• Radiation Oncology Journal
• /
• v.15 no.1
• /
• pp.19-26
• /
• 1997

Purpose : This study is to report experience with Fractionated Stereotactic Radiation Therapy (FSRT) for locally recurrent nasopharynx cancer after curative conventional radiation therapy. Materials and Methods : Three Patients with locally recurrent and symptomatic nasopharynx cancer were given FSRT as reirradiation method between the Period of September of 1995 and August of 1996 For two Patients, application of FSRT is their third radiation therapy directed to the nasopharynx. Two patients were given low dose chemotherapy as radiation sensitizer concurrently with FSRT Authors used 3-dimensional coordinate system by individually made, relocatable Gill-Thomas-Cosman (GTC) stereotactic frame and multiple non-coplanar arc therapy dose Planning was done using Xknife-3. Total of 45 Gy/18 fractions or 50 Gy/20 fractions were given. Results : Authors observed satisfactory symptomatic improvement and remarkable objective tumor size decrease by follow-up MR images taken 1 month Post-FSRT in ali three patients, while no neurologic side effect attributable to reirradiation was noticed. Two died at 7 and 9 months with loco-regional and distant seeding outside FSRT field, while one patient is living for 4 month. Conclusion Authors experienced satisfactory therapeutic effectiveness and safety of FSRT as reirradiatlon method for locally recurrent nasopharynx cancer Development of more effective systemic chemotherapeutic regimen is desired for distant metastasis

• The Korean Journal of Nuclear Medicine Technology
• /
• v.20 no.1
• /
• pp.47-51
• /
• 2016

Purpose By ingestion of 18F-FDG of kidney of PET/CT during the inspection, if additional examination is required, depending on whether you want to water intake, we want to confirm a change in the rate of decrease of F-18 FDG of the kidney. Materials and Methods The 80 patients without kidney disease were performed PET/CT examination. Device was analyzed after setting the kidney to a three-dimensional region of interest. In patients require additional examination, and inspection after 30 minutes, a PET/CT torso examination after the water of the 500 cc ingested at a time. After the addition of both water intake group and no hydration group of kidney of SUV, it was compared with PET/CT torso scan. Results High and low of the kidney SUV did not show a significant difference in the rate of decrease. Reduction rates of background (BKG) of additional examination was 2.8% and reduction rates of SUV was 49.7% (Hydration) : -6.8% (No hydration), so did show a significant difference. In the image blind test, the average point score of hydration and no hydration was 34.25 : 17.25. Conclusion An undercurrent of 18F-FDG in the kidney at the time of torso examination, it was confirmed that the reduction rate after the addition of water intake is high. It is considered that can be expected to improve the quality of an image due to a decrease in elongation through the kidneys examination with additional fluid intake as needed intake.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.4
• /
• pp.43-53
• /
• 2005

This study is to define how the difference of athletic change influence on the last regrasp after somersault in Belle movement of parallel bars. For his study, the following conclusion was produced by analysis of athletic change by means of three dimensional visual image in three athlete of nation. 1. As the picture of S1, there are total used time(2.01 sec), S3(2.17 sec) and S2(2.19 sec). In case of a short needed time, it is difficult for them to perform the remaining movement of the vertical elevating flight easily and comfortably, it is judged as performing the small movement with restrict swing. 2 In the change of body center sped by each event, it is calculated as $-89.1^{\circ}$ the narrowest in S1, $-81.96^{\circ}$ the widest and then $86.34^{\circ}$ in S3. In E3 event, average compound speed is 4.07m/s, S2 showed the fastest speed of 4.14m/s whereas S1 the narrowest angle of 3.95m/s. 3. A shoulder joint and coxa are the period of mention in E3. In E4 which was pointed out the longest vertical distance, S2 that is indicated the highest vertical height as the period of detach in parallel bars. showed -3.91m. This is regarded as a preparatory movement for dynamic performance after using effectively elastic movement of shoulder joint and coxa while easily going up with turning back movement. In the 5th phrase, long airborne time and vertical change position is showed as the start while regrasping securely air flight movement from high position. 4. In E5, a long flight time and a long vertical displacement were shown as the regrasp after somersault efficiently in high position with stability from the point of the highest peak of the center of the body. Especially, S2 is marked as a little bit long position, while S1 is reversely indicated as performing somersault and unstable motion in a low position. 5. In E3, at the point of the largest extension of the shoulder joint and hip joint the shoulder joint is largely marked in $182^{\circ}$ and the hip point $182^{\circ}$ in S2. The shoulder joint is marked at the smallest angle in $177^{\circ}$ and the hip point $176^{\circ}$ in S1. And S1 is being judged by its performance of the less self - confident motion with lessening a breath of swing. S2 makes the most use of flexion and extension of the shoulder joint and the hip joint effectively. It was performed greatly with swinging and dropping the rotary movement and the rotary inertia naturally. 6. In E6, as the point of regrasp of the upper arm in parallel bars it is recognized by the that of components of vertical and horizontal velocity stably. During this study, the insufficient thing and the study on the parallel bars at a real game later are more activated than now. If it is really used as the basic materials by means of Belle Picked Study of Super E level after Bell movement, you may perceive the technique movement previously and perform without difficulty. Especially, such technique as crucifix is quite advantageous for oriental people thanks to small body shape condition. In conclusion we will nicely prepare for our suitable environment to gradually lessen trials and errors by analyzing and studying kinematically this movement.

• Restorative Dentistry and Endodontics
• /
• v.34 no.4
• /
• pp.324-332
• /
• 2009

The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained cortical bone, trabecular bone, periodontal ligament, 4 mm apical root canal filling, and post-and-core. Six combinations of three parallel type post (zirconia ceramic, glass fiber, and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. A 50 N static occlusal load was applied to the palatal surface of the crown with a $60^{\circ}$angle to the long axis of the tooth. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. An increase of the elastic modulus of the post material increased the stress, but shifted the maximum stress location from the dentin surface to the post material. Buccal side of cervical region (junction of core and crown) of the glass fiber post restored tooth was subjected to the highest stress concentration. Maximum von Mises stress in the remaining radicular tooth structure for low elastic modulus resin core (29.21 MPa) was slightly higher than that for high elastic modulus resin core (29.14 MPa) in case of glass fiber post. Maximum displacement of glass fiber post restored tooth was higher than that of zirconia ceramic or stainless steel post restored tooth.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.8
• /
• pp.618-626
• /
• 2019

Stem cell therapy is not expected to bestow any therapeutic benefit because of the low engraftment rates after transplantation.Various cell-carrying scaffolds have been developed in order to overcome this problem. When the scaffold is formed by 3-dimensional (3D) printing, it is possible to create various shapes of scaffolds for specific regions of injury. At the same time, scaffolds provide stem cells as therapeutic-agents and mechanically support an injured region. PCL is not only cost effective, but it is also a widely used material for 3D printing. Therefore, rapid and economical technology development can be achieved when PCL is printed and used as a cell carrier. Yet PCL materials do not perform well as cell carriers, and only a few cells survive on the PCL surface. In this study, we tried to determine the conditions that maximize the cell-loading capacity on the PCL surface to overcome this issue. By applying a plasma treated condition and then collagen coating known to improve the cell loading capacity, it was confirmed that the 3% collagen coating after plasma treatment showed the best cell engraftment capacity during 72 hours after cell loading. By applying the spheroid cell culture method and scaffold structure change, which can affect the cell loading ability, the spheroid cell culture methods vastly improved cell engraftment, and the scaffold structure did not affect the cell engraftment properties. We will conduct further experiments using PCL material as a cell carrier and as based the excellent results of this study.

• Korean Journal of Heritage: History & Science
• /
• v.51 no.2
• /
• pp.4-21
• /
• 2018

This paper reviewed the legitimacy of the name of those sixteen pieces of hat artifacts known in Korean as pyeongjeongmo and currently housed by the National Palace Museum. This was undertaken in order to rectify the error of calling them pyeongjeongmo. Also, the paper suggested pyeongjeongmo's production method to apply representation of the artifacts or production of Joseon officials' hats as representation of ritual costumes in the royal court. The name pyeongjeongmo originated from pyeongjeonggeon. Gyeongguk Daejeon recorded that noksas wore yugak-pyeongjeonggeon and seoris wore mugak-pyeongjeonggeon, but the pyeongjeongmo artifacts housed in the National Palace Museum have been found irrelevant to those pyeongjeonggeons put on by both noksas and seoris. Rather, they has been confirmed as corresponding to dugeon or jogeon worn by byeolgams or suboks who served at the palace of the crown prince or princess. Through the investigation of the artifacts, the researchers could find out the tailoring and sewing methods, the finished look, and the folding manner of pyeongjeonggeon. Although the structure of pyeongjeonggeon was generally consistent, the frontal look was slightly different depending on the folding manner, resulting in three distinguished types of pyeongjeonggeon. Regardless, the pyeongjeongmo was made with one piece of fabric by a flat tailoring and folding method to create a three-dimensional hat. The finished shape appeared low in the front and high in the back side structure. The head girth was 55~59 cm, and the height was 19.4~21.5 cm. To make it with one piece of fabric, the head girth part was tailored in the same direction as the strands. Based on the artifact Changdeok 23820, this paper has also suggested a finished reproduction through the processes of preparing the materials, mounting, making the center ornaments, sewing and folding. The tailoring was completed with black silk fabric which was cut in a unique shape designed in advance, and hemp fabric which was mounted to the former. The top part of the head was finished with black threads, and the center line at the back was fixed with decolored cotton threads by blanket stitches with 3.5~4 cm intervals. Bamboo strands were inserted in the inside of the front-folded part, which then was fixed by patterned stitches with white cotton thread. At the back, a small bamboo clasp was attached so that one can lock it to the headband and prevent it from falling off.

• The Journal of Korean Society for Radiation Therapy
• /
• v.27 no.1
• /
• pp.61-71
• /
• 2015

Purpose : 3D Printers are used to create three-dimensional models based on blueprints. Based on this characteristic, it is feasible to develop a bolus that can minimize the air gap between skin and bolus in radiotherapy. This study aims to compare and analyze air gap and target dose at the branded 1 cm bolus with the developed customized bolus using 3D printers. Materials and Methods : RANDO phantom with a protruded tumor was used to procure images using CT simulator. CT DICOM file was transferred into the STL file, equivalent to 3D printers. Using this, customized bolus molding box (maintaining the 1 cm width) was created by processing 3D printers, and paraffin was melted to develop the customized bolus. The air gap of customized bolus and the branded 1 cm bolus was checked, and the differences in air gap was used to compare $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$ and $V_{95%}$ in treatment plan through Eclipse. Results : Customized bolus production period took about 3 days. The total volume of air gap was average $3.9cm^3$ at the customized bolus. And it was average $29.6cm^3$ at the branded 1 cm bolus. The customized bolus developed by the 3D printer was more useful in minimizing the air gap than the branded 1 cm bolus. In the 6 MV photon, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 102.8%, 88.1%, 99.1%, 95.0%, 94.4% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 101.4%, 92.0%, 98.2%, 95.2%, 95.7%, respectively. In the proton, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 104.1%, 84.0%, 101.2%, 95.1%, 99.8% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 104.8%, 87.9%, 101.5%, 94.9%, 99.9%, respectively. Thus, in treatment plan, there was no significant difference between the customized bolus and 1 cm bolus. However, the normal tissue nearby the GTV showed relatively lower radiation dose. Conclusion : The customized bolus developed by 3D printers was effective in minimizing the air gap, especially when it is used against the treatment area with irregular surface. However, the air gap between branded bolus and skin was not enough to cause a change in target dose. On the other hand, in the chest wall could confirm that dose decrease for small the air gap. Customized bolus production period took about 3 days and the development cost was quite expensive. Therefore, the commercialization of customized bolus developed by 3D printers requires low-cost 3D printer materials, adequate for the use of bolus.

• Radiation Oncology Journal
• /
• v.28 no.4
• /
• pp.193-204
• /
• 2010

Purpose: To analyze the treatment outcomes, complications, prognostic factors after a long-term follow-up of patients with nasopharyngeal carcinoma treated with radiation therapy (RT) alone or concurrent chemoradiation therapy (CCRT). Materials and Methods: Between December 1981 and December 2006, 190 eligible patients with non-metastatic nasopharyngeal carcinoma were treated at our department with a curative intent. Of these patients, 103 were treated with RT alone and 87 patients received CCRT. The median age was 49 years (range, 8~78 years). The distributions of clinical stage according to the AJCC 6th edition included I: 7 (3.6%), IIA: 8 (4.2%), IIB: 33 (17.4%), III: 82 (43.2%), IVA: 31 (16.3%), IVB: 29 (15.3%). The accumulated radiation doses to the primary tumor ranged from 66.6~87.0 Gy (median, 72 Gy). Treatment outcomes and prognostic factors were retrospectively analyzed. Acute and late toxicities were assessed using the RTOG criteria. Results: A total of 96.8% (184/190) of patients completed the planned treatment. With a mean follow-up of 73 months (range, 2~278 months; median, 52 months), 93 (48.9%) patients had relapses that were local 44 (23.2%), nodal 13 (6.8%), or distant 49 (25.8%). The 5- and 10-year overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) rates were 55.6% and 44.5%, 54.8% and 51.3%, in addition to 65.3% and 57.4%, respectively. Multivariate analyses revealed that CCRT, age, gender, and stage were significant prognostic factors for OS. The CCRT and gender were independent prognostic factors for both DFS and DSS. There was no grade 4 or 5 acute toxicity, but grade 3 mucositis and hematologic toxicity were present in 42 patients (22.1%) and 18 patients (9.5%), respectively. During follow-up, grade 3 hearing loss in 9 patients and trismus in 6 patients were reported. Conclusion: The results of our study were in accordance with findings of previous studies and we confirmed that CCRT, low stage, female gender, and young age were related to improvement in OS. However, there are limitations in the locoregional control that can be achieved by CCRT with 20 conventional radiation therapy. This observation has led to further studies on clarifying the efficacy of concurrent chemotherapy by intensity modulated radiation therapy.