Room: Karl Dean Ballroom A1
Purpose: High dose gradient characteristic of the brachytherapy makes in vivo dosimetry challenging.To address this, we have developed a novel nanotechnology based gel dosimeter that changes color upon incidence of ionizing radiation.
Methods: The gel dosimeter contains monovalent gold ions which are converted to zerovalent gold atoms by ionizing radiation. These gold nanoparticles have a characteristic pink/maroon color which can be used to quantify radiation exposure via a basic spectrophotometer. The 1 mm thick gels are placed uniformly onto the caps of Valencia and Leipzig applicators and irradiated to prescription dose.
Results: This intensity of color change corresponds to the intensity of radiation dose delivered to the patientâ€™s surface. The gel response to radiation dose is linear from 100 cGy to 800 cGy which is the typical dose range for HDR skin brachytherapy.
Conclusion: This study concludes that the nanotechnology based gel is a promising and reliable dosimeter for skin HDR in vivo dosimetry with clinically acceptable accuracy. In vivo gel dosimetry provided a true dose spectrum across the surface of the applicators. This novel method holds great promise in the field of HDR Brachytherapy.