Introduction: In radiotherapy treatment planning system (TPS), basic input is the data from computed tomography (CT) scan, which takes into account the effect of inhomogeneities in dose calculations. Measurement of CT numbers may be affected by scanner-specific parameters. Therefore, it is important to verify the effect of different CT scanning protocols on Hounsfield unit (HU) and its impact o...

Background: This study aimed to evaluate the dose calculation accuracy of EclipseTM treatment planning system (TPS) in a heterogeneous chest phantom with the intensity modulated radiotherapy (IMRT) technique using EBT3 film and Delta4. Materials and Methods: Two IMRT plans (A and B) were prepared for radiotherapy of the heterogeneous chest phantom. Plan A was between the left lung and the surro...

introduction: polymer gels are modern dosimeters providing three dimensional dose distributions. these dosimeters can be used in brachytherapy in which the tumor dimension is relatively small and the dose gradient is high. in this study, the ability of the magica polymer gel was investigated for assessing the absolute dose values as well as the dose distribution of low dose rate (ldr) ir-192 wi...

introduction polymer gel dosimeters offer a practical solution to 3d dose verification for conventional radiotherapy as well as intensity-modulated and stereotactic radiotherapy. in this study, egsnrc calculated and pagat polymer gel dosimeter measured dose profiles from single shot irradiation with 18 mm collimator of gamma knife in homogeneous and inhomogeneous phantoms were compared with eac...

Introduction The Gamma Knife system is designed solely for non-invasive treatment of brain disorders, and it benefits from stereotactic surgical techniques. Dose calculations required in the system are performed by GammaPlan code; in this code, brain tissue is considered uniform. In the present study, we evaluated the effect of Gamma Knife system on the obtained dose through simulating a real ...

In the internal dose evaluation, the specific absorbed fraction (SAF) and S-value are calculated from the reference phantom based on Caucasian data. The differences in height and weight between Caucasian and Asian may lead to inaccurate dose estimation. In this study, we developed the Taiwanese reference phantoms. 40 volunteers were recruited. Magnetic resonance images (MRI) were obtained, and ...

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...

introduction: secondary radiation such as photoelectrons, auger electrons and characteristic radiations cause a local boost in dose for a tumor when irradiated with an external x-ray beam after being loaded with elements capable of activating the tumor, e.g.; i and gd. materials and methods:  in this investigation, the mcnpx code was used for simulation and calculation of dose enhancement facto...

The purpose of this paper is to report on commissioning and clinical implementation of a customized system for pediatric stereotactic conformal radiotherapy (SCRT). The system is based on the Pinnacle treatment-planning system and its interfaces with other equipment: (1) Beam models were optimized for our compact blocking system and a new LINAC. (2) Three CT-to-density conversion tables were ev...