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Title:Nevarnost determinističnih učinkov sevanja pri bolnikih med znotrajžilno premostitvijo aorte s pokrito žilno opornico
Authors:ID Kuhelj, Dimitrij (Author)
ID ŠERUGA, TOMAŽ (Mentor) More about this mentor... New window
ID ŠKRK, DAMIJAN (Comentor)
Files:.pdf DR_Kuhelj_Dimitrij_2014.pdf (28,41 MB)
MD5: 7F55399423328F95DD1613BA90E8D69D
 
Language:Slovenian
Work type:Dissertation
Organization:MF - Faculty of Medicine
Abstract:Uvod: Razvoj malo invazivnih znotrajžilnih metod v preteklih desetletjih je omogočil hiter razvoj intervencijske radiologije. Pri tovrstnih posegih je pričakovati višje izpostavljenosti ionizirajočemu sevanju tako bolnikov kot osebja, kar potrjujejo tudi poročila o jatrogenih poškodbah v 90-ih letih prejšnjega stoletja ne le pri obsevanju tumorjev ampak tudi pri posegih v intervencijski kardiologiji in radiologiji. Uporaba pokritih žilnih opornic pri zdravljenju bolezni aorte je v istem obdobju postala alternativa kirurškem zdravljenju, danes je velik del bolnikov uspešno zdravljen s tako, znotrajžilno metodo. Teze doktorske naloge: Glede na trajanje in vrsto posega smo predvideli, da je pri nekaterih bolnikih, zdravljenih s to metodo, doza ionizirajočega sevanja presegla prag determinističnih učinkov. Predvidevali smo, da vrednosti vstopne kožne doze (VKD) pri naših pacientih ne bodo presegle 4 Gy ter da bo odstotek bolnikov, pri katerih bo presežena deterministična doza ionizirajočega sevanja, manjši od 3%. Predvidevali smo tudi, da zgolj čas uporabe ionizirajočega sevanja (čas diaskopije), edina do raziskave praktično redno dokumentirana vrednost, ni primerna za ugotavljanje obremenitve bolnikov z ionizirajočim sevanjem. Večina modenih angiografskih rentgenskih aparatov ima možnost spremljanja drugih dozimetričnih količin. Ugotoviti nameravamo katere količine so boljši pokazatelj obsevanosti bolnikov. Materiali in metode: V prvi del naše raziskave smo vključili 179 bolnikov, ki smo jih med oktobrom 2002 in julijem 2008 zdravili na Kliničnem inštitutu za radiologijo Univerzitetnega kliničnega centra Ljubljana z znotrajžilno vstavitvijo aortne pokrite žilne opornice. Pri 172 bolnikih smo pridobili podatke o času diaskopije, produktu doze in površine sevalnega polja (DAP) ter skupne doze v referenčni točki aparata (Dr). Pri 19-ih bolnikih smo avtomatske meritve aparata primerjali še z odčitki na GafChromic filmih. Podatke smo primerjali s prospektivno zbranimi podatki za 171 bolnikov (drugi del raziskave), ki so bili zdravljeni med majem 2010 in decembrom 2013 na novejšem aparatu. Rezultati: Vrednosti vstopne kožne doze (VKD) so bile na starejšem aparatu v skladu s pričakovanji, saj pri nobenem bolniku niso presegle 4 Gy- najvišja izmerjena doza je bila 2,73 Gy. V skladu s pričakovanji je bil tudi odstotek bolnikov (4 bolniki, 2,3%), ki so prejeli kožno dozo, ki bi lahko povzročila deterministične učinke ionizirajočega sevanja. Primerjava podatkov na novejšem aparatu (drugi del raziskave) je pokazala, da so prejete doze IOS na novejšem večje; VKD je presegla 4 Gy pri 11-ih bolnikih (6,4%), pri dveh je bila celo višja od 6 Gy. Delovanje novejšega aparata smo zato v sodelovanju s proizvajalcem optimizirali ter s tem znatno znižali obsevanost pacientov, kar potrjujejo meritve in rezultati na manjši skupini pacientov. Čas diaskopije se ni izkazal kot vrednost, primerna za ugotavljanje obremenitve bolnikov z ionizirajočim sevanjem zato smo ga v praksi nadomestili z DAP in Dr (VKD). Zaključki: Znotrajžilna vstavitev aortne pokrite žilne opornice je pogosto uporabljana in manj invazivna kot kirurška metoda pri zdravljenju sprememb aorte. Srednjeročni rezultati zdravljenja so dobri. Število tako zdravljenih bolnikov narašča, vse več je tudi mlajših. Četudi poseg opravi izkušen zdravnik, se pri majhnem številu bolnikov ne moremo izogniti determinističnim učinkom sevanja. Dozno obremenitev na aparatih je potrebno preveriti ter aparate optimizirati, saj doze na modernejših aparatih niso vedno nižje. O prekoračenju mejne doze IOS je potrebno bolnika obvestiti ter mu primerno svetovati ob eventuelnem nastanku sprememb na koži.
Keywords:aortna žilna opornica, znotrajžilno zdravljenje, ionizirajože sevanje, deterministični učinki
Place of publishing:Maribor
Year of publishing:2014
PID:20.500.12556/DKUM-46609 New window
COBISS.SI-ID:512439096 New window
NUK URN:URN:SI:UM:DK:5YUGXINV
Publication date in DKUM:23.10.2014
Views:2567
Downloads:218
Metadata:XML DC-XML DC-RDF
Categories:MF
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Secondary language

Language:English
Title:The risk for deterministic effects of ionising radiation in patients during endovascular aortic stent graft implantation
Abstract:ABSTRACT Introduction: A trend towards minimally invasive procedures, present in last decades, lead to expansion of endovascular procedures. Although less invasive than surgery, during certain procedures high radiation doses to the skin can be delivered. In 1990s', publications of iatrogenic radiation injuries have appeared in the literature, concerning not only radiotherapy but also procedures in interventional cardiology and radiology. In the same period, stent graft implantation for pathology of the aorta has, in some patients, became an alternative to large surgical procedure. Many patients with such pathology are successfully treated endovasculary today. Thesis of the study: Our expectations about exceeded deterministic levels of ionising radiation were based on a procedure type and duration. The maximum entrance skin dose (VKD) of 4 Gy was predicted and the procentage of patients in whom deterministic doses were reached was expected under 3%. Fluoroscopy time, the only value recorded untill the study is not a good predictor of the radiation exposure. Most modern machines offers additional dosimetric quantities and their signifficance will be determined. Materials and methods: 179 consecutive patients, treated endovasculary with aortic stent grafts in Clinical Radiology Institute, University Medical Centre Ljubljana between October 2002 and July 2008 were included in the first part of the present study. Data of the automatic measurement of DAP, cumulative dose in interventional reference point (CDirp) and fluoroscopy times were analysed in 172 patients and in 19 GafChromic films were added to objectivise automatic measurements. The data were compared with data prospectively collected on 171 patients (second part of the study), treated between May 2010 and December 2013 on a newer machine. Results: The values of entrance skin dose- ESD in the first series were in expected limits- maximum of 2,73 Gy as was the percentage of patients receiving skin dose, which might cause possible deterministic effect (4 patients; 2,3%). Surprisingly, data comparison showed higher doses on a newer machine; the level of 4 Gy was exceeded in 11 patients (6,4%), in two ESD was even higher than 6 Gy. At the beginning of 2014, the new machine was optimised accordingly together with specialist, provided by the manufacturer. Based on simulated dose measurements and the data from the smaller patients' sample, the dose was lowered significantly. Fluoroscopy time showed poor correlation with dose quantities and has been exchanged with DAP and CD irp in daily practice. Conclusions: Endovascular stent graft implantation is less invasive as surgical procedure and widely used. Mid-term results of the procedure are encouraging. The number of procedures is growing worldwide, more younger patients are treated this way. In a small number of patients, deterministic doses can be reached, even in departments with well-trained staff and with newest equipment. The doses of ionising radiation, produced by angiographic machines should be assessed and optimization should be performed accordingly, modern equipment is not always safer. Operators should inform their patients of possible skin changes after receiving high radiation doses and proper support should be given after their eventual outbreak.
Keywords:aortic stent graft, endovascular therapy, ionising radiation, deterministic effects


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