Purpose: To assess the bleaching times of OSLDs by using high-intensity light emission diodes (LEDs) of different spectra emession.
Methods: An in-house system to bleach OSLDs was developed. For bleaching, it was used LEDs of white, blue, yellow and red emission spectra. The LEDs are based on the SMD 2835 model which operates between 1 to 3 W. A batch of pre-screened OSLD (Landauer, USA) with its associated reader were used for this study (MicroStar, Landauer, USA). The OSLD were uniformly irradiated up to 2.0 Gy with a 6X photon beam (TrueBeam STx, Varian, USA). The readout and handling of the OSLDs were in agreement with TG-191 recommendations. After OSLDs readout measurement, the dosemeters were bleached using the different light sources. The bleaching time was recording. Commonly, the OSLD are bleached with white fluorescent light with optimal filters. Previous reports showed bleaching times down to 24 hrs.
Results: The blue light LED operating at 3 W showed the best results, it might bleach an OSLD irradiated with 2 Gy in less than 2 hours.
Conclusion: Using LEDs for OSLD bleach is 10 times faster than using fluorescent light sources. These results may improve the use of OSLD in clinical practice for several applications in radiation therapy.
Funding Support, Disclosures, and Conflict of Interest: This work was funded by "Fondo Sectorial de Investigacion en Salud y Seguridad Social" of the National Council of Research and Technology (CONACYT) with the grant A3-S-37057.