background: to evaluate the dosimetric difference between conventional and three-dimensional conformal radiotherapy (3d-crt) using 6 and 18 mv x-ray photons. materials and methods: computed tomography scans of 26 pelvic patients were acquired and transferred to the 3d treatment planning system. for each patient, 8 conventional plans (3, 4, 5 and 6 fields) and one 3d-crt plan were prepared using...

background: identify the optimal technique of radiotherapy for patients with high grade glioma. our initial year of experience with rapidarc radiation therapy. materials and methods: planning ct scans of 50 patients with grade iv glioma were reviewed and three plan sets by 3d conformal radiotherapy (3dcrt), intensity modulated radiotherapy (imrt) and rapid arc (ra) were generated and the plans ...

Background: Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) techniques are used for the treatment of patients with laryngeal cancer. Objective: This study aimed to investigate the effects of these 2 treatment techniques on the planning target volume (PTV) (laryngeal cancer), dose homogeneity, dose of organs at...

Background: The aim of this study was to develop and implement a Monte Carlo framework for evaluation of patient specific out-of-field organ equivalent dose (OED). Materials and Methods: Dose calculations were performed using a Monte Carlo-based model of Oncor linac and tomographic phantoms. Monte Carlo simulations were performed using EGSnrc user codes. Dose measurements were performed using r...

BACKGROUND We investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy. METHODS We included 17 pediatric medulloblastoma patients to represent the variability in tumor location relative to the hippocampal region. T...

background: 3dcrt (three-dimensional conformal radiotherapy) and imrt (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. however, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. the purpose of this study is to evaluate the imp...

Background: 3DCRT (three-dimensional conformal radiotherapy) and IMRT (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. However, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. The purpose of this study is to evaluate the imp...

Introduction: The use of electronic portal imaging devices (EPIDs) is a method for the dosimetric verification of radiotherapy plans both pretreatment and in-vivo. The aim of this study was to test a 2D EPID-based dosimetry algorithm for dose verification of some plans inside a homogenous and anthropomorphic phantom and in-vivo, as well. Materials and Methods: </strong...

aims: it was aimed to investigate postoperative conformal radiotherapy planning that provides the best target volume and the least dose for critical organs in cancers of stomach. methods: this study was conducted on the ct simulation images of thirty patients diagnosed with gastric cancer. target volumes and the organs at risk were contoured. ap-pa reciprocal parallel field conventional plan an...

Background: The aim of this study was to compare the differences of the dosimetric parameters between three-dimensional conformal radiotherapy (3D-CRT) and simultaneous-integrated boost intensity-modulated radiotherapy (SIB-IMRT) techniques in the prone and supine positions for breast irradiation. Materials and Methods: Ten patients underwent a computed tomography simulation in both the prone a...