Vision-based radiochromic film densitometer: setup and uncertainty analysis for its potential clinical usage

In this research, an alternative radiochromic film readout system based on computer vision was instrumented with a commercial camera and a 6500 K temperature light-emitting diode. This arrangement works in transmission mode as the standardized flatbed scanner used in clinical dosimetry tasks. Scanner was employed as a reference to compare the optical density response. Nine 3× 3 cm 2 samples of EBT3 film were irradiated within a dosimetric range from 0 to 15 Gy taking a 100-pixel region of interest from each one for noise, optical density uncertainty, and reproducibility analysis for the three colour components. The densitometer prototype has a better response to optical density, 43% more sensitivity than the scanner in all channels, and a maximum of 0.93 for the red one; the best noise rejection is in the green component. However, the noise and lowest total uncertainty results are found in the scanner. Future work must focus on noise reduction and the robustness of the opto-electronic instrumentation to enhance the long-term reproducibility of the prototype.