• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.265-275
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• 2000

The thyroid gland is an interesting endocrine organ where a spectrum of tumors with different behavior arise. At one end of spectrum there is differentiated thyroid carcinoma (DTC) with excellent prognosis, whereas at the other end of the spectrum is anaplastic thyroid cancer which has universally poor outcome. Radioiodine (I-131) therapy has been in use for the treatment of thyroid diseases since 1946. It was introduced by Seidlin et al. 1) Although the use of I-131 has been vouge for a long time, its use in therapy for well differentiated thyroid cancer is still controversial 2). This is because, thyroid cancers (TC) are generally slow growing tumors, with low mortality and normal spans of survival. To record recurrence and mortality, long term follow up studies over a period of two to three decades are needed to establish definite conclusions on the acceptable mode of treatment The incidence of the disease being very low a large number of cases needed to establish a meaningful statistical data is lacking as most published reports feat with small series. Here again in the problem encountered are the differing protocols for treatment with I-131, the indications for treatment which may include or exclude ablation of residual thyroid tissue, cervical nodal and distal metastases. The dosage of I-131 used for ablation of residual thyroid tissue and metastatic disease also vary. The most reliable conclusion regarding I-131 treatment are obtained from studies reported on a large series of patients followed over a period of 2 decades or more from a single institute with a more or less unchanged protocol of management.

• Journal of Korean Neurosurgical Society
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• v.62 no.3
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• pp.353-360
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• 2019

Epilepsy surgery that eliminates the epileptogenic focus or disconnects the epileptic network has the potential to significantly improve seizure control in patients with medically intractable epilepsy. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has been an established option for epilepsy surgery since the US Food and Drug Administration cleared the use of MRgLITT in neurosurgery in 2007. MRgLITT is an ablative stereotactic procedure utilizing heat that is converted from laser energy, and the temperature of the tissue is monitored in real-time by MR thermography. Real-time quantitative thermal monitoring enables titration of laser energy for cellular injury, and it also estimates the extent of tissue damage. MRgLITT is applicable for lesion ablation in cases that the epileptogenic foci are localized and/or deep-seated such as in the mesial temporal lobe epilepsy and hypothalamic hamartoma. Seizure-free outcomes after MRgLITT are comparable to those of open surgery in well-selected patients such as those with mesial temporal sclerosis. Particularly in patients with hypothalamic hamartoma. In addition, MRgLITT can also be applied to ablate multiple discrete lesions of focal cortical dysplasia and tuberous sclerosis complex without the need for multiple craniotomies, as well as disconnection surgery such as corpus callosotomy. Careful planning of the target, the optimal trajectory of the laser probe, and the appropriate parameters for energy delivery are paramount to improve the seizure outcome and to reduce the complication caused by the thermal damage to the surrounding critical structures.

• Progress in Medical Physics
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• v.20 no.4
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• pp.225-234
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• 2009

Geant4 (GEometry ANd Tracking) provides various packages specialized in modeling electromagnetic interactions. The validation of Geant4 physics models is a significant issue for the applications of Geant4 based simulation in medical physics. The purpose of this study is to evaluate accuracy of Geant4 electromagnetic physics for proton therapy. The validation was performed both the Continuous slowing down approximation (CSDA) range and the stopping power. In each test, the reliability of the electromagnetic models in a selected group of materials was evaluated such as water, bone, adipose tissue and various atomic elements. Results of Geant4 simulation were compared with the National Institute of Standards and Technology (NIST) reference data. As results of comparison about water, bone and adipose tissue, average percent difference of CSDA range were presented 1.0%, 1.4% and 1.4%, respectively. Average percent difference of stopping power were presented 0.7%, 1.0% and 1.3%, respectively. The data were analyzed through the kolmogorov-smirnov Goodness-of-Fit statistical analysis test. All the results from electromagnetic models showed a good agreement with the reference data, where all the corresponding p-values are higher than the confidence level $\alpha=0.05$ set.

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.53-63
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• 2005

Number of fixtures supporting prosthesis for rehabilitation of partial edentulism in distal area is an important factor in distal area to the bone tissue response around dental implant. Optimal number and optimal positioning of dental implant has leaded to the stable condition of bone tissue and successful long-term treatment outcome. This clinical and radiographic study was performed to document and evaluate the short-term result of occlusal rehabilitation by means of implant-supported fixed prostheses (ISPs) especially for partial edentulism in distal area in patients treated for advanced periodontal disease and to verify the number of fixture affecting the bone tissue response. A total of 30 consecutive patients referred because of advanced periodontal disease were included. Before the implant therapy was initiated, periodontal treatment was performed and the outcome evaluated during at least a 6-month period. An individual maintenance care program was designed for each patient. All 75 implants were placed using a 2-stage surgical approach. The patients were divided into 2 groups, in one of which two fixtures were placed and in the other of which three fixtures were placed with tripodal geometry. Following installation of the ISPs, all patients underwent a baseline examination including evaluation of i) oral hygiene, and ii) periodontal/ peri-implant conditions, and iii) radiographs. These examinations were repeated annually during the 1 or 2-year observation period. The results were as follows: 1.No single implant was lost during the observation follow-up period. 1.The percentage of plaque harboring surfaces and bleeding units upon probing were found to be low (<10%), and no soft tissue complications were recorded. 1.Two-fixture group showed bone destruction ranged from 0.0mm to 1.5mm and the mean was 0.31mm. Three-fixture group showed more bone destruction of 0.51mm. There was no statistically difference between two groups. These results suggested that the factor for success is not the number of fixture but the strict maintenance of peri-implant tissue health and initial stability of fixture.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.1 no.2
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• pp.117-121
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• 2008

Prolotherapy can be defined as the injection of growth factors or growth factor production stimulants to grow normal cells or tissue. Even though it has been a controversal procedure for decades, it is currently gaining in popularity among many physicians. The term prolotherapy was coined by Hacket in the 1950s to imply proliferation of normal tissue at ligamentous and tendinous entheses. The procedure has been described by other terms, such as sclerotherapy, regenerative injection therapy, and stimulated ligament repair. Incomplete healing from sprains or strains is common and can lead to chronic pain, joint instability and laxity, and is a risk factor for the development of osteoarthritis. Prolotherapy is commonly used for these musculoskeletal conditions which are refractory to usual care therapies. The proliferant solution and technique varies according to physicial training and preferance. Commonly reported proliferants include 10% to 25% dextrose, P2G and sodium morrhuate. High resolution ultrasound imaging of musculoskeletal tissue is increasing in popularity because of patient tolerability, low cost, ability to visualize tissue in real time motion and superior resolution of highly organized tissue such as a tendon. This procedure can be introduced by ultrasound imaging and tissue growth and repair after this procedure in a tendon or a ligament can be documented with ultrasound.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2410-2414
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• 2020

Heavy ions have a high potential for destroying deep tumors that carry the highest dose at the peak of Bragg. The peak caused by a single-energy carbon beam is too narrow, which requires special measures for improvement. Here, carbon-12 (¹²C) ion with different energies has been used as a source for calculating the dose distribution in the water phantom, soft tissue and bone by the code of Monte Carlobased FLUKA code. By increasing the energy of the initial beam, the amount of absorbed dose at Bragg peak in all three targets decreased, but the trend for this reduction was less severe in bone. While the maximum absorbed dose per bone-mass unit in energy of 200 MeV/u was about 30% less than the maximum absorbed dose per unit mass of water or soft tissue, it was merely 2.4% less than soft tissue in 400 MeV/u. The simulation result showed a good agreement with experimental data at GSI Darmstadt facility of biophysics group by 0.15 cm average accuracy in Bragg peak positioning. From 200 to 400 MeV/u incident energy, the Bragg peak location increased about 18 cm in soft tissue. Correspondingly, the bone and soft tissue revealed a reduction dose ratio by 2.9 and 1.9. Induced neutrons did not contribute more than 1.8% to the total energy deposited in the water phantom. Also during ¹²C ion bombardment, secondary fragments showed 76% and 24% of primary 200 and 400 MeV/u, respectively, were present at the Bragg-peak position. The combined treatment of carbon ions with neutron or electron beams may be more effective in local dose delivery and also treating malignant tumors.

• The Korean Journal of Nuclear Medicine
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• v.37 no.2
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• pp.120-127
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• 2003

Purpose: To evaluate diagnostic sensitivity of nuclear imaging in the detection of residual thyroid tissue and metastatic lesion, we have compared neck scintigrams with Tc-99m pertechnetate (Tc-99m scan) and high dose I-131 iodide (I-131 scan) in patients with differentiated thyroid cancer. Subjects and Methods: One hundred thirty-five thyroidectomized patients for differentiated thyroid cancer were enrolled in this study. Twenty-three had a previous history of radioiodine therapy. Planar and pin-hole images of anterior neck with Tc-99m were acquired at 20 minutes after injection, followed by I-131 scan three days after high-dose radioiodine therapy within 7 days interval. Patients were asked to discontinue thyroid hormone replacement more than 4 weeks. Results: All subjects were in hypothyroid state. Seventy out of 135 patients (51.9%) showed concordant findings between Tc-99m and I-131 scans. I-131 scan showed higher number of uptake foci in all of 65 patients showing discordant finding. Tc-99m scan showed no thyroid bed uptake in 34 patients, whereas 23 of them (67.6%) showed bed uptake in I-131 scan. Tc-99m scan did not show any uptake in thyroid bed in 11 of 112 patients without previous history of radioiodine therapy, but 9 of them showed bed uptake in I-131 scan. Tc-99m scan showed no bed uptake in all of the 23 patients with previous history of radioiodine therapy, in contrast 14 of them (60.9%) showed bed uptake in I-131 scan. Conclusion: These results suggest that Tc-99m scan has poor detectability for residual thyroid tissue or metastatic lesion in thyroidectomized differentiated thyroid cancer patients, compared to high dose I-131 therapy scan. Tc-99m scan could not detect any remnant tissue or metastatic lesion in patients with previous history of radioiodine treatment, especially.

• Journal of the Korean Society of Radiology
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• v.7 no.4
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• pp.285-291
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• 2013

In this study, compare and analyze the dose distribution and availability of radiation therapy when using a different devices to TNI(Total Lymphnodal Irradiation). Test subjects(patients) are 15 people(Male 7, Female 8). Acquire CT Simulation images of the 15 people using Somatom Sansation Open 16 channel and then acquired images was transferred to each treatment planning system Pinnacle Ver 8.0 and Tomotherapy Planning System and separate the tumor tissue and normal tissues(whole lung, spinal cord, Rt kidney, Lt kidney). Tumor prescription dose was set to 750 cGy. and then Compare the Dose Compatibility, Normal Tissue's Absorbed Dose, Dose Distribution and DVH. Statistical analysis was performed SPSS Ver. 18.0 by paired sample Assay. The absorbed dose in the tumor tissue was $751.0{\pm}4.7cGy$ in tomotherapy planning, $746.9{\pm}14.1cGy$ in linac. Tomotherapy's absorbed dose in the tumor was more appropriate than linac. and These values are not statistically significant(p>0.05). Tomotherapy plan's absorbed dose in the normal tissues were less than linac's plan. This value was statistically significant(p<0.05) excepted of whole lung. In DVH, appropriated on tumor and normal tissues in tomotherapy and linac but tomotherapy's TER was better than linac. Namely, a result of Absorbed dose in tumor and normal tissue, Dose distribution pattern, DVH, Both radiation therapy devices were appropriated in radiation therapy on TER. The Linac has a short treatment time(about 15-20 min) and open space on treatment time. It cause infant and pediatric patients to receiving uncomfortable treatment. So, In this case, it will be fine that Linac based therapy was restricted use. and if the patient was cooperative, it will be show a better prognosis that Tomotherapy using Radiation Therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.2051-2054
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• 2015

Background: Radiation therapy is a key part of the combined modality treatment for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL), which can achieve locoregional control of disease. The 3D-conformal radiation oncology can be extended-field (EFRT), involved-field (IFRT) and involved node (INRT). New techniques have resulted in a smaller radiation field and lower dose for critical organs such as lung heart and breast. Materials and Methods: In our research, we made a virtual simulation for one patient who was treated in four different radiotherapeutic techniques: mantle field (MFRT), EFRT, IFRT and INRT. After delineatiion we compared dose-volume histograms for each technique. The fusion of CT for planning radiotherapy with the initial PET/CT was made using Softver Xio 4.6 in the Focal program. The dose for all four techniques was 36Gy. Results: Our results support the use of PET/CT in radiation therapy planning. With IFRT and INRT, the burden on the organs at risk is less than with MFRT and EFRT. On the other hand, the dose distribution in the target volume is much better with the latter. Conclusions: The aim of modern radiotherapy of HL and NHL is to reduce the intensity of treatment and therefore PET/CT should be used to reduce and not increase the amount of tissue receiving radiation.

• The Journal of the Korean dental association
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• v.58 no.6
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• pp.336-345
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• 2020

Peri-apical implant lesion, also known as 'retrograde peri-implantitis' can occur with multifactorial etiological factors. The purpose of this case report is to demonstrate resolution of periapical implant lesion by removal of causative factors and saving implant by regenerative therapy. A 54-year old male patient with mild dull pain around implant on the right mandibular second premolar area due to persistent peri-apical infection of the adjacent first premolar was treated. Extraction of tooth with symptomatic apical periodontitis and regenerative therapy on the buccal fenestration area of the implant and extraction site were performed. After 6-month reentry, notable regenerated bone tissue around implant was found, and implant placement on the previous extraction site was performed. After 14-month follow-up from the regenerative therapy, neither biological nor mechanical complication could be found around the implant, evidenced by high implant stability, normal clinical probing depth, and absence of discomfort spontaneously and during masticatory function. In conclusion, surgical intervention including regenerative therapy using bone graft and barrier membrane on periapical implant lesion can be suggested as one of the treatment options considering the extent of periapical lesion.