바로가기  >

이달의 연구자 바로가기 click

Abstract
Purpose: The aims of this study were to develop a flexible film dosimeter applicable to the irregular surface of a patient for in vivo dosimetry and to evaluate the device's dosimetric characteristics.

Methods: A flexible film dosimeter with active layers consisting of radiochromic-sensitive films and flexible silicone materials was constructed. The dose-response, sensitivity, scanning orientation dependence, energy dependence, and dose rate dependence of the flexible film dosimeter were tested. Irradiated dosimeters were scanned 24 h post-irradiation, and the region of interest was 5 mm × 5 mm. Biological stability tests ensured the safety of application of the flexible film dosimeter for patients. A preliminary clinical study with the flexible film dosimeter was implemented on four patients.

Results: The red channel demonstrated the highest sensitivity among all channels, and the response sensitivity of the dosimeter decreased with the applied dose, which were the same as the characteristics of GAFCHROMIC EBT3 radiochromic films. The flexible film dosimeter showed no significant energy dependence for photon beams of 6 MV, 6 MV flattening filter-free (FFF), 10 MV, and 15 MV. The flexible film dosimeter showed no substantial dose rate dependence with 6 or 6 MV FFF. In terms of biological stability, the flexible film dosimeter demonstrated no cytotoxicity, no irritation, and no skin sensitization. In the preliminary clinical study, the dose differences between the measurements with the flexible film dosimeter and calculations with the treatment planning system ranged from -0.1% to 1.2% for all patients.

Conclusions: The dosimeter developed in this study is a flexible film capable of attachment to a curved skin surface. The biological test results indicate the stability of the flexible film dosimeter. The preliminary clinical study showed that the flexible film dosimeter can be successfully applied as an in vivo dosimeter.

그림 . (a) 개발한 dosimeter의 구성 및 (b) 실험에 사용한 dosimeter의 크기, (c) 개발한 dosimeter를 적용한 예 및 (d) dosimeter의 단면도

Affiliations

Jin Dong Cho  1   2   3 , Jaeman Son  1   4 , Jiwon Sung  1   4 , Chang Heon Choi  1   2   4 , Jin Sung Kim  3 , Hong-Gyun Wu  1   2   4   5   6 , Jong Min Park  1   2   4   7 , Jung-In Kim  1   2   4
1 Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.
2 Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, 03080, Republic of Korea.
3 Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea.
4 Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea.
5 Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
6 Cancer Research Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
7 Robotics Research Laboratory for Extreme Environments, Advanced Institute of Convergence Technology, Suwon, 16229, Republic of Korea.