Verification and uniformity control of doses for ⁹⁰ Sr/ ⁹⁰ Y intravascular brachytherapy sources using radiochromic film dosimetry

Abstract

Intravascular brachytherapy (IVBT) is a useful treatment modality for the recurrence of in-stent restenosis following drug-eluting stents (DES) or IVBT failure. The objective of this study was to measure the dose rate of 90Sr/90Y IVBT sources for comparison with that given by the manufacturer and to control the dose uniformities of these sources along the source axis. The dose rates of 90Sr/90Y beta sources were measured with a radiochromic film in a custom-made phantom. The films for calibration were irradiated using 60Co photon beams. The results for the three sources were 4.5%, 2.3%, and 3.5% higher than the corresponding certificate values. Maximum and minimum of the dose rates varied within ±10% of those at source center; and maximum dose discrepancy for the first 90Sr/90Y source train was 8.2%; for the second source train, 7.1%; and for the third source train, 5.1%. Our study showed that the dose rates given by the manufacturer for the three 90Sr/90Y IVBT sources were reliable and dose uniformities were within ±10% along two thirds of the treatment length.

The use of gel dosimetry to measure the 3D dose distribution of a90Sr/90Y intravascular brachytherapy seed

“…Thus, the continued use of beta-emitting sources in clinical applications (Ortolani et al 2005, Price et al 2007 and the concerns of guaranteeing a precise treatment of the patient have attracted the attention of more than one investigator. Various research groups have evaluated the dose distributions around these sources theoretically by Monte Carlo simulation (Asenjo et al 2002, Holmes et al 2006 or experimentally using thermoluminescent dosemeters and/or radiochromic film (Demir et al 2008, Duggan et al 1999, Holmes et al 2006, Roa et al 2004, Soares et al 1998. Until now, radiochromic film has been one of the most convenient techniques, which offers spatial resolution better than 0.1 mm in 2D (Chiu-Tsao et al 2007, ICRU 2004.…”