The aim of this study was to develop and apply an evaluation method for assessing the accuracy a novel 3D EPID back-projection algorithm in vivo dosimetry. Dosimetry Check (DC) 5.8 evaluated. A slab phantom homogeneously filled, or with air bone inserts, used fluence reconstruction different squared fields. VMAT plans anatomical sites were delivered on anthropomorphic phantom. Dose distribution...

Introduction: Multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. In this work, we investigated MR-based MAGIC gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. Materials and Methods: A heterogeneous slab phantom including bones was made....

AIM The aim of the paper is to examine the relation between the increase of the photon dose in water in the region of electronic disequilibrium - so-called build-up region - and the distance of the bolus from the water surface for the applied parameters of X-ray beams. MATERIALS AND METHODS PDD measurements were carried out using the plane-parallel ionization chamber Markus in the automatic w...

PURPOSE To improve patient safety and treatment quality, verification of dose delivery in radiotherapy is desirable. We present a simple, easy-to-implement, open-source method for in vivo planar dosimetry of conformal radiotherapy by electronic portal imaging device (EPID). METHODS Correlation ratios, which relate dose in the mid-depth of slab phantoms to transit EPID signal, were determined ...

The large angle dependence of the Hp(10) response in PADC-based personal neutron dosemeters constitutes a serious concern in operational radiation protection dosimetry. For planar dosemeters, the typical Hp(10) response falls by half or more when the incidence angle changes from 0 to 60 . To reduce this source of systematic uncertainty, configurations based on multiple detectors at different an...

AIM The aim of the study was to estimate the dose at the reference point applying an aSi-EPID device in the course of patient treatment. MATERIALS AND METHODS The method assumes direct proportionality between EPID signal and dose delivered to the patient reference point during the treatment session. The procedure consists of treatment plan calculation for the actual patient in the arc techniq...

The purpose of this study is to compare performance of several dosimetric meth-ods in heterogeneous phantoms irradiated by 6 and 18 MV beams. Monte Carlo (MC) calculations were used, along with two versions of Acuros XB, anisotropic analytical algorithm (AAA), EBT2 film, and MOSkin dosimeters. Percent depth doses (PDD) were calculated and measured in three heterogeneous phantoms. The first two ...

The 6 MV flattening filter-free (FFF) beam has been commissioned for use with compensators at our institution. This novel combination promises advantages in mitigating tumor motion due to the reduced treatment time made possible by the greatly increased dose rate of the FFF beam. Given the different energy spectrum of the FFF beam and the beam hardening effect of the compensator, the accuracy o...

The aim of this study was to demonstrate how dosimetry with an amorphous silicon electronic portal imaging device (a-Si EPID) replaced film and ionization chamber measurements for routine pre-treatment dosimetry in our clinic. Furthermore, we described how EPID dosimetry was used to solve a clinical problem. IMRT prostate plans were delivered to a homogeneous slab phantom. EPID transit images w...

Telecobalt machine is one of the essential equipment needed in many cancer centers and still prominently used for the treatment of a variety of cancer cases in developing countries. This study aims to evaluate the impact of tissue heterogeneity corrections on 3D treatment planning system (Prowess). The human body contains a variety of tissues and cavities which vary widely in their physical and...