Πλοήγηση ανά Συγγραφέα "Kappas, C."
Αποτελέσματα 1-20 από 34
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Beam quality and dose perturbation of 6 MV flattening-filter-free linac
(2014)The aim of this study is twofold: (a) determination of the spectral differences for flattening-filter-free (FFF) versus standard (STD) linac under various clinical conditions, (b) based on an extensive list of clinically ... -
Clinical validation of the LKB model and parameter sets for predicting radiation-induced pneumonitis from breast cancer radiotherapy
(2006)The choice of the appropriate model and parameter set in determining the relation between the incidence of radiation pneumonitis and dose distribution in the lung is of great importance, especially in the case of breast ... -
A comparison of Monte Carlo simulation with experimental dosimetric techniques for a 6 MV stereotactic radiotherapy unit
(2004)Purpose: To compare Monte Carlo simulation with conventional dosimetry techniques for stereotactic radiotherapy (SRT), since accurate dosimetry of narrow photon beams is very complicated and has often been questioned, ... -
Correlation between radiation-induced telomerase activity and human telomerase reverse transcriptase mRNA expression in HeLa cells
(2006)Purpose: To quantify and correlate human telomerase reverse transcriptase (hTERT) mRNA expression with telomerase activity (TA) after ionizing irradiation of HeLa cells. Materials and methods: TA and hTERT mRNA expression ... -
Dosimetric and radiobiological evaluation of dose distribution perturbation due to head heterogeneities for Linac and Gamma Knife stereotactic radiotherapy
(2008)Introduction. In SRT/SRS, dedicated treatment planning systems are used for the calculation of the dose distribution. The majority of these systems utilize the standard TMR/OAR formalism for dose calculation as well as ... -
Evaluation of dose-response models and parameters predicting radiation induced pneumonitis using clinical data from breast cancer radiotherapy
(2005)The purpose of this work is to evaluate the predictive strength of the relative seriality, parallel and LKB normal tissue complication probability (NTCP) models regarding the incidence of radiation pneumonitis, in a large ... -
Fast spectroscopic multiple analysis (FASMA) for brain tumor classification: a clinical decision support system utilizing multi-parametric 3T MR data
(2015)A clinical decision support system (CDSS) for brain tumor classification can be used to assist in the diagnosis and grading of brain tumors. A Fast Spectroscopic Multiple Analysis (FASMA) system that uses combinations of ... -
Field flatness and symmetry of photon beams: Review of the current recommendations
(2003)Flatness and symmetry are main parameters determining the quality of a photon beam produced by linear accelerators. The quality assurance in routine clinical practice of radiotherapy and consequently the treatment-outcome ... -
A free software for the evaluation and comparison of dose response models in clinical radiotherapy (DORES)
(2009)Purpose: The aim of this work was to develop a user-friendly and simple tool for fast and accurate estimation of Normal Tissue Complication Probabilities (NTCP) for several radiobiological models, which can be used as a ... -
Geometrical pre-planning for conformal radiotherapy
(2007)The optimum selection of beams and arcs in conformal techniques is of the outmost importance in modern radiotherapy. In this work we give a description of an analytic method to aid optimum selection, which is based on ... -
A geometry based optimization algorithm for conformal external beam radiotherapy
(2003)A geometric solution of the problem of optimal orientation of beams in conformal external radiotherapy is presented. The method uses geometric derived quantities which consider the intersection volume between organs at ... -
hTERT regulation by NF-kappa B and c-myc in irradiated HER2-positive breast cancer cells
(2011)Purpose: Telomerase activity (TA), frequently observed in cancer, compensates for telomere shortening thus preventing cell senescence and conferring resistance to therapy. In the present study, we investigated the expression ... -
Impact of beam quality on megavoltage radiotherapy treatment techniques utilizing gold nanoparticles for dose enhancement
(2013)This study determines the optimal clinical scenarios for gold nanoparticle dose enhancement as a function of irradiation conditions and potential biological targets using megavoltage x-ray beams. Four hundred and eighty ... -
An inhomogeneity correction algorithm for irregular fields of high-energy photon beams based on Clarkson integration and the 3D beam subtraction method
(2006)A number of treatment-planning systems still use conventional correction methods for body inhomogeneities. Most of these methods (power law method, tissue-air ratio (TAR), etc.) consider only on-axis points, rectangular ... -
Magnetic Resonance Spectroscopy of the Breast at 3T: Pre- and Post-Contrast Evaluation for Breast Lesion Characterization
(2012)Purpose. To determine whether in vivo proton magnetic resonance spectroscopy at 3T can provide accurate breast lesion characterization, and to determine the effect of gadolinium on the resonance of tCho. Methods. Twenty-four ... -
A modification of flattening filter free linac for IMRT
(2011)Purpose: This study investigates the benefits of a modified flattening filter free (FFF) linac over the standard (STD) linac equipped with the flattening filter. Energy and angular spread of the electron beam of the FFF ...