The NCRP has recently defined RBE values and a new quantity (Gy-Eq) for use in estimation of deterministic effects in space shielding and operations. The NCRP's RBE for neutrons is left ambiguous and not fully defined. In the present report we will suggest a complete definition of neutron RBE consistent with the NCRP recommendations and evaluate attenuation properties of deterministic effects (...

BACKGROUND This study was designed to compare the quality assurance (QA) results of four dosimetric tools used for intensity modulated radiation therapy (IMRT) and to suggest universal criteria for the passing rate in QA, irrespective of the dosimetric tool used. MATERIALS AND METHODS Thirty fields of IMRT plans from five patients were selected, followed by irradiation onto radiochromic film,...

Low dose rate brachytherapy is a widely used modality for the treatment of prostate cancer. Most clinical treatment planning systems currently in use approximate all tissue to water, neglecting the existence of inhomogeneities, such as calcifications. The presence of prostatic calcifications may perturb the dose due to the higher photoelectric effect cross section in comparison to water. This s...

Introduction: Orthogonal radial fields are those in which the central axes are perpendicular to each other. An example of these orthogonal fields is the set of craniospinal orthogonal fields that are used for radiotherapy of medulloblastoma. Craniospinal radial fields consist of two parallel-opposed fields for brain exposure and one or two posterior spinal fields for spinal cord exposure. The m...

BACKGROUND Intensity-modulated proton therapy (IMPT) has the potential to spare dose to organs at risk (OAR) when compared to intensity-modulated radiotherapy (IMRT) while maintaining excellent clinical outcomes. METHODS Ten patients with nasopharyngeal carcinoma (NPC) were identified for whom IMPT was planned; 9 patients also had a comparison photon-based IMRT plan generated. Dosimetric comp...

background:  radiochromic film is used for radiation dose measurement, xr-rv3 is used in fluoroscopy and ebt2 film in radiation therapy. the aim was to determine if the dosimetric properties of these two films are comparable in megavolt photon beams. materials and methods: comparison measurements included: calibration curves, heterogeneous phantom dose profiles, and nasopharynx dose distributio...

In the last decade, many efforts have been made to characterize anatomic changes of head and neck organs at risk (OARs) and the dosimetric consequences during radiotherapy. This review was undertaken to provide an overview of the magnitude and frequency of these effects, and to investigate whether we could find criteria to identify head and neck cancer patients who may benefit from adaptive rad...

PURPOSE To quantify the dosimetric impact of applicator displacements and applicator reconstruction-uncertainties through simulated planning studies of virtual applicator shifts. MATERIAL AND METHODS Twenty randomly selected high-dose-rate (HDR) titanium tandem-and-ovoid (T&O) plans were retrospectively studied. MRI-guided, conformal brachytherapy (MRIG-CBT) plans were retrospectively generat...

Software for modelling by Monte Carlo (MC) method the dosimetric devices such as dosimetric wedge (ModeDW) and stack (ModeStEB) irradiated with scanned electron beam on moving conveyer was developed by authors. Integration of computer modelling of a dose distribution in films located in a wedge and stack made of arbitrary materials expands the procedure opportunities of the dosimetric devices i...