• Radiation Oncology Journal
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• v.21 no.1
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• pp.44-65
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• 2003

Purpose : To conduct nationwide surgery on the principles In radiotherapy for rectal center, and develop the framework of a database of Korean Patterns of Care Study. Materials and Methods : A consensus committee was established to develop a tool for measuring the Patterns in radiotherapy Protocols for rectal cancer. The Panel was composed of radiation oncologists from 18 hospitals in Seoul Wetropolltan area. The committee developed a survey format to analyze radiation oncologist's treatment principles for rectal cancer. The survey items developed for measuring the treatment principles were composed of 1) 8 eliglblllty criteria, 2) 20 Items for staging work-ups and prognostic factors, 3) 7 Items for principles of combined surgery and chemotherapy, 4) 9 patient set-ups, 5) 19 determining radiation fields, 6) S radiotherapy treatment pians, 7) 4 physicalilaboratory examination to monitor a patient's condition during treatment, and 8) 10 follow-up evaluations. These items were sent to radiation oncoioglsts In charge of gastrolntestlnal malignancies in all hospitals (48 hospitals) In Korea to which 30 replies were received (63$\%$). Results : Most of the surrey Items were replied to without no major between the repliers, but with the fellowing items only 50$\%$ of repliers were in agreement : 1) Indications of preoperative radiation, 2) use of endorectal ultrasound, CT scan, and bone scan for staging work-ups, 3) principles of combining chemotherapy with radiotherapy, 4) use of contrast material for small bowel delineation during simulation, 5) determination of field margins, and 6) use of CEA and colonoscopy for follow-up evaluations. Conclusions : The Items where considerable disaggrement was shown among the radiation oncologists seemed to make no serious difference In the treatment outcome, but a practical and reasonable consensus should be reached by the committee, with logical processes of agreement. These Items can be used for a basic database for the Patterns of Care Study, which will survey the practical radiotherapy Patterns for rectal cancer in Korea.

• Journal of Oral Medicine and Pain
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• v.31 no.2
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• pp.185-197
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• 2006

The aim of this study was to investigate the beneficial effect of a daily dose of 300 mg of ASU taken for more than 3 months on the subjects diagnosed as osteoarthritis of temporomandibular joint by RDC/TMD. Total 68 outpatients(15-54y) of female except menopause in Orofacial Pain Clinics of the Pusan National University Hospital were randomly assigned to either an ASU group(n=36) or a placebo group(n=32). The pain, noise and limited mouth opening(LOM) were evaluated by numerical analogue scale(NAS, range 0-10) and maximum comfortable opening(MCO) were measured by milimeter scale. The difference of simple uptake rate(SUR) on bone scan, hot spot(HS) on coronal SPECT, condylar bony changes on CT between the ASU and placebo groups were compared to investigate the objective effect. The obtained results were as follows. 1. Comparison of the NAS of pain, noise, LOM and MCO before treatment and 3, 6 and 9 months after treatment showed no significant difference between the ASU and placebo groups. 2. Comparison of the NAS of pain, noise, LOM and MCO before treatment and 3, 6 and 9 months after treatment showed no significant difference between the ASU and placebo groups without splint treatment, but showed more increased MCO in the ASU group than the placebo group with splint treatment at 6, 9 months after treatment. 3. Comparison of the NAS of pain before treatment and 3, 6 and 9 months after treatment that the NAS of pain at first visit divided into two groups(above or below 6) showed more decreased the NAS of pain in the ASU group than the placebo group that the NAS of pain at first visit was above 6. 4. Comparison of the NAS of pain, noise, LOM and MCO during 6 months period showed improvement of clinical symptoms within group, but no significant difference between subjects. 5. The simple uptake ratio(SUR) on bone scan and hot spot(HS) on coronal SPECT showed more increased SUR and HS in affected side than non-affected side of the ASU and placebo groups. 6. Comparing of condylar bony changes, osseous remodeling were observed highest, osteophyte lowest in the affected and non-affected side of the two groups. After treatment, comparison of condylar bony changes were observed more decreased erosive features in the ASU group than the placebo group.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.74-79
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• 2017

Purpose Proton therapy can deliver an optimal dose to tumor while reducing unnecessary dose to normal tissue as compared the conventional photon therapy. As proton beams are irradiated into tissue, various positron emitters are produced via nuclear fragmentation reactions. These positron emitters could be used for the dose verification by using PET. However, the short half-life of the radioisotopes makes it hard to obtain the enough amounts of events. The aim of this study is to investigate the effect of off-line PET imaging scan time on the PET image quality. Materials and Methods The various diameters of spheres (D=37, 28, 22 mm) filled with distilled water were inserted in a 2001 IEC body phantom. Then proton beams (100 MU) were irradiated into the center of the each sphere using the wobbling technique with the gantry angle of $0^{\circ}$. The modulation widths of the spread out bragg peak were 16.4, 14.7 and 9.3 cm for the spheres of 37, 28 and 22 mm in diameters respectively. After 5 min of the proton irradiation, the PET images of the IEC body phantom were obtained for 50 min. The PET images with different time courses (0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min) were obtained by dividing the frame with a duration of 10 min. In order to evaluate the off-line PET image quality with the different time courses, the contrast-to-noise ratio (CNR) of the PET image calculated for each sphere. Results The CNRs of the sphere (D=37 mm) were 0.43, 0.42, 0.40, 0.31 and 0.21 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNRs of the sphere (D=28 mm) were 0.36, 0.32, 0.27, 0.19 and 0.09 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNR of 37 mm sphere was decreased rapidly after 30 min of the proton irradiation. In case of the spheres of 28 mm and 22 mm, the CNR was decreased drastically after 20 min of the irradiation. Conclusion The off-line PET imaging time is an important factor for the monitoring of the proton therapy. In case of the lesion diameter of 22 mm, the off-line PET image should be obtained within 25 min after the proton irradiation. When it comes to small size of tumor, the long PET imaging time will be beneficial for the proton therapy treatment monitoring.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.243-249
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• 1997

Purpose : In radiation therapy, NTCF is very importart indicator of selecting the optimal treatment plan. In our study, we tried to find out usefullness of NTCP in lung cancer by comparng the incidence of radiation pneumonitis with NTCP. Materials and Methods : From August 1993 to December 1994, thirty six patients with locally advanced non=small cell lung cancer were treated by concurrent chemoradiation therapy. Total dose of radiation therapy was 6480cGy (120cGy, bid) and chemotherapeutlc agents were mitomycin C. vinblastion, cisplatin (2 cycles, 4 weeks interval). We evaluated the development of raniation pneumonitis by CT scan, chest x-rar and clinical symptoms. We used grading system of South Western Oncology Group (SWOG) for radiation pneumanitis. Dose Volume Histograms (DVH) were analyzed for ipsilateral and whole lung, Non uniform DVH was translated to uniform DVH by effective volume method. With these data, we calculated NTCP for ipsilateral and whole lung. Finally we compared the clinical results to NTCP. Results : Eight of thrity six patients developed radiation pneumonitis. Of these 8 patients , 6 had grade I severity and 2 had grade II. The average NTCP value cf the patients who showed radiation pneumonitis was significantly higher than that uf the patients without pneumonitis $(66\%\;vs.\;26.4\%)$. But the results of pulmonary function test was not correlated with NTCP. Conclusion : NTCP of lung is very good indicator for selecting rival treatment planning in lung cancer. According to the results of NTCP, it may be possible to adjust target volume and optimize target dose. In the near future, we are going to anaiyze the effect of hyperfractionation and concurrent chemotherapy in addition to NTCP.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.41-52
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• 2002

Purpose : 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device (RGRD) for using during CT simulation, dose planning and beam delivery at identical breathing period conditions. Using RGRD, reducing the treatment margin for organ (thorax or abdomen) motion due to breathing and improve dose distribution for 3D conformal radiotherapy. Materials and Methods : The internal organ motion data for lung cancer patients were obtained by examining the diaphragm in the supine position to find the position dependency. We made a respiratory gating radiotherapy device (RGRD) that is composed of a strip band, drug sensor, micro switch, and a connected on-off switch in a LINAC control box. During same breathing period by RGRD, spiral CT scan, virtual simulation, and 3D dose planing for lung cancer patients were peformed, without an extended PTV margin for free breathing, and then the dose was delivered at the same positions. We calculated effective volumes and normal tissue complication probabilities (NTCP) using dose volume histograms for normal lung, and analyzed changes in doses associated with selected NTCP levels and tumor control probabilities (TCP) at these new dose levels. The effects of 3D conformal radiotherapy by RGRD were evaluated with DVH (Dose Volume Histogram), TCP, NTCP and dose statistics. Results : The average movement of a diaphragm was 1.5 cm in the supine position when patients breathed freely. Depending on the location of the tumor, the magnitude of the PTV margin needs to be extended from 1 cm to 3 cm, which can greatly increase normal tissue irradiation, and hence, results in increase of the normal tissue complications probabiliy. Simple and precise RGRD is very easy to setup on patients and is sensitive to length variation (+2 mm), it also delivers on-off information to patients and the LINAC machine. We evaluated the treatment plans of patients who had received conformal partial organ lung irradiation for the treatment of thorax malignancies. Using RGRD, the PTV margin by free breathing can be reduced about 2 cm for moving organs by breathing. TCP values are almost the same values $(4\~5\%\;increased)$ for lung cancer regardless of increasing the PTV margin to 2.0 cm but NTCP values are rapidly increased $(50\~70\%\;increased)$ for upon extending PTV margins by 2.0 cm. Conclusion : Internal organ motion due to breathing can be reduced effectively using our simple RGRD. This method can be used in clinical treatments to reduce organ motion induced margin, thereby reducing normal tissue irradiation. Using treatment planning software, the dose to normal tissues was analyzed by comparing dose statistics with and without RGRD. Potential benefits of radiotherapy derived from reduction or elimination of planning target volume (PTV) margins associated with patient breathing through the evaluation of the lung cancer patients treated with 3D conformal radiotherapy.

• Tuberculosis and Respiratory Diseases
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• v.39 no.3
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• pp.236-241
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• 1992

Background: As well as fiberoptic bronchoscopy, chest computerized tomographic scan can now differentiate the benign from malignant causes and the obstructive from non-obstructive causes of lung collapse. This study was designed to evaluate the usefulness of chest CT scan and fiberoptic bronchoscopy in the diagnosis of middle lobe syndrome. Method: We reviewed the clinical features, roentgenographic changes, pathologic findings and bronchoscopic findings in 16 patients with middle lobe syndrome who were admitted to Severance Hospital during period of January, 1987 through January, 1992. Results: The male to female ratio was 1:1. The most common symptoms were cough and sputums. Crackle was the most common physical finding. Underlying disease was lung cancer, pulmonary tuberculosis and endobronchial tuberculosis in 3 each other, benign stenosis in 2, lung abscess, broncholithiasis, bronchial chondroma, pneumonia and nonspecific inflammation in 1 each other. Conclusion: We conclude that the combination of chest computerized tomogram and fiberoptic bronchoscopy was most desirable for the diagnosis of middle lobe syndrome.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.317-322
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• 2009

Purpose: $^{18}$F-flurodeoxyglucose (FDG) uptake on positron emission tomography (PET) scan has been found to reflect tumor aggressiveness and prognosis in various types of cancer. However, pattern of FDG uptake in biliary malignancies and its clinical significance have not been studied well. The purpose of this study was to assess the additional value of $^{18}$F-FDG PET in differential diagnosis and prognosis of cholangiocarcinoma (CC) according to the tumor location and tumor morphology. Materials and Methods: From April 2005 to May 2008, eighty two patients (M:F = 55:27, age 66.2$\pm$9.6 yrs) with CC underwent $^{18}$F-FDG PET. For semiquantitative analysis, the maximum standardized uptake value (SUV$_{max}$) was obtained from the primary tumor. The difference of SUV$_{max}$ according to the tumor location and tumor growth pattern, such as scirrhous type, nodular type, polypoid type were compared. Results: Overall sensitivity of PET scan was 81.7% in CC. SUV$_{max}$ on PET scan in intrahepatic CC was significantly higher compared to extrahepatic CC. In extrahepatic CC, polypoid type showed significantly higher SUV$_{max}$ compared to scirrhous type. Conclusion: $^{18}$F-FDG PET may have a significant impact on clinical decision-making and on the management of intrahepatic cholangiocarcinoma. And it is related to the shape of the tumor and the sensitivity of detection is higher in the mass-forming type than in the scirrhous type.

• Tuberculosis and Respiratory Diseases
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• v.60 no.6
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• pp.625-630
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• 2006

Background: Pulmonary hypertension in COPD patients is the result of a direct effect of tobacco smoke on the intrapulmonary vessels with the abnormal production of the mediators that control vasoconstriction, vasodilatation, and vascular cell proliferation, which ultimately lead to aberrant vascular remodeling and physiology. COPD patients are prone to the developmint of an acute and chronic thromboembolism with an elevation of the plasma procoagulant and fibrinolytic markers However, the roles of the coagulation and fibrinolysis system on the right ventricular dysfunction in COPD patients are not well defined. We examined the alteration of the coagulation and fibrinolysis system in COPD patients according to the right ventricular function measured using cardiac multidetector computed tomography (MDCT). Methods: The right ventricular ejection fraction (RVEF) was measured using cardiac MDCT in 26 patients who were diagnosed with COPD according to the definition of the GOLD guideline. The plasma level of thrombin antithrombin (TAT) and plasminogen activator inhibitor (PAI)-1 were measured using an enzyme linked immunoassay. Results: The plasma TAT was markedly elevated in COPD patients ($10.5{\pm}19.8{\mu}g/L$) compared with those of the control ($3.4{\pm}2.5{\mu}g/L$) (p<0.01). However, the plasma PAI-1 in COPD patients ($29.6{\pm}20.7ng/mL$) was similar to that in the controls. The plasma TAT showed a significant inverse relationship with the RVEF measured by the cardiac MDCT in COPD patients (r=-0.645, p<0.01). However, the plasma PAI-1 did not show a relationship with the RVEF (r=0.022, p=0.92). Conclusion: These results suggest that the coagulation system in COPD patients is markedly activated, and that the plasma level of TAT might be a marker of a right ventricular dysfunction in COPD patients.

• 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 the Institute of Electronics Engineers of Korea SP
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• v.43 no.6 s.312
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• pp.28-35
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• 2006

Statistical models of shape variability based on active shape models (ASMs) have been successfully utilized to perform segmentation and recognition tasks in two-dimensional (2D) images. Three-dimensional (3D) model-based approaches are more promising than 2D approaches since they can bring in more realistic shape constraints for recognizing and delineating the object boundary. For 3D model-based approaches, however, building the 3D shape model from a training set of segmented instances of an object is a major challenge and currently it remains an open problem in building the 3D shape model, one essential step is to generate a point distribution model (PDM). Corresponding landmarks must be selected in all1 training shapes for generating PDM, and manual determination of landmark correspondences is very time-consuming, tedious, and error-prone. In this paper, we propose a novel automatic method for generating 3D statistical shape models. Given a set of training 3D shapes, we generate a 3D model by 1) building the mean shape fro]n the distance transform of the training shapes, 2) utilizing a tetrahedron method for automatically selecting landmarks on the mean shape, and 3) subsequently propagating these landmarks to each training shape via a distance labeling method. In this paper, we investigate the accuracy and compactness of the 3D model for the human liver built from 50 segmented individual CT data sets. The proposed method is very general without such assumptions and can be applied to other data sets.