One of the most innovative methods for coping with the rare tumor is the Boron Neutron Capture Therapy (BNCT), which exploits the neutron capture reaction of the boron for selecting and treating precisely the tumor. One of the main aspects during the treatment is the monitoring of the dose given; from the neutron capture processes, gamma at 478 keV are generated, which are then detected through an imaging system as the SPECT. By monitoring these gammas, it is possible to evaluate the dose administrated to the patient. This is the main objective of the BNCT-SPECT. In this Master Thesis, the BNCT Nagoya (Japan) facility has been considered and accurately simulated with the Monte Carlo code FLUKA. This thesis includes a comparison between two different collimators and presents an analysis on detection system's optimization, with the objective of maximizing the detected gamma rays generated by the boron neutron capture. Moreover, an analysis of the gamma contributions from the surrounding (background) is provided along with a study aimed at reducing them. Finally, a first approach to the tomographic reconstruction is presented, directed at obtaining an image from the gamma emitted at 478 keV. This study is conducted at LENA (Laboratorio Energia Nucleare Applicata) at Pavia, accurately reproduced in the simulations. To reach this aim, a new function in FLUKA was implemented, to track the events and allow for the reconstruction of the image. Simulated data are then compared with the experimental ones, to validate the code and demonstrate that it can be used faithfully for image reconstruction. From Nagoya simulations, background contributions were analyzed in detail, leading to an optimization of the existing setup. This has resulted in a significant reduction of background fluctuations, enhancing the detection of gamma rays at 478 keV. From LENA simulations, it was confirmed the validity of the FLUKA code for events reconstruction, due to a strong correlation between simulated and experimental data.
Uno dei metodi più innovativi per combattere i tumori rari è la Boron Neutron Capture Therapy (BNCT), che utilizza la reazione di cattura neutronica del boro per selezionare e trattare con precisione il tumore. Un aspetto fondamentale durante il trattamento è il monitoraggio della dose somministrata; dai processi di cattura neutronica si generano raggi gamma a 478 keV, i quali vengono rilevati attraverso un sistema di imaging come la SPECT. Monitorando questi raggi gamma, è possibile valutare la dose somministrata al paziente. Questo è l’obiettivo principale della BNCT-SPECT. In questa tesi, la struttura BNCT di Nagoya (Giappone) è stata considerata e accuratatamente simulata con il codice Monte Carlo FLUKA. Questa tesi include un confronto tra due collimatori differenti e presenta un'analisi dell'ottimizzazione del sistema di rilevamento, con l'obiettivo di massimizzare i raggi gamma rilevati generati dalla cattura neutronica del boro. Inoltre, è fornita un'analisi dei contributi gamma provenienti dall'ambiente circostante ("fondo"), insieme a uno studio volto a ridurre tali contributi. Infine, viene presentato un primo approccio alle ricostruzioni tomografiche, mirato a ricavare un'immagine dai raggi gamma emessi a 478 keV. Questo studio è stato condotto al LENA (Laboratorio Energia Nuclere Applicata) a Pavia, anch'esso accuratemente riprodotto nelle simulazioni. Per raggiungere questo obiettivo, è stata implementata una nuova funzione in FLUKA per tracciare gli eventi e consentire la ricostruzione dell'immagine. I dati simulati sono quindi confrontati con i dati sperimentali, al fine di validare il nuovo codice e dimostrare che possa essere utilizzato in modo accurato per la ricostruzione delle immagini. Dalle simulazioni condotte a Nagoya, i contributi provenienti dal fondo sono stati analizzati in modo approfondito, portando a un’ottimizzazione del setup esistente. Questo ha comportato una significativa riduzione delle fluttuazioni del fondo, migliorando il rilevamento dei raggi gamma a 478 keV. Dalle simulazione al LENA, invece, è stato confermata la validità del codice FLUKA per la ricostruzione degli eventi, grazie ad una buona corrispondenza tra i dati simulati e i dati sperimentali.
Single-photon emission computed tomography for boron neutron capture therapy applications: a Monte Carlo feasibility study
Santini, Letizia
2023/2024
Abstract
One of the most innovative methods for coping with the rare tumor is the Boron Neutron Capture Therapy (BNCT), which exploits the neutron capture reaction of the boron for selecting and treating precisely the tumor. One of the main aspects during the treatment is the monitoring of the dose given; from the neutron capture processes, gamma at 478 keV are generated, which are then detected through an imaging system as the SPECT. By monitoring these gammas, it is possible to evaluate the dose administrated to the patient. This is the main objective of the BNCT-SPECT. In this Master Thesis, the BNCT Nagoya (Japan) facility has been considered and accurately simulated with the Monte Carlo code FLUKA. This thesis includes a comparison between two different collimators and presents an analysis on detection system's optimization, with the objective of maximizing the detected gamma rays generated by the boron neutron capture. Moreover, an analysis of the gamma contributions from the surrounding (background) is provided along with a study aimed at reducing them. Finally, a first approach to the tomographic reconstruction is presented, directed at obtaining an image from the gamma emitted at 478 keV. This study is conducted at LENA (Laboratorio Energia Nucleare Applicata) at Pavia, accurately reproduced in the simulations. To reach this aim, a new function in FLUKA was implemented, to track the events and allow for the reconstruction of the image. Simulated data are then compared with the experimental ones, to validate the code and demonstrate that it can be used faithfully for image reconstruction. From Nagoya simulations, background contributions were analyzed in detail, leading to an optimization of the existing setup. This has resulted in a significant reduction of background fluctuations, enhancing the detection of gamma rays at 478 keV. From LENA simulations, it was confirmed the validity of the FLUKA code for events reconstruction, due to a strong correlation between simulated and experimental data.| File | Dimensione | Formato | |
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2024_12_Santini_Tesi_01.pdf
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Descrizione: Testo tesi
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29.01 MB
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2024_12_Santini_Executive Summary_02.pdf
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Descrizione: Executive Summary
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2.63 MB
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2.63 MB | Adobe PDF | Visualizza/Apri |
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https://hdl.handle.net/10589/229713