magistrsko delo
Gašper Razdevšek (Author), Andrej Studen (Mentor), Luka Snoj (Co-mentor)

Abstract

V primerjavi s konvencionalno radioterapijo z žarki X, velja obsevanje s protoni v teoriji za boljšo terapevtsko tehniko. To je posledica bolj ugodne dozne porazdelitve protonskega žarka, ki omogoča manjšo dozno obremenitev zdravih tkiv in boljšo kontrolo tumorja. Po drugi strani pa je protonska terapija bolj občutljiva na premike in spremembe v anatomiji. Dodajanje velikih varnostnih robov pri planiranju obsevanja, močno zmanjša prednost protonske terapije. Do največjih premikov prihaja v prsnem košu med dihanjem. Večina protonskih centrov (še) ne obseva pljučnih tumorjev, saj dozni plani s trenutnimi tehnikami obsevanja niso znatno boljši ter ni klinično potrjenih prednosti v primerjavi s konformnimi fotonskimi plani. V magistrskem delu je na konkretnem primeru predstavljen proces simulacije predvidene dozne porazdelitve pri pacientu, ki med obsevanjem diha. Obravnavani sta bili dve dihalni fazi - faza vdiha in izdiha. Skupna dozna porazdelitev se ocenjuje v prostoru ene (referenčne) dihalne faze, zato je bila dozna porazdelitev iz faze izdiha transformirana v prostor faze vdiha. Transformacija je bila pridobljena v procesu registracije slik s pomočjo programa Elastix, dozna porazdelitev pa je bila simulirana po metodi Monte Carlo s pomočjo programa MCNP.

Keywords

radioterapija;protonska terapija;registracija slik;izračun doze;premikanje organov;računalniška tomografija;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FMF - Faculty of Mathematics and Physics
Publisher: [G. Razdevšek]
UDC: 615.849
COBISS: 3237476 Link will open in a new window
Views: 652
Downloads: 249
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Other data

Secondary language: English
Secondary title: Proton therapy: dose simulation in dynamic system
Secondary abstract: In principle, proton therapy offers a substantial clinical advantage over conventional photon therapy. This is due to a more favorable depth-dose distribution of protons, which allows greater sparing of normal tissues and improve local tumor control. On the other hand, proton therapy is more sensitive to movements and changes in the anatomy. Adding large safety margins in treatment planning dramatically reduces the benefits of proton therapy. The biggest movements happen in the thorax during breathing. Most proton therapy centers do not (yet) irradiate lung tumors, since treatment plans with current irradiation techniques are not significantly better and there are no clinical evidence supporting its benefits compared to conformal photon plans. In this master's thesis, the process of simulation of the predicted dose distribution is presented for a patient that breathes during the treatment. Two breathing phases were considered - the inhalation and the exhalation phase. The comulative dose distribution is evaluated in one (reference) respiratory phase. Dose distribution from the exhalation phase was transformed into the inhalation phase. The transformation was obtained in the process of image registration using the program Elastix and the dose distribution was simulated with MCNP Monte Carlo code.
Secondary keywords: radiotherapy;proton therapy;image registration;dose calculation;organ motion;computed tomography;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Fak. za matematiko in fiziko, Oddelek za fiziko
Pages: XI, 62 str.
ID: 10959603