The Active Tissue Equivalent Dosimeter (ATED) is a low-cost, easy-to-use and compact tissue equivalent proportional counter designed for use aboard spacecraft, satellites, aircraft, unmanned aerial vehicles high-altitude balloons. ATED was rigorously tested at particle accelerator facilities utilizing heavy ions of charge energy similar to Galactic Cosmic Rays (GCRs). Upon completion the ground...

OBJECTIVES In this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (CTAC), using the bilinear scaling method. METHODS The measured attenuation coefficient (μm) was compared to the theoretical attenuation coefficient (μt), using four different CT scanners and an RMI 467 phantom. The effective energy of CT beam X-rays was calculated, using the alumin...

Presence of interfaces between high and low atomic number (Z) materials, often encountered in diagnostic imaging and radiation therapy, leads to radiation dose perturbation. It is characterized by a very narrow region of sharp dose enhancement at the interface. A rapid falloff of dose enhancement over a very short distance from the interface makes the experimental dosimetry nontrivial. We use a...

Background: The present study aimed to investigate the equivalent dose in vital organs, including heart and lung, due to secondary particles produced during breast proton therapy. Materials and Methods: The numerical ORNL female-phantom was improved and simulated using the Monte Carlo MCNPX code. The depth-dose profile of proton beams with different energies was simulated. The proper energy ran...

This study is aimed at verifying the dosimetric performance of a treatment planning system (TPS) and to as well compare the accuracy of the measured absorbed dose of the solid water phantom against the inhouse phantom. In this study, a phantom for use in radiotherapy treatment planning of human trunk anatomical region has been designed with six hollows for inserting materials mimicking differen...

introduction: this study investigates to what extent the computed dose received by lung tissue in a commercially available treatment planning system (tps) for 192ir high-dose-rate breast brachytherapy is accurate in view of tissue inhomogeneities and presence of ribs. materials and methods: a ct scan of the breast was used to construct a patient-equivalent phantom in the clinical treatment plan...

*Corresponding author: Dr. Tayyeb Allahverdi Pourfallah, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran. Fax: +98 21 88973653 E-mail: [email protected] Background: Polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. MRI Polymer gel dosimeters are tissue equi...

Nanosilicate-polysaccharide composite hydrogels are a well-studied class of materials in regenerative medicine that combine good 3D printability, staining, and biological properties, making them an excellent candidate material for complex bone scaffolds. The aim this study was to develop hydrogel suitable printing has radiological properties similar those the natural protocols their histologica...

An investigation was performed of the changes in image quality and patient dose as a result of increasing filtration for fluoroscopy performed under automatic brightness control. Filtration was added either at the x-ray tube housing (i.e., scatter-free geometry) or adjacent to a tissue equivalent phantom simulating the patient (i.e., with-scatter geometry). Patient doses were expressed in terms...

An accurate and fast radiation dose calculation is essential for successful radiation radiotherapy. The aim of this study was to implement a new graphic processing unit (GPU) based radiation therapy treatment planning for accurate and fast dose calculation in radiotherapy centers. A program was written for parallel running based on GPU. The code validation was performed by EGSnrc/DOSXYZnrc. Mor...