SU-E-T-467: Monte Carlo Dosimetric Study of the New Flexisource Co-60 High Dose Rate Source.

Purpose: Recently, a new HDR 60Co brachytherapy source, Flexisource Co-60, has been developed (Nucletron B.V.).

SU-E-T-316: New Design of the Valencia Applicators to Reduce Radiation Leakage.

Purpose: The Valencia applicators are designed to treat skin lesions with the microSelectron-HDR afterloader. Although the radiation is highly directed to the treatment area, radiation might leak through the backside of the applicator. Recently, the manufacturer has introduced a new applicator design to reduce such radiation leakage.

Prenatal exposure to organochlorine compounds and neuropsychological development up to two years of life.

Polychlorinated biphenyls (PCB), hexachlorobenzene (HCB), and dichlorodiphenyl dichloroethylene (pp'DDE) are persistent, bioaccumulative, and toxic environmental pollutants with potential neurotoxic effects. Despite a growing body of studies investigating the health effects associated with these compounds, their specific effects on early neuropsychological development remain unclear. We investigated such neuropsychological effects in a population-based birth cohort based in three regions in Spain (Sabadell, Gipuzkoa, and Valencia) derived from the INMA [Environment and Childhood] Project.

Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: report of the AAPM and ESTRO.

Purpose: Recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO) on dose calculations for high-energy (average energy higher than 50 keV) photon-emitting brachytherapy sources are presented, including the physical characteristics of specific (192)Ir, (137)Cs, and (60)Co source models.

Methods: This report has been prepared by the High Energy Brachytherapy Source Dosimetry (HEBD) Working Group. This report includes considerations in the application of the TG-43U1 formalism to high-energy photon-emitting sources with particular attention to phantom size effects, interpolation accuracy dependence on dose calculation grid size, and dosimetry parameter dependence on source active length.

Values for αβ and γδ T-lymphocytes and CD4+, CD8+, and CD56+ subsets in healthy adult subjects: assessment by age and gender.

Background: Normal reference values in healthy subjects for T-lymphocytes for both types of receptors, αβ and γδ, and their subsets are yet to be defined. The aim of this study was to measure peripheral blood αβ and γδ total T-lymphocytes and their subsets in a population of healthy subjects, in order to obtain valid reference values for studies in human pathology.

Methods: We studied a total of 157 healthy subjects, 78 men and 79 women, establishing their levels of CD3+, CD4+, CD8+, CD56+, αβCD3+, αβCD3+CD4+, αβCD3+CD8+, αβCD3+CD56+, γδCD3+, γδCD3+CD4-CD8-, γδCD3+CD8+, and γδCD3+CD56+ T-cells by flow cytometry.

[Trend in lead exposure in the Spanish child population in the last 20 years. An unrecognized example of health in all policies?].

Objective: To describe the time trend in atmospheric lead concentrations in Spain, from before lead was banned as a gasoline additive to the present, and to determine the trend in lead body burden in the Spanish child population.

Methods: We obtained the annual average for atmospheric lead levels in several Spanish cities from the 1980s to the present. A literature search was conducted to identify published studies on lead concentrations in populations of Spanish children.

Impact of the Tiloop Bra® mesh in CT images and dose delivery in breast radiotherapy.

A new titanized breast mesh, TiLOOP Bra, is currently available for implantation in patients who require radiotherapy. The purpose of this work is to study the dosimetric effect of the presence of a TiLOOP Bra mesh on breast radiation treatment and radiographic imaging. The dosimetric effects have been measured for three X-ray energies: 1.

Understanding the complexity of IgE-related phenotypes from childhood to young adulthood: a Mechanisms of the Development of Allergy (MeDALL) seminar.

Mechanisms of the Development of Allergy (MeDALL), a Seventh Framework Program European Union project, aims to generate novel knowledge on the mechanisms of initiation of allergy. Precise phenotypes of IgE-mediated allergic diseases will be defined in MeDALL. As part of MeDALL, a scientific seminar was held on January 24, 2011, to review current knowledge on the IgE-related phenotypes and to explore how a multidisciplinary effort could result in a new integrative translational approach.

Severe chronic allergic (and related) diseases: a uniform approach--a MeDALL--GA2LEN--ARIA position paper.

Concepts of disease severity, activity, control and responsiveness to treatment are linked but different. Severity refers to the loss of function of the organs induced by the disease process or to the occurrence of severe acute exacerbations. Severity may vary over time and needs regular follow-up.

Prenatal exposure to mercury and infant neurodevelopment in a multicenter cohort in Spain: study of potential modifiers.

Vulnerability of the central nervous system to mercury is increased during early development. This study aimed to evaluate whether cord blood total mercury levels may have a negative effect on both mental and psychomotor development in a maternal-birth cohort from moderate-high fish consumption areas. Study subjects were 1,683 child participants in the INMA (Environment and Childhood) Project from 4 areas of Spain between 2003 and 2010.

Dosimetry comparison between TG-43 and Monte Carlo calculations using the Freiburg flap for skin high-dose-rate brachytherapy.

Purpose: The purpose of this work was to evaluate whether the delivered dose to the skin surface and at the prescription depth when using a Freiburg flap applicator is in agreement with the one predicted by the treatment planning system (TPS) using the TG-43 dose-calculation formalism.

Methods And Materials: Monte Carlo (MC) simulations and radiochromic film measurements have been performed to obtain dose distributions with the source located at the center of one of the spheres and between two spheres. Primary and scatter dose contributions were evaluated to understand the role played by the scatter component.

Radiation leakage study for the Valencia applicators.

Introduction And Purpose: The Valencia applicators which are accessories of the microSelectron-HDR afterloader (Nucletron, Veenendaal, The Netherlands) are designed to treat skin lesions. These cup-shaped applicators are an alternative to superficial/orthovoltage x-ray treatment units. They limit the irradiation to the required area using tungsten-alloy shielding, and are equipped with a tungsten-alloy flattering filter allowing the treatment of skin tumors, the oral cavity, vaginal cuff, etc.

Characterizing mortality effects of particulate matter size fractions in the two capital cities of the Canary Islands.

Most of the studies differentiating the effect of size-classified particulate matter (PM) exposure have been carried out in cities where the average levels of fine particles (PM(2.5)) were higher than those of coarse particles (PM(10-2.5)).

Maternal vitamin D status in pregnancy and risk of lower respiratory tract infections, wheezing, and asthma in offspring.

Background: Adequate vitamin D status in mothers during pregnancy may influence the health status of the child later in life. We assessed whether maternal circulating 25-hydroxyvitamin D (25[OH]D) concentrations in pregnancy are associated with risk of lower respiratory tract infections, wheezing, and asthma in the offspring.

Methods: Data were obtained from 1724 children of the INfancia y Medio Ambiente (INMA) Project, a population-based birth cohort study.

Indoor air pollution from gas cooking and infant neurodevelopment.

Background: Gas cooking is a main source of indoor air pollutants, including nitrogen dioxide and particles. Because concerns are emerging for neurodevelopmental effects of air pollutants, we examined the relationship between indoor gas cooking during pregnancy and infant neurodevelopment.

Methods: Pregnant mothers were recruited between 2004 and 2008 to a prospective birth cohort study (INfancia y Medio Ambiente) in Spain during the first trimester of pregnancy.

Pre-natal exposure to dichlorodiphenyldichloroethylene and infant lower respiratory tract infections and wheeze.

The aim of our study was to examine whether pre-natal exposure to dichlorodiphenyldichloroethylene (DDE) increases the risk of lower respiratory tract infections (LRTIs) and wheeze in infants. The study is based on a birth cohort of 1,455 mother-child pairs. Maternal serum concentrations of DDE, polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) were measured during pregnancy.

Birth weight and prenatal exposure to polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE): a meta-analysis within 12 European Birth Cohorts.

Objectives: Exposure to high concentrations of persistent organochlorines may cause fetal toxicity, but the evidence at low exposure levels is limited. Large studies with substantial exposure contrasts and appropriate exposure assessment are warranted. Within the framework of the EU (European Union) ENRIECO (ENvironmental Health RIsks in European Birth Cohorts) and EU OBELIX (OBesogenic Endocrine disrupting chemicals: LInking prenatal eXposure to the development of obesity later in life) projects, we examined the hypothesis that the combination of polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) adversely affects birth weight.

Outdoor, but not indoor, nitrogen dioxide exposure is associated with persistent cough during the first year of life.

Background And Aims: Because their lungs and immune system are not completely developed, children are more susceptible to respiratory disease and more vulnerable to ambient pollution. We assessed the relation between prenatal and postnatal nitrogen dioxide (NO(2)) levels and the development of lower respiratory tract infections (LRTI), wheezing and persistent cough during the first year of life.

Methods: The study population consisted of 352 children from a birth cohort in Valencia, Spain.

The use of nomograms in LDR-HDR prostate brachytherapy.

Purpose: The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR).

Prenatal exposure to residential air pollution and infant mental development: modulation by antioxidants and detoxification factors.

Background: Air pollution effects on children's neurodevelopment have recently been suggested to occur most likely through the oxidative stress pathway.

Objective: We aimed to assess whether prenatal exposure to residential air pollution is associated with impaired infant mental development, and whether antioxidant/detoxification factors modulate this association.

Methods: In the Spanish INfancia y Medio Ambiente (INMA; Environment and Childhood) Project, 2,644 pregnant women were recruited during their first trimester.

Exposure to trihalomethanes through different water uses and birth weight, small for gestational age, and preterm delivery in Spain.

Background: Evidence associating exposure to water disinfection by-products with reduced birth weight and altered duration of gestation remains inconclusive.

Objective: We assessed exposure to trihalomethanes (THMs) during pregnancy through different water uses and evaluated the association with birth weight, small for gestational age (SGA), low birth weight (LBW), and preterm delivery.

Methods: Mother-child cohorts set up in five Spanish areas during the years 2000-2008 contributed data on water ingestion, showering, bathing, and swimming in pools.

QA of dynamic MLC based on EPID portal dosimetry.

Purpose: Dynamic delivery of intensity modulated beams (dIMRT) requires not only accurate verification of leaf positioning but also a control on the speed of motion. The latter is a parameter that has a major impact on the dose delivered to the patient. Time consumed in quality assurance (QA) procedures is an issue of relevance in any radiotherapy department.

Serotypes and clones causing invasive pneumococcal disease before the use of new conjugate vaccines in Catalonia, Spain.

Objectives: The objective of this study was to learn the serotype distribution and clonal composition of pneumococci causing invasive pneumococcal disease (IPD) in children and adults in Spain before the introduction of new 10-valent (PCV10) and 13-valent (PCV13) conjugate vaccines.

Methods: This is a 1-year prospective study including all patients with culture-proved IPD admitted to 30 medical centers in Catalonia, Spain, during the year 2009.

Results: A total of 614 episodes of IPD occurred in 612 patients.