• Advances in nano research
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• v.10 no.5
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• pp.461-470
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• 2021

Infection is one of the major mortality causes throughout the globe. Nuclear medicine plays an important role in diagnosis of deep infections such as osteomyelitis, arthritis infection, heart valve and heart prosthesis infections. Techniques such as labeled leukocytes are sensitive and selective for tracking the inflammations but they are not suitable for differentiating infection from inflammation. Anionic linear-globular dendrimer-G₂ was synthesized then conjugation to gemifloxacin antibiotic. The structures were identified by FT-IR, ¹H-NMR, C-NMR, LC-MS and DLS. The toxicity of gemifloxacin and dendrimer-gemifloxacin complex was compared by MTT test. Dendrimer-G₂-gemifloxacin was labeled by Technetium-99m and its in-vitro stability and radiochemical purity were investigated. In-vivo biodistribution and SPECT imaging were studied in a rabbit model. Identify and verify the structure of the each object was confirmed by FT-IR, ¹H-NMR, C-NMR and LC-MS, also, the size and charge of this compound were 128 nm and -3/68 mv respectively. MTT test showed less toxicity of the dendrimer-G₂-gemifloxacin than free gemifluxacin (P < 0.001). Radiochemical yield was > %98. Human serum stability was 84% up to 24 h. Biodistribution study at 50 min, 24 and 48 h showed that the complex is significantly absorbed by the intestine and accumulation in the lungs and affects them, finally excreted through the kidneys, biodistribution results are consistent with results from full image means of SPECT/CT technique.

• Journal of radiological science and technology
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• v.45 no.6
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• pp.553-560
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• 2022

The purpose of this study is to evaluate the clinical risk according to the applicator heterogeneity, mislocation, and tissue heterogeneity correction through a dose verification program during brachytherapy of cervical cancer. We performed image processing with MATLAB on images acquired with CT simulator. The source was modeled and stochiometric calibration and Monte-Carlo algorithm were applied based on dwell time and location to calculate the dose, and the secondary cancer risk was evaluated in the dose verification program. The result calculated by correcting for applicator and tissue heterogeneity showed a maximum dose of about 25% higher. In the bladder, the difference in excess absolute risk according to the heterogeneity correction was not significant. In the rectum, the difference in excess absolute risk was lower than that calculated by correcting applicator and tissue heterogeneity compared to the water-based calculation. In the femur, the water-based calculation result was the lowest, and the result calculated by correcting the applicator and tissue heterogeneity was 10% higher. A maximum of 14% dose difference occurred when the applicator mislocation was 20 mm in the Z-axis. In a future study, it is expected that a system that can independently verify the treatment plan can be developed by automating the interface between the treatment planning system and the dose verification program.

• Journal of Digestive Cancer Research
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• v.5 no.2
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• pp.120-124
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• 2017

A-49-year-old male patient with no specific medical history was admitted to the clinic because of persistent epigastric pain radiating to back for 4 months. He had multiple parenchymal tumors in body and tail of pancreas, para-spinal muscle, and mediastinum on abdomen CT image. Cytologic examination of the pancreas which was done by endoscopic ultrasound guided fine needle aspiration (EUS-FNA) showed adenocarcinoma, whereas histological examination of the para-spinal mass showed undifferentiated sarcoma. Histologic examination of the pancreatic mass was made through endoscopic ultrasound guided fine needle biopsy (EUS-FNB) for accurate diagnosis, and the histologic examination of both the pancreas and posterior mediastinal mass showed the same undifferentiated sarcoma. Therefore, we reviewed the cytopathic tissue obtained from the pancreas for the first time, and it was confirmed to be similar to histologic findings in the mediastinal mass.

• Journal of Periodontal and Implant Science
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• v.53 no.5
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• pp.388-401
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• 2023

Purpose: This study investigated the accuracy of free-hand implant surgery performed by an experienced operator compared to static guided implant surgery performed by an inexperienced operator on an anterior maxillary dental model arch. Methods: A maxillary dental model with missing teeth (No. 11, 22, and 23) was used for this in vitro study. An intraoral scan was performed on the model, with the resulting digital impression exported as a stereolithography file. Next, a cone-beam computed tomography (CBCT) scan was performed, with the resulting image exported as a Digital Imaging and Communications in Medicine file. Both files were imported into the RealGUIDE 5.0 dental implant planning software. Active Bio implants were selected to place into the model. A single stereolithographic 3-dimensional surgical guide was printed for all cases. Ten clinicians, divided into 2 groups, placed a total of 60 implants in 20 acrylic resin maxillary models. Due to the small sample size, the Mann-Whitney test was used to analyze mean values in the 2 groups. Statistical analyses were performed using SAS version 9.4. Results: The accuracy of implant placement using a surgical guide was significantly higher than that of free-hand implantation. The mean difference between the planned and actual implant positions at the apex was 0.68 mm for the experienced group using the free-hand technique and 0.14 mm for the non-experienced group using the surgical guide technique (P=0.019). At the top of the implant, the mean difference was 1.04 mm for the experienced group using the free-hand technique and 0.52 mm for the non-experienced group using the surgical guide technique (P=0.044). Conclusions: The data from this study will provide valuable insights for future studies, since in vitro studies should be conducted extensively in advance of retrospective or prospective studies to avoid burdening patients unnecessarily.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.577-583
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• 2021

Objective: To report the authors' experience in performing thoracic endovascular aortic repair (TEVAR) for zone 2 lesions after traumatic aortic injury (TAI). Materials and Methods: This retrospective review included 10 patients who underwent zone 2 TEVAR after identification of aortic isthmus injury by CT angiography (CTA) upon arrival at the emergency room of a regional trauma center from 2016 to 2019. Patients were classified into two groups: those who underwent left subclavian artery (LSA) embolization concurrently with the main TEVAR procedure, and those in whom LSA embolization was not performed during the main procedure, but was planned as a bailout treatment if type II endoleak was noted on follow-up CTA images. Pre-procedural and procedure-related factors and post-procedure prognosis were compared between the groups. Results: There were no differences in pre-procedural factors, occurrence of endoleaks, and post-procedure prognosis (including mortality) between patients in the two groups. The duration of the procedure was shorter in the non-LSA embolization group (61 minutes vs. 27 minutes, p = 0.012). During follow-up, type II endoleak did not occur in either group. Conclusion: Delaying preventative LSA embolization until stabilization of the patient would be desirable when performing zone 2 TEVAR for TAI, in the absence of endoleak on the completion aortography image taken after complete deployment of the stent graft.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.2
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• pp.137-143
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• 2013

Purpose: We are to find out the difference of calculated dose of treatment planning system (TPS) and measured dose in case of inhomogeneous organ structure. Materials and Methods: Inhomogeneous phantom is made with solid water phantom and cork plate. CT image of inhomogeneous phantom is acquired. Treatment plan is made with TPS (Pinnacle3 9.2. Royal Philips Electronics, Netherlands) and calculated dose of point of interest is acquired. Treatment plan was delivered in the inhomogeneous phantom by ARTISTE (Siemens AG, Germany) measured dose of each point of interest is obtained with Gafchromic EBT2 film (International Specialty Products, US) in the gap between solid water phantom or cork plate. To simulate lung cancer radiation treatment, artificial tumor target of paraffin is inserted in the cork volume of inhomogeneous phantom. Calculated dose and measured dose are acquired as above. Results: In case of inhomogeneous phantom experiment, dose difference of calculated dose and measured dose is about -8.5% at solid water phantom-cork gap and about -7% lower in measured dose at cork-solid water phantom gap. In case of inhomogeneous phantom inserted paraffin target experiment, dose difference is about 5% lower in measured dose at cork-paraffin gap. There is no significant difference at same material gap in both experiments. Conclusion: Radiation dose at the gap between two organs with different electron density is significantly lower than calculated dose with TPS. Therefore, we must be aware of dose calculation error in TPS and great care is suggested in case of radiation treatment planning on inhomogeneous organ structure.

• Journal of Gastric Cancer
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• v.9 no.2
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• pp.51-56
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• 2009

Purpose: Peritoneal recurrence has been reported to be the most common form of recurrence of gastric cancer. Peritoneal recurrence can generally be suggested by several types of image studies and also if there is evidence of ascites or Bloomer's rectal shelf. It can be confirmed by explorative laparotomy, but diagnostic laparoscopy is a good alternative method and laparoscopic surgery has also been widely used. We reviewed and analyzed the ability of diagnostic laparoscopy to detect peritoneal recurrence or carcinomatosis, and especially for gastric cancer. Materials and Methods: We performed a retrospective review the 45 gastric cancer patients who were operated via diagnostic laparoscopy between 2004. 2. and 2009. 3. We analyzed the perioperative clinical characteristics and the accuracy of the diagnostic methods. Results: The study groups included 14 patients who had confirmed gastric cancer, but they suspected to have carcinomatosis, and 31 patients who had previously underwent gastric resection, but they suspected to have recurrence. The mean operation time was $44.1\pm26.9$ minutes and the mean postoperative hospital stay was $2.7\pm2.8$ days. There was one case of operation-related complication and no postoperative mortality occurred. The sensitivities for detecting peritoneal recurrence or carcinomatosis were 92.1% for diagnostic laparoscopy, 29.7% for detecting ascites and rectal shelf on the physical examination, 86.5% for abdominal computed tomography, 69.2% for PET CT and 18.8% for CEA. Conclusion: Diagnostic laparoscopy does not require a long operation time or a long hospital stay, and it showed a low complication rate in our study. It has high sensitivity for detecting peritoneal recurrence of gastric cancer. It can be an alternative diagnostic confirmative method and it is useful for deciding on further treatment.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.1
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• pp.22-29
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• 2000

Purpose : The purpose of the current study was to report the results of curettage and en bloc excision as well as to introduce how to excise the nidus percutaneously with Halo-mill. Material and Methods : Twenty patients(14 men and 6 women) were evaluated, who had operative treatments after diagnosed as osteoid osteoma from March 1990 to January 1998. These patients ranged in age from 7 to 42 years(average: 20.8 years). Locations were 9 femurs, 6 tibias, 2 vertebras, 1 ulna, 1 maxilla and 1 skull. Nine femoral lesions included 5 proximal metaphysis, 2 neck and 2 diaphysis, while 5 tibial lesions included 3 diaphysis, 1 proximal metaphysis and 1 distal metaphysis. We used simple radiography, bone scan, CT and MRI for the accurate diagnosis and localization. As for surgical treatments, while excision and curettage had to need open-exposure of lesion, the percutaneous excision of nidus did not need openexposure : guided Halo-mill into K-wire inserted to nidus under image intensifier. Results : Simple radiography showed that 10 cases had typical nidus and others had only cortical sclerosis. Bone scan was performed at 14 cases and all had hot uptake except one case. We used CT in 10 cases and MRI in 4 cases as diagnostic methods, of which 1 case didn't reveal nidus at CT. Surgical treatment consisted of 6 curettages, 11 excisions, 2 percutaneous excisions with halo-mill and 1 total elbow arthroplasty. We used 7mm sized Halo-mill. During the follow-up period, all patient relieved symptoms and there were no recurrences. All had histologically typical findings except one which had hyperostosis without nidus. Conclusion : Complete removal of the nidus is the most important factor in the treatment. We could excise the nidus percutaneously in 2 cases with the minimal injury to surrounding soft tissues. If we could evaluate the precise location, size of nidus and percutaneous acccesibility, the percutaneous excision of nidus with Halo-mill could be an alternative method as a treatment of osteoid osteoma.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.79-86
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• 2009

Background: Background: Computed tomography (CT) is the main tool for detecting abnormalities of the thoracic aorta, but conventional CT only shows the cross-sectional images. These CT images have some limitations fo accuratly measuring the thoracic aortic diameters at various levels. Multidetector computed tomography (MDCT) overcomes these limitations. We measured the thoracic aortic diameter perpendicular to the loop-shaped thoracic aortic course and this was studied in relation to age, gender, height, weight, the body surface area, the body mass index and the presence of hypertension. Material and Method: Thirty hundred thirty one patients (males: 141 patients and females: 190 patients) who had no abnormalities of the thoracic aorta were investigated using MDCT aortography. They were divided into three age categories: 20~39 years old, 40~59 years old and over age 60. The image was reformed with multiplanar reconstruction and the diameter of the aorta was measured perpendicular to the aortic course at 5 anatomic segments. Level A was the mid-ascending aorta, level B was the distal ascending aorta, level C was the aortic arch, level D was the aortic isthmus and level E was the mid-descending aorta. Result: The mean age was 49.5 years old for males and 54.9 years old for females (p<0.05). The mean diameter of the thoracic aorta at level A was 31.1 mm, that at level B was 30.2 mm, that at level C was 26.5 mm, that at level D was 24.0 mm and that at level E was 22.6 mm. The diameters at all the levels were gradually increased with age. Hypertensive patients had larger diameters than did the non-hypertensive population. There was a positive correlation between the ascending aortic diameter (levels A&B) and height and the body surface area, but there were no statistical differences at the aortic arch (level C) and the descending aorta (levels D&E). There were no statistical differences of the weight and body mass index at all levels. Conclusion: The diameters of the thoracic aortas were directly correlated with gender, age and hypertension. Height and the body surface area were only correlated with the ascending aorta. Weight and the body mass index have no statistical difference at all levels. We measured the age related thoracic aortic diameters and the upper normal limits and we provide this data as reference values for the thoracic aortic diameter in the Korean population.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.48-52
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• 2013

Purpose: The Molybdenum which is the raw material of $^{99}Mo-^{99m}Tc$ generator is produced from the nuclear reactor. However, output has dwindled as the two nuclear reactors supplying the bulk of radioactive material-one in Chalk River, Ontario and the other in Petten, the Netherlands-have been closed for repairs or maintenance. This resulted in the enhancement of its price. So $^{99}Mo-^{99m}Tc$ generator using$(n,{\gamma})^{99}Mo$ is developed by Korea Atomic Energy Research Institute (KAERI). Medicinal availability of this generator is evaluated in this study. Materials and Methods: The radioactivity of $^{99m}Tc$ eluted in generator 1, 2 and 3 unit developed by KAERI was measured. The quality control test of generator such as appearance test, pH test, LAL test, sterility test, chemical impurity (Al) test and radiochemical purity test were performed. Planar and SPECT/CT image sof SD rat (6 weeks, Female) at 2 hr after injection of $^{99m}Tc-HDP$ (hydroxymethylenediphosphonate) (TechneScan HDP, Malinckrodt Medical, Dutch) and $^{99m}Tc-DPD$ (diphosphono-1, 2-propanedicarboxylicacid) (TECEOS, CIS bio international, France) which were labeled with $^{99m}Tc$ eluted in KAERI and commercial generator (40.5 GBq, Malinckrodt Medical, Dutch) using SPECT/CT camera (Symbia, Siemense, Germany) were obtained respectively. Results: The mean radioactivity of $^{99m}Tc$ elution generator 1unit was 4.18 GBq (113 mCi), generator 2 unit was 4.73 GBq (128 mCi) and generator 3 unit was 3.33 GBq (90 mCi). All quality control tests were within normal limit except pyrogentest. Pyrogen test was positive. Planar and SPECT/CT images of rat injected $^{99m}Tc-HDP$ which was labeled with $^{99m}Tc$ eluted in commercial generator show increased uptake in bone, stomach and bowl. Planar images show increased uptake in liver and bone in case of $^{99m}Tc-DPD$. However, images of rat injected $^{99m}Tc-HDP$ and $^{99m}Tc-DPD$ which were labelled $^{99m}Tc$ eluted in KAERI generator show increased uptake in bone, liver and spleen. Conclusion: If shortcoming is removed such as pyrogen and liver appearance, domestic role as an alternative generator is thought to be able to fill and to secure the national medical service by supplying $^{99m}Tc$ when the supply of $^{99m}Tc$ be comes short.