Učinkovitost zmanjševanja doze na dojke z uporabo svinčene zaščite pri računalniški tomografiji glave : magistrsko delo

Zalokar, Nika (author), Mekiš, Nejc (mentor), Škrk, Damijan (reviewer)

Uvod: Računalniška tomografija (CT) največ prispeva k izpostavljenosti pacientov ionizirajočemu sevanju. CT slikanje glave je najbolj pogosto izvajano CT slikanje, pri katerem so dojke, ki spadajo v skupino organov z najvišjo radiosenzitivnostjo, izpostavljene sipanemu sevanju, čeprav ležijo izven primarnega polja slikanja. Svinčeno zaščitno pregrinjalo se v diagnostični radiologiji uporablja že dolgo in preprečuje tveganje za nastanek stohastičnih učinkov sevanja. Namen: Namen magistrske naloge je bil ugotoviti, ali, in če, za koliko, uporaba svinčene zaščite pri CT slikanju glave zmanjša absorbirano dozo na dojke ter kakšne so razlike glede na spiralno in sekvenčno tehniko slikanja. Metode dela: Meritve smo izvedli z elektronskim dozimetrom EDD 30. Dozo smo najprej merili na antropomorfnem fantomu v dveh ustanovah, UKC MB in SB CE. Meritve smo izvedli brez uporabe svinčene zaščite in s svinčeno zaščito ekvivalentne debeline svinca 0,5 mm, ovito okoli pacientke oziroma fantoma, pri čemer smo uporabili sekvenčno in spiralno tehniko slikanja. Meritve smo kasneje izvedli še na 120 pacientkah v obeh ustanovah ob uporabi spiralne tehnike slikanja. Rezultati: Absorbirana doza na dojke se je pri meritvah na fantomu v UKC MB znižala za 86 % (p<0,001) pri sekvenčni tehniki, pri spiralni tehniki pa za 82 % (p<0,001), ko smo uporabili svinčeno zaščito. V SB CE se je absorbirana doza na dojke pri sekvenčni tehniki slikanja znižala za 91 % (p<0,001) ob uporabi svinčene zaščite, pri spiralni tehniki slikanja pa za 86 % (p<0,001). Pri meritvah v kliničnem okolju se je v UKC MB absorbirana doza ob uporabi svinčene zaščite znižala za 74 % (p<0,001), v SB CE pa za 81 % (p<0,001). Razprava in zaključek: Glede na v povprečju visok odstotek (78 %) statistično značilnega znižanja absorbirane doze na dojke ob uporabi svinčene zaščite med CT slikanjem glave, dejstvo, da so dojke eden izmed najbolj radiosenzitivnih organov, visoko število CT slikanj glave ter relativno preprost ščitenja dojk, ki ne vpliva na kakovost slik, se uporaba svinčene zaščite priporoča v klinični praksi.

• Language: Slovenian
• Keywords: magistrska dela, radiološka tehnologija, CT slikanje glave, svinčena zaščita, znižanje doze, ščitenje dojk
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [N. Zalokar]
• Year: 2020
• Number of pages: 42 str., [3] str. pril.
• PID: 20.500.12556/RUL-117643
• UDC: 616-07
• COBISS.SI-ID: 59677443
• Publication date in RUL: 18.07.2020

Secondary language

• Language: English
• Title: Lead shielding efficiency in dose reduction on breasts during computed tomography of the head : master thesis

Abstract

Introduction: Computed tomography (CT) is one of the biggest contributors to the radiation exposure of the patients. The most frequently performed CT examination is the head CT examination during which the breasts, that are one of the most radiosensitive organs, are exposed to scatter radiation regardless of not being included in the primary field. Lead apron is an efficient dose reduction tool that prevents stochastic effects caused by ionising radiation. Purpose: The aim was to investigate how does the use of lead shielding influence the absorbed dose received by the breasts during head CT and whether there are any differences between the spiral and sequential imaging technique. Methods: The measurements were performed using an electronic dosimeter EDD 30. Measurements were performed on an anthropomorphic phantom in two different institutions, UKC MB and SB CE, without the use of lead shielding and with the lead shielding of 0,5 mm equivalent lead density, wrapped around the phantom or patient to discover any differences in the absorbed dose to the breasts. Measurements were also performed on 120 patients in clinical environment. Results: During the phantom measurements, the lead shielding reduced the absorbed dose to the breasts in UKC MB by 86 % (p<0,001) and 82 % (p<0,001) during the sequential and spiral technique, respectively, and by 91 % (p<0,001) and 86 % (p<0,001) in SB CE during the sequential and spiral technique, respectively. During the measurements on female patients, the absorbed dose to the breasts has been reduced by 74 % (p<0,001) in UKC MB and by 81 % (p<0,001) in SB CE, with the use of shielding. Discussion and conclusion: Considering the high and significant average of 78 % absorbed dose reduction during the head CT examination, carcinogenic effect of radiation, high radiosensitivity of the breasts, high frequency of the head CT scans and relatively easy use of lead shielding which has no effect on image quality, the use of shielding during head CT is highly recommendable.

• Keywords: master's theses, radiologic technology, head CT, lead shielding, breasts dose reduction, breast shielding