Pomen dodatne geometrične verifikacije s funkcijo Auto beam hold pri obsevanju raka prostate : diplomsko delo

Ficko, Tara (avtor), Ribar, Anja (avtor), Žager Marciuš, Valerija (mentor), Salmič, Klemen (komentor), Starc, Tina (recenzent)

Uvod: Rak prostate je najpogostejši rak moških pri nas in po svetu. Ena izmed metod zdravljenja raka prostate je zdravljenje z obsevanjem. Pri raku prostate lahko obsevamo samo prostato ali pa tudi medenične bezgavke in semenske vezikle. Prostata je zaradi fizioloških dejavnikov, kot so polnjenost mehurja in rektuma, kontrakcije mišic ter dihanja, zelo premičen organ. Premiki prostate se dogajajo tako med posamezno frakcijo, čemur pravimo intrafrakcijski premiki, kot tudi med dnevnimi obsevanji, interfrakcijski premiki. Z namenom sledenja intrafrakcijskih premikov in želje po natančnem obsevanju, zdravnik pred obsevanjem, v prostato implantira tri zlate markerje, lego katerih spremljamo pred in med obsevanjem. Za sledenje intrafrakcijskih premikov med obsevanjem raka prostate z vstavljenimi fiducialnimi zlatimi markerji se uporablja Auto beam hold funkcija (ABH), ki primerja položaj markerja glede na referenčni položaj in v primeru izpada interesnega področja obsevanje prekine. Obsevanje največkrat izvedemo z volumetrično modulirano ločno terapijo (VMAT) obsevalno tehniko. Namen: Namen diplomskega dela je ugotoviti potrebo po dodatni slikovni verifikaciji s slikovnim sistemom On board Imager (OBI) ob uporabi funkcije ABH pri obsevanju raka prostate z vstavljenimi fiducialnimi zlatimi markerji, zaradi gibanja prostate med obsevanjem. To smo ugotovili s pregledom vseh potrebnih dodatnih slikanj, vsak dan med obsevanjem in izpisom velikosti premikov v lateralni, longitudinalni in vertikalni smeri. Metode dela: Uporabili smo deskriptivno raziskovalno metodo in statistično analizo podatkov. Primerjali smo translacijske premike glede na frakcije in obseg področja obsevanja. V raziskavo so vključeni podatki 40 bolnikov, ki so bili obsevani zaradi raka prostate radikalno in pa 20 bolnikov, ki so poleg prostate obsevali tudi medenične bezgavke, od meseca junija 2020 naprej. Vsi bolniki so imeli v prostato vstavljene zlate markerje in bili obsevani z VMAT obsevalno tehniko na linearnem pospeševalniku True Beam (Varian), na Onkološkem inštitutu Ljubljana. Rezultati: Iz dobljenih rezultatov statistične analize smo ugotovili, da se pri obsevanju raka prostate največji premiki pojavijo v longitudinalni smeri, superiorno (1,64 mm). Ugotovili smo tudi, da število frakcij vpliva na število intrafrakcijskih premikov. Pri obsevanju raka prostate vključno z medeničnimi bezgavkami, se pri višjem številu doseženih frakcij obsevanja, pojavi večje število premikov. Razprava in zaključek: Ugotovimo lahko, da se največji premiki dogajajo v longitudinalni smeri, superiorno, kar je lahko posledica različnih vzrokov. Na premike lahko vpliva ne-sproščenost bolnika in mišic medeničnega dna med obsevanjem, različna polnjenost mehurja in rektuma ter različno število frakcij obsevanja. Ugotovimo lahko tudi potrebo po dodatni slikovni verifikaciji s funkcijo ABH, ki je zaradi različnih premikov prostate ključna za doseganje dobrih rezultatov zdravljenja.

• Jezik: Slovenski jezik
• Ključne besede: diplomska dela, radiološka tehnologija, rak prostate, obsevanje raka prostate, intrafrakcijski premiki
• Vrsta gradiva: Diplomsko delo/naloga
• Tipologija: 2.11 - Diplomsko delo
• Organizacija: ZF - Zdravstvena fakulteta
• Kraj izida: Ljubljana
• Založnik: [T. Ficko; A. Ribar]
• Leto izida: 2022
• Št. strani: 29 str., [3] str. pril.
• PID: 20.500.12556/RUL-139551
• UDK: 616-07
• COBISS.SI-ID: 120430595
• Datum objave v RUL: 04.09.2022

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: The importance of additional geometrical verification with Auto beam hold function in prostate cancer irradiation : diploma work

Izvleček

Introduction: Prostate cancer is the most common male cancer in the world. One of the treatment methods for prostate cancer is radiation therapy. When it comes to radiation of prostate cancer, we can irradiate only the prostate or also the pelvic lymph nodes and seminal vesicles. The prostate is a very mobile organ, due to physiological factors such as bladder and rectal filling, muscle contractions, and respiration. Prostate displacement can occur during one fraction treatment, called an intrafraction movement, as well as between daily irradiations, called an interfraction movement. In order to monitor intrafraction movements, the doctor inserts three golden markers in the prostate before radiation, the position of which we track before and during irradiation. For that purpose, we use the Auto Beam Hold (ABH) function, which compares the position of the marker according to the reference position, and in the case, they fall out of the tolerance position, the irradiation stops. The radiation is most often performed using the Volumetric Modulated Arc Therapy (VMAT) radiation technique. Purpose: The purpose of our diploma work is to determine the need for an additional image verification with the On-Board Imager (OBI) system using the ABH function when irradiating prostate cancer, with inserted fiducial markers, due to the movement of the prostate during irradiation. We figure that out by reviewing all necessary additional imaging daily and displaying the magnitude of the displacements in lateral, longitudinal, and vertical directions. Methods: We have used the descriptive method and statistical analysis. We have compared translation movements of the prostate relating to fractions and the field of irradiation. The study includes data from 40 patients who were irradiated radically for prostate cancer and 20 patients who were irradiated for prostate cancer including the pelvic lymphatic nodes. All of the patients had gold markers inserted into the prostate and were irradiated with the VMAT technique on the Varian, True Beam linear accelerator at Onkološki inštitut Ljubljana. Results: From obtained results and statistic analysis we found out, that in prostate cancer irradiation the biggest displacement occurs in the longitudinal, superior direction (1,64 mm). We also found out the number of fractions impacts the number of intrafraction movements, when irradiating prostate cancer including lymphatic nodes the higher the number of fractions, the higher the number of movements. Discussion and conclusion: To conclude the biggest movements occurs in a longitudinal, superior direction, which can be caused by a variety of causes. Movements can be affected by non-relaxation of the patient and pelvic muscles during irradiation, bladder and rectal filling, and a number of radiation fractions. We can also identify the need for additional verifications with ABH function, which is crucial for achieving good treatment results, due to all prostate movements.

• Ključne besede: diploma theses, radiologic technology, prostate cancer, prostate cancer irradiation, intrafraction movements