• The Korean Journal of Nuclear Medicine
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• v.24 no.2
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• pp.244-253
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• 1990

Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows: 1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were ischemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5). pericardial effusion(5), post cardiac surgery(3), col pulmonale (2), endocarditis(1) and right ventricular tumor(1). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion(p<0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipultion respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical molies in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image-is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.8-17
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• 1996

The purpose of this study is a comparative evaluation of range motion, especially extension deficit between the group of total patellectomy and that of intact patella, after reconstruction of the patellar tendon in the prosthetic replacement of a proximal tibia. Between 1990 and 1994, 15 patients who had a primary malignancy on proximal tibia were operated on. All patients were evaluated clinically and radiographically. Two patients were excluded because one had a deep infection treated with arthrodesis of the knee and the other was a composite allograft. The mean follow-up of the 13 patients was 27 months(15-47), including 10 osteosarcomas, 1 chondrosarcoma, 1 malignant fibrous histiocytoma and 1 malignant giant cell tumor. Eleven patients had a resection of the proximal tibia and 2 had an extracapsular total knee resection with distal femur. Reconstruction of the defect was done in 8 cases with a custom-made Link Endo-Model Total Rotation Knee Joint Prosthesis, and in 5 with How Medica Modular Resection System (HMRS). We used two methods to reconstruct the ligamentum patellae. Fixation of the patellar tendon to the prosthesis only with suturing and/or stapling(group SS) was done in 7. Transposition of gastrocnemius muscle to enhance fixation and to cover the prosthesis(group TG) was done in 6. Regardless of fixation methods, total patellectomy was done in 5 either to lengthen the patellar tendon or to make primary skin closure easier or for both. In 8 cases, patella was left intact or resurfaced with polyethylene prosthesis. Active extension was measured while the patient was in a sitting position. There is no statistically meaningful difference in terms of extension deficit (Wilcoxon rank test, p=0.8800) between patellectomy group and intact patella group, and between group of fixation only with suturing and that of gastrocnemius transposition. Two cases of extension deficit over 30 degree were seen in group SS and in the group of intact patella. Conclusively, total patellectomy could be an option without increasing the risk of extension deficit when primary skin closure is difficult or patellar tendon is a little bit short to be fixed. There is no rating in the Enneking system of functional evaluation that this finding into consideration.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.343-349
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• 2018

Dose rate regulated tracking is known to be an efficient method which adaptively delivers tracking treatments when patient breathing is irregular. The Motion Management Interface (MMI, Varian Medical System, CA), which provides beam on/off switching during treatment is available for clinic. Study is to test if delivering the adaptive tumor tracking is feasible for irregular breathing using beam switching with MMI. 55 free breathing RPM traces acquired from lung cancer patients are used. The first day RPM traces of the patients are utilized to design preprogrammed tracking MLC patterns, of which periods are intentionally reduced by 20% in order to catch up the variation of patient breathing irregularity in the treatment day. Eligibility criteria for this technique are the variation of amplitude and period less than 20%. An algorithm which determines beam on/off every 100 ms by considering the preprogrammed (MLC) positions and current breathing positions is developed. Tracking error and delivery efficacy are calculated by simulating the beam-switching adaptive tracking from the RPM traces. Breathing patterns of 38 patients (70%) met the eligibility criteria. Tracking errors of all of the cases who meet the criteria are less than 2 mm (average 1.4 mm) and the average delivery efficacy was 71%. Those of rest of the cases are 1.9 mm and 48%. Adaptive tracking with beam switching is feasible if patient selection is based on the eligibility criteria.

• Progress in Medical Physics
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• v.23 no.3
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• pp.169-176
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• 2012

Frameless method in brain radiosurgery has advantages relative to rigid head-frame method in terms of patient friendly and flexible application of multi-fractionation. However, it has also disadvantages and the most negative point is that it cannot control the patient motion during treatment as lowly as the level of the frame-based radiosurgery, which could affect to the treatment accuracy. In the present study, we analyzed the geometric uncertainty of the intra-fraction motion using the actual treatment records of 294-CyberKnife treatments for brain tumors. Based on the analysis, we statistically presented the magnitude of intra-fraction motion in frameless radiosurgy. The result could provide the quantitative information to determine the adequate treatment margins to compensate the intra-fraction movements.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.109-112
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• 2011

Purpose: Neurofibromas may present as multiple or solitary lesions. Although there is no predilection site for solitary lesions, they are rare on the hand. In addition, solitary intramuscular neurofibromas are a very rare pathological type. Here, we report a rare solitary intramuscular neurofibroma in the hand. This paper examines the clinical characteristics of intramuscular neurofibroma arising from the lumbricalis in order to enable a correct diagnosis and treatment. Methods: A 32-year-old male presented with a painless mass on the palm. The physical examination revealed a $3{\times}2$ cm protruding mass that was non-tender to palpation. The vascular and sensory examinations were unremarkable, while the motor examination showed mild difficulty with flexion and extension. Magnetic resonance imaging demonstrated an enhancing solid mass between the thenar eminence and second metacarpophalangeal joint. The diagnosis of an intramuscular neurofibroma was confirmed following surgical excision and histological evaluation. Results: The pathological examination was consistent with a neurofibroma, with delicate fascicles and loose fusiform cells in a fibrous stroma, with oval or spindle-shaped nuclei and scant cytoplasm. The background matrix was pale staining and had focal myxoid stroma. There was no significant nuclear pleomorphism and no mitoses. Immunohistochemistry with S-100 was slightly positive. At the 6-month follow-up, motor and sensory function were intact and the range of motion was full. Conclusion: A neurofibroma is a rare tumor of the hand, especially the intramuscular type. Hand surgeons should consider the diagnosis of this tumor based on the examination and imaging.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.497-499
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• 2009

Purpose: Leiomyoma is a rare benign tumor of nonstriated muscles. Leiomyoma is most commonly found in the uterus and rarely occur in the hand. 150 cases of leiomyoma of the hand have been reported in the English literature; however, to the best of our knowledge only four of these have been in children and none were reported in Korean literature. We present a case of leiomyoma in the hand of a 8 - year - old boy, which is a rare site for localization and unusual for age. Methods: A 8 - year - old boy presented with a painless mass on the ulnar side of his thumb. Physical examination revealed a $1.2{\times}1.2cm$ round, rubbery mass that was nontender to palpation. The vascular, sensory, and motor exams were otherwise unremarkable. Further evaluation with CT demonstrated an enhancing mass at dorsoulnar aspect of 1st proximal phalangeal region suggestive of a hemangioma versus other enhancing solid mass. The diagnosis of a leiomyoma was confirmed following surgical excision with histologic evaluation. Results: At 3 months follow - up, the incision was healed, motor and sensory function were intact, and there were full range of motion. Neither recurrence nor postoperative complication were observed. Conclusion: Leiomyoma is a rare tumor of the hand, especially in children. Diagnosing hand tumors in children is more difficult than in adults, hand surgeons should be aware of the diagnostic possibilities based on examination and imaging of a hand tumor ; however, surgical excision with histologic examination is required for definitive diagnosis.

• Progress in Medical Physics
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• v.28 no.4
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• pp.171-180
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• 2017

The purpose of this study is to install a system that compensated for the respiration motion using an articulated robotic manipulator couch which enables a wide range of motions that a Stewart platform cannot provide and to evaluate the performance of various prediction algorithms including proposed algorithm. For that purpose, we built a miniature couch tracking system comprising an articulated robotic manipulator, 3D optical tracking system, a phantom that mimicked respiratory motion, and control software. We performed simulations and experiments using respiratory data of 12 patients to investigate the feasibility of the system and various prediction algorithms, namely linear extrapolation (LE) and double exponential smoothing (ES2) with averaging methods. We confirmed that prediction algorithms worked well during simulation and experiment, with the ES2-averaging algorithm showing the best results. The simulation study showed 43% average and 49% maximum improvement ratios with the ES2-averaging algorithm, and the experimental study with the $QUASAR^{TM}$ phantom showed 51% average and 56% maximum improvement ratios with this algorithm. Our results suggest that the articulated robotic manipulator couch system with the ES2-averaging prediction algorithm can be widely used in the field of radiation therapy, providing a highly efficient and utilizable technology that can enhance the therapeutic effect and improve safety through a noninvasive approach.

• Progress in Medical Physics
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• v.23 no.2
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• pp.91-98
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• 2012

Verification of internal organ motion during treatment and its feedback is essential to accurate dose delivery to the moving target. We developed an offline based internal organ motion verification system (IMVS) using cine EPID images and evaluated its accuracy and availability through phantom study. For verification of organ motion using live cine EPID images, a pattern matching algorithm using an internal surrogate, which is very distinguishable and represents organ motion in the treatment field, like diaphragm, was employed in the self-developed analysis software. For the system performance test, we developed a linear motion phantom, which consists of a human body shaped phantom with a fake tumor in the lung, linear motion cart, and control software. The phantom was operated with a motion of 2 cm at 4 sec per cycle and cine EPID images were obtained at a rate of 3.3 and 6.6 frames per sec (2 MU/frame) with $1,024{\times}768$ pixel counts in a linear accelerator (10 MVX). Organ motion of the target was tracked using self-developed analysis software. Results were compared with planned data of the motion phantom and data from the video image based tracking system (RPM, Varian, USA) using an external surrogate in order to evaluate its accuracy. For quantitative analysis, we analyzed correlation between two data sets in terms of average cycle (peak to peak), amplitude, and pattern (RMS, root mean square) of motion. Averages for the cycle of motion from IMVS and RPM system were $3.98{\pm}0.11$ (IMVS 3.3 fps), $4.005{\pm}0.001$ (IMVS 6.6 fps), and $3.95{\pm}0.02$ (RPM), respectively, and showed good agreement on real value (4 sec/cycle). Average of the amplitude of motion tracked by our system showed $1.85{\pm}0.02$ cm (3.3 fps) and $1.94{\pm}0.02$ cm (6.6 fps) as showed a slightly different value, 0.15 (7.5% error) and 0.06 (3% error) cm, respectively, compared with the actual value (2 cm), due to time resolution for image acquisition. In analysis of pattern of motion, the value of the RMS from the cine EPID image in 3.3 fps (0.1044) grew slightly compared with data from 6.6 fps (0.0480). The organ motion verification system using sequential cine EPID images with an internal surrogate showed good representation of its motion within 3% error in a preliminary phantom study. The system can be implemented for clinical purposes, which include organ motion verification during treatment, compared with 4D treatment planning data, and its feedback for accurate dose delivery to the moving target.

• Journal of Radiation Protection and Research
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• v.44 no.3
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• pp.103-109
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• 2019

Background: Four-dimensional computed tomographic (4DCT) images are increasingly used in clinic with the growing need to account for the respiratory motion of the patient during radiation treatment. One of the reason s that makes the dose evaluation using 4DCT inaccurate is a change of the patient respiration during the treatment session, i.e., intrafractional uncertainty. Especially, when the amplitude of the patient respiration is greater than the respiration range during the 4DCT acquisition, such an organ motion from the larger respiration is difficult to be represented with the 4DCT. In this paper, the method to generate images expecting the organ motion from a respiration with extended amplitude was proposed and examined. Materials and Methods: We propose a method to generate extra-phase images from a given set of the 4DCT images using deformable image registration (DIR) and linear extrapolation. Deformation vector fields (DVF) are calculated from the given set of images, then extrapolated according to respiratory surrogate. The extra-phase images are generated by applying the extrapolated DVFs to the existing 4DCT images. The proposed method was tested with the 4DCT of a physical 4D phantom. Results and Discussion: The tumor position in the generated extra-phase image was in a good agreement with that in the gold-standard image which is separately acquired, using the same 4DCT machine, with a larger range of respiration. It was also found that we can generate the best quality extra-phase image by using the maximum inhalation phase (T0) and maximum exhalation phase (T50) images for extrapolation. Conclusion: In the present study, a method to construct extra-phase images that represent expanded respiratory motion of the patient has been proposed and tested. The movement of organs from a larger respiration amplitude can be predicted by the proposed method. We believe the method may be utilized for realistic simulation of radiation therapy.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.161-171
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• 2015

Image-guided radiation therapy (IGRT) is a process of incorporating imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), Positron emission tomography (PET), and ultrasound (US) during radiation therapy (RT) to improve treatment accuracy. It allows real-time or near real-time visualization of anatomical information to ensure that the target is in its position as planned. In addition, changes in tumor volume and location due to organ motion during treatment can be also compensated. IGRT has been gaining popularity and acceptance rapidly in RT over the past 10 years, and many published data have been reported on prostate, bladder, head and neck, and gastrointestinal cancers. However, the role of IGRT in lymphoma management is not well defined as there are only very limited published data currently available. The scope of this paper is to review the current use of IGRT in the management of lymphoma. The technical and clinical aspects of IGRT, lymphoma imaging studies, the current role of IGRT in lymphoma management and future directions will be discussed.