C. Andenna - Academia.edu (original) (raw)

Papers by C. Andenna

Journal of experimental & clinical cancer research : CR, 2006

Intensity-modulated radiotherapy (IMRT) (1) is an advanced form of 3-D conformal radiotherapy. It... more Intensity-modulated radiotherapy (IMRT) (1) is an advanced form of 3-D conformal radiotherapy. It uses non uniform spatial modifications in the intensity of the beams across the irradiated field. Consequently, it is necessary to develop sophisticated tools to compare measured and calculated dose distributions in order to verify the accuracy of the results of the planned dose distribution. Different methods have been developed to evaluate the accordance between measured and calculated doses, such as the point-to-point dose difference or the evaluation of the distance between two closed points having the same dose value (2-4). The verification method proposed by Low (5-7) seems to be more complete since it takes into account both the dose difference (DD) and the distance to agreement (DTA), allowing to define a "score", the gamma value, at each point of interest. A software tool (DDE: Dose Distribution Evaluator), based on Low's method, to evaluate the agreement between ...

… International Congress of …, 2008

Caccia B, Andenna C, Frustagli G, Valentini S, Petetti E. MonteCarlo dose calculation in photon b... more Caccia B, Andenna C, Frustagli G, Valentini S, Petetti E. MonteCarlo dose calculation in photon beam radiotherapy: a dosimetric characterization. In: 12. International Congress of the International Radiation Protection Association (IRPA). Proceedings ; October 19-24, 2008; Buenos ...

Radiation Protection Dosimetry, 2014

This study aims at evaluating the effects of different lung densities on dose distribution after ... more This study aims at evaluating the effects of different lung densities on dose distribution after irradiation at different field sizes, by comparing experimental measurements, GEANT4 Monte Carlo (MC) simulations and two TPS calculation algorithms on ad hoc phantoms. Irradiations were performed with a Varian Clinac 2100 C/D with a nominal energy of 6 MV. Dosimetric experimental measurements were obtained with radiochromic films. A model based on GEANT4 MC code was developed to simulate both the accelerator and the phantoms. Results of dose distribution show an acceptable agreement between MC simulations and experimental measurements, both in the tumour-equivalent region and in the normal tissue-equivalent ones. On the opposite, results vary among the TPS algorithms, especially in regions of lung-equivalent material at low density, but also at the interface between lung- and tumour-equivalent materials.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, May 1, 2015

The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using t... more The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using the Geant4 Monte Carlo toolkit. Simulations are validated against experimental data available in literature for a range of energy between 0.5 and 2.8 MeV for Al and Fe targets and for a value of energy of 70 keV for Al, Ag, W and Pb targets. All three independent sets of electromagnetic models available in Geant4 to simulate bremsstrahlung are tested. A quantitative analysis is performed reproducing with each model the energy spectrum for the different configurations of emission angles, energies and targets. At higher energies (0.5-2.8 MeV) of the impinging electrons on Al and Fe targets, Geant4 is able to reproduce the spectral shapes and the integral photon emission in the forward direction. The agreement is within 10-30%, depending on energy, emission angle and target material. The physics model based on the Penelope Monte Carlo code is in slightly better agreement with the measured data than the other two. However, all models overestimate the photon emission in the backward hemisphere. For the lower energy study (70 keV), which includes higher-Z targets, all models systematically underestimate the total photon yield, while still providing a reasonable agreement between 10 and 50%. The results of this work are of potential interest for medical physics applications, where knowledge of the energy spectra and angular distributions of photons is needed for accurate dose calculations with Monte Carlo and other fluence-based methods.

Safety and Security Engineering III, Jun 19, 2009

The consequence assessment of a major accident involving a release of toxic gas by a pipeline is ... more The consequence assessment of a major accident involving a release of toxic gas by a pipeline is usually performed through the evaluation of the associated hazard area, which is an area where the concentration of the toxic substance exceeds a fixed threshold level and induces harmful effects in people and the environment; its extension represents a significant source of information required for the development of both safety and security strategies associated with dangerous pipelines. Since the threshold level adopted in the calculation strongly affects the extent of this hazard area, the purpose of this paper is to analyse such influence and the potential implications on the decisional process concerning prevention, preparedness and response actions in the case of major accidents. The paper describes the methodological approach adopted for this purpose, as well as the main results obtained using the threshold levels most commonly applied in the industrialized countries. Although the estimate of the hazard areas involves a high level of uncertainty, this study aims at supporting the development of pipeline safety and security strategies, thus increasing the overall safety level in this vital sector.

Fatigue & Fracture of Engineering Materials & Structures

ABSTRACT

ABSTRACT A study was undertaken on a controlled rolled Fe 510D structural plate steel. Macro-toug... more ABSTRACT A study was undertaken on a controlled rolled Fe 510D structural plate steel. Macro-toughness properties were determined and found to be different at the surface and the center of the plate. Quantitative microscopy indicated that two populations of the ferrite grain size existed, one fine and one relatively coarse. The mean diameter of the coarse grains was higher at the center of the plate relative to the surface. Experiments to define local cleavage parameters indicated that the null ductility temperature was slightly lower in surface specimens relative to center specimens. The critical cleavage stress was defined for a range of temperatures. Models of cleavage proposed by Smith and Hahn indicated that the dimension of the coarse grains played a fundamental role in determining the critical cleavage stress. The applicability of the two models to the fracture process are assessed.

1. European Workshop …, 2006

Andenna C, Amati G, Benassi M, Caccia B, D'Angelo A, Frustagli G, Iaccarino G, Mattia M, Occ... more Andenna C, Amati G, Benassi M, Caccia B, D'Angelo A, Frustagli G, Iaccarino G, Mattia M, Occhigrossi A, Valentini S, Zicari S. Montecarlo in radiotherapy: a distributed application. In: 1. European Workshop on Monte Carlo Treatment Planning of the European Workgroup on MCTP. ...

… Workshop on Room- …, 2006

Chauvie S, Andenna C, Amati G, Caccia B, Mattia M, Mascialino B, Guatelli S, Frustagli G, Valenti... more Chauvie S, Andenna C, Amati G, Caccia B, Mattia M, Mascialino B, Guatelli S, Frustagli G, Valentini S. Geant4 modelling of anatomy through DICOM interface. In: 15. International Workshop on Room-Temperature Semiconductor X-and Gamma-Ray Detectors. Abstracts ; October 24 ...

Journal of Physics: Conference Series, 2007

New technologies in cancer radiotherapy need a more accurate computation of the dose delivered in... more New technologies in cancer radiotherapy need a more accurate computation of the dose delivered in the radiotherapeutical treatment plan, and it is important to integrate sophisticated mathematical models and advanced computing knowledge into the treatment planning (TP) process. We present some results about using Monte Carlo (MC) codes in dose calculation for treatment planning. A distributed computing resource located in the Technologies and Health Department of the Italian National Institute of Health (ISS) along with other computer facilities (CASPUR -Inter-University Consortium for the Application of Super-Computing for Universities and Research) has been used to perform a fully complete MC simulation to compute dose distribution on phantoms irradiated with a radiotherapy accelerator. Using BEAMnrc and GEANT4 MC based codes we calculated dose distributions on a plain water phantom and air/water phantom. Experimental and calculated dose values below ±2% (for depth between 5 mm and 130 mm) were in agreement both in PDD (Percentage Depth Dose) and transversal sections of the phantom. We consider these results a first step towards a system suitable for medical physics departments to simulate a complete treatment plan using remote computing facilities for MC simulations .

Rapporti ISTISAN, 2006

Mattia M, Caccia B, Amati G, Andenna C, Benassi M, D'Angelo A, Frustagli G, Iaccarino G, Mar... more Mattia M, Caccia B, Amati G, Andenna C, Benassi M, D'Angelo A, Frustagli G, Iaccarino G, Marzi S, Occhigrossi A, Valentini S, Zicari C. Trattamento radioterapeutico: calcolo avanzato per l'ottimizzazione del piano di cura. In: Caccia B, Mattia M, Grisanti F, ed. Convegno nazionale Sistemi di ...