Search results for "brachytherapy"
showing 10 items of 168 documents
Tratamiento del carcinoma de labio mediante braquiterapia de alta tasa de dosis
2005
Dado los diferentes métodos terapéuticos para el cáncer de labio, el objetivo del presente estudio es valorar los resultados obtenidos en un grupo prospectivo de 28 pacientes afectos de carcinoma de labio tratados mediante moldes externos de braquiterapia de alta tasa de dosis. Tanto por la remisión completa que ocurrió en todos los casos, la buena tolerancia a la terapia, la ausencia de complicaciones y de recurrencias, la facilidad de empleo de los moldes, la precisión en el posicionamiento de la fuente en la repetición diaria del tratamiento y la seguridad que ofrece en cuanto a radioprotección, concluímos que esta terapéutica probablemente se convierta en la de uso habitual en los próxi…
Erratum: “TG-43 U1 based dosimetric characterization of model 67-6520 Cs-137 brachytherapy source”
2012
Purpose: Brachytherapy treatment has been a cornerstone for management of various cancer sites, particularly for the treatment of gynecological malignancies. In low dose rate brachytherapy treatments,C137s sources have been used for several decades. A new C137s source design has been introduced (model 67-6520, source B3-561) by Isotope Products Laboratories (IPL) for clinical application. The goal of the present work is to implement the TG-43 U1 protocol in the characterization of the aforementioned C137s source. Methods: The dosimetriccharacteristics of the IPLC137s source are measured using LiF thermoluminescent dosimeters in a Solid Water™ phantom material and calculated using Monte Carl…
Technique for routine output verification of Leipzig applicators with a well chamber
2005
The H-type Leipzig applicators are accessories of the microSelectron-HDR system (Nucletron, Veenendaal, The Netherlands) for treatment of superficial malignancies. Recently, the dose rate distributions in liquid water for the whole set of applicators using both source models available for the microSelectron-HDR afterloaders have been obtained by means of the experimentally validated Monte Carlo (MC) code GEANT4. Also an output table (cGy/hU) at 3 mm depth on the applicator central axis was provided. The output verification of these applicators by the user, prior to their clinical use, present practical problems: small detectors such as thermoluminescent dosimeters or parallel-plate ionizati…
Radiation leakage study for the Valencia applicators
2011
Abstract 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. The tungsten-alloy thickness to shield radiation is not the same in all parts of the applicators. This fact led us to question whether the leakage radiation differs depending on where it is me…
TU-E-116-01: Clinical Implementation for Advanced Brachytherapy Dose Calculation Algorithms Beyond the TG-43 Formalism
2013
With the recent introduction of heterogeneity correction algorithms for brachytherapy, the AAPM community is still unclear on how to commission and implement these into clinical practice. The recently‐published AAPM TG‐186 report discusses important issues for clinical implementation of these algorithms. In this practical medical physics course, specific examples on how to perform the commissioning process are presented, as well as descriptions of the clinical impact from recent literature reporting comparisons of TG‐43 and heterogeneity‐based dosimetry. A proposed commissioning flowchart will be discussed, guiding the audience through the clinical process. Further, QA tests specific to the…
Évaluation par questionnaire des pratiques de la curiethérapie de prostate en France
2017
Resume Introduction La curietherapie des cancers de la prostate s’est progressivement implantee dans l’arsenal therapeutique comme une alternative a la prostatectomie radicale et a la radiotherapie externe. Dans le groupe des patients presentant un cancer de pronostic favorable, les survies specifiques depassent 95 % a 10 ans. L’objectif de cette etude est de decrire la place actuelle et les pratiques de la curietherapie en France. Materiel et methodes Un questionnaire realise en association avec l’Association francaise d’urologie (AFU) et la Societe francaise de radiotherapie oncologique (SFRO) et evaluant les differentes pratiques de la curietherapie en France a ete adresse a tous les uro…
Dosimetric perturbations of a lead shield for surface and interstitial high-dose-rate brachytherapy.
2014
In surface and interstitial high-dose-rate brachytherapy with either (60)Co, (192)Ir, or (169)Yb sources, some radiosensitive organs near the surface may be exposed to high absorbed doses. This may be reduced by covering the implants with a lead shield on the body surface, which results in dosimetric perturbations. Monte Carlo simulations in Geant4 were performed for the three radionuclides placed at a single dwell position. Four different shield thicknesses (0, 3, 6, and 10 mm) and three different source depths (0, 5, and 10 mm) in water were considered, with the lead shield placed at the phantom surface. Backscatter dose enhancement and transmission data were obtained for the lead shields…
Risk assessment of component failure modes and human errors using a new FMECA approach: application in the safety analysis of HDR brachytherapy
2014
Failure mode, effects and criticality analysis (FMECA) is a safety technique extensively used in many different industrial fields to identify and prevent potential failures. In the application of traditional FMECA, the risk priority number (RPN) is determined to rank the failure modes; however, the method has been criticised for having several weaknesses. Moreover, it is unable to adequately deal with human errors or negligence. In this paper, a new versatile fuzzy rule-based assessment model is proposed to evaluate the RPN index to rank both component failure and human error. The proposed methodology is applied to potential radiological over-exposure of patients during high-dose-rate brach…
A generic TG-186 shielded applicator for commissioning model-based dose calculation algorithms for high-dose-rate Ir-192 brachytherapy
2017
PurposeA joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and comparisons with model-based dose calculation algorithms (MBDCAs). Its main goal is to facilitate a smooth transition from the AAPM Task Group No. 43 (TG-43) dose calculation formalism, widely being used in clinical practice for brachytherapy, to the one proposed by Task Group No. 186 (TG-186) for MBDCAs. To do so, in this work a hypothetical, generic high-dose rate (HDR) Ir-19…