Razvoj večlistnega kolimatorskega sistema v radioterapiji : diplomsko delo

Božjak, Primož (author), Potočnik, Denis (author), Žager Marciuš, Valerija (mentor), Medič, Mojca (reviewer)

Uvod: Radioterapija je eden od treh temeljnih načinov zdravljenja raka, pri katerem se za dosego terapevtskega učinka uporablja ionizirajoče sevanje. Cilj zdravljenja je odmeriti natančno določeno dozo sevanja na predhodno določeno tumorsko tarčno prostornino tkiva ob čim manjši okvari zdravega tkiva. V preteklosti so se za oblikovanje obsevalnih polj uporabljali svinčeni bloki in individualne zaščite, danes pa se uporablja večlistni kolimatorski sistem (MLC sistem), ki je sestavni del linearnega pospeševalnika in je največkrat sestavljen iz 120 ali 160 lističev, ki so konfigurirani v pare. Pomembne lastnosti MLC sistemov so: debelina lističev, prepustnost čez lističe in med sosednjimi lističi, število lističev in hitrost premikanja lističev. Namen: Namen diplomskega dela je preko sistematičnega pregleda literature predstaviti, kakšni so bili MLC sistemi za oblikovanje obsevalnih polj v linearnem pospeševalniku v preteklosti in kakšni sistemi se uporabljajo danes. Glavni cilj je preko sistematičnega pregleda literature opredeliti in razjasniti razvoj MLC sistema v radioterapiji in njegovega doprinosa za bolnike, katerih rakasto obolenje zdravijo z obsevanjem. Metode dela: V diplomskem delu sva uporabila deskriptivno metodo s sistematičnim pregledom literature. Osredotočila sva se na literaturo s področja MLC sistemov v radioterapiji, kako je potekal njihov razvoj, kakšne so njihove lastnosti, razvoj ter novosti na področju planiranja in obsevanja v radioterapiji. Navedeno literaturo sva iskala od oktobra 2019 do marca 2020 po slovenskih in mednarodnih bibliografskih bazah. Rezultati: Predstavila sva ugotovitve člankov uporabljenih za sistematični pregled. Razvijali so se vsi parametri MLC sistemov. Velik poudarek je bil na zmanjševanju debeline lističev, prepustnosti čez lističe in povečevanju hitrosti premikanja lističev. Razvijali so se tudi MLC lokalizacijski sistemi. Razprava in zaključek: Ugotovila sva, da so se vsi parametri, katerih razvoj sva predstavila, zelo izboljšali. Debelina lističev se je iz 1 cm ali več, zmanjšala na 5 mm ali manj, število lističev se je iz 80 povečalo na 120 ali 160, prepustnost lističev se je zmanjšala na manj kot 1 %, hitrost premikanja lističev se je zvišala iz 1 cm/s do tudi 5 cm/s. Vse te izboljšave so pripomogle k splošno boljšim rezultatom zdravljenja z obsevanjem.

• Language: Slovenian
• Keywords: diplomska dela, radiološka tehnologija, večlistni kolimatorski sistemi, razvoj večlistnega kolimatorskega sistema, linearni pospeševalniki, oblikovanje obsevalnih polj v radioterapiji
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [P. Božjak, D. Potočnik]
• Year: 2020
• Number of pages: 40 str.
• PID: 20.500.12556/RUL-118685
• UDC: 616-07
• COBISS.SI-ID: 27006211
• Publication date in RUL: 30.08.2020

Secondary language

• Language: English
• Title: Development of multi-leaf collimator system in radiotherapy : diploma work

Abstract

Introduction: Radiotherapy is one of the three basic ways of treating cancer in which ionizing radiation is used to achieve a therapeutic effect. The goal of treatment is to deliver a precisely determined dose of radiation to a predetermined tumor target volume of tissue with as little damage to healthy tissue as possible. In the past, lead blocks and individual protections were used to design irradiation fields, but today a multi-leaf collimator system (MLC system) is used. MLC system is an integral part of a linear accelerator and usually consists of 120 or 160 tungsten leaflets configured in pairs. Important features of MLC systems are: leaf thickness, leaf and interleaf transmission, number of leaflets and leaflet speed. Purpose: The purpose of this diploma thesis is to present, through a systematic review of the literature, what MLC systems for the design of irradiation fields in a linear accelerator were used in the past, and what systems are in use today. The main goal is to define and clarify the development of the MLC system in radiotherapy and its contribution to patients whose cancer is treated with radiation through a systematic review of the literature. Methods: In the diploma work we used a descriptive method with a systematic review of the literature. We focused on the literature in the field of MLC systems in radiotherapy, how their development took place, what are their properties, development and innovations in the field of planning in radiotherapy. We searched for the mentioned literature from October 2019 to March 2020 in Slovenian and international bibliographic databases. Results: We have presented all the findings of the articles used for the systematic review. All the parameters of MLC systems were being developed with strong emphasis being on reducing the leaf thickness, transmission over the leaves and in increasing leaflet speed. MLC localization systems have also been developed. Discussion and conclusion: We found that all the parameters whose development we presented were greatly improved. The thickness of the leaflets decreased from 1 cm or more to 5 mm or less, the number of leaflets increased from 80 to 120 or 160, the leaf transmission decreased to less than 1%, the speed of leaflet movement increased from 1 cm/s up to 5 cm/s. All of these improvements have contributed to better results of radiotherapy.

• Keywords: diploma theses, radiologic technology, multi-leaf collimator systems, development of multi-leaf collimator systems, linear accelerator, design of radiation fields in radiotherapy