Ruthenium-106 (¹⁰⁶Ru) plaques are specific applicators dedicated for intraocular brachytherapy. Small tumor volume and presence of vital organs in its close vicinity as well as appearance of very high dose gradient regions around the employed plaques cause unique challenges in plaque-based brachytherapy. Therefore, access to 3D dose distribution for each brachytherapy plaque is quite helpful to decide about tumor volume coverage and overexposure of surrounding sensitive organs. Current study aims to measure the 3D dose distribution for two commercially available ¹⁰⁶Ru plaques using film dosimetry.

COB (a notched-shape plaque) and CGD (a fully circular plaque) ¹⁰⁶Ru plaques were used and dose distributions in different planes were measured by simultaneously employing a 3D printed eyeball phantom and Gafchromic EBT3 films. Finally, 3D dose distributions were acquired by interpolating the measured 2D dose data at different planes.

The results showed that employing the COB plaque tilts the isodose curves toward the non-notched edge of the plaque, while no isodose tilting was observed for CGD plaque. The obtained 3D dose distributions were different for studied plaques. Non-uniform 3D dose distributions were found for both plaques which can be attributed to the plaque design and reference point position on plaque central axis.

Finally, it can be concluded that the obtained 3D dose distributions can specify the optimal tumor shape which can be adequately covered by brachytherapy plaque with minimizing the dose non-uniformity and hot point formation inside the treated volume. Obtained 3D dose distribution for each plaque can be employed for patient treatment planning.

Ruthenium-106 ( ¹⁰⁶ Ru) 斑块是专用于眼内近距离放射治疗的特定涂药器。小肿瘤体积和在其附近存在重要器官以及在所用斑块周围出现非常高的剂量梯度区域对基于斑块的近距离放射治疗提出了独特的挑战。因此，获得每个近距离放射治疗斑块的 3D 剂量分布对于决定肿瘤体积覆盖和周围敏感器官的过度暴露非常有帮助。目前的研究旨在使用胶片剂量测定法测量两个市售¹⁰⁶ Ru 斑块的 3D 剂量分布。

使用 COB（缺口形斑块）和 CGD（全圆形斑块）¹⁰⁶ Ru 斑块，并通过同时使用 3D 打印眼球模型和 Gafchromic EBT3 薄膜测量不同平面中的剂量分布。最后，通过在不同平面插入测量的 2D 剂量数据来获得 3D 剂量分布。

结果表明，使用 COB 斑块使等剂量曲线向斑块的无缺口边缘倾斜，而未观察到 CGD 斑块的等剂量倾斜。对于所研究的斑块，获得的 3D 剂量分布是不同的。发现两个斑块的 3D 剂量分布不均匀，这可归因于斑块设计和斑块中心轴上的参考点位置。

最后，可以得出结论，获得的 3D 剂量分布可以指定最佳肿瘤形状，该形状可以被近距离放射治疗斑块充分覆盖，同时最大限度地减少治疗体积内的剂量不均匀性和热点形成。获得的每个斑块的 3D 剂量分布可用于患者治疗计划。