Radiation therapy is a vital fortreatment of cancers and forms the part of first line of treatment in > 30% of patients in the United States.Radiotherapy involves delivery of the high-energy radiations to the tumors; however, the mechanism of cell killing is not tumor specific leading to substantial morbidity by exposure of normal tissues to excessive radiation doses. Thus, to maximize the therapeutic outcomes and reduce the radiation-associated toxicities demands selective and precise delivery of the radiation doses in patients sparing the healthy tissue. The advances in external-beam and image-guided such as MR/CT-guided radiation therapy provides high-precision dose delivery and real-time knowledge of the target volume location for effective treatment. However, these procedures are expensive, time intensive, and not patient compliant. Thus, there is a need for the development of guided radiation therapy methods with potential for clinical translation. Our study focuses on the development of fluorescence dye based dosimeters for guided delivery of optimum radiation doses for the treatment of cancers. The radiosensitive dyes can undergo degradation and can be used as an indicator for radiation doses. We screened Fluorescein and cyanine dyes for their sensitivity to radiation exposures by measuring the fluorescence and absorbance changes using IVIS and spectrophotometer, respectively. Our preliminary results suggested that Indocyanine green (ICG), an FDA-approved dye was most responsive to the radiations. Looking ahead, this study marks just the initial step in a broader research process, with the next phase involving animal testing to evaluate sensitive of the ICG in physiological settings in tumor models. Overall, the sensitivity of ICG to radiation can be employed for guiding the administration of precise radiation doses and ensuring complete irradiation of the target tissue for improved treatment outcomes.