Naslov (srp)

Kalibracija radiohromatskog filma zasnovana na gradijentnim radijacionim poljima : doktorska disertacija

Autor

Pecić, Stevan S., 1996-

Doprinosi

Nikolić, Zoran, 1967-
Belča, Ivan, 1964-
Milošević, Nebojša
Vasilić, Rastko, 1971-

Opis (eng)

This dissertation explores the development of an alternative approach to radiochromicfilm calibration, focusing on the use of gradient radiation fields. Compared to uniformlyirradiated film, the advantage of the gradient is that one exposure contains a large numberof different and previously known dose values, allowing for more efficient calibration.The methodology developed in this work includes experimental and numerical calibrationtechniques with an emphasis on the application of a physical wedge filter as the basic dosegradient. The dynamic range coefficient is defined, the evaluation of which indicates a significantinfluence of parameters such as depth and field size, while the influence of beam qualityis negligible. The measurement uncertainty of the calibration for the case of the gradient fieldwas examined, where the maximum deviations were defined and the total uncertainty modelobtained by uncertainty propagation was presented. Taking into account the importance ofthe film scanning process, the topics of spatial resolution and the effect of lateral responseartifacts were discussed in particular.In order to extend the calibration range, the methodology shows possibilities of extrapolationand combination of multiple gradients. Through the formalism of the described method,the possibilities of optimizing the positioning of the gradients for a more even distribution ofcalibration points were analyzed, with a demonstration of the optimization of the procedurethrough a histogram of calibration points. Optimization of the gradient placement enabledconvergence for seven exposures in the range [1, 10] Gy and eight exposures in the range[1, 20] Gy. Based on the existing results, an algorithm for the general case of gradient fieldcalibration is presented.The methodology has the potential to be implemented within standard clinical settings,enabling routine film measurement and simplifying quality control procedures. Automationof the protocol opens the possibility of wide application, especially for complex gradient fieldscharacteristic of modern therapeutic sources.

Opis (srp)

Ova disertacija istražuje razvoj alternativnog pristupa kalibraciji radiohromatskog filma, fokusirajući se na upotrebu gradijentnih radijacionih polja...

Opis (srp)

Fizika - Primenjena fizika / Physics - Applied Physics Datum odbrane: 29.05.2025.

Jezik

srpski

Datum

2024

Licenca

Ovo delo je licencirano pod uslovima licence
Creative Commons CC BY-NC-ND 3.0 AT - Creative Commons Autorstvo - Nekomercijalno - Bez prerada 3.0 Austria License.

http://creativecommons.org/licenses/by-nc-nd/3.0/at/legalcode

Predmet

OSNO - Opšta sistematizacija naučnih oblasti, Radioaktivnost

Radiohromatski film, Radijaciona dozimetrija, Medicinska fizika

OSNO - Opšta sistematizacija naučnih oblasti, Radioaktivnost

Radiochromic film, Radiation dosimetry, Medical physics