Ocena korekcije položaja bolnika z metodo dvojne registracije pri obsevanju raka prostate : diplomsko delo

Hribar, Mojca (author), Poljanec, Neja (author), Žager Marciuš, Valerija (mentor)

Uvod: Rak prostate je najpogostejši rak pri moških v Evropi, in tudi v Sloveniji. Velikost varnostnega roba pri obsevanju prostate vpliva na dozo, ki jo bodo prejeli kritični organi, zato se le ta v procesu izdelave obsevalnega plana natančno določi z upoštevanjem fizioloških premikov prostate, sprememb velikosti prostate in odstopanj pri nastavitvi bolnika v položaj za obsevanje. Pomembno je preprečevanje intrafrakcijskih premikov, ki so definirani kot premiki znotraj posamezne frakcije obsevanja. Namen: V diplomskem delu smo ugotavljali, kakšne so povprečne razlike premikov pri bolnikih med kostnimi strukturami in mehkim tkivom prostate v x, y in z smeri ter kakšne so razlike premikov za vsako od teh smeri. Metode dela: Zbrali smo podatke o premikih pri štirinajstih bolnikih z vstavljenimi zlatimi markerji, ki so radikalno obsevali rak prostate na linearnem pospeševalniku Versa HD (Elekta) na Onkološkem inštitutu v Ljubljani. Pri primerjanju načrtovane in dejanske slike smo uporabili metodo dvojne registracije. Za analizo in ovrednotenje podatkov smo uporabili računalniški program Microsoft Excel 2016 in IBM SPSS Statistics 24. Rezultati: Iz dobljenih rezultatov in statistične analize smo ugotovili, da so razlike premikov med kostnimi strukturami in mehkim tkivom prostate najmanjše v smeri x, saj so vsi premiki manjši od planiranega varnostnega roba za obsevanje raka prostate (5–7 mm). V y in z smeri pa smo ugotovili premike, ki so tudi večji od planiranega varnostnega roba (>7 mm). Razprava in zaključek: Sklepamo lahko, da se večji premiki v y in z smeri lahko pojavijo zaradi različne polnjenosti mehurja in črevesja, sproščenosti bolnika, pa tudi zaradi spremembe oblike prostate pri pripravi in predpripravi na obsevanje na računalniško tomografskem (CT) simulatorju in/ali pri samem obsevanju.

• Language: Slovenian
• Keywords: rak prostate, intrafrakcijski premiki, radioterapija
• Work type: Bachelor thesis/paper
• Organization: ZF - Faculty of Health Sciences
• Year: 2019
• PID: 20.500.12556/RUL-110426
• COBISS.SI-ID: 5686635
• Publication date in RUL: 14.09.2019

HRIBAR, Mojca and POLJANEC, Neja, 2019, Ocena korekcije položaja bolnika z metodo dvojne registracije pri obsevanju raka prostate : diplomsko delo [online]. Bachelor’s thesis. [Accessed 20 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=110426

Secondary language

• Language: English
• Title: Evaluation of patient’s position correction with dual registration for radiotherapy of prostate cancer : diploma work

Abstract

Introduction: Prostate cancer is the most common cancer in men in Europe and Slovenia. The size of the safety margin affects the dose received by the critical organs. Therefore, the safety margin needs to be thoroughly defined when making a radiation plan. All the physiological movements of the prostate, changes in the size of the prostate and the deviations in the patient`s radiation position setting need to be taken into account. It is important to prevent the intrafractional motions, which are defined as movements within each fraction of radiation. Purpose: In our diploma work we wanted to figure out the movement differences between bone structures and soft prostate`s tissue in x, y and z directions in different patients. We also measured the differences between each of these directions for every patient. Methods: We collected data on movements in 14 patients with inserted golden markers, which radically treated their prostate cancer on linear accelerator Versa HD (Elekta) at the institute of oncology in Ljubljana. For analysis and evaluation of the data we used Microsoft Excel 2016 and IBM SPSS Statistics 24. Results: From our data and statistical analysis we found out that movement differences between bone structures and soft prostate`s tissue are the smallest from the x directions, because none of the differences exceeded the planned safety margin (5–7 mm). But there is a small percentage of movement differences in y and z directions, which exceeded the planned safety margin for radiation of prostate (>7mm). Discussion and conclusion: Bigger movements in y and z directions may occur due to different bladder or rectum loading, the patient's relaxation, and changes in the shape of the organ before the preparation for radiation on computed tomography (CT) simulator, during preparation for radiation and/or when radiation is in session.

• Keywords: prostate cancer, intrafractional motion, radiotherapy