• 대한두경부종양학회지
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• 제33권1호
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• pp.39-41
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• 2017

Salivary gland tumors comprise almost 5% of head and neck malignancies, and minor salivary gland tumor which account for 10-15% of all salivary gland neoplasm are infrequently malignant. The mucoepidermoid carcinoma (MEC) is second most common tumor in minor salivary gland. It usually presents as a painless, rubbery-hard or soft mass, which may be fixed or mobile into the underlying structure. The predilection sites of intraoral MEC are palate, cheek, mandible, lip, and tongue, etc. There are very few published reports of MEC occurred in retromolar trigone. Only one case has been reported so far. Recently, we experienced a-70-year old man with a mass in retromolar trigone, which was finally diagnosed as MEC. We report the unique case with literature review.

• 대한두경부종양학회지
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• 제33권1호
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• pp.35-38
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• 2017

The extranodal nasal NK/T-cell lymphoma was formerly known as lethal midline granuloma due to its most common clinical pattern like a destructive midline facial tumor. It often spread to other extranodal sites, such as skin, soft tissue, testis, upper respiratory tract, and gastrointestinal tract etc. For this reason, the term of extranodal NK/T-cell lymphoma, nasal type is preferred. Its disease entity may have a prominent admixture of inflammatory cells and necrotic tissues, further causing difficulty in diagnosis. A 44-year-old man was visited to our clinic with complaints of dysphagia and odynophagia during six months. He underwent three times punch biopsies and then, two times incisional biopsies. Finally, He was diagnosed as extranodal NK/T-cell lymphoma, nasal type involving oropharynx and supraglottis. We report an extremely rare case of extranodal NK/T-cell lymphoma, nasal type occurred in oropharynx and supraglottis with a brief review of literature.

• 대한두경부종양학회지
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• 제37권1호
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• pp.23-27
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• 2021

Mantle cell lymphoma (MCL) is a rare subtype of B-cell neoplasm and it accounts for about 3~6% of all non-Hodgkin's lymphomas. It occurs mainly in middle-aged or elderly man, involving the extra-nodal sites such as gastrointestinal tract, bone marrow and Waldeyer's ring. The incidence of the MCL in salivary gland is about 3%. The blastoid MCL is a rare variant and it has a very aggressive clinical course. It is extremely rare to be arising from the parotid gland. To our knowledge, similar case has not been reported in domestic literature, one case has been described in English literature. We experienced a rare and unique disease entity and report it with brief literature review.

• 대한두경부종양학회지
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• 제39권2호
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• pp.27-30
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• 2023

A 65-year-old patient who underwent total thyroidectomy 10 years ago was suspected of having a parathyroid adenoma, and minimally invasive parathyroidectomy was planned. Preoperative ultrasonography(USG) and 99mTc MIBI scan indicated a left lower parathyroid lesion. In the first operation, intraoperative parathyroid hormone monitoring (IOPTH) was not possible due to hospital circumstances. Although no adenomatous lesion was found in the expected surgical field, surgery was completed after removing lesions around the left lower parathyroid gland. However, post-surgery, parathyroid hormone did not decrease at all, so a second operation was performed with IOPTH preparation. In the second operation, intraoperative ultrasonography was performed, and a suspected adenoma lesion was removed from the left upper lesion. He has been under follow-up for 3 years without complications. Surgeon-peformed intraoperative USG and preoperative scintigraphy had advantages in determining the localization of parathyroid lesion even withiout IOPTH.

• 대한두경부종양학회지
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• 제33권2호
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• pp.71-73
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• 2017

Dysplastic epiglottis is extremely rare congenital malformation, which usually occurs in association with other laryngeal anomalies. Hypoplasia is the most common type in epiglottic malfomations. Other abnormalities include rudimentary, aplasia and bifid etc. Mostly, they are found in infancy and early childhood, and diagnosis at adulthood is extremely rare. A 69-year-old man with chronic cough and globus sense visited our clinic. Laryngoscopic findings revealed a unique form of epiglottis. He had no history of laryngeal trauma, tumors, head and neck surgery, and radiation. There was no another anomaly in the laryngo-pharynx. Because of a mass-like lesion at the apex of epiglottis, we performed the laryngeal microsurgery. The pathology revealed as granulation tissue. We report a rare and unique case of dysplastic epiglottis in elderly patient with a brief literature review.

• 한국의학물리학회지:의학물리
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• 제30권2호
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• pp.59-63
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• 2019

Purpose: To manage radiation measurement equipment, a web-based management program has been developed in this study. Materials and Methods: This program is based on a web service and Java Server Pages (JSP) and employs compatibility and accessibility. Results: The first step in the workflow has been designed to create accounts for each user or organization and to log in. The program consists of two parts: fields for listed instruments, and measurement information. The instruments for measuring radiation listed in this program are as follows: ionization chambers, survey meters, thermometers, barometers, electrometers, and phantoms. Instrument properties can be put in the recording fields and browsing for associated instruments can be performed. The main part of the program is the cross-calibration for each ion chamber. For instance, the ionization chamber to be used as a relative dosimeter can be registered by cross-calibration data with a reference chamber calibrated by an accredited laboratory. This program supports methods using the central axis transfer theory for cross-calibration for the ionization chambers. The reference and field ionization chambers were placed in a solid water phantom along the beam central axis at two different depths, and then the positions were switched. Each measured value was used for calculating the cross-calibration factor. Conclusions: Because many instruments are used and managed in radiation oncology departments, systematic, traceable recording is very important. The web-based program developed in this study is expected to be used effectively in the maintenance of radiation measurement instruments.

• 대한방사선기술학회지:방사선기술과학
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• 제45권6호
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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.

• 한국의학물리학회지:의학물리
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• 제32권4호
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• pp.137-144
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• 2021

Purpose: This study aimed to investigate the accuracy of head scatter factor (S_c) by applying a developed multi-leaf collimator (MLC) scatter source model for an unflattened photon beam. Methods: Sets of S_c values were measured for various jaw-defined square and rectangular fields and MLC-defined square fields for developing dual-source model (DSM) and MLC scatter model. A 6 MV unflattened photon beam has been used. Measurements were performed using a 0.125 cm³ cylindrical ionization chamber and a mini phantom. Then, the parameters of both models have been optimized, and S_c has been calculated. The DSM and MLC scatter models have been verified by comparing the calculated values to the three S_c set measurement values of the jaw-defined field and the two S_c set measurement values of MLC-defined fields used in the existing modeling, respectively. Results: For jaw-defined fields, the calculated S_c using the DSM was consistent with the measured S_c value. This demonstrates that the DSM was properly optimized and modeled for the measured values. For the MLC-defined fields, the accuracy between the calculated and measured S_c values with the addition of the MLC scatter source appeared to be high, but the only use of the DSM resulted in a significantly bigger differences. Conclusions: Both the DSM and MLC models could also be applied to an unflattened beam. When considering scattered radiation from the MLC by adding an MLC scatter source model, it showed a higher degree of agreement with the actual measured S_c value than when using only DSM in the same way as in previous studies.

• 대한두경부종양학회지
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• 제33권2호
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• pp.63-66
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• 2017

The tumor in accessory parotid gland (APG) is rarely occurred and its incidence is about 7.7% of all parotid gland neoplasms, but has a higher frequency of malignancy than major salivary glands. The mucoepidermoid carcinoma is the most common malignancy in APG, while B-cell lymphoma is less than 2%. It is often appeared as superficial mass in mid-cheek area. This lesion requires differential diagnosis with epidermoid cyst, lipoma, neurogenic tumors, Stensen's duct stone, lymphadenopathy and hemangioma etc. The mucosa associated lymphoid tissue (MALT) lymphoma, which is also termed extra-nodal marginal zone B-cell lymphoma tends to be localized disease for long time and has a relatively indolent course. We recently encountered a 69-year-old man with superficial solitary mass on the right cheek area that finally diagnosed as MALT lymphoma in APG. We report the rare and unique case with brief literature review.

• 대한두경부종양학회지
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• 제36권1호
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• pp.49-52
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• 2020

The most common cause of primary hyperparathyroidism is a single adenoma accounts for more than 85% and about 1-2% in multiple occurrence. The adenoma arises mainly in the neck and rarely in the mediastinum. The simultaneous occurrence is extremely rare. A 73-year-old man came to our clinic complained about sense of falling forward during last eight months. The brain MRI and vestibular function test showed non-specific findings but total calcium and intact parathyroid hormone levels were markedly elevated. Radiologic studies and sesta-MIBI scan revealed multiple masses in lower paratracheal area and superior mediastinum. We performed mass excision with transcervical approach and all of them were diagnosed as parathyroid adenoma. After surgery, intact PTH and calcium levels returned to the normal range and his symptoms were dramatically improved. We report the unique and rare disease entity with a brief literature review.