Evaluation of the electrical properties of a lead (II) iodide based-dosimeter based on mechanical flexibility for surface dose measurements in radiotherapy

• Published in: Journal of instrumentation Vol. 15; no. 8; p. P08008
• Main Authors: Han, M.J., Yang, S.W., Jung, J.H., Heo, S.U., Kim, J.Y., Cho, S.J., Cho, H.L., Park, S.K.
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.08.2020
• Subjects: Electrical properties; Evaluation; Flexibility; Linearity; Radiation therapy; Unit cell
• ISSN: 1748-0221; 1748-0221
• DOI: 10.1088/1748-0221/15/08/P08008

In radiotherapy, point doses via surface dose measurement are confirmed using a dosimeter attached to the patient's skin. This results in an error margin of about 11.8% or higher because the attachment site is visually confirmed. Thus, a digital flexible array dosimeter that can analyse body surface area is needed. Here, a lead (II) iodide (PbI2)-based unit cell flexible dosimeter was developed, and its electrical properties were evaluated based on its mechanical flexibility by assessing its reproducibility and linearity for bending. The relative standard deviation (RSD) for measurement by the sensor over 10,000 cycles was 1.74% and 2.21% at 6 MV and 15 MV, respectively, which is higher than RSD's evaluation criterion (<1.5%). Although the linearity of measurement by the sensor over 10,000 cycles met the evaluation criteria of a coefficient of determination R2>0.9990, the sensitivity at 15 MV was lower than that at 6 MV. The results of this study confirm the applicability and usefulness of the PbI2-based flexible dosimeter in radiation measurements.