Objectives The aim of this in vitro study was to evaluate how a deviation from the horizontal plane, affects the image quality in two different CBCT-devices. Methods A phantom head SK150 (RANDO, The Phantom Laboratory, Salem, NY, USA) was examined in two CBCT-units: Accuitomo 80 and Veraviewepocs 3D R100 (J. Morita Mfg. Corp. Kyoto, Japan). The phantom head was placed with the hard palate par...

in present pet/ct scanners, pet attenuation correction is performed by relying on the information given by ct scan. in the ct-based attenuation correction methods, dual-energy technique (dect) is the most accurate approach, which has been limited due to the increasing patient dose. in this feasibility study, we have introduced a new method that can implement dual-energy technique with only a si...

In our study, we aimed to measure the dose exposed by fetus during three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated (IMRT) treatment techniques in pregnant patients who had undergo due breast cancer with thermoluminescence dosimetry (TLD) compare these measurements planning system (TPS). 2.5 mm- thick computed tomography (CT) images of Alderson Rando phantom device were...

The aim of this study was to assess effective doses of a lateral cephalogram radiograph with and without thyroid shield and compare the differences with the radiation dose of a hand-wrist radiograph. Thermoluminescent dosimeters were placed at 19 different sites in the head and neck of a tissue-equivalent human skull (RANDO phantom). Analogue lateral cephalograms with and without thyroid shield...

PURPOSE The study was aimed to compare online 6 degree-of-freedom image registrations of TrueBeam cone-beam computed tomography and BrainLab ExacTrac X-ray imaging systems for intracranial radiosurgery. METHODS Phantom and patient studies were performed on a Varian TrueBeam STx linear accelerator (version 2.5), which is integrated with a BrainLab ExacTrac imaging system (version 6.1.1). The p...

1Radiation Medicine Department, Nuclear Engineering Faculty, Shahid Beheshti University, Tehran, Iran 2Radiation Medicine Department, Nuclear Engineering Faculty, Shahid Beheshti University, Tehran, Iran 3Radiotherapy Physics Department, Cancer Institute of Tehran, Tehran, Iran 4Medical Physics Department, Medical Faculty, Iran University of Medical Science, Tehran, Iran 5Radiation Medicine Dep...

With image-guided tomotherapy, highly targeted total marrow irradiation (TMI) has become a feasible alternative to conventional total body irradiation. The uncertainties in patient localization and intrafraction motion of the whole body during hour-long TMI treatment may pose a risk to the safety and accuracy of targeted radiation treatment. The feasibility of near-infrared markers and optical ...

Total body irradiation (TBI) is used as a preconditioning regimen prior to bone marrow transplant for treatment of hematologic malignancies. During TBI, large volumes of normal tissue are irradiated, and this can lead to toxicities, most significantly in the lungs. Intensity modulated total marrow irradiation (IMTMI) may be able to reduce these toxicities by directly targeting the bone marrow w...

PURPOSE To find the optimal slice thickness (Δτ) setting for patient registration with kilovoltage cone-beam CT (kVCBCT) on the Varian On Board Imager (OBI) system by investigating the relationship of slice thickness to automatic registration accuracy and contrast-to-noise ratio. MATERIALS AND METHOD Automatic registration was performed on kVCBCT studies of the head and pelvis of a RANDO anth...