background: in radiotherapy, wedge filters are used for optimizing the tumor dose distribution in patients. the attenuation in beam intensity due to the presence of wedge filter is compensated by means of a wedge factor measured at the central axis of the beam. the field size, depth and ssd dependence of wedge factor have been assessed for 9mv radiations of neptun pc linear accelerator. materia...

introduction evaluation of the delivered dose of externally wedged photon beams by external diode dosimeters during the treatment process requires the estimation of exit surface dose correction factors in various wedge angles and field sizes. materials and methods a system of absorbed dose evaluation, using p-type diode dosimeters placed on the exit surface of a phantom, was characterized for e...

Introduction Evaluation of the delivered dose of externally wedged photon beams by external diode dosimeters during the treatment process requires the estimation of exit surface dose correction factors in various wedge angles and field sizes. Materials and Methods A system of absorbed dose evaluation, using p-type diode dosimeters placed on the exit surface of a phantom, was characterized for e...

BACKGROUND Wedge filters can be used as missing tissue compensators or wedge pairs to alter the shape of isodose curves so that two beams can be angled with a small hinge angle at a target volume without creating a hotspot. AIM In this study the dosimetric properties of Varian Enhanced Dynamic Wedge (EDW) and physical wedges (PW) were analyzed and compared. MATERIALS AND METHODS Ionometric ...

Background: In radiotherapy, wedge filters are used for optimizing the tumor dose distribution in patients. The attenuation in beam intensity due to the presence of wedge filter is compensated by means of a wedge factor measured at the central axis of the beam. The field size, depth and SSD dependence of wedge factor have been assessed for 9MV radiations of Neptun PC linear accelerator. Materia...

Siemens Virtual Wedge factor may drift significantly due to increase in output as dose rate decreases. This variation of output is caused by defective sample and hold boards in the dosimetry circuit due to radiation damage. In this note, we present a simple model based on the principle of Virtual Wedge operation and the measured output variation with dose rate to quantitatively describe Virtual...

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 ...

background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

Background: One of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment.Objective: In the present study the impact of wedge and block on neutron contamination production is investigated. The evaluations are conducted for a 15 MV Siemens Primus linear accelerator. Methods: Simulations were performed using MCNPX Monte...