This paper investigates the accuracy of the two available calculation algorithms of the Oncentra MasterPlan three-dimensional treatment planning system (TPS)-- the pencil beam method and collapsed-cone convolution--in modeling the Varian enhanced dynamic wedge (EDW). Measurements were carried out for a dual high energy (6-15 MV) Varian DHX-S linear accelerator using ionization chambers for beam...

Enhanced dynamic wedge factors (EDWF) are characterized by a strong field size dependence. In contrast to physical wedge factors, the EDWF decrease as the field size is increased: for 6 MV 60 degrees wedge, the EDWF decreases by 50% when the field size is increased from 4 x 4 cm2 to 20 x 20 cm2. A method that eliminates the field size dependence of EDWF was developed and investigated in this wo...

The linear accelerator (linac) is a device that uses highfrequency electromagnetic waves to accelerate charged particles such as electrons to high energies through a linear tube. The high-energy electron beam can be used for treating superficial tumours, or it can be made to strike a target to produce x-rays for treating deep-seated tumours. In the majority of instances, the collimated beam eme...

The linear accelerator (linac) is a device that uses highfrequency electromagnetic waves to accelerate charged particles such as electrons to high energies through a linear tube. The high-energy electron beam can be used for treating superficial tumours, or it can be made to strike a target to produce x-rays for treating deep-seated tumours. In the majority of instances, the collimated beam eme...

The linear accelerator (linac) is a device that uses highfrequency electromagnetic waves to accelerate charged particles such as electrons to high energies through a linear tube. The high-energy electron beam can be used for treating superficial tumours, or it can be made to strike a target to produce x-rays for treating deep-seated tumours. In the majority of instances, the collimated beam eme...

The nonphysical wedge is a modality that uses computer-controlled jaw motion to generate wedge-shaped dose distributions. There are Varian enhanced dynamic wedges (EDWs) and Siemens virtual wedges (VWs). We recently commissioned dynamic wedges on both Varian and Siemens LINACs. The beam data, acquired with a Wellhofer chamber array and a Sun Nuclear profiler, are used for modeling in the ADAC P...