introduction: to measure radiation exposures rate in low-risk patients having stress-only and stress-rest myocardial perfusion imaging. methods: this was a prospective study conducted from january 2012 till november 2012 upon patients with low pre-test probability for coronary artery disease (cad). a stress mpi (stress-only if mpi is normal and no resting study) followed by a resting mpi study...

abstract background: the radiological impact of the use of phosphate fertilizers in soil is due to the internal irradiation of the lung by the alpha particles, short lived radon-thoron progeny and the external irradiation of the body by gamma rays emitted from radionuclides in situ. this paper describes the results of gamma spectrometric measurements of the concentration of the natural radionuc...

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...

Background: Best dose distribution in target volume and control of Organ at Risk (OAR) dose are the two main goals in brachytherapy. Materials and Methods: In this study in vivo dosimetry in 4 rectal points was performed by Transillumination Dosimeter (TLD) s and the measured doses were compared in different patients. One point was reported to have the maximum dose in each patient and the very ...

Interstitial brachytherapy represents the treatment of choice for small tumours, regionally localized in the oral cavity and the oropharynx. In the technical setting, continuous low-dose-rate (LDR) brachytherapy represented for many years the gold standard for administering radiation in head and neck brachytherapy. Large series of head and neck cancer patients treated with LDR brachytherapy hav...

The capability of the TrueBeam treatment system to deliver step and shoot IMRT plans at low dose rates was evaluated. Beam characteristics during low dose rates (5 to 100 MU/min) were evaluated for consistency using a planar ion chamber array. MU constancy, linearity, and beam profile symmetry were all found to be equivalent within 0.5%. The response of the Scandi Dos Delta 4 system was also ev...

BACKGROUND AND PURPOSE Theoretical calculations suggest that pulsed dose-rate irradiation (PDR) should have approximately the same effectiveness as continuous low dose-rate (CLDR) when the same total dose is given in the same overall time, unless large doses per pulse (> 2 Gy) are used and/or non-exponential or very short half-times of repair (< 0.5 h) are present in the irradiated tissues. How...