Radiation-responsive Nanosensor Gel (RaNG): A New way to Monitor Cancer Radiotherapy Doses
Presented By Subhadeep Dutta, Arizona State University Graduate Student
Radiotherapy using ionizing radiation (e.g. X rays) still remains a mainstay of treatment modalities in clinic for different types of cancers. Overexposure to radiation can induce toxicity and damage to healthy tissue, whereas underdosing can lead to poor efficacies of tumor ablation. Robust radiation sensors are in critical demand to ensure effective delivery of radiation to patients undergoing radiotherapy. Currently existing sensors possess several inherent limitations in rapid radiation detection because of their sensitivity to light and heat, fragility, long processing times, dose dependence, complexity of application process and / or high costs. Commonly used NanodotsTM require separate read-out devices, do not conform to tissue morphologies and are expensive as well. We developed a novel easy-to-use Radiation-responsive Nanosensor Gel (RaNG)-technology, based on the formation of maroon-colored gold nanoparticles from their colorless precursor formulations, with exposure to different levels of ionizing radiation. By measuring the intensity of color developed with a simple bench-top absorbance spectrophotometer, we were able to precisely detect doses typically administered in fractional cancer radiotherapy (i.e. ranging from 0-5Gy) and beyond. Topographical distribution of delivered radiation doses was qualitatively and quantitatively determined and efficacy of the hydrogel sensor was validated using different ionizing radiation sources including protons, electrons, photons and radioactive isotopes. Translational capability of the nanosensor was demonstrated using anthropomorphic phantoms and in live canine patients undergoing clinical radiotherapy treatments (in collaboration with Banner MD Anderson Cancer Center). Our results manifest a new generation of low-cost nanosensor for colorimetric detection of radiation dose to improve patient safety in clinical radiotherapy and trauma care.