Monte Carlo simulations are more and more popular trend in nuclear medicine imaging. They were also widely used in radiotherapy and brachytherapy with use of more general simulation software. GATE (Geant4 Application for Tomographic Emission) is a platform developed on general Monte Carlo code designed for simulating and tracking the passage of particles through matter (Geant4) but is specifica...

Introduction: Long-term teletherapy program is not suitable for old and working patients and those living in areas where little access to primary health care is available. Accelerated partial breast irradiation (APBI) using high dose rate (HDR) brachytherapy is an appropriate alternative for these patients due to its limited number of fractions. The AccuBoost is a system for delivering APBI. Th...

Intracoronary brachytherapy using beta or gamma radiation is currently the most efficient type of therapy for preventing the recurrence of coronary in-stent restenosis. Its implementation depends on the interaction among interventionists, radiotherapists, and physicists to assure the safety and quality of the method. The authors report the pioneering experience in Brazil of the treatment of 2 p...

The potential use of high resolution collimators with standard radiographic detectors in place of conventional gamma cameras for high resolution microscintigraphy is presented. Polycapillary multiple hole collimators are shown to provide 10-100 micron scale spatial resolution. A series of images from arrays of 125I brachytherapy seeds in Lucite phantoms display resolution better than 0.1 mm wit...

Introduction: Brachytherapy is a type of radiotherapy in which radioactive sources are used in proximity of tumors normally for treatment of malignancies in the head, prostate and cervix. Materials and Methods: The Cs-137 Selectron source is a low-dose-rate (LDR) brachytherapy source used in a remote afterloading system for treatment of different cancers. This system uses active and inactive sp...

CH: Choroidal Hemangioma; CCH: Circumscribed Choroidal Hemangioma; DCH: Diffuse Choroidal Hemangioma; Gy: Gray; TTT: Transpupillary Thermotherapy: PDT: Photodynamic Therapy; EBRT: External Beam Radiotherapy; PBT: Proton Beam Radiation; PB: Plaque Brachytherapy; GKRS: Gamma Knife Radiosurgery; VEGF: Vascular Endothelial Growth Factor; CGE: Cobalt Gray Equivalent; RD: Retinal Detachment; CME: Cys...

background; environmental gamma ray refers to the gamma radiation from terrestrial sources and building materials. in enclosed spaces radiation can become a health hazard leading to potential increase in the rates of lung cancer. the goal of this study is to assess the exposure to natural gamma radiation of children in the schools of zanjan province. method; the natural gamma radiation was asse...

Microquasars are X-ray binary systems with non-thermal radio emission originated in jet-like features. They are attractive sites for gamma-ray production, since relativistic particles in the jet should traverse locally strong both photon and matter fields. In this review we discuss whether some of the unidentified gammaray sources detected by the EGRET instrument of the Compton Gamma-Ray Observ...

Current brachytherapy dose calculations ignore applicator attenuation and tissue heterogeneities, assuming isolated sources embedded in unbounded medium. Conventional Monte Carlo (MC) dose calculations, while accurate, are too slow for practical treatment planning. This study evaluates the efficacy of correlated sampling in reducing the variance of MC photon transport simulation in typical brac...