background: the aim of this work was to study the output factors for linac using different ionization chambers and build up caps. materials and methods: output factors were measured for open square fields (3 × 3 cm to 40 × 40 cm) defined by collimator jaws for 6 and 15 mv photon beams from a varian clinac 2100c accelerator were measured. the measurements in air were performed using compact cyli...

Background: The aim of this work was to study the output factors for Linac using different ionization chambers and build up caps. Materials and Methods: Output factors were measured for open square fields (3 × 3 cm to 40 × 40 cm) defined by collimator jaws for 6 and 15 MV photon beams from a Varian Clinac 2100C accelerator were measured. The measurements in air were performed using Com...

Introduction: The head scatter factor (Sc) is one of the important parameters for monitor unit (MU) calculation. There are multiple factors that impact the Sc values, such as, head structures, back scattering in to dose monitoring chambers, wedges and so on. This study aimed to investigate the variations of SC with different build-up cap materials, wall thickness, Source to ...

ID: 18837 Title: Improved Collimator Scattering Factor (Sc) Measurements for Small Fields Using Build-Up Caps in Robotic Radiosurgery Purpose:The Monte Carlo calculation algorithm in the MultiPlan (Accuray, Palo Alto, CA) treatment planning system used for CyberKnife (Accuray) robotic radiosurgery requires in-air measurements. In this study, results were compared for the impact of build-up caps...

PURPOSE The Monte Carlo calculation algorithm in the MultiPlan (Accuray, Palo Alto, CA) treatment planning system used for CyberKnife (Accuray) robotic radiosurgery requires in-air measurements. In this study, results were compared for the impact of build-up caps using a diode detector for small field in-air measurements. METHODS Two acrylic caps custom-made for the SFD diode detector (IBA, G...

This article presents methods for handling Multiple Masters (several type styles such as regular and bold joined in one font file) beyond the conventional applications such as generating semibold fonts. The “boldness” information in an MM font can be used to change the size of glyphs without changing the stroke weight. The method helps to create small caps, Cyrillic lowercase and – since the ho...

background when a primary radiation interacts with a medium, the secondary radiations are produced, that the contribution of these secondary radiation should considered in the calculation of dose. build-up factor is a dosimetric correction factor to assume effect of secondary radiation in calculation of dose. calculation of this factor is very difficult and time consuming. due to significance o...