Department of Radiation Biophysics, Research Institute for Radiation Biology and Medicine (RIRBM), Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551, Japan.
Phoenix Leader Education Program (Hiroshima Initiative) for Renaissance from Radiation Disaster, Hiroshima University, Kasumi 1-2-3 Minami-ku, Hiroshima 734-8553, Japan.
Biomed Phys Eng Express. 2024 Jul 9;10(5). doi: 10.1088/2057-1976/ad5cf8.
Gafchromic film, a commercially available radiochromic film, has been developed and widely used as an effective tool for radiation dose verification and quality assurance in radiotherapy. However, the orientation effect in scanning a film remains a concern for practical application in beam profile monitoring. To resolve this issue, the authors introduced a novel method using an overhead scanner (OHS) coupled with a tracing light board instead of a conventional flatbed scanner (FBS) to read Gafchromic EBT3 films. We investigated the orientation effect of the EBT3 film with a regular hexagonal shape after irradiation with 5 Gy x-rays (160 kV, 6.3 mA) and compared the digitized images acquired using a commercially available OHS (CZUR Aura) and a conventional FBS (EPSON GT-X980). As a result, RGB color intensities acquired from the OHS showed significantly lower orientation effect of the color intensities of RGB components than those from FBS. This finding indicates the high potential of the proposed method for achieving more precise two-dimensional dosimetry. Further studies are required to confirm the effectiveness of this method under different irradiation conditions over a wider dose range.
Gafchromic 膜是一种市售的放射性化学胶片，已被开发并广泛用于放射治疗中的辐射剂量验证和质量保证。然而，在扫描胶片时的取向效应仍然是在束流轮廓监测的实际应用中的一个关注点。为了解决这个问题，作者引入了一种新的方法，使用 overhead scanner (OHS) 结合 tracing light board 而不是传统的 flatbed scanner (FBS) 来读取 Gafchromic EBT3 胶片。我们研究了照射 5 Gy X 射线（160 kV，6.3 mA）后的具有规则六边形形状的 EBT3 胶片的取向效应，并比较了使用市售的 OHS (CZUR Aura) 和传统的 FBS (EPSON GT-X980) 获得的数字化图像。结果表明，从 OHS 获得的 RGB 颜色强度的取向效应明显低于从 FBS 获得的 RGB 分量的颜色强度。这一发现表明，该方法在更广泛的剂量范围内，在不同的照射条件下，实现更精确的二维剂量测定具有很高的潜力。需要进一步的研究来确认这种方法在更广泛的剂量范围内，在不同的照射条件下的有效性。
