장비정도관리에 Calibrator[I-125] Set 적용

김지나,안재석,원우재,Kim, Ji-Na,An, Jae-seok,Won, Woo-Jae 대한핵의학기술학회 2015 핵의학 기술 Vol.19 No.2

Purpose Lately, in accordance with the increasing interest about Healthcare accreditation program and International laboratory accreditation scheme, requirements about the instrument quality management are gradually taking shape. In nuclear medicine In vitro laboratory, the most typical instruments are multi detector gamma counter and automatic dispensing system. Each laboratory continue with the quality control adequate for circumstances. The purpose of this study is to application and establish the new Calibrator[I-125]Set which is efficient at standardization of equipment quality management. Materials and Methods Deviation between detectors were measured with 12 solid samples of the Calibrator[I-125]Set. their activities differ from each other by less than 1%. Multi detector gamma counters are GAMMA-10;Shinjin medics. Inc, Goyansi, Korea(Gamma counter A), SR300;Stratec biomedical systems AG, Gewerbestr, Germany(Gamma counter B) and COBRA II; Packard Instrument Co. Inc, Meriden, USA(Gamma counter C). Evaluation of two automatic dispensing system used A, B liquid tracer of the Calibrator[I-125]Set. After dispensing and counting, calculated using the ratio of the measured value and proposed value. We used solution A for 20, 25ul and solution B for 50, 100ul. Method of data analysis and reference range was provided by kit documentation. Furthermore, we could calculate our counter efficiency indirectly. Results The CV(%) of measured values by Gamma counter A, B, C are 0.34, 0.70, 1.30. Calculated value are 1.05314, 2.10419, 4.08485. Provided reference range is less than 3. A dispensing system's calculated values are 0.986, 0.989, 1.023, 1.017 and B are 0.874, 0.725, 1.021, 0.904. Provided reference range is from 0.95 to 1.05. Also, counter's efficiency are 74.18, 72.79, 74.32% at counter A, B, C and efficiency of the one detector counter is 79.26%. Conclusion If using this Calibrator[I-125]Set after verifying whether quality assurance, is applicable to equipment quality management on behalf of the role of gold standard.

Thyrogen 투여 후 측정된 Thyroglobulin 농도변화

김지나,안재석,원우재,Kim, Ji-Na,An, Jae-seok,Won, Woo-Jae 대한핵의학기술학회 2018 핵의학 기술 Vol.22 No.1

Purpose Assessment of Serum Thyroglobulin (sTg) value in total thyroidectomy patients having an ablation dose of radioactive iodine indicates remaining cancer or metastasis. Especially, sTg in patients on withdrawal thyroxine or thyrogen administration for radioiodine ablation is an important indicator to determine the direction of further treatment and prognosis. Current guidelines suggest measurement of sTg is performed at 72 hours after the last injection of thyrogen. and assumes that sTg reaches maximum serum levels at that time. The purpose of this study is to evaluate the variation of sTg measured after thyrogen administration. Materials and Methods We compared with sTg performed at 24hours(D0) and 72hours(D2) after the last injection of thyrogen. We reviewed D0 and D2 from 276 patients were divided them into three groups according to ablation dose of radioactive iodine, 5mCi(A group), 30~80mCi(B group) and 100~200mCi(C group). We used T-test for comparison between D0 and D2. sTg was measured in serum using immunoradiometric assay (Tg-plus RIA; BRAHMS, Berlin, Germany). Results There is no critical variation between D0 and D2 in A group(n=100)(P=0.32), The case of increase(D2>D0) is 45, no change(D2=D0) is 23, decrease(D2<D0) is 32. The biggest increase is the 3.0 ng/mL from 2.9 to 5.9 in A group. In B group(n=155, 30mCi:154, 80mCi:1), the difference is meaningful(P<0.05) and D2>D0 is 91, D2=D0 is 28, D2<D0 is 36. The biggest increase is 2.6 ng/mL from 3.5 to 6.1. In C group(n=21, 100mCi:19, 200mCi:2), D2>D0 is 19, D2=D0 is 2. The biggest increase is 143.6 ng/mL from 98.4 to 242. Conclusion There was a significant difference in the group over 30mCi. and the case of D2>D0 is 45%, 58.7%, 90.5% for each group. therefore, D2 increased as the dose of radioactive iodine increased. Furthermore, the most sTg values of D0 and D2 are variation under 2.0 ng/mL, so reproducibility as well as sensitivity of sTg will be important at values below 2ng/mL.

갑상선암에서의 혈중 Thyroglobulin 농도와 침생검 검체 Washout Solution의 Thyroglobulin 농도와의 상관관계

안재석,김지나,원우재,An, Jae-Seok,Kim, Ji-Na,Won, Woo-Jae 대한핵의학기술학회 2009 핵의학 기술 Vol.13 No.3

목적: 혈중 thyroglobulin 농도 측정(혈중 TG)은 갑상선암 수술 후 재발 및 전이여부를 판단하는데 중요한 지표이다. 최근엔 혈중 TG와 함께 침생검 검체의 washout solution을 이용한 TG 농도 측정(washout TG)이 추적 검사에 빈번히 사용되고 있다. 본 연구는 혈중 TG와 washout TG간에 어떠한 연관성이 있는지 알아보고자 한다. 대상 및 방법: 2007년 1월부터 2008년 2월까지 국립암센터에 내원한 갑상선암 환자 중 washout TG 와 혈중 TG를 함께 측정한 47명 중 혈중 Anti-Tg Ab 양성(${\geq}$100 U/mL)인 환자 6명을 제외한 41명을 대상으로 하였다. 혈중 TG와 washout TG와 세포검사결과와의 연관성도 조사하였다. 결과 및 결론: Washout TG는 혈중 TG보다 현저하게 높았으며 두 경우의 검사결과 간에 유의한 차이를 보였다(p=0.0394). washout TG와 세포검사결과와의 일치도는 87.8%, 혈중 TG와의 일치도는 56.1%였다. washout TG가 양성인 경우는 28명(세포검사결과 양성: 24, 양성의심: 4), 음성인 경우는 13명(세포검사결과 양성의심: 1, 음성: 12)이었다. serum TG가 양성인 경우는 26명(세포검사결과 양성: 17, 양성의심: 3, 음성: 6), 음성인 경우는 15명(세포검사결과 양성: 8, 양성의심: 1, 음성: 6)이었다. 갑상선암에서의 추적 검사로써 washout TG와 혈중 TG가 상호보완적으로 시행되어질 때 재발과 전이를 찾아내는데 유용하다. Purpose: The most widely accepted tool for follow up management of thyroid cancer patients is serum thyroglobulin (Tg) measurement, but its value is limited by the interference of anti-thyroglobulin antibodies (anti-Tg Ab). Recently thyroglobulin measurement in the wash out of fine-needle aspiration biopsy specimens (Tg-FNAB) is frequently used for differential diagnosis of recurrences/metastases. The aim of this study was the investigation of the diagnostic utility of Tg-FNAB compared with serum Tg. Materials and Methods: We enrolled 41 consecutive patients with thyroid cancer who were evaluated for Tg-FNAB between January 2007 and February 2008 retrospectively. We ruled out 6 patients who anti-Tg Ab positive (${\geq}$100 U/mL) in the RIA (BRAHMS anti-Tgn RIA 100Det; BRAHMS Aktiengesell schaft, Berlin, Germany). Serum Tg and Tg-FNAB were measured by immunoradiometric assay (BRAHMS Tg pluS RIA 100 Det; BRAHMS Aktienge sellschaft, Berlin, Germany). We evaluated for Tg-FNAB compared with serum Tg and corresponding cytological smear. To compare the values of the two the t-test was used. Results: Tg-FNAB values were significantly higher (median 1,060 ng/mL, range 0.2~434,000 ng/mL) than serum Tg (median 2.5 ng/mL, range 0.9~131 ng/mL) (p=0.0394). The rate of correspondence with Tg-FNAB between cytological result was 87.9% and 65.9% in the case of serum Tg. Tg-FNAB was positive in 28 (24 with positive and 4 with suspicious cytology). Of the remaining 13 patients with negative Tg-FNAB, 1 had suspicious and 12 had unsuspicious cytology. serum Tg was positive in 26 (17 with positive and 3 with suspicious and 6 with unsuspicious cytology), Of the remaining 15 patients with negative serum Tg, 8 was positive in cytological result and 1 had suspicious and 6 had unsuspicious cytology. Conclusions: Tg-FNAB measurement is more accurate with high sensitivity (87.9%) than serum Tg (65.9%). The Tg-FNAB was a useful predictor for detecting recurrences/metastases with serum Tg.

Thyroglobulin 검사 시 재검선별 및 결과보고절차마련

김지나,박광서,원우재,Kim, Ji-Na,Park, Kwang-Seo,Won, Woo-Jae 대한핵의학기술학회 2014 핵의학 기술 Vol.18 No.1

Purpose: Serum thyroglobulin (Tg) determination has been reported to be a sensitive indicator of persistent or recurrent differentiated thyroid cancer (DTC) after total thyroidetectomy. In patients free of metastasese and recurrences after a complete thyroidectomy and radioiodine removal for DTC, the Tg is usually <1 ng/mL or can no longer be detected even with TSH stimulation. Therefore, report in low Tg levels and selecting criteria for retest is very important. The purpose of this study was to establish selecting criteria for retest which is efficient at reliability improvement and Turn around time (TAT). Materials and Methods: Sera from 137 patients with DTC were divided into two groups as first(<1.0 ng/mL or >4.0 ng/mL) and second(1.0-4.0 ng/mL). In case of group(<1.0 ng/mL) is in patient free of metastases and recurrences, >4.0 ng/ml is low coefficient of variation (CV%) at internal quality control and good linearity at standard curve. Therefore first group began with Delta/Panic check (D/P) and second group surveyed with the latest results. In that the latest results were <1.0 ng/ml, we checked the thyroxin withdrawal. Finally selected specimen retested with raw specimen. Results: In first group, we was able to reduce the retest rate(30.8% to 7.7%). and In second group, 40% to 5%. The total retest rate was 7.3%. Conclusion: If using the selecting criteria for retest, is helpful to accuracy and quickness of the result report.

9-(4-[$^{18}F$] Fluoro-3-hydroxymethylbutyl) guanine 합성의 자동화와 최적화에 관한 연구

안재석,홍성탁,강세훈,원우재,An, Jae-Seok,Hong, Sung-Tack,Kang, Se-Hun,Won, Woo-Jae 대한핵의학기술학회 2011 핵의학 기술 Vol.15 No.2

단순 헤르페즈 제1형 티미딘 키나제(Herpes simplex virus type 1 thymidine kinase. HSV1-tk) 유전자는 보고 유전자(reporter gene)로서 필요한 조건뿐만 아니라 별도의 치료 유전자를 따로 이입할 필요가 없다는 장점을 가지고 있어 유전자 영상과 치료에서 가장 널리 사용되는 유전자 중 하나이다. 본 연구는 HSV1-tk 보고 유전자의 기질로서 많이 사용하고 있는 9-(4-[$^{18}F$] Fluoro-3-hydroxymethylbutyl) guanine ([$^{18}F$] FHBG) 합성의 자동화와 더불어 최적의 합성 조건을 구현하기 위하여 실행하게 되었다. [$^{18}F$] FHBG 합성의 자동화를 위해 Explora-RN (CTI, USA) module을 사용하였다. 최적의 합성수율 조건을 찾기 위하여 반응시간의 변화(3 min, 5 min, 10 min)와 반응온도의 변화($110^{\circ}C$, $120^{\circ}C$, $130^{\circ}C$)를 주었다. 또한 precursor 용량의 변화(5 mg, 7 mg, 10 mg)에도 합성수율이 어떻게 영향을 미치는지 알아보았다. [$^{18}F$] fluorination 단계에서 가장 높은 합성수율을 보인 반응온도는 $130^{\circ}C$였고, 반응시간은 5분이었다. 반면 precursor의 용량 변화 실험에서는 10 mg을 넣었을 때의 합성 수율($32{\pm}1.2%$)에 비하여 5 mg과 7 mg의 양에서는 안정된 값을 얻지 못하였다. [$^{18}F$] FHBG 합성의 Explora-RN 모듈에서의 자동화를 완성하였고 최적의 합성수율을 재현할 수 있는 반응시간과 반응온도, precursor의 농도를 찾았다. 하지만 감량 precursor 방법은 낮은 농도에서 비교적 큰 편차를 보여 안정된 값을 얻지는 못하였다. 이에 따라 임상에 직접 적용하기 위해서 더 많은 연구가 시행되어져야 할 것이다. Purpose: The HSV1-tk reporter gene system is the most widely used system because of its advantage is that it is possible to monitor directly without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. This study was performed to automate 9-(4-[$^{18}F$] Fluoro-3-hydroxymethylbutyl) guanine ([$^{18}F$] FHBG) that are widely used as substrate for the HSV1-tk reporter gene in living organisms with positron emission tomography (PET) and find the optimized conditions of synthesis. Materials and Methods: Fully automated synthesis of [$^{18}F$] FHBG was performed using Explora-RN (CTI, USA) module. We have changed of reaction time (3, 5, 10 min) and temperature (110, 120, $130^{\circ}C$) for the optimized conditions of synthesis. Also we experimented to find the optimal concentration of precursor (5, 7, 10 mg). Results: [$^{18}F$] FHBG was purified by HPLC system and collected at around 10-12 min. Synthesis using Explora-RN module showed a $32.0{\pm}1.2%$ yield of radiochemical (decay corrected), the purity was greater than 98%. And the entire synthesis time was less than 48 min. Temperature of the highest synthesis yield was $130^{\circ}C$, reaction time was 5 minutes and concentration of precursor was 10 mg (recommended volume in manual) (n=36). In contrast to radiochemical yield of precursor 10 mg ($32{\pm}1.2%$), yield of 5 and 7 mg precursor was unstable. Conclusion: Automation of [$^{18}F$] FHBG synthesis at Explora-RN module has been completed. In addition, we were able to obtain optimized reaction time, temperature and concentration of precursor. Therefore this study would be provided more rapid synthesis and higher radiochemical yield.

Open Source를 이용한 MicroPACS의 구성과 활용

유연욱,김용근,김영석,원우재,김태성,김석기,You, Yeon-Wook,Kim, Yong-Keun,Kim, Yeong-Seok,Won, Woo-Jae,Kim, Tae-Sung,Kim, Seok-Ki 대한핵의학기술학회 2009 핵의학 기술 Vol.13 No.1

목적 : Small-scalled PACS, Pc-based PACS로 표현되는 MicroPACS 시스템 구축에 대한 관심도가 급격하게 증가하고 있는 추세이다. MicroPACS 시스템은 PACS를 작은 규모에서 사용할 수 있도록 구성해놓은 것이고, 이 시스템을 구성하기 위해서는 DICOM viewer나 연결프로그램 등이 필요하다. 이것은 공개소스프로그램(Open Source Program)을 통해서 어느 누구나 쉽게 무료로 다운로드를 받을 수 있게 되어있다. 본 논문은 Open source program으로 MicroPACS를 직접 구성해보았고, 저장매체로서의 활용가치를 측정하기위하여 성능, 안정성 측면에서 기존의 광 저장매체(CD, DVDRAM)와 비교 분석하였다. 실험재료 및 방법 : 1. 소형 PACS를 구축하기 위해서 먼저 다음 기준에 맞는 DICOM Server Software를 검색한다. (1) 윈도우체제에서 사용가능할 것. (2) Free ware일 것. (3) PET/CT scanner와 호환되어야 할 것. (4) 사용하기 쉬워야 할 것. (5) 저장의 한계가 없어야 할 것. 2. (1) MicroPACS의 성능을 평가하기 위해 환자 1명의 Data ($^{18}F$-FDG Torso PET/CT)를 현재 Back-up장치로 쓰이는 광 저장매체(CD, DVD-RAM)와 MicroPACS에 저장하는데 소요되는 시간(Back up time)과 workstation으로 복구되기까지의 시간(Retrieval time)을 비교해 보았다. (2) PET/CT 검사를 시행했던 환자 1명의 병록번호와 검사 시행날짜를 핵의학과 직원 7명을 대상으로 알려주고 Data를 찾는데 소요되는 시간을 MicroPACS와 광 저장매체(CD, DVD-RAM)에서 각각 측정하여 비교하였다. 3. 기존의 백업장치로 쓰였던 CD들 중에서 2004년부터 2006년까지 500장을 무작위로 뽑아서 loading을 하였고 그중에서 얼마만큼의 에러가 발생하였는지를 측정하여 MicroPACS의 안정성을 비교평가하였다. 결과 : 1. Server와 DICOM viewer 기능을 갖춘 11개의 open source software 중에서 Conquest DICOM Server를 선택하였다. 2. (1) Backup과 Retrieval 시간 비교(단위 : 분)는 다음과 같다; DVD-RAM(5.13,2.26)/Conquest DICOM Server (1.49,1.19) by GE DSTE (p<0.001), CD (6.12,3.61)/Conquest (0.82,2.23) by GE DLS (p<0.001), CD (5.88,3.25)/Conquest (1.05,2.06) by SIEMENS. (2) CD ($156{\pm}46$초), DVD-RAM ($115{\pm}21$초) and Conquest DICOM Server ($13{\pm}6$초). 3. 1년간 MicroPACS에서의 데이터손실은 없었으며(0%), 500장의 CD 중에서 14개(2.8%)가 Loading하는데 실패하였다. 결론 : 현재 많은 병원에서 도입되고 있는 Full PACS를 open source software를 통하여 소규모의 PACS로 재현해 보았고, 그 결과 가능하다는 결론이 나왔다. 데이터 저장의 유용성을 평가한 결과에서 MicroPACS를 이용하는 것이 기존의 광저장매체를 사용하는 것보다 효율적이고 작업속도가 향상 된다는 것을 확인할 수 있다. Purpose: Recently, most hospitals are introducing the PACS system and use of the system continues to expand. But small-scaled PACS called MicroPACS has already been in use through open source programs. The aim of this study is to prove utility of operating a MicroPACS, as a substitute back-up device for conventional storage media like CDs and DVDs, in addition to the full-PACS already in use. This study contains the way of setting up a MicroPACS with open source programs and assessment of its storage capability, stability, compatibility and performance of operations such as "retrieve", "query". Materials and Methods: 1. To start with, we searched open source software to correspond with the following standards to establish MicroPACS, (1) It must be available in Windows Operating System. (2) It must be free ware. (3) It must be compatible with PET/CT scanner. (4) It must be easy to use. (5) It must not be limited of storage capacity. (6) It must have DICOM supporting. 2. (1) To evaluate availability of data storage, we compared the time spent to back up data in the open source software with the optical discs (CDs and DVD-RAMs), and we also compared the time needed to retrieve data with the system and with optical discs respectively. (2) To estimate work efficiency, we measured the time spent to find data in CDs, DVD-RAMs and MicroPACS. 7 technologists participated in this study. 3. In order to evaluate stability of the software, we examined whether there is a data loss during the system is maintained for a year. Comparison object; How many errors occurred in randomly selected data of 500 CDs. Result: 1. We chose the Conquest DICOM Server among 11 open source software used MySQL as a database management system. 2. (1) Comparison of back up and retrieval time (min) showed the result of the following: DVD-RAM (5.13,2.26)/Conquest DICOM Server (1.49,1.19) by GE DSTE (p<0.001), CD (6.12,3.61)/Conquest (0.82,2.23) by GE DLS (p<0.001), CD (5.88,3.25)/Conquest (1.05,2.06) by SIEMENS. (2) The wasted time (sec) to find some data is as follows: CD ($156{\pm}46$), DVD-RAM ($115{\pm}21$) and Conquest DICOM Server ($13{\pm}6$). 3. There was no data loss (0%) for a year and it was stored 12741 PET/CT studies in 1.81 TB memory. In case of CDs, On the other hand, 14 errors among 500 CDs (2.8%) is generated. Conclusions: We found that MicroPACS could be set up with the open source software and its performance was excellent. The system built with open source proved more efficient and more robust than back-up process using CDs or DVD-RAMs. We believe that the operation of the MicroPACS would be effective data storage device as long as its operators develop and systematize it.

방사면역측정법에 의한 랩시노겐의 측정실험

신금철 ( C H Shin ),원우재 ( U J Won ),서일택 ( I T Seo ) 대한임상검사과학회 1991 대한임상검사과학회지(KJCLS) Vol.23 No.1

Serum pepsinogen assay by radioimmunoassay is necessary test to diagnostic of the digestive system disease . Assay result is 20-SOng/ml in normal serum, display more than 80ng/ml in patient``s serum. Recovery test is 96-107 percent and dilution test display almost a straight line. In the precision, coefficient of variation of within-assay is 6. 9% in the low level, 4. 8% in the middle level and 3. 5% in the high level. Coefficient of variation of between-assay display 11.7% in the low, 7.4% in the middle and 5.4% in the high level.

자동검체분주기의 신뢰성 평가 보고

노경운 ( K W Rho ),원우재 ( U J Won ),김현주 ( H J Kim ),서일택 ( I T Seo ) 대한임상검사과학회 1994 대한임상검사과학회지(KJCLS) Vol.26 No.1

방사성동위원소 및 방사성의약품 분주장치의 자체제작

홍성탁,박광서,김석기,원우재,Hong, Sung-Tack,Park, Kwang-Seo,Kim, Seok-Ki,Won, Woo-Jae 대한핵의학기술학회 2010 핵의학 기술 Vol.14 No.2

PET 검사의 의료보험 급여화 및 연구용 수요가 증가하면서 작업종사자들의 피폭이 문제가 되고 그 문제점들을 해결하기 위해 고가의 의료장비 구입이 필요하게 되었다. 하지만 cyclotron실에서 운영하는 장비들은 수 천만원에서 수 억원을 호가하는 고가의 장비들이 많이 있어 의료기관에서 구입하기 어려운 점이 있다. 작업자가 원하는 기능만 갖춘 장비를 해당 부속품 구입이 가능하다면 적은 비용으로도 충분히 자체 제작할 수 있다. 국립암센터 핵의학과에서는 적은 비용으로 장비를 제작, 사용하고 작업자의 업무까지 개선한 두가지 의료장비를 사례 별로 소개하려고 한다. 첫 번째 사례는 방사성동위원소($^{18}F$) 분주장치로 국립암센터 핵의학과 cyclotron실에서는 의공학과와의 협력으로 시중에서 구할 수 있는 아크릴판 1개, 3-way valve 7개, tubing 등을 구하여 분주기 본체를 만들어 hot cell 내부에 설치하고, switching box를 hot cell 밖에 설치하여 외부에서 분주장치를 조절할 수 있게 제작하였다. 이 제작된 분주기 본체를 cyclotron에서 생산된 방사성동위원소 transfer line에 설치하였다. 두 번째 사례는 $^{18}F$-FDG 자동 분주기로 국립암센터 핵의학과 cyclotron실에서는 의공학과와의 협력으로 분주기의 본체가 되는 부분은 cavro pump syringe를 사용하였고, 일정량을 분주할 수 있는 프로그램은 의공학과가 자체 제작하였다. $^{18}F$-FDG 자동 분주기는 hot cell 내부에 설치하고 자동분주기에 케이블선을 사용하였으며 hot cell 밖의 PC에 연결하여 PC에서 $^{18}F$-FDG 자동 분주기를 조절할 수 있게 제작하였다. 첫 번째 사례인 방사성동위원소($^{18}F$) 분주장치는 2007년 3월부터 현재까지 국립암센터에 cyclotron실에서 사용해 본 결과 생산된 방사성동위원소를 switching box를 사용하여 간단하게 원하는 방사성의약품 합성 module로 보낼 수 있었고, collecting vial 내 transfer line을 조정하여 생산된 방사성동위원소를 여러 합성 module로 분배할 수도 있게 되었다. 두 번째 사례인 $^{18}F$-FDG 자동 분주기는 2009년 8월부터 현재까지 국립암센터에 cyclotron실에서 사용해 본 결과 원하는 vial에 방사성의약품을 분배할 수 있었다. 두 가지 사례를 통하여 국립암센터 핵의학과 cyclotron실에서 고가의 장비를 최소가격으로 자체 제작하여 비용 절감 효과를 얻을 수 있었고 작업종사자의 방사선 피폭량을 감소시켰으며 다수의 부서가 협력하여 자발적으로 공동의 문제를 해결하는 프로세스를 확립시켰다. Purpose: As PET test came to be covered by the pay system of medical insurance (July 1, 2006) and the needs for it becoming increased for laboratory purpose, it became necessary to purchase expensive medical equipments to solve those problems. However, as most of equipments that are operated by cyclotron are very expensive as to amount from tens of millions up to hundreds of millions of won, it is difficult to purchase those equipments from the point of medical organizations. It may be possible to self manufacture those equipments with least costs if their parts functions that meets the operators demands. The Nuclear Medicine department of National Cancer Center (NCC) is trying to manufacture and use equipments that can be made with least costs, including introducing 2 medical equipments that can improves the operator's works. Materials and Methods: Example 1: Self production of radioisotope($^{18}F$) divider was fabricated. The NCC's Nuclear Medicine department acquired one acrylic panel, seven 3-way valve, tubing etc. that can be found in the market to make the main body of divider in cooperation with biomedical engineering, and placed them inside hot cell, and installed switching box outside of hot cell to make it possible to control them from outside. This main body of divider were placed in radioisotope transfer line that are manufactured in the cyclotron. Example 2: Self production of $^{18}F$-FDG automated divider was fabricated. The NCC's Nuclear Medicine department used cavro pump syringe that consists the main body of divider in cooperation with biomedical engineering, biomedical engineering developed programs that divides a certain amount. $^{18}F$-FDG automated divider is placed inside hot cell, and cable chords were used in the equipment, and then it was connected to PC outside hot cell to make it possible to control the $^{18}F$-FDG automated divider. Results: From the NCC's Nuclear Medicine department tests that were carried out from March, 2007 until now, we found out that radioisotope can be sent to radiopharmaceuticals composite module we want, and from the tests that are carried out at NCC's Nuclear Medicine department using $^{18}F$-FDG automated divider since August, 2009 it was possible to distribute radiopharmaceuticals into vial intended. Conclusion: Through the two examples above, we found out that costs can be reduced by self manufacturing expensive equipments from NCC's cyclotron room with least costs. Also, it decreased radiation exposure dose on workers, and set up problem solving processes in cooperation with lots of parties related.

방사성 동위원소를 이용한 핵의학과 검사에서 병동 간호사의 방사선 피폭선량 평가

정재훈,이충운,유연욱,서영덕,최호용,김윤철,김용근,원우재,Jeong, Jae Hoon,Lee, Chung Wun,You, Yeon Wook,Seo, Yeong Deok,Choi, Ho Yong,Kim, Yun Cheol,Kim, Yong Geun,Won, Woo Jae 대한핵의학기술학회 2017 핵의학 기술 Vol.21 No.1

Purpose Radiation exposure management has been strictly regulated for the radiation workers, but there are only a few studies on potential risk of radiation exposure to non-radiation workers, especially nurses in a general ward. The present study aimed to estimate the exact total exposure of the nurse in a general ward by close contact with the patient undergoing nuclear medicine examinations. Materials and Methods Radiation exposure rate was determined by using thermoluminescent dosimeter (TLD) and optical simulated luminescence (OSL) in 14 nurses in a general ward from October 2015 to June 2016. External radiation rate was measured immediately after injection and examination at skin surface, and 50 cm and 1 m distance from 50 patients (PET/CT 20 pts; Bone scan 20 pts; Myocardial SPECT 10 pts). After measurement, effective half-life, and total radiation exposure expected in nurses were calculated. Then, expected total exposure was compared with total exposures actually measured in nurses by TLD and OSL. Results Mean and maximum amount of radiation exposure of 14 nurses in a general ward were 0.01 and 0.02 mSv, respectively in each measuring period. External radiation rate after injection at skin surface, 0.5 m and 1 m distance from patients was as following; $376.0{\pm}25.2$, $88.1{\pm}8.2$ and $29.0{\pm}5.8{\mu}Sv/hr$, respectively in PET/CT; $206.7{\pm}56.6$, $23.1{\pm}4.4$ and $10.1{\pm}1.4{\mu}Sv/hr$, respectively in bone scan; $22.5{\pm}2.6$, $2.4{\pm}0.7$ and $0.9{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. After examination, external radiation rate at skin surface, 0.5 m and 1 m distance from patients was decreased as following; $165.3{\pm}22.1$, $38.7{\pm}5.9$ and $12.4{\pm}2.5{\mu}Sv/hr$, respectively in PET/CT; $32.1{\pm}8.7$, $6.2{\pm}1.1$, $2.8{\pm}0.6$, respectively in bone scan; $14.0{\pm}1.2$, $2.1{\pm}0.3$, $0.8{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. Based upon the results, an effective half-life was calculated, and at 30 minutes after examination the time to reach normal dose limit in 'Nuclear Safety Act' was calculated conservatively without considering a half-life. In oder of distance (at skin surface, 0.5 m and 1 m distance from patients), it was 7.9, 34.1 and 106.8 hr, respectively in PET/CT; 40.4, 199.5 and 451.1 hr, respectively in bone scan, 62.5, 519.3 and 1313.6 hr, respectively in myocardial SPECT. Conclusion Radiation exposure rate may differ slightly depending on the work process and the environment in a general ward. Exposure rate was measured at step in the general examination procedure and it made our results more reliable. Our results clearly showed that total amount of radiation exposure caused by residual radioactive isotope in the patient body was neglectable, even comparing with the natural radiation exposure. In conclusion, nurses in a general ward were much less exposed than the normal dose limit, and the effects of exposure by contacting patients undergoing nuclear medicine examination was ignorable. 목적: 핵의학 검사를 시행한 병동 환자의 시간과 거리에 따른 방사선량률을 측정하여 방사성동위원소 투여를 받은 환자가 병동 간호사에게 미치는 피폭을 예측하고 실제 총 피폭량과 비교하여 보고자 한다. 대상 및 방법: 병동에서 근무하고 있는 간호사 14명을 대상으로 열형광 선량계와 광자극 선량계를 이용하여 방사선 피폭선량을 측정하였고 핵의학 검사를 시행한 환자 50명(PET/CT 20명, Bone scan 20명, Myocardial SPECT 10명)을 대상으로 방사성동위원소 투여 직후와 검사시행 직후에 표면, 50cm, 1m에서 외부 방사선량률을 측정하였다. 측정 결과를 바탕으로 유효반감기를 도출한 후 병동 간호사가 받을 수 있는 피폭량을 예측하였다. 그리고 열형광선량계와 광자극선량계로 측정된 병동 간호사의 실제 총 피폭량과 비교 하였다. 결과: 병동 간호사 14명을 대상으로 한 피폭선량 측정결과 평균값과 최대값은 각각 분기당 0.01 mSv, 0.02 mSv 이었고 핵의학 검사를 시행 받은 환자의 선량률은 표면, 50cm, 1m 거리 순으로 PET/CT는 $376.0{\pm}25.2{\mu}Sv/hr$, $88.1{\pm}8.2{\mu}Sv/hr$, $29.0{\pm}5.8{\mu}Sv/hr$ 이고 Bone scan은 $206.7{\pm}56.6{\mu}Sv/hr$, $23.1{\pm}4.4{\mu}Sv/hr$, $10.1{\pm}1.4{\mu}Sv/hr$이고 Myocardial SPECT는 $22.5{\pm}2.6{\mu}Sv/hr$, $2.4{\pm}0.7{\mu}Sv/hr$, $0.9{\pm}0.2{\mu}Sv/hr$이다. 또한 검사를 시행한 후 측정한 선량률은 표면, 50cm, 1m 거리 순으로 PET/CT는 $165.3{\pm}22.1{\mu}Sv/hr$, $38.7{\pm}5.9{\mu}Sv/hr$, $12.4{\pm}2.5{\mu}Sv/hr$ 이고 Bone scan은 $32.1{\pm}8.7{\mu}Sv/hr$, $6.2{\pm}1.1{\mu}Sv/hr$, $2.8{\pm}0.6{\mu}Sv/hr$이고 Myocardial SPECT는 $14.0{\pm}1.2{\mu}Sv/hr$, $2.1{\pm}0.3{\mu}Sv/hr$, $0.8{\pm}0.2{\mu}Sv/hr$이다. 위의 결과를 바탕으로 유효반감기를 도출한 후 검사종료 30분 후 원자력안전법에서 규정하는 일반인 선량한도까지 도달하는데 걸리는 시간을 반감기를 고려치 않고 보수적으로 계산하면 PET/CT는 표면, 50cm, 1m 거리 순으로 7.9시간, 34.1시간, 106.8시간이며 Bone scan은 40.4시간, 199.5시간, 451.1시간이고 Myocardial SPECT는 62.5시간, 519.3시간, 1313.6시간이다. 결론: 본 연구 결과에 의하면 병동 간호사는 일반인 선량한도 보다 훨씬 적은 피폭량을 받는 것으로 나타나, 실질적으로 판단할 때 핵의학 검사를 시행한 환자로 인하여 받는 피폭의 영향은 미미한 것으로 판단된다.