Dose Distribution Verification in stereotactc radiosurgery using radiochromic gel dosimeter

Česká verzia

Authors: P. Kozubíková ¹; J. Šolc ²; J. Novotný Jr. ^1,3,4; K. Pilařová ¹; J. Pipek ¹; J. Končeková ^1,3
Authors place of work: Fakulta jaderná a fyzikálně inženýrská, ČVUT v Praze, Praha, Česká republika ¹; Inspektorát ionizujícího záření, Český Metrologický Institut, Praha, Česká Republika ²; Oddělení lékařské fyziky, Nemocnice Na Homolce, Praha, Česká Republika ³; Onkologická klinika-Radioterapie, Fakultní Nemocnice v Motole, Praha, Česká Republika ⁴
Published in the journal: Lékař a technika - Clinician and Technology No. 2, 2015, 45, 61-64
Category: Původní práce

Summary

3D verification in stereotactic radiosurgery is not a trivial task since there is not available appropriate detector and the process of verification is time consuming as well. The aim of the study was to perform assessment of radiochromic gel dosimeter based on Turnbull blue dye for verification of patient treatment plan at Leksell Gama Knife Perfexion. Gel dosimeter was fixed with stereotactic frame and irradiated with a prescription dose of 40 Gy to 50% isodose. Dosimeter was evaluated two hours after irradiation using home made optical CT scanner. The comparison between the gel measurements and the treatment planning system calculation are presented in the form of 2D isodoses, 1D profile and gamma analysis (1 mm 3%) for the central slices. Measured relative dose distribution in a central slice and measured profiles show excellent correspondence with TPS. There were observed small discrepancies in low dose region according to gamma analyses results. This was probably caused by problems with dose distribution coregistration and set up positioning errors.

Keywords:
Gel dosimetry, Stereotactic radiotherapy, Leksell Gamma Knife, verification

Zdroje

[1] Šolc J., Spěváček V. 2007 New radiochromic gel for 3D dosimetry based on Turnbullblue:characteristics and optical computed tomography evaluation Book of Abstracts: IEEE Medical Imaging Conf. (New Jersey: IEEE Engineering in Medicine and Biology Society) p 468).

[2] Pilařová K., Kozubíková P., Šolc J., Spěváček V. 2014 Characteristicsofpolyacrylamide gel with THPC and Turnbull Blue gel dosimeters evaluated using optical tomography. Radiation Physics and Chemistry, 104, p 283–286.

[3] Šolc J, Spěváček V 2009 New Radiochromic gel for 3D dosimetry based on Turbullblue basic properties Phys. Med. Biol. 54 p 5095-101.

[4] J. Šolc, Vývoj nových typů radiochromních gelových dozimetrů a vyhodnocení jejich odezvy metodou optické výpočetní tomografie, disertační práce, ČVUT, FJFI, Katedra dozimetrie a aplikace ionizujícího záření Praha, 2007.