In this thesis, the use of radiofrequency ablation (RFA) and irreversible electroporation (IRE) as minimally invasive treatments for localized tumors is explored. RFA employs electromagnetic waves to generate heat and destroy tissues, offering advantages such as minimal invasiveness and adaptability to various tissues. However, it has disadvantages, such as the risk of damaging surrounding healthy tissues due to the generated heat. Non-thermal ablative techniques, with a specific focus on IRE, have emerged as promising alternatives to reduce thermal damage to surrounding healthy structures, including delicate structures like blood vessels. The study aims to evaluate the temperature distribution, ablation size, and reproducibility of ablation zones using commercial devices for RFA and IRE. For RFA, the goal is to compare the obtained results with those provided by the device manufacturer, while for IRE, understanding the relationship between energy parameters and tissue effects is sought using a finite element model developed in COMSOL Multiphysics and ex vivo experiments. RFA experiments were conducted with two different setups, a single antenna (200 W-12 min) and a double antenna (200 W-9 min), on three different ex vivo bovine organs: liver, kidneys, and lungs. Results showed similar dimensional outcomes for the liver and kidneys as expected, but different results for the lungs, possibly due to the neglect of thermal and electrical properties of tissues. IRE experiments were consistently conducted with two different setups, one with a voltage of 1500 V and another with a voltage of 3000 V, on apples and potatoes, showing temperature increase up to 20 °C. Future work may include in vivo experiments on tumor tissues to assess the effectiveness of the proposed method and advance research towards the clinical application of the discussed techniques.
Il presente lavoro di tesi ha esplorato l'utilizzo dell'ablazione a radiofrequenza (RFA) e dell'elettroporazione irreversibile (IRE) come trattamenti minimamente invasivi per il trattamento tumori localizzati. La RFA impiega onde elettromagnetiche per generare calore e distruggere i tessuti, offrendo vantaggi come la minimale invasività e l'adattabilità a vari tessuti. Tuttavia, presenta svantaggi, come il rischio di danneggiare tessuti sani circostanti a causa del calore generato. Le tecniche ablative non termiche, con particolare attenzione all'IRE, sono emerse come alternative promettenti per ridurre il danno termico alle strutture circostanti sane e alle strutture più delicate come i vasi sanguigni. Lo studio si propone di valutare la distribuzione di temperatura, la dimensione dell'ablazione e la riproducibilità delle zone di ablazione utilizzando dispositivi commerciali per RFA ed IRE. Per la RFA, l'obiettivo è confrontare i risultati ottenuti con quelli forniti dal produttore del dispositivo stesso, mentre per l'IRE si cerca di comprendere la relazione tra i parametri di energia e gli effetti sui tessuti, utilizzando un modello ad elementi finiti in COMSOL e esperimenti ex vivo. Gli esperimenti di RFA sono stati condotti con due setup differenti uno a singola antenna (200 W-12 min) e uno a doppia antenna (200 W-9 min) in tre diversi organi bovini ex vivo: fegato, reni e polmoni. Le prove effettuate hanno mostrato risultati dimensionali simili per fegato e reni rispetto a quelli attesi, ma risultati differenti per i polmoni, probabilmente a causa della mancata considerazione delle proprietà termiche ed elettriche dei tessuti. Gli esperimenti con IRE invece sono stati sempre condotti con due setup differenti, uno con voltaggio a 1500 V e uno con voltaggio a 3000V, su mele e patate, ottenendo un incremento di temperatura fino a 20 °C. I lavori futuri potrebbero includere esperimenti su tessuti tumorali in vivo per valutare l’efficacia del metodo proposto e proseguire le indagini verso l’uso clinico delle tecniche discusse.
Characterization of thermal effects of medical devices used for radiofrequency and irreversible electroporation tumor ablation
GIRGI, CLARA
2022/2023
Abstract
In this thesis, the use of radiofrequency ablation (RFA) and irreversible electroporation (IRE) as minimally invasive treatments for localized tumors is explored. RFA employs electromagnetic waves to generate heat and destroy tissues, offering advantages such as minimal invasiveness and adaptability to various tissues. However, it has disadvantages, such as the risk of damaging surrounding healthy tissues due to the generated heat. Non-thermal ablative techniques, with a specific focus on IRE, have emerged as promising alternatives to reduce thermal damage to surrounding healthy structures, including delicate structures like blood vessels. The study aims to evaluate the temperature distribution, ablation size, and reproducibility of ablation zones using commercial devices for RFA and IRE. For RFA, the goal is to compare the obtained results with those provided by the device manufacturer, while for IRE, understanding the relationship between energy parameters and tissue effects is sought using a finite element model developed in COMSOL Multiphysics and ex vivo experiments. RFA experiments were conducted with two different setups, a single antenna (200 W-12 min) and a double antenna (200 W-9 min), on three different ex vivo bovine organs: liver, kidneys, and lungs. Results showed similar dimensional outcomes for the liver and kidneys as expected, but different results for the lungs, possibly due to the neglect of thermal and electrical properties of tissues. IRE experiments were consistently conducted with two different setups, one with a voltage of 1500 V and another with a voltage of 3000 V, on apples and potatoes, showing temperature increase up to 20 °C. Future work may include in vivo experiments on tumor tissues to assess the effectiveness of the proposed method and advance research towards the clinical application of the discussed techniques.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/219572