PURPOSE In the presence of random uncertainties, delivered radiation treatment doses in patient likely exhibit a statistical distribution. The expected dose and variance of this distribution are unknown and are most likely not equal to the planned value since the current treatment planning systems cannot exactly model and simulate treatment machine. Relevant clinical questions are 1) how to qua...

Intensity-modulated radiation therapy (IMRT) quality assurance (QA) is often performed using a 2D device and compares measured and computed fluence maps to determine if a field passes or fails certain dose and position criteria. The effects of a measured deviation to the 3D patient spatial dosimetry and dose volume histogram (DVH) are largely unknown because they cannot be analyzed using commer...

background iran has a widespread diagnostics and clinical support services (dcss) network that plays a crucial role in providing diagnostic and clinical support services to both inpatient and outpatient care. however, very little is known on the application of quality assurance (qa) policies in dcss units. this study explores the extent of application of eleven qa strategies in dcss units withi...

background: health system pharmacies, like other health care professional, practice under a number of mandated stan­dards. basic concepts of quality assurance (qa) standards should be applied to hospital pharmacy practice. the survey re­ported here is to assess qa system implementation and its standard indicators observation in tehran university of medical sci­ences (tums) hospitals' pharmacies...

Using an EPID for patient specific IMRT QA is an efficient way to verify patient plans prior to the treatment. Our centres’ current EPID dosimetry method is based on a water equivalent depth approach, where EPID images of each IMRT field are converted to dose images and compared to Treatment planning system calculated dose images using a commercial software tool. Two physicists across two sites...

The motivation for this study was to reduce physics workload relating to patient- specific quality assurance (QA). VMAT plan delivery accuracy was determined from analysis of pre- and on-treatment trajectory log files and phantom-based ionization chamber array measurements. The correlation in this combination of measurements for patient-specific QA was investigated. The relationship between del...

The use of image-guided patient positioning requires fast and reliable Quality Assurance (QA) methods to ensure the megavoltage (MV) treatment beam coincides with the integrated kilovoltage (kV) or volumetric cone-beam CT (CBCT) imaging and guidance systems. Current QA protocol is based on visually observing deviations of certain features in acquired kV in-room treatment images such as markers,...

PURPOSE A software program (MU-EPID) has been developed to perform patient specific IMRT pre-treatment QA verification using an electronic portal imaging device. METHODS The software converts measured images of intensity modulated beams delivered to an EPID, into fluence maps that can be imported in the treatment planning system. The dose can then be calculated in the patient anatomy and comp...