INTENSITY-MODULATED AND 3D-CONFORMAL RADIOTHERAPY FOR WHOLE-VENTRICULAR IRRADIATION AS COMPARED WITH CONVENTIONAL WHOLE-BRAIN IRRADIATION IN THE MANAGEMENT OF LOCALIZED CENTRAL NERVOUS SYSTEM GERM CELL TUMORS

Purpose: To compare the sparing potential of cerebral hemispheres with intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) for whole-ventricular irradiation (WVI) and conventional whole-brain irradiation (WBI) in the management of localized central nervous system germ cell tumors (CNSGCTs). Methods and Materials: Ten cases of patients with localized CNSGCTs and submitted to WVI by use of IMRT with or without a ""boost"" to the primary lesion were selected. For comparison purposes, similar treatment plans were produced by use of 3D-CRT (WVI with or without boost) and WBI (opposed lateral fields with or without boost), and cerebral hemisphere sparing was evaluated at dose levels ranging from 2 Gy to 40 Gy. Results: The median prescription dose for WVI was 30.6 Gy (range, 25.2-37.5 Gy), and that for the boost was 16.5 Gy (range, 0-23.4 Gy). Mean irradiated cerebral hemisphere volumes were lower for WVI with IMRT than for 3D-CRT and were lower for WVI with 3D-CRT than for WBI. Intensity-modulated radiotherapy was associated with the lowest irradiated volumes, with reductions of 7.5%, 12.2%, and 9.0% at dose levels., compared with 3D-CRT. Intensity-modulated radiotherapy provided of 20, 30, and 40 Gy, respectively statistically significant reductions of median irradiated volumes at all dose levels (p = 0.002 or less). However, estimated radiation doses to peripheral areas of the body were 1.9 times higher with IMRT than with 3D-CRT. Conclusions: Although IMRT is associated with increased radiation doses to peripheral areas of the body, its use can spare a significant amount of normal central nervous system tissue compared with 3D-CRT or WBI in the setting of CNSGCT treatment. (C) 2010 Elsevier Inc.

A Monte Carlo-based procedure for independent monitor unit calculation in IMRT treatment plans.

Intensity-modulated radiotherapy (IMRT) treatment plan verification by comparison with measured data requires having access to the linear accelerator and is time consuming. In this paper, we propose a method for monitor unit (MU) calculation and plan comparison for step and shoot IMRT based on the Monte Carlo code EGSnrc/BEAMnrc. The beamlets of an IMRT treatment plan are individually simulated using Monte Carlo and converted into absorbed dose to water per MU. The dose of the whole treatment can be expressed through a linear matrix equation of the MU and dose per MU of every beamlet. Due to the positivity of the absorbed dose and MU values, this equation is solved for the MU values using a non-negative least-squares fit optimization algorithm (NNLS). The Monte Carlo plan is formed by multiplying the Monte Carlo absorbed dose to water per MU with the Monte Carlo/NNLS MU. Several treatment plan localizations calculated with a commercial treatment planning system (TPS) are compared with the proposed method for validation. The Monte Carlo/NNLS MUs are close to the ones calculated by the TPS and lead to a treatment dose distribution which is clinically equivalent to the one calculated by the TPS. This procedure can be used as an IMRT QA and further development could allow this technique to be used for other radiotherapy techniques like tomotherapy or volumetric modulated arc therapy.

Development and Testing of An Automatic Lung IMRT Planning Algorithm

Knowledge-based radiation treatment is an emerging concept in radiotherapy. It

mainly refers to the technique that can guide or automate treatment planning in

clinic by learning from prior knowledge. Dierent models are developed to realize

it, one of which is proposed by Yuan et al. at Duke for lung IMRT planning. This

model can automatically determine both beam conguration and optimization ob-

jectives with non-coplanar beams based on patient-specic anatomical information.

Although plans automatically generated by this model demonstrate equivalent or

better dosimetric quality compared to clinical approved plans, its validity and gener-

ality are limited due to the empirical assignment to a coecient called angle spread

constraint dened in the beam eciency index used for beam ranking. To eliminate

these limitations, a systematic study on this coecient is needed to acquire evidences

for its optimal value.

To achieve this purpose, eleven lung cancer patients with complex tumor shape

with non-coplanar beams adopted in clinical approved plans were retrospectively

studied in the frame of the automatic lung IMRT treatment algorithm. The primary

and boost plans used in three patients were treated as dierent cases due to the

dierent target size and shape. A total of 14 lung cases, thus, were re-planned using

the knowledge-based automatic lung IMRT planning algorithm by varying angle

spread constraint from 0 to 1 with increment of 0.2. A modied beam angle eciency

index used for navigate the beam selection was adopted. Great eorts were made to assure the quality of plans associated to every angle spread constraint as good

as possible. Important dosimetric parameters for PTV and OARs, quantitatively

re

ecting the plan quality, were extracted from the DVHs and analyzed as a function

of angle spread constraint for each case. Comparisons of these parameters between

clinical plans and model-based plans were evaluated by two-sampled Students t-tests,

and regression analysis on a composite index built on the percentage errors between

dosimetric parameters in the model-based plans and those in the clinical plans as a

function of angle spread constraint was performed.

Results show that model-based plans generally have equivalent or better quality

than clinical approved plans, qualitatively and quantitatively. All dosimetric param-

eters except those for lungs in the automatically generated plans are statistically

better or comparable to those in the clinical plans. On average, more than 15% re-

duction on conformity index and homogeneity index for PTV and V40, V60 for heart

while an 8% and 3% increase on V5, V20 for lungs, respectively, are observed. The

intra-plan comparison among model-based plans demonstrates that plan quality does

not change much with angle spread constraint larger than 0.4. Further examination

on the variation curve of the composite index as a function of angle spread constraint

shows that 0.6 is the optimal value that can result in statistically the best achievable

plans.

Retirement Investors' Club Plan Document; Fund Fees Comparison, 2005

The Retirement Investors’ Club (RIC) (also referred to as 457/401(a) deferred compensation) is a voluntary retirement savings program designed to help you meet your need for income at retirement and lower your current income taxes. Your contributions to RIC are automatically withdrawn from your paycheck and you are credited with an employer match. You may enroll*and make changes at any time. Other advantages are explained below…keep reading about this excellent employee benefit!

A comparison of two editions of the RIBA plan of work

The RIBA Plan of Work describes the way a construction process should be organized. Although not officially approved by the RIBA council, a new plan of work was published in 2000 with the intention of replacing the RIBA Plan of Work, so it is useful to analyse both in terms of the organizational structure they impose upon construction projects. Using analytical principles from organizational theory, both plans are analysed by converting them into organizational matrices and assessing their relative complexities, the load on participants, decentralization of responsibility, number of interfaces and the extent to which they provide for co-ordination and control. This demonstrates first, that the analysis of organizational structure is an appropriate approach for undertaking comparisons of such documents; and second, that while both plans of work are of roughly equal complexity, the new one is more demanding on the participants; produces a higher number of interfaces between processes, and provides for more co-ordination than the old one. Neither plan deals with controlling the output of individuals, leaving it as an internal matter for each participating organization.

Comparison of the Pershing II program with the acquisition plan recommended by the Commission on Government Procurement, Department of Defense : report to the Congress /

"B-182956."

Rudiments of geography, on a new plan, designed to assist the memory by comparison and classification; with numerous engravings of manners, customs, & curiosities. Accompanied with an atlas, exhibiting the prevailing religions, forms of government, degrees of civilization, and the comparative size of towns, rivers and mountains /

Mode of access: Internet.

Rudiments of geography, on a new plan : designed to assist the memory by comparison and classification, with numerous engravings of manners, customs, and curiosities accompanied with an atlas, exhibiting the prevailing religions, froms of government, degrees of civilization, and the comparative size of towns, rivers, and mountains /

Mode of access: Internet.

Bullwhip effect, in production control: a comparison between traditional methods and LPS

21th Annual Conference of the International Group for Lean Construction (IGLC 21), July 2013, Fortaleza, Brazil

Comparison of two osteoporotic fracture management pathways: experience at 1 year

Introduction: Osteoporosis presenting as low-impact fractures to traumatology units is often undiagnosed and under-treated. Results from the Osteocare study in Lausanne (a nurse based intervention, passive pathway) showed that only 19% of patients received management for osteoporosis, and in the literature [1], the rate is between 10-25%. We have evaluated a different management concept, based on the systematic assessment of patients with osteoporotic fractures during and after hospitalization (active pathway). Methods: Inpatients admitted to the Department of Musculoskeletal Medicine for a fragility fracture were identified by a nurse according to a predefined questionnaire and were then clinically evaluated by a doctor. Based on the results, a management plan was proposed to the patients. Patients could choose between follow up either by their GP or by the Centre of Bone Disease of the CHUV. For patients who chose follow-up in our Centre, we assessed their adherence to medical follow-up 1 year inclusion. The results of patients who had been evaluated in our cohort between the 1 November 2008 and the 1 December 2009 were analysed. Results: 573 inpatients received specific management of their osteoporotic fracture over 18 months. The mean age was 77 y (31-99), 81% were women (203 hip fractures, 40 pelvis fractures, 101 arm fractures, 57 vertebral fractures, 63 ankle fractures, and 25 others sites). During the study period, 303 patients received a proposition of a specific treatment. 39 (13%) chose a follow up with the GP, 19 (6%) dead and 245 (81%) preferred a follow up in our Centre. After 1 year, 166 (67%) patients are under follow up in our outpatient clinic. Conclusion: With an active clinical pathway that starts during the hospitalization, consisting on a nursing evaluation followed by a medical consultation by an expert in osteoporosis, the adherence increased from 19% to 67% in terms of follow up. These results lead us to propose a consultation with a doctor experienced in osteoporosis after all osteoporotic fractures.

Comparison between standard radiography and spiral CT with 3D reconstruction in the evaluation, classification and management of tibial plateau fractures.

The aim of this study was to compare the diagnostic efficiency of plain film and spiral CT examinations with 3D reconstructions of 42 tibial plateau fractures and to assess the accuracy of these two techniques in the pre-operative surgical plan in 22 cases. Forty-two tibial plateau fractures were examined with plain film (anteroposterior, lateral, two obliques) and spiral CT with surface-shaded-display 3D reconstructions. The Swiss AO-ASIF classification system of bone fracture from Muller was used. In 22 cases the surgical plans and the sequence of reconstruction of the fragments were prospectively determined with both techniques, successively, and then correlated with the surgical reports and post-operative plain film. The fractures were underestimated with plain film in 18 of 42 cases (43%). Due to the spiral CT 3D reconstructions, and precise pre-operative information, the surgical plans based on plain film were modified and adjusted in 13 cases among 22 (59%). Spiral CT 3D reconstructions give a better and more accurate demonstration of the tibial plateau fracture and allows a more precise pre-operative surgical plan.

Comparison between artificial neural networks and maximum likelihood classification in digital soil mapping

Soil surveys are the main source of spatial information on soils and have a range of different applications, mainly in agriculture. The continuity of this activity has however been severely compromised, mainly due to a lack of governmental funding. The purpose of this study was to evaluate the feasibility of two different classifiers (artificial neural networks and a maximum likelihood algorithm) in the prediction of soil classes in the northwest of the state of Rio de Janeiro. Terrain attributes such as elevation, slope, aspect, plan curvature and compound topographic index (CTI) and indices of clay minerals, iron oxide and Normalized Difference Vegetation Index (NDVI), derived from Landsat 7 ETM+ sensor imagery, were used as discriminating variables. The two classifiers were trained and validated for each soil class using 300 and 150 samples respectively, representing the characteristics of these classes in terms of the discriminating variables. According to the statistical tests, the accuracy of the classifier based on artificial neural networks (ANNs) was greater than of the classic Maximum Likelihood Classifier (MLC). Comparing the results with 126 points of reference showed that the resulting ANN map (73.81 %) was superior to the MLC map (57.94 %). The main errors when using the two classifiers were caused by: a) the geological heterogeneity of the area coupled with problems related to the geological map; b) the depth of lithic contact and/or rock exposure, and c) problems with the environmental correlation model used due to the polygenetic nature of the soils. This study confirms that the use of terrain attributes together with remote sensing data by an ANN approach can be a tool to facilitate soil mapping in Brazil, primarily due to the availability of low-cost remote sensing data and the ease by which terrain attributes can be obtained.

Intégration du concept de capacité de support d’un plan d’eau aux apports en phosphore à l’aménagement du territoire au Québec : Réalité ou utopie?

Ce mémoire a comme objectif de présenter une revue de la littérature et une analyse comparative des différents modèles existants pour le calcul de la capacité de support d’un plan d’eau aux apports en phosphore. Ce document a aussi pour but d’évaluer les différentes options pour l’utilisation de ce genre d’outil au Québec, ainsi que d’amorcer une réflexion sur les applications possibles de ce concept au niveau local, en lien avec l’aménagement du territoire des bassins versants. L’analyse comparative des modèles théoriques, combinée à la réflexion d’acteurs clés impliqués actuellement dans un processus qui consiste à tester leur utilisation dans les Laurentides au Québec, a permis de mettre en relief l’importance de calibrer les modèles régionalement. De plus, certains avantages semblent résider dans l’utilisation d’un modèle de nature empirique afin d’effectuer les prédictions sur les apports naturels et totaux en phosphore pour les lacs de cette région. Par contre, l’utilisation d’une approche de type « bilan de masse », s’avère tout de même indispensable afin de relativiser l’importance des différents apports anthropiques en phosphore du bassin versant. Dans l’avenir, l’utilisation de tels modèles permettra possiblement de justifier certaines mesures restrictives au développement des bassins versants, qui pourront s’insérer parmi les outils d’urbanisme actuels. Ce sont principalement les municipalités qui détiennent les pouvoirs nécessaires afin d’intégrer les prescriptions découlant de ce genre d’analyse à l’aménagement du territoire des bassins versants. Plusieurs outils d’urbanisme, tels que les plans d’aménagement d’ensemble (PAE) ou bien les règlements de zonage et de lotissement, semblent donner assez de latitude afin de permettre aux municipalités d’intervenir en ce sens. Toutefois, les modèles de capacité de support ne pourront pas être utilisés afin de calculer un nombre précis d’habitations qu’il est possible de construire dans le bassin versant d’un lac.

Plan Exportador CI. ABASQUIM Ltda.

El desarrollo de este trabajo de tesis constituye el esfuerzo de La Secretaria de Desarrollo Económico, Maloka, CIDEM, Universidad del Rosario y de la estudiante por contribuir con el aprendizaje y desarrollo de los pequeños y medianos empresarios colombianos, en virtud de que, en el país no existe la adecuada capacitación y formación académica y practica para crear, desarrollar y gerenciar empresas que cuenten con la capacidad y habilidad de introducir y penetrar de manera exitosa sus productos en mercados externos y así aumentar la presencia, calidad y competitividad del país con respecto a otros mercados. El referido trabajo se llevo a cabo en cinco módulos que sirvieron como base en la toma de decisiones y definición de estrategias, estos módulos son: Inteligencia de Mercados, Costos, Logística, Comercialización y Plan Exportador.

Plan exportador Ingenio Moda

El presente plan exportador se realizó para una microempresa del programa: Red de empresarios innovadores de la Alcaldía de Bogotá, en conjunto con Maloka. INGENIO MODA es una empresa de confecciones que lleva 5 años en el mercado. Actualmente se especializa en 3 líneas: 1. METALLIK: Ropa causal y formal para mujeres entre 15 y 30 años. Con facilidad de adaptación a cualquier ocasión de uso. 2. POP institucional: Uniformes institucionales, que tienen como objetivo resaltar la imagen corporativa de las empresas. 3. ASESORIA EN DISEÑO: Diseño externo para otras empresas y asesoría en presentación de colecciones. Para el presente trabajo se decidió trabajar sobre blusas de algodón de la línea METALLIK, con posición arancelaria: 611420. En la realización del plan exportador se trabajaron 5 fases: 1. INTELIGENCIA DE MERCADOS: Donde se analizaron los 5 países Latinoamericanos más factibles para introducirse en el mercado. Se analizaron varios aspectos económicos, culturales, facilidad de entrada, costo del país, competencia, entro otros dentro de la matriz de CIDEM (Universidad del Rosario), para escoger junto con el empresario los tres países mas convenientes para abarcar con el producto seleccionado. Para este plan exportador se escogieron: Costa Rica, Chile y México. 2. COSTOS INTERNOS: Esta fase tuvo como objetivo principal estudiar el costo de producción interna del producto seleccionado, para establecer políticas de ventas adecuadas y analizar la competitividad con las demás empresas con presencia en los países seleccionados. 3. PRECIO Y LOGISTICA INTERNACIONAL: Se trabajó sobre el precio del producto puesto en los países. Todos los aspectos necesarios a analizar para trasladar el producto al lugar escogido: Contratación de SIA, escogencia del seguro, del mejor modo de traslado (Naviero o Aire), condiciones de empaque para las condiciones del traslado y por ultimo, comparación de este precio final con los precios existentes en el mercado seleccionado. 4. ESTRATEGIAS COMERCIALES INTERNACIONALES: Después de haber analizado los aspectos técnicos de traslado y venta del producto, es necesario estudiar a los países escogidos en aspectos culturales, climáticos, geográficos, económicos, en fin, todos los aspectos relevantes para hacer al producto atractivo en el mercado a abarcar. De acuerdo con esto, se estructuraron las estrategias mas adecuadas para cada país, esto con el objetivo de garantizar la aceptación del producto. 5. PLAN EXPORTADOR: Por ultimo, teniendo en cuenta toda la información anterior, se realizó el plan exportador mas adecuado para Ingenio Moda. Que tiene como propósito ser una guía para que la empresa pueda abarcar el mercado exterior con éxito.