Monte Carlo simulation of the energy released by neutrons on organic compounds for EPR dosimetry

2022

In this work we report the analyses of the energy released per unit mass in organic compounds used for EPR dosimetry exposed to neutron beams in order to predict the increase in dose achievable by addition of gadolinium (Gd) inside the pellets. In particular, Monte Carlo (MC) simulations were carried out for alanine, ammonium tartrate and phenolic compounds irradiated with neutron beams with different energy spectra at various depths inside a water phantom. The addition of gadolinium increases sensitivity of these dosimeters to neutrons thanks to the high gadolinium cross section for neutron capture and to the large number of secondary particles (mainly Auger and internal conversion electro…

Terapia trans-cranica ad ultrasuoni focalizzati guidati da Risonanza Magnetica (tcMRgFUS) utilizzando un sistema integrato con uno scanner RM da 1.5T…

2018

Scopo Negli ultimi anni la terapia transcranica ad ultrasuoni focalizzati guidati da risonanza magnetica (tcMRgFUS) per il trattamento di disordini neurologici quali il tremore essenziale (ET) e il Parkinson tremorigeno (PD) è stata effettuata utilizzando esclusivamente scanner RM da 3T. Presentiamo i risultati ottenuti con il primo sistema tcMRgFUS mai integrato con uno scanner RM da 1.5T. Materiali e metodi 23 pazienti (19 ET; 4 PD) sono stati selezionati per essere sottoposti a tcMRgFUS (talamotomia monolaterale; target: nucleo ventrale intermedio, VIM). I pazienti arruolati sono stati valutati prima del trattamento e 2 giorni dopo. L'efficacia del trattamento è stata valutata utilizzand…

Could alanine/EPR dosimetry be useful for ultra-high dose rate beams used for FLASH radiotherapy?

In the last years a large interest has aroused towards radiation therapy treatments with dose rates much larger with respect to the conventional ones since experiments support the evidence of a considerable normal tissue sparing effect. Indeed, in-vivo experiments showed an increasing of the therapeutic window for dose rates over 50 Gy/s [2]. If confirmed, the ‘FLASH effect’ has the potential to re-shape the future of radiation treatments, with a significant impact on many oncology patients. Significant dosimetric challenges should be dealt with for Ultra-high dose rate (UHDR) beams for FLASH radiotherapy [4]. In particular, ionization chambers are affected by ion recombination effects, alt…

Studio preliminare di parcellizzazione talamica per l’identificazione del target di trattamento applicato alle talamotomie trans-craniche mediante ul…

2018

Introduzione La tcMRgFUS consente di effettuare una vera e propria esplorazione neurofunzionale per confermare ed ottimizzare il target lesionale prima di indurre una lesione cerebrale permanete. La scelta del target di trattamento si basa tuttavia su coordinate stereotassiche che non tengono conto delle diversità anatomiche di ciascun individuo. L'ottimizzazione del target di trattamento viene effettuata sulla base del feedback del paziente durante la procedura stessa. Materiali e metodi È’ stato utilizzato uno scanner RM da 1.5T per acquisire sequenze morfologiche 3D e ultrastrutturali (DTI) in pazienti successivamente sottoposti a tcMRgFUS. È stata effettuata una segmentazione delle aree…

Machine learning classification for COVID19 patients performed on small datasets of CT scans.

2022

In this work we evaluated the possibility of carrying out classifications of the outcome of patients with COVID19 disease through machine learning (ML) techniques working on small datasets of computed tomography (CT) images. In fact, one of the most common problems for medical artificial intelligence (AI) applications is the limited availability of annotated clinical data for model training. In the framework of the artificial intelligence in medicine (AIM) project funded by INFN, we analyzed datasets of CT scans of 79 subjects combined with clinical data containing information relating to positive outcome (no need for intensive care) or poor prognosis (admission into intensive care unit and…

Dosimetric characterization of an ultra-high dose rate beam for FLASH radiotherapy through alanine EPR dosimetry

2022

Experimental evidence is growing, supporting the evidence of a considerable normal tissue sparing effect when treatments are delivered with dose rates much larger with respect to the conventional ones [1]. In particular, an increasing of the therapeutic window has been demonstrated for dose rates over 50 Gy/s, over a large variety of in-vivo experiments [2]. If confirmed, the ‘FLASH effect’ has the potential to re-shape the future of radiation treatments, with a significant impact on many oncology patients [3]. Ultra-high dose rate (UHDR) beams for FLASH radiotherapy present significant dosimetric challenges [4]. Ionization chambers are affected by ion recombination effects, although novel …