• Radiation Oncology Journal
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• v.3 no.2
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• pp.163-168
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• 1985

Intraocular melanoma is the most common primary occular malignancy in adult above the age of 20. Before treatment of intraocular melanoma, it is essential to do complete work-ups including LFT (LDH, SGPT), chest X-ray, whole body bone scan. Also, liver-spleen and brain scan will be done if clinically indicated. Though, malignant melanoma is radioresistant, however, show rapid tumor shrinkage after irradiation with total tumor dose of 7,000 to 8,000 rads in 7-8 weeks.

• Radiation Oncology Journal
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• v.2 no.1
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• pp.115-122
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• 1984

Total 125 patinets with primary and metastatic Ewing's sarcoma were treated in various ways between 1963 to 1977. Patients were divided into 3 groups according to the treatment methods. Group 1 was nonprotocol patients with or without chemotherapy. Total 58 patients were entered. Group 1 was divided into 2 subgroups. 33 patients were treated locally without chemotherapy and 25 Patients were treated with local therapy and nonprotocol chemotherapy. Group 2 was treated with local therapy and plus T-2 regimen multiagent chemotherapy. 29 patients were entered. Group 3 was treated with local therapy and T-6 regimen multiagent chemotherapy. 38 patients were entered. Local treatments for primary tumor were surgery and/or radiation therapy. Radiation dose ranged between 2,000 and 8,000 rad. Patients with pulmonary metastases received bilateral pulmonary RT. Local recurrence rate was analyzed according to treatment groups and was $16.8\%$. Local 15 yr survival was $33\%$ and 8 yr survival of T-6 group was $64.9\%$. An analysis of time were pattern of recurrence of each group, and the correlation of with radiation dose with local recurrence done. This study concluded that intensive multiagent chemotherapy RT and/or surgery (T-6 regimen) reduced distant metastases, and produced significant increase in local control and survival.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.295-296
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• 2015

This study deals with the generalization of the Elliptic Restricted Three-Body Problem (ER3BP) by considering the effects of radiation and oblate spheroid primaries. This may illustrate a gas giant exoplanet orbiting its host star with eccentric orbit. In the three dimensional case, this generalization may possess two additional equilibrium points ($L_{6,7}$, out-of-plane). We determine the existence of $L_{6,7}$ in ER3BP under the effects of radiation (bigger primary) and oblateness (small primary). We analytically derive the locations of $L_{6,7}$ and assume initial approximations of (${\mu}-1$, ${\pm}\sqrt{3A_2}$), where ${\mu}$ and $A_2$ are the mass parameter and oblateness factor, respectively. The fixed locations are then determined. Our results show that the locations of $L_{6,7}$ are periodic and affected by $A_2$ and the radiation factor ($q_1$).

• Radiation Oncology Journal
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• v.35 no.2
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• pp.185-188
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• 2017

Primary liver tumor, especially hepatocellular carcinoma (HCC), is a common cause of cancer death worldwide. The incidence is generally higher in Asian countries than in western countries. Carcinogenesis of HCC is often associated with hepatitis viral infections. Current standard treatment of HCC is surgical resection or transplantation in patients with early stage disease. However, the patient with advanced stage disease, surgical resection is often limited. Sorafenib or other treatment modalities are not so effective as well. We report a case of unusual radiation super-sensitivity in advanced stage HCC, and review the literature.

• Radiation Oncology Journal
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• v.33 no.4
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• pp.301-309
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• 2015

Purpose: To identify prognostic factors for disease progression and survival of patients with extracranial oligometastatic breast cancer (EOMBC), and to investigate the role of radiation therapy (RT) for metastatic lesions. Materials and Methods: We retrospectively reviewed the medical records of 50 patients who had been diagnosed with EOMBC following standard treatment for primary breast cancer initially, and received RT for metastatic lesions, with or without other systemic therapy between January 2004 and December 2008. EOMBC was defined as breast cancer with five or less metastases involving any organs except the brain. All patients had bone metastasis (BM) and seven patients had pulmonary, hepatic, or lymph node metastasis. Median RT dose applied to metastatic lesions was 30 Gy (range, 20 to 60 Gy). Results: The 5-year tumor local control (LC) and 3-year distant progression-free survival (DPFS) rate were 66.1% and 36.8%, respectively. High RT dose (${\geq}50Gy_{10}$) was significantly associated with improved LC. The 5-year overall survival (OS) rate was 49%. Positive hormone receptor status, pathologic nodal stage of primary cancer, solitary BM, and whole-lesion RT (WLRT), defined as RT whose field encompassed entire extent of disease, were associated with better survival. On analysis for subgroup of solitary BM, high RT dose was significantly associated with improved LC and DPFS, shorter metastasis-to-RT interval (${\leq}1month$) with improved DPFS, and WLRT with improved DPFS and OS, respectively. Conclusion: High-dose RT in solitary BM status and WLRT have the potential to improve the progression-free survival and OS of patients with EOMBC.

• Radiation Oncology Journal
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• v.3 no.1
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• pp.19-28
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• 1985

Twenty-four cases of pituitary adenoma, 13 males and 11 females with the age ranging from 11 to 65 years, received radiation therapy(RT) on the pituitary area with 6MV linear accelerator during past 25 months at the Division of Radiation Therapy, Kangnam St. Mary's Hospital, Catholic Medical College. Of 24 cases of RT, 20 were postoperative and 4 primary. To evaluate the effect of RT, we analysed the alteration of the endocrinologic tests, neurologic abnormalities, major clinical symptoms, endocrinologic changes and improvement in visual problems after RT. The results were as follows ; 1. Major clinical symptoms were headache, visual defects, diabetes insipidus, hypogonadisms and general weakness in decreasing order of frequency. 2. All but the one with Nelson's syndrome showed abnormal neuroradiologic changes in the sella turcica with an invasive tumor mass around supra· and para-sellar area. 3. Endocrinological classifications of the patient were 11 prolactinoma, 4 growth hormone -secreting tumors, 3 ACTH-secreting tumors consisting of one Cushing's disease and two Nelson's syndrome, and 6 nonfunctioning tumors. 4. Eleven of 14 patients, visual problems were improved after treatment but remaining 3 were unchanged. 5. Seven of 11 prolactinomas returned to normal hormonal level after postoperative and primary RT and 3 patients are being treated with bromocriptine (BMCP) but one lost case. 6. Two of 4 growth hormone·secreting tumor returned to normal level after RT but the remaining 2 are being treated with BMCP, as well.

• Radiation Oncology Journal
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• v.7 no.2
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• pp.235-245
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• 1989

Rhabdomyosarcoma is a highly malignant soft tissue sarcoma that can arise in any site of the body containing striated muscle or its mesenchymal analgae. It is the most common childhood sarcoma with two peak age frequencies, one at ages 2 to 6, and one in the adolescence. The site, stage and extent of disease, and pathologic characteristics of the tumor contribute to prognostic factors that influence therapeutic decisions. The results of treatment of 52 patients with rhabdomyosarcoma, who were treated at Department of Radiation Oncology, Yonsei University College of Medicine, Yosei Cancer Center from 1976 to 1987 were retrospectively analyzed. The most frequent clinical group and primary sites were IRS group III (57.7%) and head and neck (42.3%) including orbit (11.5%) and parameningeal region(13.5%). The overall and disease free 5 year survival rate of eligible 41 patients were 31.7%, 29.3%, respectively. The complete remission (CR) rate was 50% in clinical group III and 0% in IV. Primary tumors of the orbit, clinical group 1 and embryonal subtype had the best prognosis. The Survival rate was improved by additiion of chemotherapy to operation and radiation therapy.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.549-555
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• 2018

The medical imaging technique images the contrast formed based on the difference in absorption coefficient of X-rays which changes according to the composition and thickness of the object. At this time, not only primary rays entering the image detector but also scattered rays greatly affect the image quality. Therefore, in this paper, Forward scattering rate and Scattered to primary ratio analysis were performed through Monte Carlo simulation in order to consider influence of scattered ray generated according to object thickness and radiation exposure area change on image quality. In the study, the Forward scattering rate corresponding to the thickness of the object was analyzed at a maximum of 15.3%p and the Scattered to primary ratio was analyzed at 2.00 to 4.54, but it was analyzed as maintaining a constant value for radiation exposure area change. Based on these results, the thickness of the object should be considered as a factor influencing the quality of the image, but radiation exposure area verified that it is a factor that does not affect the image quality. We believe that the results of this research can be utilized as basic information of scattered radiation to improve image quality.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.224-230
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• 2010

Purpose: We designed the aft-multiple-slit (AMS) system to reduce scatter in cone-beam computed tomography (CBCT). As a preliminary study, we performed a Monte Carlo N-Particle Transport Code (MCNP) simulation to verify the effectiveness of this system. Materials and Methods: The MCNPX code was used to build the AMS geometry. An AMS is an equi-angled arc to consider beam divergence. The scatter-reduced projection images were compared with the primary images only and the primary plus scatter radiation images with and without AMS to evaluate the effectiveness of scatter reduction. To obtain the full 2 dimensional (2D) projection image, the whole AMS system was moved to obtain closed septa of the AMS after the first image acquisition. Results: The primary radiation with and without AMS is identical to all the slit widths, but the profiles of the primary plus scattered radiation varied according to the slit widths in the 2D projection image. The average scatter reduction factors were 29%, 15%, 9%, and 8% when the slit widths were 5 mm, 10 mm, 15 mm, and 20 mm, respectively. Conclusion: We have evaluated the scatter reduction effect of the AMS in CBCT imaging using the Monte Carlo (MC) simulations. A preliminary study based on the MCNP simulations showed a mount of scatter reduction with the proposed system.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7025-7029
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• 2015

Background: The optimal sequence and extent of multimodality therapy remains to be defined for extrapulmonary small cell carcinoma because of its rarity. The purpose of our study was to assess the response to neoadjuvant chemotherapy followed by chemoradiation/radiation in patients with extrapulmonary small cell carcinoma. Materials and Methods: Four consecutively diagnosed patients were included in this study. The primary tumor site was oropharynx in three patients and esophagus in one. The patients with the limited disease were treated with chemotherapy followed by concurrent chemoradiation (n=2) or radiotherapy (n=1). The patient with the extensive disease with the primary site in vallecula was treated with chemotherapy and palliative radiotherapy to the metastatic site. Results: The median follow-up was 22.5 months (range, 8-24 months). Three patients with the limited disease (base of tongue, n=2; esophagus, n=1) were in complete remission. The patient with the extensive disease died of loco-regional tumor progression at 8 months from the time of diagnosis. Conclusions: The combination of chemotherapy and radiotherapy is the preferred therapeutic approach for patients with extrapulmonary small cell carcinoma. Induction chemotherapy followed by concurrent chemoradiation or radiation provides a good loco-regional control in patients with limited disease.