Interventional radiology (IR) procedures are widely performed and play important roles in achieving minimally-invasive treatment and diagnosis [1,2]. During IR procedures, medical staff are exposed to scattered X-rays, and therefore it is required to reduce their occupational radiation doses. In order to monitor the radiation dose of medical staff, personal dosimeters are generally used [3,4]. These commercial dosimeters were developed to measure the amount of the exposure dose, but it is well known that their angular dependences are not negligibly small as represented in Fig....

[A concept of a novel triple-type dosimeter] [Fig 2] Figure 2 shows the concept of our triple-type dosimeter. It consists of three active-type dosimeters (RaySafe i2, Unfors RaySafe, Billdal, Sweden) [9]. In order to derive the incident angle, two dosimeters 1 and 2 having titanium-sloped filters are placed side by side; the dosimeter was shielded with lead, and incident X-rays are affected by different X-ray attenuations in sloped filters for creating enlarged angular dependence. As shown by the dashed ellipses in Fig. 2, the responses...

[Fig 6] Figure 6 shows the measured results of the angular dependence of a triple-type dosimeter. They correspond to the dashed ellipses in Fig. 1. As shown in Figs. 6(a) and (b), different trends were observed between dosimeters 1 and 2 due to the titanium-sloped filter. It was found that the design of these dosimeters could achieve the concept proposed in this study. The response value of dosimeter 3 was constant in the range of -40 to +40 degrees, and a large variation was observed...

In this study, we investigated the development of a novel active-type dosimeter which can derive the incident angle and absolute dose of X-rays during IR procedures. We hope that our method will help reduce the occupational exposure dose for medical staff.

T. Asahara: Nothing to disclose H. Hayashi: Nothing to disclose T. Maeda: Nothing to disclose S. Goto: Nothing to disclose D. Kobayashi: Nothing to disclose C. Lee: Nothing to disclose Y. Kanazawa: Nothing to disclose N. Maeda: Nothing to disclose M. Honda: Nothing to disclose

Cazzato RL, De Marini P, Leonard-Lorant I, et al. Percutaneous thermal ablation of sacral metastases: Assessment of pain relief and local tumor control. Diagn Interv Imaging. 2021;102(6): 355-361. doi:10.1016/j.diii.2020.12.008 Matsui Y, Iguchi T, Tomita K, et al. Radiofrequency Ablation for Stage I Non-Small Cell Lung Cancer: An Updated Review of Literature from the Last Decade. Interv Radiol. 2020;5(2): 43-49. doi:10.22575/interventionalradiology.2020-0007 Yamashita K, Higashino K, Hayashi H, et al. Pulsation and Collimation During Fluoroscopy to Decrease Radiation: A Cadaver Study. JBJS Open Access. 2017;2(4): e0039. doi:10.2106/jbjs.oa.17.00039...