Geometrična verifikacija pri obsevanju bolnic z rakom dojk v zadržanem globokem vdihu z uporabo AlignRT-sistema : magistrsko delo

Berk, Alen (author), Marinko, Tanja (mentor), Žager Marciuš, Valerija (comentor), Salmič, Klemen (comentor), Oblak, Irena (reviewer)

Uvod: S ciljem zaščite okoliških zdravih tkiv se obsevanje raka dojk pogosto izvaja v zadržanem globokem vdihu z uporabo AlignRT-sistema. To je sistem za optično zaznavanje bolnikove površine, ki na podlagi poravnave referenčne in dejanske površine interesnega področja omogoča korekcijo in nadzor nad obsevalnim položajem. Namen: Namen magistrskega dela je raziskati natančnost in ponovljivost AlignRT-sistema pri obsevanju bolnic z rakom dojk v zadržanem globokem vdihu, preučiti vplive posameznih značilnosti bolnic na velikost nastavitvene napake in optimizirati proces geometrične verifikacije, ki se na OIL izvaja s pomočjo AlignRT-sistema ter IGRT-slikovne verifikacije iz ortogonalnih smeri in tangencialnega obsevalnega kota. Metode dela: V empiričnem delu smo retrospektivno analizirali podatke iz obsevanj petdesetih bolnic, ki so bile razdeljene na dve skupini (s sočasnim dodatkom doze na ležišče tumorja in brez). Analizirali smo podatke o premikih v šestih prostostnih stopnjah, starosti, kvadrantu tumorja in velikosti košarice nedrčka. Rezultati: V primerjavi skupin bolnic glede na vrsto obsevanja smo v primerjanih značilnostih odkrili statistično značilno razliko v kategoriji starosti (p = 0.022), pri čemer je bila skupina bolnic s sočasnim dodatkom doze na ležišče mlajša. Povprečna skupna velikost premikov je bila v primeru desetih bolnic večja od zastavljenih toleranc za translacijske in rotacijske premike (5 mm in 3°). Po kontrolnem tangencialnem slikanju so tri bolnice brez sočasnega dodatka doze na ležišče v LONG(+) smeri v povprečju presegale toleranco 5 mm. Statistično značilno povezavo starosti in skupne povprečne velikosti premikov smo odkrili v LONG(+) (p = 0.015, ? = - 0.342) in ROLL(+) smeri (p = 0.045, ? = -0.285). V primerjavi med zgornjima in spodnjima kvadrantoma dojke smo v smeri LAT(+) odkrili statistično značilno večje povprečne skupne velikosti premikov za skupino spodnjih kvadrantov (p = 0.012). V primerjavi notranjih in zunanjih, smo to odkrili v smeri PITCH(-), kjer so bili premiki večji pri skupini notranjih kvadrantov (p = 0.041). Razprava in zaključek: Z rezultati smo utemeljili potrebo po vsakodnevni komplementarni uporabi AlignRT-sistema ter IGRT-slikovne verifikacije iz ortogonalnih smeri in tangencialnega kota. Starost bolnic in lokacija tumorja vplivata na velikost nastavitvene napake ob uporabi AlignRT-sistema.

• Language: Slovenian
• Keywords: magistrska dela, radiološka tehnologija, rak dojk, obsevanje v zadržanem globokem vdihu, AlignRT, nastavitvena napaka
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [A. Berk]
• Year: 2023
• Number of pages: 67 str., [5] str. pril.
• PID: 20.500.12556/RUL-151075
• UDC: 616-07
• COBISS.SI-ID: 167321603
• Publication date in RUL: 28.09.2023

Secondary language

• Language: English
• Title: Geometric verification in deep inspiration breath-hold breast cancer radiation therapy using AlignRT : master thesis

Abstract

Introduction: Breast cancer radiation therapy often employs deep inspiration breath-hold techniques to protect nearby organs at risk. AlignRT is an optical surface tracking system that allows patient position correction and control during radiation. Purpose: Our study investigates the accuracy and reproducibility of the AlignRT system during deep inspiration breath-hold radiation for breast cancer patients. We aim to assess the influence of patient characteristics on setup errors and optimize our institution's (OIL) geometric verification process, which combines AlignRT, orthogonal and tangential treatment verification imaging. Methods: We retrospectively analyzed the data of fifty patients, categorized into two groups: those with a simultaneous integrated boost to the tumor bed and those without. Data included shifts in six degrees of freedom, patient age, tumor location, and cup size. Results: Comparing patient groups receiving different radiation types, we found a statistically significant age difference (p = 0.022), with the simultaneous boost group being younger. The average total magnitude of shifts exceeded the predefined tolerances for translational and rotational shifts (5 mm and 3°) in ten patients. In patients without simultaneous boost, three on average exceeded the 5 mm tolerance in the LONG(+) direction after tangential control imaging. Age correlated significantly with the average total shift magnitude in the LONG(+) (p = 0.015, ρ = -0.342) and ROLL(+) (p = 0.045, ρ = -0.285) directions. In comparing the upper and lower breast quadrants, the lower quadrant group exhibited significantly larger average total shifts in the LAT(+) direction (p = 0.012). Similarly, in the comparison between the inner and outer quadrants, the inner quadrant group showed significantly larger shifts in the PITCH(-) direction (p = 0.041). Discussion and conclusion: In our study, we have confirmed the need for complementary use of AlignRT and treatment verification imaging that consists of both orthogonal and tangential imaging. We have additionally confirmed a connection between age and the extent of setup errors, as well as an impact of tumor location on the magnitude of setup errors.

• Keywords: master's theses, radiologic technology, breast cancer, deep inspiration breath-hold, AlignRT, setup error