Model-based dose calculation algorithms have recently been incorporated into brachytherapy treatment planning systems, and their introduction requires critical evaluation before clinical implementation. Here, we present an experimental evaluation of Oncentra® Brachy Advanced Collapsed-cone Engine (ACE) for a multichannel vaginal cylinder (MCVC) applicator using radiochromic film. A uniform dose...

The purpose of this work was to investigate the influence of a new transmission detector on 6 MV x-ray beam properties. The device, COMPASS (IBA Dosimetry, Germany), contains 1600 plane parallel ionization chambers with a detector spacing of 6.5 mm and an active volume of 0.02 cm3. Surface dose measurements were carried out using a Markus chamber and radiochromic film for a range of field sizes...

abstractbackground: as fluoroscopy or different angiographies are usually evaluated using tl dosimeter. thismethod is a time-consuming procedure therefore, radiologists are usually worried and unawareof their exact radiation dose received during each fluoroscopy or angiography. in this study, anew trend for quick estimation of effective dose based on measuring air-absorbed dose of thescattered ...

The purpose of the study was to investigate the use of the equivalent square formula for determining the surface dose from a rectangular photon beam. A 6 MV therapeutic photon beam delivered from a Varian Clinac 23EX medical linear accelerator was modeled using the EGS4nrc Monte Carlo simulation package. It was then used to calculate the dose in the build-up region from both square and rectangu...

In external beam radiation therapy (EBRT), skin dose measurement is important to evaluate dose coverage of superficial target volumes. Treatment planning systems (TPSs) are often inaccurate in this region of the patient, so in vivo measurements are necessary for skin surface dose estimation. In this work, superficial dose distributions were measured using radiochromic translucent poly(vinyl alc...

We investigated radiation doses to 149 adult patients who underwent interventional neuroradiologic procedures, consisting of 132 patients who had diagnostic imaging examinations and 17 patients who had therapeutic procedures. The interventional procedures were carried out on a biplane system capable of performing fluoroscopy and digital subtraction angiography (DSA). The x-ray imaging system wa...

OBJECTIVE To assess effects of off-centering, automatic exposure control, and padding on attenuation values, noise, and radiation dose when using in-plane bismuth-based shields for CT scanning. MATERIALS AND METHODS A 30 cm anthropomorphic chest phantom was scanned on a 64-multidetector CT, with the center of the phantom aligned to the gantry isocenter. Scanning was repeated after placing a b...

background: pet/ct imaging using [18f]-fdg is utilized in clinical oncology for tumor detecting, staging and responding to therapy procedures. essential consideration must be taken for radiation staff due to high gamma radiation in pet/ct and cyclotron center. the aim of this study was to assess the staff exposure regarding whole body and organ dose and to evaluate environment dose in pet/ct an...

background: we have validated the monitor unit calculations from a commercially available treatment planning system (tps) for three intensity modulated radiotherapy (imrt) planning techniques for tangential breast irradiation by using ionization chamber measurements. materials and methods: treatment plans were generated for forty-two breast patients by a forward planned field in field technique...

We have studied the accuracy of statistical parameters of dose distributions in brachytherapy using actual clinical implants. These include the mean, minimum and maximum dose values and the variance of the dose distribution inside the PTV (planning target volume), and on the surface of the PTV. These properties have been studied as a function of the number of uniformly distributed sampling poin...