OBJECTIVES In pediatric radiotherapy, the enhanced radiosensitivity of the developing tissues combined with the high overall survival, raise the possibility of late complications. The present study aims at comparing two dimensional (2D) and three dimensional (3D) planning regarding dose homogeneity within target volume and dose to organs at risk (OARs) to demonstrate the efficacy of 3D in decre...

background and purpose: study skills is one important factor influencing academic achievement of students . we must replace ineffective models and habits of study with more fruitful skills in order to gain better learning. this study investigates the study skills and habits of medical students and their educational achievement. methods: based on a pilot study the sample size was estimates as 40...

The purpose of this study is to assess the difference between 4D liver dose calculations versus standard 3D treatment planning and to investigate the dosimetric gain of gating on radiation dose to normal tissue. 4DCT scans are collected for 25 patients with hepatic tumors treated by proton radiotherapy. The 4D treatment planning process explicitly takes into account respiratory motion of abdomi...

Methods for planning sample size (SS) for the standardized mean difference so that a narrow confidence interval (CI) can be obtained via the accuracy in parameter estimation (AIPE) approach are developed. One method plans SS so that the expected width of the CI is sufficiently narrow. A modification adjusts the SS so that the obtained CI is no wider than desired with some specified degree of ce...

MEAN-SHIFT CLUSTERING AS ASSISTANCE IN THE HYPERTHERMIA TREATMENT PLANNING Jaroslav Vorlíček, Jan Rusz Department of Electromagnetic Field, Faculty of Electrical Engineering, Czech Technical University in Prague Department of Circuit Theory, Faculty of Electrical Engineering, Czech Technical University in Prague; Laboratory of Biocybernetics, Institute of Pathological Physiology, First Faculty ...

we find the greatest values $alpha_{1} $ and $alpha_{2} $, and the least values $beta_{1} $ and $beta_{2} $ such that the inequalities $alpha_{1} c(a,b)+(1-alpha_{1} )h(a,b)

Background: To reduce the dose to normal tissues surrounding the treated breast, a uniform magnetic field was used within a humanoid phantom in breast radiotherapy. Materials and Methods: Monte Carlo simulations were performed with GEANT4, irradiating humanoid phantoms in a magnetic field. To reconstruct phantoms, computed tomography (CT) data slices of four patients were used for the Monte Car...

In this paper, we first extend the stochastic dominance (SD) theory by introducing the first three orders of both ascending SD (ASD) and descending SD (DSD) to decisions in business planning and investment to risk-averse and risk-loving decision makers so that they can compare both return and loss. We provide investors with more tools for empirical analysis, with which they can identify the fir...

PURPOSE To evaluate the relationship between the primary breast volume and dose received by the ipsilateral lung, heart (for left-breast cancers), and contralateral breast during primary breast irradiation using intensity-modulated radiation therapy (IMRT). METHODS AND MATERIALS Sixty-five patients with breast carcinoma were treated using 6-MV photons with IMRT technique using the Eclipse Pla...