A5013604722- Advanced Radiotherapy Techniques
- Medical Imaging Techniques and Applications
- Radiation Dose and Imaging
- Radiation Therapy and Dosimetry
- Advanced X-ray and CT Imaging
- Radiation Detection and Scintillator Technologies
- Ultrasound and Hyperthermia Applications
- Radiation Effects and Dosimetry
- Photoacoustic and Ultrasonic Imaging
- Brain Metastases and Treatment
- Glioma Diagnosis and Treatment
- Radiomics and Machine Learning in Medical Imaging
- Lung Cancer Diagnosis and Treatment
- Effects of Radiation Exposure
- Nuclear Physics and Applications
- Optical Imaging and Spectroscopy Techniques
- Radiation Shielding Materials Analysis
- Advanced Measurement and Metrology Techniques
- Particle Accelerators and Free-Electron Lasers
- Radiative Heat Transfer Studies
- Cardiac Imaging and Diagnostics
- Radioactive Decay and Measurement Techniques
- Radioactive contamination and transfer
- Infrastructure Maintenance and Monitoring
- Digital Radiography and Breast Imaging
National and Kapodistrian University of Athens
2011-2020
Greek Atomic Energy Commission
2018
Budapest University of Technology and Economics
2018
Nicolaus Copernicus University
2016
University of Bydgoszcz
2016
Centre hospitalier universitaire de Québec
2015
University of Crete
2011
University Hospital of Heraklion
2009
Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism model-based calculation algorithms (MBDCAs), treatment planning systems (TPSs) using MBDCA require set well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct comparison TG-43 reference data. Such should be made available use software commissioning process performed...
Purpose: The aim of this work is the dosimetric validation a deterministic radiation transport based treatment planning system ( BRACHYVISION ™ v. 8.8, referred to as TPS in following) for multiple source dwell position brachytherapy applications employing shielded applicator homogeneous water geometries. Methods: calculations an irradiation plan seven VS2000 high dose rate (HDR) positions and partially (GM11004380) were compared corresponding Monte Carlo (MC) simulation results, well...
Purpose: To measure the output factors (OFs) of small fields formed by variable aperture collimator system (iris) a CyberKnife (CK) robotic radiosurgery system, and determine correction for microchamber four diode detectors. Methods: OF measurements were performed using PTW PinPoint 31014 microchamber, detectors (PTW‐60017, −60012, −60008, SunNuclear EDGE detector), TLD‐100 microcubes, alanine dosimeters, EBT films, polymer gels 5 mm, 7.5 10 12.5 15 mm iris collimators at 650 800 1000 source...
Purpose: The aim of this work is to validate a deterministic radiation transport based treatment planning system (TPS) for single brachytherapy source dosimetry in homogeneous water geometries. Methods: TPS results were obtained using the option BRACHYVISION v. 8.8 three characteristic designs (VS2000, GMPlus HDR, and PDR) with each either centered 15 cm radius spherical phantom, or positioned at varying distance away from phantom center. Corresponding MC simulations performed MCNPX code...
Purpose: The aim of this work is to implement a recently proposed dosimetric formalism for nonstandard fields the calibration and small field output factor measurement robotic stereotactic radiosurgery system. Methods: Reference dosimetry measurements were performed in nonstandard, 60 mm diameter machine specific reference (msr) using Farmer ion chamber, five other cylindrical chambers with cavity lengths ranging from 16.25 down 2.7 mm, alanine dosimeters. Output 5, 7.5, 10, 15 sizes...
Purpose: To compare TG43‐based and Acuros deterministic radiation transport‐based calculations of the BrachyVision treatment planning system (TPS) with corresponding Monte Carlo (MC) simulation results in heterogeneous patient geometries, order to validate quantify accuracy improvement it marks relative TG43. Methods: Dosimetric comparisons form isodose lines, percentage dose difference maps, volume histogram were performed for two voxelized mathematical models resembling an esophageal a...
Purpose A joint working group was created by the American Association of Physicists in Medicine (AAPM), European Society for Radiotherapy and Oncology (ESTRO), Australasian Brachytherapy Group (ABG) with charge, among others, to develop a set well‐defined test case plans perform calculations comparisons model‐based dose calculation algorithms (MBDCAs). Its main goal is facilitate smooth transition from AAPM Task No. 43 (TG‐43) formalism, widely being used clinical practice brachytherapy, one...
Abstract Following the clinical introduction of Elekta Unity MR-linac, there is an urgent need for development dosimetry protocols and tools, not affected by presence a magnetic field. This work presents benchmarking methodology comprising 2D/3D passive involving on-couch adaptive treatment planning, unique step in MR-linac workflows. Two identical commercially available 3D-printed head phantoms (featuring realistic bone anatomy MR/CT contrast) were employed. One phantom incorporated film...
In single-isocenter stereotactic radiosurgery/radiotherapy (SRS/SRT) intracranial applications, multiple targets are being treated concurrently, often involving non-coplanar arcs, small photon beams and steep dose gradients. search for more rigorous quality assurance protocols, this work presents evaluates a novel methodology patient-specific pre-treatment plan verification, utilizing 3D printing technology. patient's planning CT scan, the external contour bone structures were segmented...
There is an acknowledged need for the design and implementation of physical phantoms appropriate experimental validation model-based dose calculation algorithms (MBDCA) introduced recently in 192Ir brachytherapy treatment planning systems (TPS), this work investigates whether it can be met. A PMMA phantom was prepared to accommodate material inhomogeneities (air Teflon), four plastic catheters, as well 84 LiF TLD dosimeters (MTS-100M 1 × mm3 microcubes), two radiochromic films (Gafchromic...
The total system error (TSE) of a CyberKnife® was measured using two phantom-based methods and one patient-based method. standard radiochromic film (RCF) end-to-end (E2E) test an anthropomorphic head neck phantom isocentric treatment delivery used with the 6Dskull, Fiducial Xsight® spine (XST) tracking methods. More than 200 RCF-based E2E results covering period from installation in 2006 until 2017 were analyzed respect to method, hardware software versions, secondary collimation system,...
To perform a comparative study of heterogeneities and finite patient dimension effects in 60Co 192Ir high-dose-rate (HDR) brachytherapy.Clinically equivalent plans were prepared for 19 cases (8 breast, 5 esophagus, 6 gynecologic) using the Ir2.A85-2 Co0.A86 HDR sources, with TG-43 based treatment planning system (TPS). Phase space files obtained two source designs MCNP6, validated through comparison to single dosimetry results literature. Dose water, taking into account specific anatomy...
Abstract The Gamma Knife Icon allows the treatment of brain tumors mask‐based single‐fraction or fractionated schemes. In clinic, uniform axial expansion 1 mm around gross tumor volume (GTV) and a 1.5 in superior inferior directions are used to generate planning target (PTV). purpose study was validate this margin scheme with two clinical scenarios: (a) patient’s head remaining right below high‐definition motion management (HDMM) threshold, (b) frequent interruptions followed by plan...
The nearly tissue equivalent MRI properties and the unique ability of registering 3D dose distributions polymer gels were exploited to assess total geometrical accuracy in clinical Gamma Knife applications, taking into account combined effect unit's mechanical accuracy, delivery precision distortions inherent MR images used for irradiation planning. Comparison between planned experimental data suggests that MR-related due susceptibility effects dominate which was found within 1 mm....
A source model is a prerequisite of all based dose calculation algorithms. Besides direct simulation, the use pre-calculated phase space files (phsp models) and parameterized phsp models has been proposed for Monte Carlo (MC) to promote efficiency ease implementation in obtaining photon energy, position direction. In this work, file generic 192Ir design (Ballester et al 2015) obtained from MC simulation. This used configure comprising appropriate probability density functions (PDFs) sampling...
The VIP polymer gel–MRI method and EBT Gafchromic films were employed to obtain relative dosimetry results for the Gamma Knife (GK) radiation fields of 4 mm 18 nominal diameter. Results are compared corresponding calculations GammaPlan Treatment Planning System (TPS) in form 1D profiles 2D distributions. Measured planned datasets found close agreement within experimental uncertainties. A is shown Dose Volume Histogram (DVH) that available only through application gel method.
2nd ESTRO Forum 2013 S371
A regulatory authority for radiation safety should continuously evaluate and improve the national framework, in line with current requirements standards. In this context, Greek Atomic Energy Commission initiated a series of concerted actions. The dose to population due public medical exposures was assessed. assessment exposure based on measurements radon concentrations dwellings, radionuclide environmental samples, air rates; typical examinations or procedures data their frequency. mean...
We investigated the potential of low-dose CT angiography for accurate assessment in-stent restenoses (ISRs) iliac artery.
Purpose: To provide a method for calculating the transmission of any broad photon beam with known energy spectrum in range 20–1090 keV, through concrete and lead, based on superposition corresponding monoenergetic data obtained from Monte Carlo simulation. Methods: MCNP5 was used to calculate varying thickness lead concrete, point sources pertinent brachytherapy (20–1090 10 keV intervals). The three parameter empirical model introduced by Archer et al. [“Diagnostic x‐ray shielding design an...