We investigate the sensitivity of IMRT commissioning using the TG-119 C-shape phantom and credentialing with the IROC head and neck phantom to treatment planning system commissioning errors. We introduced errors into the various aspects of the commissioning process for a 6X photon energy modeled using the analytical anisotropic algorithm within a commercial treatment planning system. Errors wer...

Introduction: Human beings are naturally exposed to ionizing radiation in any environment. There are two main contributors to radiation exposures from natural sources: cosmic rays, Cosmo genic radionuclides, and radioactive nuclides that originated in the earth's crust. According to the latest data provided by the United Nations Scientific Committee on the Effects of Atomic Rad...

OBJECTIVE To evaluate knowledge of and techniques for using prescribed inhalation devices among patients with asthma or COPD treated at a tertiary teaching hospital. METHODS Patients were assessed after medical visits, and their physicians were blinded to this fact. Patients were asked to demonstrate their inhaler technique and were then interviewed regarding their knowledge of inhalation dev...

The activity concentrations of 228Ra, 226Ra and 222Rn have been analysed in 452 drinking water supplies of São Paulo State. This study started in 1994 and covered 54% of the 574 existing counties. Concentrations up to 235 and 131 mBq l-1 were observed for 226Ra and 228Ra, respectively, whereas 222Rn concentrations reached 315 Bq l-1. Radiation doses up to 0.3, 0.6 and 3.2 mSv yr-1 were estimate...

patients and methods we evaluated radiation exposure from initial and downstream testing in a prospectively collected, matched cohort evaluated for cp in the emergency department (ed) with either ccta compared with usual care over a median follow-up of 19.6 months. effective radiation dose was calculated using published conversion factors. results prospective, ecg-triggered acquisition using a ...

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...