Validation of a 3D-printed anthropomorphic eye phantom for quality assurance in external beam radiotherapy using TLD and radiochromic film.

External beam radiation therapy (EBRT) is widely used for uveal melanoma to preserve the eye and achieve effective tumor control. However, late side effects remain a concern, reinforcing the need for dose reduction to mitigate long-term toxicity. This study aims to validate a 3D-printed ocular tissue-equivalent anthropomorphic phantom, with enhanced anatomical accuracy based on the Alderson Radiation Therapy Phantom, through end-to-end dosimetric analysis using radiochromic film and thermoluminescent dosimeters (TLDs) for research and quality assurance (QA) applications in EBRT. Gafchromic EBT3 films and LiF:Mg,Ti microcube TLDs were used for dose assessment in target volume and organs at risk (OAR). Calibration and irradiation were performed using a Varian Clinac iX and a TrueBeam linear accelerator with a 6 MV photon beam. Film dosimetry, with films positioned in axial and oblique planes, was processed using the Film2Dose software and compared to the Varian Eclipse® treatment planning system (TPS) via gamma analysis. For TLD analysis, lower limit of detection verification, reproducibility tests, individual calibration, and cone beam computed tomography (CBCT) dosimetry were made prior to the treatment dosimetry to ensure accuracy. For treatment dosimetry, TLD samples were placed in regions of interest (i.e. lens, eye fundus, PTV, and optic nerve) for point dose verification and compatibility analysis against the TPS. In the film analysis, maximum dose uncertainties of up to 16% were observed in low-dose regions (<10% of prescribed dose). Gamma analysis yielded a mean passing rate of 100% for 2%/2 mm/10% threshold criterion. All TLDdose measurements demonstrate statistical compatibility with TPS predictions using Z-score-based compatibility analysis. Uncertainties below 5% were found in experimental measurements and TPS point dose assessment. These results indicate the robustness of the dosimetric methods employed and support the validation of the developed 3D-printed, tissue-equivalent anthropomorphic ocular phantom for research and quality assurance applications in EBRT.