The fastCAT application uses pre-calculated Monte Carlo (MC) CBCT phantom-specific scatter and detector response functions to reduce simulation time for megavoltage (MV) kilovoltage (kV) imaging. Pre-calculated x-ray beam energy spectra, optical spread deposition, phantom kernels are combined with GPU raytracing produce volumes. MV spectra simulated EGSnrc 2.5 6 MeV electron beams incident on a...

background: megavoltage beams used in radiotherapy are contaminated with secondary electrons. different parts of linac head and air above patient act as a source of this contamination. this contamination can increase damage to skin and subcutaneous tissue during radiotherapy.  monte carlo simulation is an accurate method for dose calculation in medical dosimetry and has an important role in opt...

It has been thought that adult nervous tissues show a remarkable degree of resistance to injury by x rays. Clemedson and Nelson (1960), after a comprehensive review of the literature, state: " Nervous tissues, especially of adult animals, show a remarkable radio-resistance." In the past few years, however, experimental work on animals (Lander, 1959; Innes and Carsten, 1961) suggests that delaye...

BACKGROUND An analysis of radiotherapy infrastructure in Korea was performed in 2006 to collect data on treatment devices, the work force and new patients for future development plans. METHODS The survey included radiotherapy centers, their major equipment and personnel. The centers were categorized into four levels: level 0 (stand-alone teletherapy units); level 1 (teletherapy, brachytherapy...

The Victorian Department of Human Services has developed a classification and funding model for non-admitted radiation oncology patients. Agencies were previously funded on an historical cost input basis. For 1996-97, payments were made according to the new Non-admitted Radiation Oncology Classification System and include four key components. Fixed grants are based on Weighted Radiation Therapy...

Traditionally, lead has been used for field shaping in megavoltage electron beams in radiation therapy. In this study, we analyze the dosimetric parameters of a nontoxic, high atomic number (Z = 83), bismuth-loaded material called Gamma Putty that is malleable and can be easily molded to any desired shape. First, we placed an ionization chamber at different depths in a solid water phantom under...

background: radiation-sensitive polymer gels are among the most promising three-dimensional dose verification tools and tissue-like phantom developed to date. objective: the aim of this study is an investigating of percentage depth dose enhancement within the gel medium with used of conformal distribution gold nanoparticle as contrast agents by high atomic number material. methods: in this work...

PURPOSE Megavoltage photon beams are typically used for therapy because of their skin sparing effect. However, a focused low-energy x-ray beam would also be skin sparing, and would have a higher dose concentration at the focal spot. Such a beam can be produced with polycapillary optics. MCNP5 was used to model dose profiles for a scanned focused beam, using measured beam parameters. The potenti...