Author: Parminder S. Basran, Wyatt Flanders, Skylar Sylvester 👨🔬
Affiliation: Cornell University 🌍
Purpose: To develop a reliable, efficient, and low-cost methodology for quantifying radiation doses using radiochromic film and a custom-built lightbox and to evaluate the system's performance compared to traditional flatbed scanners.
Methods: A light box was constructed with two diffusers to ensure uniform illumination of radiochromic film after irradiation. The film was placed on the second diffuser, and calibration strips with known dose levels were used to correlate film color changes with radiation dose. The films were photographed with a Sony Alpha 6400 camera. A mathematical model, Dose = 𝐴 / [𝐶 + (Red or Green) − Blue] + 𝐵, was used for dose calibration, fitting the measured color data to determine the relationship between color intensity and dose. The calibrated model was then applied to assess the radiation doses delivered to other films imaged under identical conditions. The lightbox system was tested against traditional flatbed scanners to evaluate its uniformity, reproducibility, and ability to eliminate common artifacts like vertical striations.
Results: The calibration method demonstrated superior uniformity and reproducibility compared to traditional scanner-based dosimetry. The lightbox system eliminates vertical striations and non-uniformities resulting from internal light reflections observed in flatbed scanners, providing a more accurate representation of the radiation dose delivered to the film. The dose calibration model yielded reliable and high-resolution results, with strong correlations between film color changes and known dose levels.
Conclusion: This work presents a novel approach to radiation dose measurement that offers improved accuracy and reproducibility over traditional methods at a fraction of the cost of expensive flatbed scanners. The use of the custom-built light box and the proposed calibration model provides a practical, artifact-free alternative to scanner-based dosimetry, which holds the potential to enhance dosimetry in clinical and research applications.