• 한국의학물리학회지:의학물리
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• 제30권1호
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• pp.32-38
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• 2019

Purpose: The objective of this study is to evaluate the geometrical accuracy of a patient-specific bolus based on a three-dimensional (3D) printed mold and casting method. Materials and Methods: Three breast cancer patients undergoing treatment for a superficial region were scanned using computed tomography (CT) and a designed bolus structure through a treatment planning system (TPS). For the fabrication of patient-specific bolus, we cast harmless certified silicone into 3D printed molds. The produced bolus was also imaged using CT under the same conditions as the patient CT to acquire its geometrical shape. We compared the shapes of the produced bolus with the planned bolus structure from the TPS by measuring the average distance between two structures after a surface registration. Results and Conclusions: The result of the average difference in distance was within 1 mm and, as the worst case, the absolute difference did not exceed ${\pm}2mm$. The result of the geometric difference in the cross-section profile of each bolus was approximately 1 mm, which is a similar property of the average difference in distance. This discrepancy was negligible in affecting the dose reduction. The proposed fabrication of patient-specific bolus is useful for radiation therapy in the treatment of superficial regions, particularly those with an irregular shape.

• 한국의학물리학회지:의학물리
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• 제28권1호
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• pp.33-38
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• 2017

Creating individualized build-up material for superficial photon beam radiation therapy at irregular surface is complex with rice or commonly used flat shape bolus. In this study, we implemented a workflow using 3D printed patient specific bolus and describe our clinical experience. To provide better fitted build-up to irregular surface, the 3D printing technique was used. The PolyLactic Acid (PLA) which processed with nontoxic plant component was used for 3D printer filament material for clinical usage. The 3D printed bolus was designed using virtual bolus structure delineated on patient CT images. Dose distributions were generated from treatment plan for bolus assigned uniform relative electron density and bolus using relative electron density from CT image and compared to evaluate the inhomogeneity effect of bolus material. Pretreatment QA is performed to verify the relative electron density applied to bolus structure by gamma analysis. As an in-vivo dosimetry, Optically Stimulated Luminescent Dosimeters (OSLD) are used to measure the skin dose. The plan comparison result shows that discrepancies between the virtual bolus plan and printed bolus plan are negligible. (0.3% maximum dose difference and 0.2% mean dose difference). The dose distribution is evaluated with gamma method (2%, 2 mm) at the center of GTV and the passing rate was 99.6%. The OSLD measurement shows 0.3% to 2.1% higher than expected dose at patient treatment lesion. In this study, we treated Mycosis fungoides patient with patient specific bolus using 3D printing technique. The accuracy of treatment plan was verified by pretreatment QA and in-vivo dosimetry. The QA results and 4 month follow up result shows the radiation treatment using 3D printing bolus is feasible to treat irregular patient skin.

• 대한방사선기술학회지:방사선기술과학
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• 제42권6호
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• pp.447-454
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• 2019

In order to improve and supplement the shielding method for electron beam treatment, we designed a patient-specific shielding method using a 3D printer, and evaluated the usefulness by comparing and analyzing the distribution of electron beam doses to adjacent organs. In order to treat 5 cm sized superficial tumors around the lens, a CT Simulator was used to scan the Alderson Rando phantom and the DICOM file was converted into an STL file. The converted STL file was used to design a patient-specific shield and mold that matched the body surface contour of the treatment site. The thickness of the shield was 1 cm and 1.5 cm, and the mold was printed using a 3D printer, and the patient customized shielding block (PCSB) was fabricated with a cerrobend alloy with a thickness of 1 cm and 1.5 cm. The dosimetry was performed by attaching an EBT3 film on the surface of the Alderson Rando phantom eyelid and measuring the dose of 6, 9, and 12 MeV electron beams on the film using four shielding methods. Shielding rates were 83.89%, 87.14%, 87.39% at 6, 9, and 12 MeV without shielding, 1 cm (92.04%, 87.48%, 86.49%), 1.5 cm (91.13%, 91.88% with PSCB), 92.66%) The shielding rate was measured as 1 cm (90.7%, 92.23%, 88.08%) and 1.5 cm (88.31%, 90.66%, 91.81%) when the shielding block and the patient-specific shield were used together. PCSB fabrication improves shielding efficiency over conventional shielding methods. Therefore, PSCB may be useful for clinical application.

• 한국의학물리학회지:의학물리
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• 제27권2호
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• pp.64-71
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• 2016

삼차원 프린터(3DP)를 이용하여 환자맞춤형 전자선 치료용 볼루스(patient specific customized bolus, PSCB)를 제작하는 절차를 고안하고 제안된 방법으로 제작한 PSCB의 선량 정확도를 평가했다. 치료계획장치에서 치료계획표적용적(PTV)에 적합한 전자선 빔과 조사면 크기를 선택하고 초기 선량계산을 수행했다. 계산된 선량분포를 기반으로 PSCB를 그리고 재계산을 수행했다. 수 차례 반복을 통해 최상의 PSCB를 설계하고 설계된 윤곽자료를 DICOMRT 프로토콜을 이용해 자체 제작한 변환프로그램으로 전송했다. PSCB의 윤곽자료는 자체 변환프로그램을 이용해 3DP에서 인식 가능한 파일(STL 포맷)로 변환한 후 3DP를 이용해 제작했다. PSCB의 유용성을 검증하기 위해 2명의 가상 환자(오목, 볼록 유형)를 생성했고 각각의 환자에 가상의 PTV와 정상장기(OAR)을 생성했다. 3D-PSCB 를 사용했을 때와 사용하지 않았을 때의 선량체적히스토그램(DVH)와 선량 특성을 비교했다. 3D-PSCB 제작의 정확도를 분석하기 위해 필름 선량측정을 통해 선량 정확도를 평가했다. 치료계획 결과와 필름을 이용한 선량분포를 중첩한 후 빔 중심축에서의 심부선량곡선을 구했고 감마분석(3% 선량 오차와 3 mm 거리오차)을 수행 했다. 2명의 가상환자 모두에서 PSCB를 사용한 경우 PTV 선량은 큰 차이를 보이지 않았다. PSCB를 사용할 경우 PSCB를 사용하지 않는 경우에 비해 OAR의 최대 선량, 최소선량, 평균선량은 각각 평균 9.7%, 36.6%, 28.3% 감소했다. 처방선량의 90% 선량($V_{90%}$)을 받는 OAR의 용적은 PSCB를 적용할 경우 약 99% 낮아졌다(14.40 vs $0.1cm^3$). 또한 처방선량의 80% 선량을 받는 OAR 체적도 PSCB를 사용할 경우 약 91% 줄었다(42.6 vs $3.7cm^3$). 감마분석 결과(3%, 3 mm) 오목 및 볼록 볼루스를 적용한 경우 각각 95%, 98% 통과율(pass rate)을 보였다. 3DP를 이용해 PSCB를 제작하는 절차를 정립하고 선량적 정확도를 평가해서 임상적용이 가능한 만족할 만한 결과를 얻었다. 3DP 기술의 빠른 발전에 힘입어 PSCB의 임상적용이 좀 더 쉬워지고 적용대상이 확장될 것으로 생각된다.

• 간호행정학회지
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• 제12권3호
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• pp.444-453
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• 2006

Purpose: The purpose of the study was to identify critical indicators for the development of efficient patient classification system in a emergency room. Method: This study involved following five steps. Step 1. Selection of the lists direct nursing services in the ER. Step 2. Measurement of the time of direct nursing services from Aug. 31st to Nov. 30th, 2005. Step 3. Classification of the patients according to the nursing care time. Step 4. The determination the critical indicators for different patient classes. Result: Determinate indicators were as follow: 3 items in the first group (vital sign checking, IV route starting, blood sampling), 3 items in the second group (vital sign checking, fluid infusion, blood sampling), 9 items in the third group (I/O checking, $O_{2}$ inhalation, suction, fluid infusion, IV bolus, Central catheter preparation & management, blood sampling, intubation preparation & management, postmortem management), 7 items in the fourth group (EKG monitoring, BP monitoring, $O_{2}$ inhalation, fluid infusion, using the specific drugs, CPR, postmortem management). Conclusion: This study can help future studies which measure nursing services standard time or assigns value to emergency nursing services.

• Journal of Trauma and Injury
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• 제36권3호
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• pp.165-171
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• 2023

Trauma remains a significant healthcare burden, causing over five million yearly fatalities. Notably, the liver is a frequently injured solid organ in abdominal trauma, especially in patients under 40 years. It becomes even more critical given that uncontrolled hemorrhage linked to liver trauma can have mortality rates ranging from 10% to 50%. Liver injuries, mainly resulting from blunt trauma such as motor vehicle accidents, are traditionally classified using the American Association for the Surgery of Trauma grading scale. However, recent developments have introduced the World Society of Emergency Surgery classification, which considers the patient's physiological status. The diagnostic approach often involves multiphase computed tomography (CT). Still, newer methods like split-bolus single-pass CT and contrast-enhanced ultrasound (CEUS) aim to reduce radiation exposure. Concerning management, nonoperative strategies have emerged as the gold standard, especially for hemodynamically stable patients. Incorporating angiography with embolization has also been beneficial, with success rates reported between 80% and 97%. However, it is essential to identify the specific source of bleeding for effective embolization. Given the severity of liver trauma and its potential complications, innovations in diagnostic and therapeutic approaches have been pivotal. While CT remains a primary diagnostic tool, methods like CEUS offer safer alternatives. Moreover, nonoperative management, especially when combined with angiography and embolization, has demonstrated notable success. Still, the healthcare community must remain vigilant to complications and continuously seek improvements in trauma care.

• The Korean Journal of Pain
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• 제9권1호
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• pp.172-177
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• 1996

We performed a study of epidural patient controlled analgesia of meperidine with or without 0.08% bupivacaine for 48 hours after Cesarean section. 51 parturients were randomly assigned to one of two treatment groups : 1) epidural 0.2% meperidine group(n:24) and 2) epidural combined group with 0.2% meperidine and 0.08% bupivacaine(n:27). All parturients used patient controlled analgesia with loading dose, 2 ml/hour continuous infusion, 1 ml bolus infusion and lockout time, 8 minutes. visual analog scales after loading doses were not significantly different in either groups. The total quantity of meperidine consumption and hourly consumption were significantly lower in the combined group than meperidine group(P<0.05). The cumulative amount of meperidine consumption were also significantly lower in the combined group than meperidine group at 6, 12, 24 and 48 hours. In combined group the hourly consumption of meperidien from 3 hours to 12 hours after loading dose was significantly lower than those of meperidine group. Above 90% of parturients were satisfied in both groups. Side effects were: numbness (2), thigh weakness (1), nausea (1), headache (1) and back pain (2) in epidural meperidine group. There were no case needed specific treatment in both groups. We conclude that analgesic effects were similar in both groups, however the amount of meperidine consumption was less for meperiding group than combined group.

• The Korean Journal of Pain
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• 제9권1호
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• pp.166-171
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• 1996

The purpose of this study is to compare the postoperative analgesic effect of morphine and meperidine, employing intravenous patient controlled analgesia after cesarean section. Among fifty nine parturients undergoing cesarean section with general anesthesia, 32 were administered morphine designated as 'morphine group', and 27 parturient administered meperidine as 'meperidine' group, during 48 hours after commencement of PCA. Doses administered, based on potency for this setting, were equivalent to 1 mg morphine or 10 mg meperidine. Loading dose was administered when parturient first complained of pain after cesarean section. This was followed with bolus dose, 1 mg for morphine group and 10 mg for meperidine group, with a lockout interval of 8 minutes between doses wherever parturient requested additional analgesia. Visual analog scale(VAS) pain scores during rest were significantly lower at only 1 and 2 hour for the meperidine group, than morphine group. Loading dose and cumulative dose at 1, 2 and 3 hours were significantly lower for meperidine group than the morphine group. There were no significant difference in total dose and hourly dose for 48 hours and cumulative dose at 6, 12, 24, and 48 hours between both groups. More than 90% of the parturients from both groups were satisfied with the analgesic effects of pain relief. Morphine group experienced side effects such as: pruritus, sedation and dizziness. Meperidine group had sedation, dizziness, nausea and local irritation. Neither group required any specific treatment for any of the above side effects. We conclude that meperidine had greater analgesic effect at early stage of post-operative period.

• Journal of Dental Anesthesia and Pain Medicine
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• 제19권4호
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• pp.181-189
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• 2019

Local anesthetic systemic toxicity (LAST) refers to the complication affecting the central nervous system (CNS) and cardiovascular system (CVS) due to the overdose of local anesthesia. Its reported prevalence is 0.27/1000, and the representative symptoms range from dizziness to unconsciousness in the CNS and from arrhythmias to cardiac arrest in the CVS. Predisposing factors of LAST include extremes of age, pregnancy, renal disease, cardiac disease, hepatic dysfunction, and drug-associated factors. To prevent the LAST, it is necessary to recognize the risk factors for each patient, choose a safe drug and dose of local anesthesia, use vasoconstrictor, confirm aspiration and use incremental injection techniques. According to the treatment guidelines for LAST, immediate application of lipid emulsion plays an important role. Although lipid emulsion is commonly used for parenteral nutrition, it has recently been widely used as a non-specific antidote for various types of drug toxicity, such as LAST treatment. According to the recently published guidelines, 20% lipid emulsion is to be intravenously injected at 1.5 mL/kg. After bolus injection, 15 mL/kg/h of lipid emulsion is to be continuously injected for LAST. However, caution must be observed for >1000 mL of injection, which is the maximum dose. We reviewed the incidence, mechanism, prevention, and treatment guidelines, and a serious complication of LAST occurring due to dental anesthesia. Furthermore, we introduced lipid emulsion that has recently been in the spotlight as the therapeutic strategy for LAST.