PURPOSE To investigate the improvement of combined monoscopic/stereoscopic prostate motion monitoring with room-mounted dual x-ray systems by adopting patient specific methods. METHODS The linac couch was used as a motion stage to simulate 40 highly dynamic real patient prostate trajectories. For each trajectory, 40 s pretreatment and 120 s treatment periods were extracted to represent a typi...

The use of solid carbon fiber table materials in radiotherapy has become more common with the implementation of image-guided radiotherapy (IGRT), since the solid materials give less imaging artifacts than the so-called tennis racket couchtops. The downside of the solid carbon fiber couch inserts is that they increase the beam attenuation, resulting in increased surface doses and inaccuracies in...

Background: The presence of small intestine in the radiation field during pelvic cancers treatment causes an interruption in radiotherapy. A non-invasive method was developed to exclude small intestine during conventional radiotherapy. Materials and Methods: The incidence of the radiation therapy interruption is highly dependent upon the area of the small intestine included in the portals and i...

Brachytherapy of local cervical cancer is generally accomplished through film-based treatment planning with the prescription directed to point A, which is invisible on images and is located at a high-dose gradient area. Through a standard reconstruction method by digitizing film points, the location error for point A would be 3mm with a condition of 30° curvature tandem, which is 10° away from ...

In X-ray radiotherapy accelerators, neutrons are produced mainly by ( , n) reaction when high energy X-rays interact with high Z materials of the linear accelerator head. These materials include the lead (Pb) used as shielding in the collimator, tungsten (W) target used for the production of X-rays and iron (Fe) in the accelerator head. These unwanted neutrons contaminate the therapeutic beam a...

Cone-beam CTs (CBCTs) installed on a linear accelerator can be used to provide fast and accurate automatic six degrees of freedom (6DoF) vector displacement information of the patient position just prior to radiotherapy. These displacement corrections can be made with 6DoF couches, which are primarily used for patient setup correction during stereotactic treatments. When position corrections ar...

The goal of this study is to develop a more appropriate shielding calculation method for computed tomography (CT) in comparison with the Japanese conventional (JC) method and the National Council on Radiation Protection and Measurements (NCRP)-dose length product (DLP) method. Scattered dose distributions were measured in a CT room with 18 scanners (16 scanners in the case of the JC method) for...

 Abstract Background: Adjacent treatment fields are commonly used in external beam radiation therapy, such as mantle and inverted-Y fields for the treatment of Hodgkin’s disease and craniospinal fields used in the treatment of medulloblastoma and head and neck tumors when the lateral neck fields are placed adjacent to the anterior supraclavicular field. In each of these situations, there is a p...