A5002694297- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Radiation Dose and Imaging
- Medical Imaging Techniques and Applications
- Advanced Fiber Laser Technologies
- Advanced X-ray and CT Imaging
- Nonlinear Photonic Systems
- Nonlinear Waves and Solitons
- Radiation Detection and Scintillator Technologies
- Laser-Matter Interactions and Applications
- Radiation Effects and Dosimetry
- Digital Radiography and Breast Imaging
- Radiation Shielding Materials Analysis
- Magnetic confinement fusion research
- Advanced MRI Techniques and Applications
- Photoacoustic and Ultrasonic Imaging
- Nonlinear Dynamics and Pattern Formation
- Lung Cancer Diagnosis and Treatment
- Optical Network Technologies
- Nuclear Physics and Applications
- Ultrasound and Hyperthermia Applications
- Photonic Crystal and Fiber Optics
- Particle accelerators and beam dynamics
- Effects of Radiation Exposure
- Photonic and Optical Devices
National and Kapodistrian University of Athens
2015-2024
National Technical University of Athens
2009-2024
Andreas Sygros Hospital
2021
University of the Aegean
2014-2018
National Centre of Scientific Research "Demokritos"
2017
Cancer Institute (WIA)
2015
Centre hospitalier universitaire de Québec
2015
National Institute of Oncology
2015
Institute of Nuclear and Particle Physics
2001-2007
Institute of Accelerating Systems and Applications
2006
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...
Following literature contributions delineating the deficiencies introduced by approximations of conventional brachytherapy dosimetry, different model-based dosimetry algorithms have been incorporated into commercial systems for (192)Ir treatment planning. The calculation settings these are pre-configured according to criteria established their developers optimizing computation speed vs accuracy. Their clinical use is hence straightforward. A basic understanding and limitations essential,...
A new microSelectron pulsed dose rate source has been designed, containing two active pellets instead of one inactive and pellet contained in the old design, to facilitate incorporation higher activity up 74 GBq (2 Ci). In this work, Monte Carlo simulation is used derive full dosimetric data following AAPM TG-43 formalism, as well per unit air kerma strength Cartesian, "away along" coordinates for both designs. The calculated constant PDR design was found equal lambda=(1.121 +/- 0.006) cGy...
The water equivalence and stable relative energy response of polymer gel dosimeters are usually taken for granted in the relatively high x-ray range external beam radiotherapy based on qualitative indices such as mass electron density effective atomic number. However, these favourable dosimetric characteristics questionable interest to brachytherapy especially case lower photon sources 103Pd 125I that currently utilized. In this work, six representative formulations well most commonly used...
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...
Since the publication of 2004 update to American Association Physicists in Medicine ( AAPM ) Task Group No. 43 Report TG ‐43U1) and its 2007 supplement ‐43U1S1), several new low‐energy photon‐emitting brachytherapy sources have become available. Many these satisfied prerequisites for routine clinical purposes are posted on Brachytherapy Source Registry managed jointly by Imaging Radiation Oncology Core Houston Quality Assurance Center IROC Houston). Given increasingly closer interactions...
Abstract Purpose In the absence of a 6D couch and/or assuming considerable intrafractional patient motion, rotational errors could affect target coverage and OAR‐sparing especially in multiple metastases VMAT‐SRS cranial cases, which often involve concurrent irradiation off‐axis targets. This work aims to study dosimetric impact such applications, under comparative perspective between single‐ two‐isocenter treatment techniques. Methods Ten patients (36 metastases) were included this study....
The introduction of model-based dose calculation algorithms (MBDCAs) in brachytherapy provides an opportunity for a more accurate and opens the possibility novel, innovative treatment modalities. joint AAPM, ESTRO, ABG Task Group 186 (TG-186) report provided guidance to early adopters. However, commissioning aspect these was described only general terms with no quantitative goals. This report, from Working on Model-Based Dose Calculation Algorithms Brachytherapy, introduced field-tested...
Dose distributions registered in water equivalent, polymer gel dosimeters were used to measure the output factors and off‐axis profiles of radiosurgical photon beams employed for CyberKnife radiosurgery. Corresponding measurements also performed using a shielded silicon diode commonly commissioning, PinPoint ion chamber, Gafchromic EBT films, reasons comparison. Polymer results this work 5, 7.5, 10 mm diameter are , respectively. Comparison shows that latter overestimate two small ( 5 beam...
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...
Modern clinical accelerators are capable of producing ion beams from protons up to neon. This work compares the depth dose distribution and corresponding averaged linear energy transfer (LET) distribution, which is related biological effectiveness, for different (¹H, ⁴He, ⁶Li, ⁸Be, ¹⁰B, ¹²C, ¹⁴N, ¹⁶O) using multi-energetic spectra in order configure spread-out Bragg peaks (SOBP).Monte Carlo simulations were performed a 5 cm SOBP at 8 water all beams. Physical LET distributions as function...
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...
The relative importance of the dose rate component owing to beta spectrum emitted by brachytherapy sources at short radial distances interest in intravascular and endobronchial applications is investigated. Separate dosimetric calculations, using Monte Carlo simulations, were performed for gamma components an ideal point source as well real designs used clinical practice including wire seed both Nucletron Varian, old new, high (HDR) designs. A significant enhancement due greater than 50% was...
This work provides full dosimetric data for the new selectSeed prostate seed source to be distributed by Nucletron B.V. The AAPM TG‐43 formalism and 1999 NIST air kerma strength calibration standard have been followed. Air strength, dose rate constant, radial functions, anisotropy factors were calculated using Monte Carlo simulation. Corresponding calculations also performed commercially available 6711 source, which is of similar design, reasons comparison. constant was 0.954±0.005 compared...
This work seeks to verify multi-shot clinical applications of stereotactic radiosurgery with a Leksell Gamma Knife model C unit employing polymer gel-MRI based experimental procedure, which has already been shown be capable verifying the precision and accuracy dose delivery in single-shot gamma knife applications. The treatment plan studied present resembles case pituitary adenoma using four 8 mm one 14 collimator helmet shots deliver prescription 15 Gy 50% isodose line (30 maximum dose)....
This work describes an experimental procedure with potential to assess the overall accuracy associated gamma knife clinical applications, from patient imaging and dosimetry planning positioning dose delivery using automated system of a Leksell Gamma Knife model C. The VIPAR polymer gel-MRI method is employed due its inherent three-dimensional feature linear response over range applications. Different gel vials were irradiated single shot treatment plans each four available collimator helmets...