Search results for " BRACHYTHERAPY"
showing 10 items of 44 documents
Design and characterization of a new high-dose-rate brachytherapy Valencia applicator for larger skin lesions
2016
Purpose: The aims of this study were (i) to design a new high-dose-rate (HDR) brachytherapy applicator for treating surface lesions with planning target volumes larger than 3 cm in diameter and up to 5 cm in size, using the microSelectron-HDR or Flexitron afterloader (Elekta Brachytherapy) with a 192Ir source; (ii) to calculate by means of the Monte Carlo(MC) method the dose distribution for the new applicator when it is placed against a water phantom; and (iii) to validate experimentally the dose distributions in water. Methods: The penelope2008MC code was used to optimize dwell positions and dwell times. Next, the dose distribution in a water phantom and the leakage dose distribution arou…
SU-E-T-530: Comparison of Analytical and Monte Carlo Calculations for Heterogeneity Corrections in LDR Prostate Brachytherapy
2013
Purpose: It is well‐known that tissue heterogeneities and calcifications have significant influence on low energy brachytherapy. The aim of this work is to study the application of a simplified analytic algorithm that could be compatible with commercial Treatment Planning System (TPS) based on TG‐43. The algorithm, based on the classic equivalent path length method, has been compared with Monte Carlo (MC) computations using Penelope2009. Methods: The analytical model scales the distance from the seed to the calculation point according to the electronic density of the medium relative to water. Then, the dose is calculated from TG‐43 consensus data (stored on a TPS) by scaling the radial dose…
Permanent seed brachytherapy for clinically localized prostate cancer: long-term outcomes in a 700 patient cohort.
2015
Abstract Purpose Few large European studies have evaluated long-term outcomes for permanent prostate brachytherapy (PPB) as monotherapy for clinically localized prostate cancer. The objective of the present study was to evaluate long-term survival in this patient profile. Methods and Materials Retrospective study of 700 patients who underwent transperineal ultrasound-guided iodine-125 PPB (145 Gy) between January 2000 and July 2012. Median age was 64.8 years (range, 35–79). Most patients (638 of 700; 91%) had low-risk disease (D'Amico criteria). Eighty-five patients (12%) received hormonal treatment. Overall survival, cause-specific survival, and biochemical relapse–free survival were calcu…
Dosimetric characteristics of a new unit for electronic skin brachytherapy
2013
PURPOSE: Brachytherapy with radioactive high dose rate (HDR) (192)Ir source is applied to small skin cancer lesions, using surface applicators, i.e. Leipzig or Valencia type. New developments in the field of radiotherapy for skin cancer include electronic brachytherapy. This technique involves the placement of an HDR X-ray source close to the skin, therefore combining the benefits of brachytherapy with the reduced shielding requirements and targeted energy of low energy X-rays. Recently, the Esteya(®) Electronic Brachytherapy System (Esteya EBS, Elekta AB-Nucletron, Stockholm, Sweden) has been developed specifically for HDR brachytherapy treatment of surface lesions. The system provides rad…
Depth determination of skin cancers treated with superficial brachytherapy: ultrasound vs. histopathology
2014
Purpose: The purpose of this study is to compare high frequency ultrasonography (HFUS) and histpathologic assessment done by punch biopsy in order to determine depth of basal cell carcinoma (BCC), in both superficial and nodular BCCs prior to brachytherapy treatment. Material and methods: This study includes 20 patients with 10 superficial and 10 nodular BCCs. First, punch biopsy was done to confirm the diagnosis and to measure tumour depth (Breslow rate). Subsequently, HFUS was done to measure tumour depth to search for correlation of these two techniques. Results: Neither clear tendency nor significance of the punch biopsy vs. HFUS depth determination is observed. Depth value differences …
RPN safety analysis to reduce the risk of malpractices in high dose rate brachytherapy
2013
A new fuzzy rule-based assessment model is proposed to evaluate the risk priority number in the Failure Mode, Effects, and Criticality Analysis (FMECA) method to rank component failures and human errors from the medical staff, leading to potential radiological over-exposure of patients during high-dose-rate brachytherapy treatment. The obtained results are relevant for a range of causes that have a reasonable probability of producing significant adverse outcomes. Thus, recommendations are provided for procedures and safety devices to reduce the occurrence of radiological over-exposure accidents. This method can solve the problems in conventional FMECA applications and improve the safety and…
Monte Carlo dosimetric study of the BEBIG Co-60 HDR source
2005
Although not as widespread as Ir-192, Co-60 is also available on afterloading equipment devoted to high dose rate brachytherapy, mainly addressed to the treatment of gynaecological lesions. The purpose of this study is to obtain the dosimetric parameters of the Co-60 source used by the BEBIG MultiSource remote afterloader (BEBIG GmbH, Germany) for which there are no dosimetric data available in the literature. The Monte Carlo code GEANT4 has been used to obtain the TG43 parameters and the 2D dose rate table in Cartesian coordinates of the BEBIG Co-60 HDR source. The dose rate constant, radial dose function and anisotropy function have been calculated and are presented in a tabular form as w…
Surface brachytherapy: Joint report of the AAPM and the GEC-ESTRO Task Group No. 253.
2020
The surface brachytherapy Task Group report number 253 discusses the common treatment modalities and applicators typically used to treat lesions on the body surface. Details of commissioning and calibration of the applicators and systems are discussed and examples are given for a risk-based analysis approach to the quality assurance measures that are necessary to consider when establishing a surface brachytherapy program.
Commissioning and periodic tests of the Esteya® electronic brachytherapy system
2015
A new electronic brachytherapy unit from Elekta, called Esteya(®), has recently been introduced to the market. As a part of the standards in radiation oncology, an acceptance testing and commissioning must be performed prior to treatment of the first patient. In addition, a quality assurance program should be implemented. A complete commissioning and periodic testing of the Esteya(®) device using the American Association of Physicists in Medicine (AAPM), Groupe Europeen de Curietherapie and the European Society for Radiotherapy & Oncology (GEC-ESTRO) guidelines for linacs and brachytherapy units as well as our personal experience is described in this paper. In addition to the methodology, r…
Dosimetry comparison between TG-43 and Monte Carlo calculations using the Freiburg flap for skin high-dose-rate brachytherapy
2012
Abstract 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. A standard treatment plan was generated using MC- and TG-43-based TPS appl…