• 한국의학물리학회지:의학물리
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• 제14권4호
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• pp.249-258
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• 2003

흡수선량 측정의 정확성을 향상시키기 위하여 기존의 공기커마 혹은 조사선량 표준에서 물 흡수선량 표준으로 선량측정의 패러다임이 변화하고 있다. 본 연구는 기존의 프로토콜에서 물 흡수선량 기반의 프로토콜로의 전환을 모색하는 입장에서 현재 임상에서 널리 사용하고 있는 IAEA TRS­277과 물 흡수선량 표준에 토대를 두고 있는 IAEA TRS­398 및 AAPM TG­51 프로토콜에 대하여 동일한 기준깊이에서 물 흡수선량을 측정하여 상호 비교하였다. Varian 2100 C/D 선형가속기로부터의 세 종류의 전자선 에너지에 대해 PTW 30002 원통형 이온함과 Markus 및 Roos 평행평판형 이온함을 사용하여 측정하였고 $^{60}$Co에서의 공기커마 및 물 흡수선량 교정정수는 식품의약품안전청으로부터 받아 사용하였다. 공기커마 표준에 기반한 프로토콜과 물 흡수선량 표준에 기반한 프로토콜간에는 2% 이내의 차이를 보임으로써 사용자 기관에서는 자체적인 확인을 거쳐 공기커마 기반의 프로토콜에서 물 흡수전량 기반 프로토콜로의 전환을 적극 검토해 볼 필요가 있다. 물 흡수선량 기반의 프로토콜간에는 원통형 이온함의 경우 0.5% 이내에서 잘 일치하였고 평행평판형 이온함의 경우에도 고 에너지 전자선을 이용한 교차 교정을 하면 0.7% 이내에서 잘 일치하였다. 사용한 모든 프로토콜과 전자선 에너지에 대해 원통형 이온함과 평행평판형 이온함간에는 2% 이내의 차이를 보였으나 선량측정의 정확성을 향상시키기 위해 물 흡수선량 표준에 기반한 프로토콜의 권고에 따라서 하한에너지 이하의 전자선의 경우는 원통형 이온함 대신에 평행평판형 이온함을 사용함이 타당하다고 사료된다.

• 한국의학물리학회지:의학물리
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• 제33권4호
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• pp.72-79
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• 2022

Purpose: The proficiency test was conducted to assess the performance of the dosimetry audit service provider in the readout practice of the dose delivered to patients in medical institutions. Methods: A certain amount of the absorbed dose to water for the high-energy X-ray from the medical linear accelerator (LINAC) installed in the Korea Research Institute of Standards and Science (KRISS) was delivered to the postal dose audit package given by the dosimetry audit service provider, in which the radio-photoluminescence (RPL) glass dosimeters were mounted. The dosimetry audit service provider read the RPL glass dosimeters and sent the readout dose value with its uncertainty to KRISS. The performance of the dosimetry audit service provider was evaluated based on the E_n number given in ISO/IEC 17043:2010. Results: The evaluated E_n number was -0.954. Based on the ISO/IEC 17043, the performance of the dosimetry service provider is "satisfactory." Conclusions: As part of the conformity assessment, the KRISS performed the proficiency test over the postal dose audit practice run by the dosimetry audit service provider. The proficiency test is in line with confirming the traceability of the medical institutions to the primary standard of absorbed dose to the water of the KRISS and ensuring the confidence of the dosimetry audit service provider.

• 치과방사선
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• 제29권1호
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• pp.255-260
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• 1999

Purpose: The objective of this study was to evaluate the possibility of substitution of the zonography for the full-mouth periapical radiography in aspect of radiation protection. Materials and Methods: Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses at brain, skin above the TMJ. parotid gland. bone marrow in the mandibular body. and thyroid gland during the full-mouth periapical radiography. panoramic radiography. and zonography were measured. Resul ts: From the zonography. the absorbed doses to the brain. the skin over the TMJ. and the parotid gland were relatively high. but the absorbed doses to the bone marrow in the mandibular body and. especially. the thyroid gland were very low. Conclusion: The zonography can be an alternative to the full-mouth periapical radiography in aspect of radiation protection.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1265-1268
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• 2023

One important issue in using radiopharmaceuticals as therapeutic and imaging agents is predicting different organ absorbed dose following their injection. The present study aims at extrapolating dosimetry estimates to a female phantom from the animal data of ⁸⁹Zr radionuclide accumulation using the Sparks-Idogan relationship. The absorbed dose of ⁸⁹Zr radionuclide in different organs of the human body was calculated based on its distribution data in mice using both MIRD method and the MCNP simulation code. In this study, breasts, liver, heart wall, stomach, kidneys, lungs and spleen were considered as source and target organs. The highest and the lowest absorbed doses were respectively delivered to the liver (4.00E-02 and 3.43E-02 mGy/MBq) and the stomach (1.83E-03 and 1.66E-03 mGy/MBq). Moreover, there was a good agreement between the results obtained from both MIRD and MCNP methods. Therefore, according to the dosimetry results, [⁸⁹Zr] DFO-CR011-PET/CT seems to be a suitable for diagnostic imaging of the breast anomalies for CDX-011 targeting gpNMB in patients with TNBC in the future.

• Imaging Science in Dentistry
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• 제30권1호
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• pp.11-15
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• 2000

Purpose: The primary objective of this study was to estimate the radiation absorbed doses in certain critical organs in the head and neck region with an Orthopos plus, a Panelipse, and a Panex-E machines. The second objective was to compare the absorbed doses between 5 inch by 12 inch and 6 inch by 12 inch image field for the Orthopos plus. Materials and Methods: Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses were measured at the thyroid gland, the submandibular gland, the parotid gland, the mouth floor, the maxillary sinus, the brain, the mandibular body, the mandibular ramus, the 2nd cervical spine and the skin over TMJ area. Results: The highest absorbed dose value was recorded at the mandibular ramus for the Orthopos plus with narrow image field. Higher absorbed dose values were recorded at the parotid gland, the mouth floor, the submandibular gland, and the 2nd cervical spine. The doses in the parotid gland were 597 μGy and 529 μGy with Orthopos plus, 638 μGy with Panelipse, and 1094μGy with Panex-E. Corresponding figures for the mandibular ramus were 2363 Gy and 1220 μGy, 248 μGy, and 118 μGy. The absorbed doses to the thyroid gland, the maxillary sinus, the brain, and the skin over TMJ were very low. Conclusion: Higher exposure values were recorded for the Orthopos plus than Panelipse and Panex-E. There was no significant differences of the absorbed doses according to the image field size.

• 한국의학물리학회지:의학물리
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• 제14권3호
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• pp.175-183
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• 2003

최근 선량측정의 정확성을 향상시키기 위하여 기존의 공기커마 교정인수에 기반한 표준측정법에서 물 흡수선량 교정인수에 기반한 표준측정법으로 변환하고 있는 추세이다. 본 연구에서는 미국의학물리학회의 AAPM TG-51과 국제원자력기구의 IAEA TRS-398 표준측정법에 대한 선량교정 프로그램을 개발하였다. 이 프로그램은 윈도우 환경에서 사용이 용이하도록 비쥬얼 C++언어를 사용하여 각각의 표준측정법에서 권고하고 있는 방법 및 절차에 따라 사용자의 편의성을 고려하여 개발하였다. 이 프로그램은 이온함에 대한 정보와 물리적인 자료에 대한 표와 그래프 값들을 수식화하여 데이터베이스화함으로써 수작업으로 인해 발생할 수 있는 실수 및 오차를 줄일 수 있다. 개발된 프로그램의 활용을 통하여 국내 실정에 적합한 물 흡수선량 표준에 기반한 표준측정법 개발에 토대를 마련하는데 있어 기여할 것으로 사료된다.

• Imaging Science in Dentistry
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• 제31권4호
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• pp.215-219
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• 2001

Purpose: The objective of this study was to estimate the radiation absorbed doses in certain critical organs in the head and neck region with 16 imaging programs available on the Orthopos/sup (R)/ panoramic machine. Materials and Methods: A Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses were measured at the thyroid gland, the submandibular gland, the parotid gland, the mouth floor. the maxillary sinus, the brain, the mandibular body, the mandibular ramus. the 2nd cervical spine and the skin over TMJ area. Results : The overall absorbed doses with imaging programs available on the Orthopos/sup (R)/ panoramic machine were much less than that of standard program (program 1) except program 8, 11, and 16. Generally, the absorbed doses to the bone marrow of the mandibular ramus and the parotid gland were high, but the absorbed doses to the bone marrow in the mandibular body, brain, maxillary sinus, and, especially, the thyroid gland were very low. Conclusion : The modified imaging programs available on the Orthopos/sup (R)/ panoramic machine can be effectively used in aspect of radiation protection.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.519-525
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• 2018

Obtaining knowledge of the absorbed dose up-taken by a certain material when it is exposed to a specific ionizing radiation field is a very important task. Even though there are a plenitude of methods for determining the absorbed dose, each one has its own strong points and also drawbacks. In this article, an innovative idea for the development of a new gamma-ray dosimetry system is proposed. The method described in this article is based on optical colorimetry techniques. A color standard is fixed to the back of a BK-7 glass plate and then placed in a point in space where the absorbed dose needs to be determined. Gamma-ray-induced defects (color centers) in the glass plate start occurring, leading to a degree of saturation of the standard color, which is proportional, on a certain interval, to the absorbed dose. After the exposure, a high-quality digital image of the sample is taken, which is then processed (MATLAB), and its equivalent $I_{RGB}$ intensity value is determined. After a prior corroboration between various well-known absorbed dose values and their corresponding $I_{RGB}$ values, a calibration function is obtained. By using this calibration function, an "unknown" up-taken dose value can be determined.

• 한국의학물리학회지:의학물리
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• 제16권3호
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• pp.116-124
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• 2005

고 에너지 광자선과 전자선의 흡수선량 결정에 대한 표준측정법은 공기커마 교정인수를 바탕으로 한 방법이 널리 사용되고 있으나 복잡한 수식과 물리적인자의 불확실성 등으로 정확도 향상에 한계가 있다. 따라서 최근 국제원자력기구와 미국의학물리학회에서 물 흡수선량을 기반으로 표준측정법을 개발하였다. 본 연구는 국제원자력기구의 IAEA TRS-398 과 미국의학물리학회의 AAPM 7e-51 물 흡수선량 표준측정법에 대한 인터넷을 기반으로 하는 선량교정 프로그램을 개발하였다. 이 프로그램은 인터넷 온라인상에서 사용할 수 있도록 C$\#$ 언어를 사용하여 각각의 표준측정법의 절차에 따라 사용자의 편의를 고려하여 개발하였다. 사용자는 인터넷을 통해 기준점에서의 두 가지 절차서에 따른 물 흡수선량을 비교할 수 있으며, 국내 각 기관에서 수행된 선량교정의 추세를 이해하고 보다 쉽게 관리할 수 있게 하였다. 웹 기반 데이터베이스를 이용하여 차후 국내 실정에 적합한 물 흡수선량 표준에 기반을 둔 표준측정법을 개발하는데 기여할 것으로 기대된다

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3018-3025
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• 2021

The authors developed a volumetric dosimetry detector system using in-house 3D-printable plastic scintillator resins. Three tumor model scintillators (TMSs) were developed using magnetic resonance images of a tumor. The detector system consisted of a TMS, an optical fiber, a photomultiplier tube, and an electrometer. The background signal, including the Cherenkov lights generated in the optical fiber, was subtracted from the output signal. The system showed 2.1% instability when the TMS was reassembled. The system efficiencies in collecting lights for a given absorbed energy were determined by calibration at a secondary standard dosimetry laboratory (k_SSDL) or by calibration using Monte Carlo simulations (k_sim). The TMSs were irradiated in a Gamma Knife® Icon^TM (Elekta AB, Stockholm, Sweden) following a treatment plan. The energies absorbed to the TMSs were measured and compared with a calculated value. While the measured energy determined with k_SSDL was (5.84 ± 3.56) % lower than the calculated value, the energy with k_sim was (2.00 ± 0.76) % higher. Although the TMS detector system worked reasonably well in measuring the absorbed energy to a tumor, further improvements in the calibration procedure and system stability are needed for the system to be accepted as a quality assurance tool.