRV3×PO); (ii) AttHRV3×IN; (iii) AttHRVPO, then 2/6VLP2×IN; (iv) AttHRVIN, then 2/6VLP2×IN; and (v) mock-inoculated controls. Subsets of pigs from each group were challenged with virulent Wa HRV [P1A(8) G1] (4 weeks post-primary inoculation) to assess protection. The AttHRVPO+2/6VLP2×IN pigs had the highest protection rates against virus shedding and diarrhea (71% each); however, these rates did not differ statistically among the vaccine groups, except for the AttHRVIN+2/6VLPIN group, which had a significantly lower protection rate (17%) against diarrhea. The isotype, magnitude, and tissue distribution of ASCs were analyzed by enzyme-linked immunospot assay. The highest mean numbers of virus-specific IgG and IgA ASCs were observed pre- and postchallenge in both intestinal and systemic lymphoid tissues of the AttHRVPO+2/6VLPIN group. Thus, the AttHRVPO+2/6VLPIN vaccine regimen using immunostimulating complexes (ISCOM) and multiple mucosal inductive sites, followed by AttHRV3×PO or IN regimens, were the most effective vaccine regimens, suggesting that either AttHRVPO+2/6VLPIN or AttHRV3×IN may be an alternative approach to AttHRV3×PO for inducing protective immunity against rotavirus diarrhea.
Impact of a Pneumococcal Conjugate Vaccination Program on Carriage among Children in Norway
Authors: Vestrheim Didrik F. , Høiby E. Arne , Aaberge Ingeborg S. , Caugant Dominique A. 
Published: January 2010

ABSTRACT
In July 2006, the seven-valent pneumococcal conjugate vaccine (PCV7) was introduced in Norway with a reduced (2 doses + 1 boost) dose schedule. Post-PCV7 shifts in pneumococcal reservoirs were assessed by two point prevalence studies of nasopharyngeal colonization among children in day care centers, before (2006) and after (2008) widespread use of PCV7. Nasopharyngeal swabs were obtained from 1,213 children, 611 in 2006 and 602 in 2008. A total of 1,102 pneumococcal isolates were recovered. Serotyping, multilocus sequence typing, and antimicrobial drug susceptibility testing were performed on all isolates. Although carriage of PCV7 serotypes decreased among both vaccinated and unvaccinated children, the overall prevalence of pneumococcal carriage remained high (80.4%) after vaccine introduction. The pneumococcal populations were diverse, and in the shift toward non-PCV7 serotypes, expansion of a limited number of established clonal complexes was observed. While non-antimicrobial-susceptible clones persisted among PCV7 serotypes, antimicrobial resistance did not increase among non-PCV7 serotypes. Direct and indirect protection of PCV7 against nasopharyngeal colonization was inferred from an overall decrease in carriage of PCV7 serotypes. No preference was found for nonsusceptible clones among the replacing non-PCV7 serotypes.
Novel Double-Antigen Sandwich Immunoassay for Human Hepatitis B Core Antibody
Authors: Li An , Yuan Quan , Huang Zhiyin , Fan Jian , Guo Ruyi , Lou Bin , Zheng Qin , Ge Shengxiang , Chen Yixin , Su Zhijun , Yeo Anthony E. T. , Chen Yu , Zhang Jun , Xia Ningshao 
Published: January 2010

ABSTRACTA novel diagnostic immunoassay testing procedure for hepatitis B virus core antibody (anti-HBc) using homogeneous purified full-length hepatitis B virus core antigen (HBcAg) capsids obtained fromEscherichia coliwas compared with Abbott Architect anti-HBc chemiluminescent microparticle immunoassay (CMIA; indirect method) against a library of specimens. A monoclonal anti-HBc neutralization confirmatory assay was then used to determine the degree of discordance between specimens. The new assay was found to be superior in both sensitivity and specificity.
Microbial Etiology of Travelers' Diarrhea in Mexico, Guatemala, and India: Importance of Enterotoxigenic
Bacteroides fragilis
and
Arcobacter
Species
Authors: Jiang Zhi-Dong , DuPont Herbert L. , Brown Eric L. , Nandy Ranjan K. , Ramamurthy Thandavaryan , Sinha Anuradha , Ghosh Santanu , Guin Sucharita , Gurleen Kaur , Rodrigues Savio , Chen Jacklyn J. , McKenzie Robin , Steffen Robert 
Published: January 2010

ABSTRACT

This study examined established enteric pathogens,
Arcobacter
species and enterotoxigenic
Bacteroides fragilis
(ETBF), in 201 U.S. and European travelers with acute diarrhea acquired in Mexico, Guatemala, and India.
Arcobacter butzleri
and ETBF were detected in 8% and 7% of diarrhea cases, respectively.
Genetic Characterization of the Capsulation Locus of
Haemophilus influenzae
Serotype e
Authors: Giufrè Maria , Cardines Rita , Mastrantonio Paola , Cerquetti Marina 
Published: January 2010

ABSTRACT

The capsulation (
cap
) locus of
Haemophilus influenzae
type e (Hie) was characterized and sequenced. No IS
1016
element was found to flank the locus. The 18.2-kb locus included 14 open reading frames (ORFs), which were grouped into three functional regions. Eight new ORFs (named
ecs1
to
ecs8
) were identified in the Hie capsule-specific region II.