Abu Mhanna Hamad Yahia, Omar Ahmad Fairuz, Radzi Yasmin Md, Akhdar Hanan Fawaz, Al Ewaidat Haytham
School of Physics, Universiti Sains Malaysia, Penang 11800, Malaysia.
Physics Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 13318, Saudi Arabia.
Materials (Basel). 2022 Apr 15;15(8):2903. doi: 10.3390/ma15082903.
The aim of this study is to compare the optical responses of external beam therapy 3 (EBT3) films exposed to X-rays and solar ultraviolet rays (SUV-rays), as a dose control technique in the clinical sector for various radiation types, energies, and absorbed doses up to 4 Gy. In this study, EBT3 films with three different expiry dates were prepared and cut into pieces of size 2 by 2 cm. The first group was exposed to 90 kVp X-rays, while the second group was exposed to the SUV-rays at noon. The analysis was performed using a visible Jaz spectrometer and an EPSON Perfection V370 Photo scanner to obtain the absorbance, the net reflective optical density (ROD) and the red-green-blue (RGB) values of the samples. The results have shown that spectroscopic measurements of the exposed expired EBT3 films with these radiation sources are able to produce primary peaks and secondary peaks at λ = 641.74 nm and λ = 585.98 nm for X-rays, and at λ = 637.93 nm and λ = 584.45 nm for SUV-rays, respectively. According to these findings, compared to 2021 films that expired shortly before the trial start date; 2018 films responded better to the absorbed dose than 2016 films when exposed to both X-ray and SUV-rays. In terms of energy dependence, the expired EBT3 2018 had the largest net ROD value. Using Lab* indices extracted from the RGB data, and despite that EBT3 films have expiry dates according to the manufacturer; all the films exhibited a substantial colour change, indicating that these films are still usable for clinical and research purposes.
本研究的目的是比较外照射放疗3（EBT3）胶片在接受X射线和太阳紫外线（SUV射线）照射后的光学响应，作为临床领域针对各种辐射类型、能量以及高达4 Gy吸收剂量的剂量控制技术。在本研究中，制备了三个不同有效期的EBT3胶片，并切成2×2 cm大小的片。第一组暴露于90 kVp的X射线下，而第二组在中午暴露于SUV射线下。使用可见Jaz光谱仪和爱普生Perfection V370 Photo扫描仪进行分析，以获得样品的吸光度、净反射光密度（ROD）和红-绿-蓝（RGB）值。结果表明，用这些辐射源照射过期的EBT3胶片进行光谱测量时，对于X射线，能够在λ = 641.74 nm和λ = 585.98 nm处产生主峰和次峰，对于SUV射线，能在λ = 637.93 nm和λ = 584.45 nm处产生主峰和次峰。根据这些发现，与在试验开始日期前不久过期的2021年胶片相比；当暴露于X射线和SUV射线时，2018年的胶片比2016年的胶片对吸收剂量的响应更好。在能量依赖性方面，过期的2018年EBT3胶片的净ROD值最大。使用从RGB数据中提取的Lab*指数，尽管根据制造商的规定EBT3胶片有有效期；但所有胶片都表现出显著的颜色变化，表明这些胶片仍可用于临床和研究目的。
