The purpose of this study was to investigate the two dimensional (2D) and three dimensional (3D) radiotherapy dosimetric properties of PRESAGE® dosimeter using an in-house optical computed tomography (OCT) imaging system known as 3DmicroHD-OCT. Dosimetric properties for verification of intensity-modulated radiation therapy (IMRT) treatment technique were studied including dose linearity, dose integration, dose rate dependence and the percentage depth dose analysis. Nine cylindrical PRESAGE® of 5 cm diameter × 5 cm height were irradiated at 6 MV photon beam with different field geometry for the dose range of 0.1–15 Gy. We also irradiated PRESAGE® in the cuvette for UV–Vis analysis for the same dose range to verify the optical density value measured by the 3DmicroHD-OCT imaging system. The irradiation was repeated with EBT film dosimetry for the 2D analysis validation. The study shows that the optical density change increases as dose deposition increases on PRESAGE®, with R² value better than 0.988. The same response was also recorded when multiple beam was integrated for the dose range investigated. The dose linearity result is consistent with the results obtained from UV–Vis spectrometry. It was also found that the dose rate variation does not affect the optical density change over the dose range investigated. PDD analysis of the PRESAGE® dosimeter investigated shows a good agreement with the ion chamber measurement. In summary, the study shows accurate 3D and 2D measurements of PRESAGE® and EBT film dosimeter were obtained using the 3DmicroHD-OCT imaging system. It shows potential for intensity-modulated radiation therapy (IMRT) treatment verification.

本研究的目的是使用称为 3DmicroHD-OCT 的内部光学计算机断层扫描 (OCT) 成像系统研究 PRESAGE® 剂量计的二维 (2D) 和三维 (3D) 放射治疗剂量特性。研究了用于验证调强放射治疗 (IMRT) 治疗技术的剂量学特性，包括剂量线性、剂量积分、剂量率依赖性和百分比深度剂量分析。9 个直径为 5 cm × 5 cm 高的圆柱形 PRESAGE® 以 6 MV 光子束照射，具有不同的场几何形状，剂量范围为 0.1-15 Gy。我们还在比色皿中照射 PRESAGE® 以进行相同剂量范围的 UV-Vis 分析，以验证 3DmicroHD-OCT 成像系统测量的光密度值。使用 EBT 胶片剂量测定重复照射以进行 2D 分析验证。研究表明，随着 PRESAGE® 上剂量沉积的增加，光密度变化增加，R²值优于 0.988。当针对所研究的剂量范围整合多光束时，也记录了相同的响应。剂量线性结果与从紫外-可见光谱法获得的结果一致。还发现剂量率变化不影响所研究剂量范围内的光密度变化。所研究的 PRESAGE® 剂量计的 PDD 分析显示与离子室测量结果非常吻合。总之，该研究表明，使用 3DmicroHD-OCT 成像系统获得了 PRESAGE® 和 EBT 胶片剂量计的准确 3D 和 2D 测量值。它显示了调强放射治疗 (IMRT) 治疗验证的潜力。