Background: The aim was to evaluate the benefit of technical advances for treatment planning: introduction of a hydrogel spacer, VMAT (volumetric modulated arc therapy) and a single biological organ at risk objective for the rectum and bladder. Initial standard was a step-and-shoot IMRT (intensity modulated radiotherapy) without a spacer and conventional organ at risk objectives.  Material...

Introduction: One of the treatment choices in breast cancer is Intra operative electron beam radiation therapy (IOERT). Due to high dose delivery in this procedure, shielding disk is used to protect organs at risk (OARs). In this study, we evaluate the OARs dose in the breast IOERT using Monte Carlo simulation with and without shielding disk in RANDO phantom. Material and Methods: Simulation ...

background: the incidence of ulcerative colitis (uc) is rising in populations with western-style diet, rich in fat and protein, and low in fruits and vegetables. in the present study, we aimed to evaluate the association between dietary protein intakes and the risk of developing incident uc.   methods : sixty two cases of uc and 124 controls were studied using country-specific food frequency qu...

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 ...

PURPOSE A cylinder applicator is the standard treatment device for intravaginal brachytherapy. However, they are limited in their ability to simultaneously spare the organs at risk (OAR), and reduce the hot spot in the vaginal mucosa, while achieving adequate dose conformality. This study aims to compare the dosimetric characteristics of single and multi-channel cylinders, and utilizes volume p...

Recent literature has investigated the risk aggregation of a portfolio X = (Xi)1≤i≤n under the sole assumption that the marginal distributions of the risks Xi are specified but not their dependence structure. There exists a range of possible values for any risk measure of S = ∑n i=1Xi and the dependence uncertainty spread, as measured by the difference between the upper bound and the lower boun...

A distortion risk measure used in finance and insurance is defined as the expected value of potential loss under a scenario probability measure. In this paper, the tail distortion risk measure is introduced to assess tail risks of excess losses modeled by the right tails of loss distributions. The asymptotic linear relation between tail distortion and Value-at-Risk is derived for heavy tailed l...

  Background: The incidence of ulcerative colitis (UC) is rising in populations with western-style diet, rich in fat and protein, and low in fruits and vegetables. In the present study, we aimed to evaluate the association between dietary protein intakes and the risk of developing incident UC.   Methods : Sixty two cases of UC and 124 controls were studied using country-specific food frequency ...