• Radiation Oncology Journal
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• 제33권4호
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• pp.337-343
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• 2015

Purpose: The purpose of this report is to describe the proton therapy system at Samsung Medical Center (SMC-PTS) including the proton beam generator, irradiation system, patient positioning system, patient position verification system, respiratory gating system, and operating and safety control system, and review the current status of the SMC-PTS. Materials and Methods: The SMC-PTS has a cyclotron (230 MeV) and two treatment rooms: one treatment room is equipped with a multi-purpose nozzle and the other treatment room is equipped with a dedicated pencil beam scanning nozzle. The proton beam generator including the cyclotron and the energy selection system can lower the energy of protons down to 70 MeV from the maximum 230 MeV. Results: The multi-purpose nozzle can deliver both wobbling proton beam and active scanning proton beam, and a multi-leaf collimator has been installed in the downstream of the nozzle. The dedicated scanning nozzle can deliver active scanning proton beam with a helium gas filled pipe minimizing unnecessary interactions with the air in the beam path. The equipment was provided by Sumitomo Heavy Industries Ltd., RayStation from RaySearch Laboratories AB is the selected treatment planning system, and data management will be handled by the MOSAIQ system from Elekta AB. Conclusion: The SMC-PTS located in Seoul, Korea, is scheduled to begin treating cancer patients in 2015.

• Radiation Oncology Journal
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• 제19권2호
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• pp.142-145
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• 2001

Purpose : Acute leukemia with hyperleukocytosis (more than $10^5/mm^3$) is at high risk of early sudden death, usually from intracerebral hemorrhage. Emergency cranial irradiation is a relatively simple approach to solve this the problem. We summarized our experience of cranial irradiation in 24 leukemic children who presented with hyperleukocytosis. Methods and Materials : Between 1990 and 1998, 40 children with acute leukemia presenting with hyperleukocytosis were referred for emergency cranial irradiation. Among these patients, 24 children were evaluable. There were 16 boys and eight girls, their ages ranged from 2 to 13 years (median 9.5 years). The initial leukocyte counts ranged $109,910/mm^3\;to\;501,000/mm^3$. Peripheral blood smear was peformed in all patients and noted the morphology of the blast. Introduction of emergency cranial irradiation was determined by the leukocyte counts (more than 100,000/mm) and the existence of the blast in peripheral blood smear. All patients were treated with intravenous hydration with alkaline fluid and oral allopurinol. Cranial irradiation started on the day of diagnosis. With 2 Gy in one fraction in 4 patients, 4 Gy in two fractions in 20 patients. Results : The WBC count had fallen in 19 patients (83%) and no intracerebral hemorrhage occurred after irradiation. There were five cases of early deaths. Four patients died of metabolic complications, and one patient with intracerebral hemorrhage. He died 5 hours after cranial irradiation. No patient had any immediate side effect from cranial irradiation. Conclusion : Our data suggest, that emergency cranial irradiation can be safely chosen and effective in childhood leukemic patients presenting with high leukocyte counts.

• Journal of the Korean Society of Radiology
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• 제7권3호
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• pp.213-219
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• 2013

Currently, about 35 cyclotrons have been operating in South Korea. Most of them are mainly used for the synthesis of radiopharmaceuticals such as $^{18}FDG$, which is a cancer tracer for nuclear medicine. Highly enriched $H_2{^{18}}O$ containing up to 98% of $^{18}O/O$ isotope ratio is used as the target for $^{18}F$ production. The price of the highly enriched $H_2{^{18}}O$ ranges 60~70 USD/g, and all of them have been imported from foreign country in spite of the very expensive price. The target (enriched $H_2{^{18}}O$) is non-radioactive before the proton beam irradiation. But, the post-irradiation target (used $H_2{^{18}}O$) must be managed following the National Radiation Safety Regulations, because it turns into radioactive by the radioactivation of the impurities within the target. Recently, nevertheless of the fast increasing amount of used $H_2{^{18}}O$ in accordance with the increasing number of nuclear medicine cases, any activation analysis on the used $H_2{^{18}}O$ have been conducted yet in Korea. In this research, activation analysis have been conducted to confirm the specific radioactivity(Bq/g) of each radioisotopes within the used $H_2{^{18}}O$. The analysis have been done on the 3 of 20g samples collected from the used $H_2{^{18}}O$ storages at different cyclotron centers. Based on the results, it was confirmed that the "used $H_2{^{18}}O$" contains gamma emitters such as $^{56}Co$, $^{57}Co$, $^{58}Co$, and $^{54}Mn$ as well as the considerable amount of beta emitter $^3H$. It was also confirmed that the only one sample contained over exemption level of gamma emitters while the specific activity of tritium was lower than the exemption level in all samples. The specific activity of radioisotopes were measured different levels in the samples depending on the elapsed time after irradiation. Further study on the activation of the "used $H_2{^{18}}O$" is definitely necessary, nevertheless the as-is results of this research must be useful in establishing a rational "used $H_2{^{18}}O$" management protocol.

• Radiation Oncology Journal
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• 제20권1호
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• pp.17-23
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• 2002

Purpose : To clarify the clinical benefit derived from the combined modality therapy (CMT) consisting of chemotherapy (CT) and involved field radiotherapy (RT) for stage I and II angiocentric lymphomas of the head and neck. Materials and Methods : Of 143 patients with angiocentric lymphoma of the head and neck treated at our hospital between 1976 and 1995, 104 patients (RT group) received involved field RT alone with a median dose of 50.4 Gy (range : 20~70 Gy), while 39 patients (CMT group) received a median 3 cycles (range : 1~6 cycles) of CT before involved field RT. The response rate, patterns of failure, complications, and survival data of the RT group were compared with those of the CMT group. Results : Despite a higher response rate, local failure was the most common pattern of failure in patients of both groups. The patterns of failure, including the systemic relapse rate were not influenced by the addition of combination CT. Although both modalities were well tolerated by the majority of patients, aberrant immunologic disorders or medical illnesses, such as a hemophagocytic syndrome, sepsis, intractable hemorrhage, or the evolution of second primary malignancies were more frequently observed in patients of the CMT group. The prognosis of patients in the RT group was relatively poor, with a 5-year overall actuarial survival rate of 38% and disease-free survival rate of 32%, respectively. However, their clinical outcome was not altered by the addition of systemic CT. Achieving complete remission was the most important prognostic factor by univariate and multivariate analyses, but treatment modality was not found to be a prognostic variable influencing survival. Conclusions : Involved field RT alone for angiocentric lymphoma of the head and neck was insufficient to achieve an improved survival rate, but the addition of CT to involved field RT failed to demonstrate any therapeutic advantage over involved field RT alone.

• Clinical and Experimental Pediatrics
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• 제48권11호
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• pp.1193-1200
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• 2005

Purpose : Invasive bacterial infection is a major cause of morbidity and mortality in children. Previously, we reported etiology of invasive infections in healthy children in 1985-1995. This study was performed to update etiology of invasive bacterial infections in the previously healthy children. Methods : We reviewed medical records of 98 episodes of invasive bacterial infections in immunocompetent children at the Seoul National University Children's Hospital in 1996-2004. Results : The frequent pathogens identified over all age groups were Streptococcus pneumoniae (33%) and Staphylococcus aureus(33%). The proportion of Salmonella species and Haemophilus influenzae has been declined to 4% each from 23% and 14%, respectively, compared to previous study. S. agalactiae was the most common isolate in the infants ${\leq}3$ months. Among the infants and children aged 3 months to 2 years and children of 2-5 years, S. pneumoniae(57%, 52%, respectively, in each group) was the most common isolates followed by S. aureus(17% and 24%, respectively). S. aureus was the most common isolates(73%) in children >5 years. Primary bacteremia was the most common clinical diagnosis(27%). S. pneumoniae was responsible for 42% of primary bacteremia, 50% of meningitis, and 69% of bacteremic pneumonia and empyema. S. aureus accounted for 80% of bone and joint infections. The case fatality rate was 8.1% for all invasive infections. Conclusion : We reviewed frequency of bacterial agents of invasive infections in children. The data may be useful for pediatricians to select adequate empirical antibiotics in the management of invasive bacterial infections.

• Radiation Oncology Journal
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• 제8권2호
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• pp.231-239
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• 1990

From May 1979 through December 1981 a total of 524 patients with carcinoma of the uterine cervix were treated by radiation therapy with curative intent. Among the 524 patients, 350 were treated with a high-dose-rate (HDR), remote-controlled, afterloading intracavitary irradiation (ICR) system using a cobalt source (Ralstron), and 168 patients received a low-dose-rate (LDR) ICR using a radium source. External beam irradiation with a total dose of 40-50 Gy to the whole pelvis followed by intracavitary irradiation with a total dose of 30-39 Gy in 10-13 fractions to point A was the treatment protocol. ICR was given three times a week with a dose of 3 Gy per fraction. Five-year actuarial survival rates in the HDR-ICR group were $77.6{\%}$ in stage IB (N=20), $68.2{\%}$ in stage II (N=182), and $50.9{\%}$ in stage III (N=148). In LDR-ICR group, 5-year survival rates were $87.5{\%}$ in stage IB (N=22), $66.3{\%}$ in stage II (N=91), and $55.4{\%}$ in stage III (N=52). Survival rates showed a statistically significant difference by stage, but there was no significant difference between the two ICR groups. Late bowel complications after radiotherapy were noted in $3.7{\%}$ of the HDR-ICR group and $8.4{\%}$ of the LDR-ICR group. There was no severe complication requiring surgical management. The incidence of bladder complications was $1.4{\%}$ in the HDR-ICR group and $2.4{\%}$ in the LDR-ICR group. The application of HDR-ICR was technically simple and easily performed on an outpatient basis without anesthesia, and the patients tolerated it very well. Radiation exposure to personnel was virtually nil in contrast to that of LDR-ICR. Within a given period of time, more patients can be treated with HDR-ICR because of the short treatment time. Therefore, the HDR-ICR system is highly recommended for a cancer center, particularly one with a large number of patients to be treated. In order to achieve an improved outcome, however, the optimum dose-fractionation schedule of HDR-ICR and optimum combination of intracavitary irradiation with external beam irradiation should be determined through an extensive protocol.

• Journal of Chest Surgery
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• 제42권1호
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• pp.63-71
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• 2009

Background: The treatment of tracheal stenosis includes less invasive bronchoscopic intervention and more invasive segmental resection & anastomosis. Depending on the patient's clinical features, sometimes all these methods are inappropriate. Silicone T-tube stenting has recently been used as an alternative, safe management of tracheal stenosis. We studied the short term and Intermediate term results of using T-tubes in patients with tracheal stenosis, and this tracheal stenosis was caused by various underlying diseases. Material and Method: We retrospectively reviewed 57 patients with tracheal stenosis and who were treated with T-tubes between Jan 1997 and Apr 2007. Based on the patient's medical records and the imaging studies, we evaluated the clinical findings and status of T-tube removal. Result: There was no T-tube related morbidity or mortality in this series. On follow-up, one patient underwent sleeve resection and end-to-end anastomosis. The T-tube could be successfully removed from 13 patients (13/57, 22.8%) without additional interventions. For another four patients, a T-tube was again inserted after removal of the first T-tube due to tracheomalacia or recurrent stenosis. Four patients died of underlying disease and cancer. The patients' gender and previous tracheostomy significantly affected T-tube removal. By contrast, multiple logistic regression analysis identified gender as a predictor of successfully removing a T-tube. Gender (p=0.033) and previous tracheostomy (p=0.036) were the two factors for success or failure of T-tube removal. Conclusion: A T-tube provided reliable patency of a stenotic airway that was caused by any etiology. We have proven that using a T-tube is safe and effective therapy for patients with tracheal stenosis for the short term or the intermediate term.

• Radiation Oncology Journal
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• 제14권2호
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• pp.167-173
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• 1996

Purpose : This analysis was to evaluate the radiation dose around a tracheostoma and spinal cord in the case of advanced laryngeal cancers in which a total laryngectomy was done before radiotherapy. Materials and Methods : The radiation dose around a tracheostoma and spinal cord was measured by thermoluminescence and film dosimetry in the phantom, Radiotherapy treatment planning was done in 12 cases of advanced laryngeal cancer and compared with the measured dose in the phantom. Results : Mean spinal cord doses in the phantom by thermoluminescence dosimetry were $86.4\%$ (with a tracheostoma), $80.1\%$ (without a tracheostoma), and the difference was $6.3\%$. Mean spinal cord doses in the phantom by film dosimetry were $84.7\%$ (with a tracheostoma), $79.0\%$ (without a tracheostoma). and the difference were $5.7\%$. Calculated spinal cord doses in the phantom were $84.0\%$ (with a tracheostoma), $78.0\%$ (without a tracheostoma), and the difference was $6.0\%$. Mean calculated spinal cord doses in 12 patients were $83.1\%$ (with a tracheostoma), $76.9\%$ (without a tracheostoma). and the difference was $6.2\%$. Measured dose of lateral and posterior wall of the tracheostoma by film was low (depth of maximum dose = 12 mm). Conclusion : In the treatment planning of the advanced laryngeal cancers, the radiation dose of the tracheostoma and spinal cord should be evaluated and be followed by an appropriate management such as a bouls or a brachytherapy boost if the dose around the tracheostoma is low.

• Radiation Oncology Journal
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• 제21권1호
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• pp.35-43
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• 2003

Purpose :To analyze the survival period, prognostic factors and complications of patients having undergone high-dose-rate intraluminal brachytherapy (HDR-ILB) as a salvage radiation therapy, while having a catheter, for percutaneous transhepatic billary drainage (PTBD), inserted due to biliary obstruction caused by a secondary malignant biliary tumor Methods and Materials : A retrospective study was performed on 24 patients having undergone HDR-ILB, with PTBD catheter Insertion, be)ween December 1992 and August 2001. Their median age was 58.5, ranging from 35 to 82 years. The primary cancer site were the stomach, gallbladder, liver, pancreas and the colon, with 12, 6, 3, 2 and 1 cases, respectively. Eighteen patients were treated with external beam radiation therapy and HDR-lLB, while slx were treated with HDR-lLB only. The 4otal external beam, and brachytherapy radiations dose were 30$\~$61.2 and 9$\~$30 Gy, with median doses of 50 and 15 Gy, respectively. Results : Of the 24 patients analyzed, 22 died during the follow-up period, with a median survival of 7.3 months. The 6 and 12 months survival rates were 54.2 (13 patients) and 20.8$\%$ (5 patients), respectively. The median survivals for stomach and gailbladder cancers were 7.8 and 10.2 months, respectively, According to the unlvariate analysis, a significant factor affecting survival of over one year was the total radiation dose (over 50 Gy) (o=0.0200), with all )he patients surviving more than one year had been Irradiated with more than 50 Gy. The acute side effects during the radiation therapy were managed with conservative treatment. During the follow-up period, 5 patients showed symptoms of cholangltis due to the radiation therapy Conclusion :An extension to the survival of those patients treated with HDR-ILB is suggested compared to the median historical survival of 4hose patients treated with external biliary drainage. A boost radiation dose could be effectively given, by performing HDR-lLB, which is a prognostic factor In addition, the acute complications of radiation therapy were effectively controlled by conservative management, and It could be regarded as a safe treatment.

• Radiation Oncology Journal
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• 제6권1호
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• pp.63-73
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• 1988

One hundred fifty-four patients with the carcinoma of the uterine cervix were studied retrospectively to assess the result and impact of treatment at Department of Radiation Oncology, Korea University, Hae-Wha Hospital from Feb 1981 through Dec. 1986. Prior to radiotherapy, the patients were evaluated and staged by recommendation of FIGO including physical examination, pelvic examination, cystoscopy, rectosigmoidoscopy, chest X-ray, IVP. Ba enema. Also, an additional pelvic CT scan was obtained for some of the patients. The patients were treated by radiotherapy alone or adjuvant postoperative irradiation; in case of radiation therapy only, whole pelvic irradiation was given with Co-60 teletherapy unit via AP and PA parallel opposing fields or 4-oblique fields, 180 cGy per day, 5 days per week and intracavitary insertion was performed. In satges Ia, Ib, and IIa with small primary lesion, external irradiation was initially given to pelvis up to $2,000\~3,000\;cGy/2frac{1}{2}\;-3frac{1}{2}$ weeks and then intracavitary insertion was performed using Fletcher-Mini-Declos Applicator with cesium-137 cources and followed by external irradiation of $1,000\~2,000\;cGy/1frac{1}{2}\;-2frac{1}{2}$weeks via AP and PA parallel opposing fields with midline shield to spare of bladder and rectum. However, if the primary lesion is large, external irradiation was given without midline shield. More than stages IIb, the patients were treated by external beam irradiation up to 5,400cGy/30f for 6 weeks via 4-oblique portals and at the dose of 5,040cGy/28f the field was cut 5cm from the top margin for spare of small bowel, and followed by intracavitary irradiation, If there was residual tumor an additional dose of $900\~l,200cGy/5\~7f$ was given to parametrium and/or residual tumor area. Total dose of radiation to A and B-point were as follows; A-point; In early stages, Ia, Ib, IIa; $8,000\~9,000$ B-point $5,000\~6,000 cGy$ A-point; In advanced stages IIb, IIIa, IIIb; $9,000\~10,000$ B-point $60,000\~7,000cGy$ The results were obtained and as fellows; 1 The patients distribution according to FIGO staging system were stage Ia 6, Ib 27, IIa 28, IIb 54, IIIa 12, IIIb 18, and stage IVa 9. 2. Value of CT scan were demonstration of cervix tumor mass, parametrial and pelvic side wall tumor spread, pelvic and inguinal lymph nodes metastases, and hydronephrosis. Three dimensional quantitative demonstration of tumor volume is also important in planning radiation therapy. Another advantage of CT scan was detection of recurrent tumor after radiation or surgery. 3. Local control rate of tumor according to the size was $91.3\%$ for less than 5cm in size and $44.6\%$ in tumor over 5cm (p<0.0068). 4. Thirty out of 50 recurrent sites has locoregional failures and 17 cases has distant metastases. And the para-aortic lymph nodes were the most common site for distant metastases. 5. The most common complication was temporal rectal bleeding which was controlled most by conservative management. However, 4 patients required for endoscopic cauterization. 6. The 5-year survival rates showed; stage la and Ib $95\%,\;stage\;IIa\;81\%\;stage\;lIb\;67\%,\;stage\;IIIa\;37.7\%,\;stage\;IIIb\;23\%$ and 3-year survival rate of stage IVa showed $11.6%$, retrospectively.