Measurement of absorbed dose in water in brachytherapy

• Autorzy: Pawłowski Piotr , Szymko Magdalena , Wołowiec Paweł , Braziewicz Janusz

Identyfikatory

DOI

10.2478/pjmpe-2024-0032

• Języki publikacji: EN

Abstrakty

EN

Introduction: The most commonly used method for measuring the activity of sources in brachytherapy involves well chambers, which are utilized to measure air kerma. Brachytherapy centers are required to employ the TG-43 algorithm, which calculates the dose distribution in water. Transitioning from air to water introduces uncertainties. The objective of this study is to develop a new method for measuring the absorbed dose in water for ¹⁹²Ir radiation. Material and Methods: A prototype ionization chamber was used in this study. To determine the absorbed dose in water measured by this chamber, the definition of absorbed dose in water was applied directly. Perturbation factors were calculated using Monte Carlo simulations, while correction factors were derived from measurements taken with the ionization chamber. A water phantom was created, along with a positioning system for the ionization chamber and a holder for the source. Corrections were calculated for polarization, recombination, saturation, and the effects of pressure and temperature on the chamber signal were taken into account. Measurements were performed at the position of the maximum chamber signal, determined before each measurement, and repeated for various air kerma values and different sources. Results: The measurement results in water were compared to those obtained from the TG-43 algorithm. Results indicate a combined measurement uncertainty of 1.26%, representing a significant improvement over the well chamber measurements. Conclusion: Preliminary results indicate the potential for improving dosimetric accuracy in brachytherapy. By using values for absorbed dose in water, uncertainties associated with converting air kerma to dose distribution in water can be eliminated.

Słowa kluczowe

EN

brachytherapy; dosimetry; HDR; ionization chamber

• Wydawca: Polskie Towarzystwo Fizyki Medycznej
• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2024
• Tom: Vol. 30, Iss. 4
• Strony: 269--273
• Opis fizyczny: Bibliogr. 15 poz., rys., tab.

Twórcy

autor

Pawłowski Piotr

• Holy Cross Cancer Center, Kielce, Poland
• Jan Kochanowski University of Kielce, Poland

• https://orcid.org/0000-0003-0643-3555

autor

Szymko Magdalena

• Central Office of Measures, Warsaw, Poland

• https://orcid.org/0000-0002-3219-9259

autor

Wołowiec Paweł

• Holy Cross Cancer Center, Kielce, Poland

• https://orcid.org/0000-0001-6698-9331

autor

Braziewicz Janusz

• Holy Cross Cancer Center, Kielce, Poland
• Jan Kochanowski University of Kielce, Poland

• https://orcid.org/0000-0002-6972-7027

Bibliografia

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Uwagi

Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025).