• Radiation Oncology Journal
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• v.11 no.1
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• pp.69-77
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• 1993

Treatment of cerebellar medulloblastoma has been much improved with modern surgical technique for gross total tumor removal and adequate radiation therapy for the whole craniospinal axis. Questions have been arosen about the optimal radiation dose for the preventive treatment of whole cranium and whole spinal axis. Recently, many authors have reported their treatment results as comparable to older data, using lower than conventional dose of 3,600 cGy-4,000 cGy. For 50 patients treated between 1981 and 1990 at the Department of Radiation Therapy of SNUH, retrospective analysis was done for the treatment result, especially the neuraxis control, by radiation dose for the presymptomatic area of the disease. Analysis only by total spinal dose did not give any significant difference. But further analysis by following patient group; 3,600 cGy/150 cGy (n=6), 3,000 cGy/150 cGy (n=10), 2,400 cGy/150 cGy (n=17) and 2,400 cGy/100-120 cGy (n=11) showed significant improvement of neuraxis control by decreasing order (p =0.003). There was no significant difference in overall survival between the groups. For the 19 patients who had been confirmed initially as having no neuraxis disease, TDF 30 was the cur-off value that could prevent neuraxis failure (p =0.004). We couldn't define any TDF value that give reasonable control for the patient group with positive CSF study at initial diagnosis.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.79-82
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• 1993

From October 1989 to March 1992, ten patients diagnosed as primary central nervous system (CNS) lymphoma were treated with radiation therapy at Asan Medical Center. To obtain pathologic diagnosis, five patients had stereotactic biopsy and the others underwent craniotomy & tumor removal. According to the classification by International Working Formulation, seven of 10 patients showed diffuse large cell types and the remaining 3 had diffuse mixed cell types. Computed tomographic scans of the brain disclosed solitary (6 cases) or multiple (4 cases) intracranial lesions. All patients received 4000 cGy/20 fx to the whole brain followed by an additional 2000 cGy/10 fx boost to the primary lesion. Six patients with initial cerebrospinal fluid (CSF involvement were treated with whole brain irradiation and intrathecal Methotrexate (IT-MTX) chemotherapy. One of them received an additional spinal irradiation after 3 cycles of IT-MTX chemotherapy because of MTX induced arachnoiditis. One patient received 3 cycles of systemic chemotherapy prior to rodiation therapy and one received 5 cycles of salvage chemotherapy for recurrence. With a median follow up time of 8 months, all patients were followed from 7 to 26 months. Radiologically seven patients showed complete remission and the remaining three showed partial remission at one month after radiotherapy. The 1 and 2 year survival rate was $86{\%}\;and\;69{\%}$ respectively. Until now, two patients expired at 7 and 14 months. These patients developed extensive CSF seeding followed by local failure. Considering initial good response to radiation therapy and low incidence of extraneural dissemination in primary CNS lymphoma, we propose to increase total tumor dose to the primary lesion by hyperfractionated radiotherapy or stereotactic radiosurgery. For the patients with CSF involvement at diagnosis, we propose craniospinal irradiation with IT MTX chemotherapy.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.136-140
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• 1999

Purpose : Prostate specific antigen (PSA) is a useful tumor marker, which is widely used as a diagnostic index and predictor of both treatment and follow-up result in prostate cancer. A prospective analysis was carried out to obtain the period of PSA normalization and the half life of PSA and to analyze the factors influencing the period of PSA normalization. The PSA level was checked before and serially after radical radiotherapy. Materials and Method : Twen쇼 patients with clinically localized prostate cancer who underwent radical external beam radiotherapy were enrolled in this study. Accrual period was from April 1993 to May 1998. Median follow-up period was 20 months. Radiotherapy was given to whole pelvis followed by a boost to prostate. Dose range for the whole pelvis was from 45 Gy to 50 Gy and boost dose to prostate, from 14 Gy to 20 Gy. The post-irradiation PSA normal value was under 3.0 ng/ml. The physical examination and serum PSA level evaluation were performed at 3 month interval in the first one year, and then at every 4 to 6 months. Results : PSA value was normalized in nineteen patients (95%) within 12 months. The mean period of PSA normalization was 5.3 (${\pm}$2.7) months. The half life of PSA Of the nonfailing patients was 2.1 (${\pm}$0.9) month. The nadir PSA level Of the nonfailing Patients waS 0.8 (${\pm}$0.5) ng/ml. The period of PSA normalization had the positive correlation with pretreatment PSA level (R$^{2}$=0.468). The nadir PSA level had no definite positive correlation with the pretreatment PSA level (R$^{2}$=0.075). The half life of serum PSA level also had no definite correlation with pretreatment PSA level (R$^{2}$=0.029). Conclusion :The PSA level was mostly normalized within 8 months (85%). If it has not normalized within 12 months, we should consider the residual disease in prostate or distant metastasis. In 2 patients, the PSA level increased 6 months or 20 months before clinical disease was detected. So the serum PSA level can be used as early diagnostic indicator of treatment failure.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.16-20
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• 2001

Purpose : To evaluate the effectiveness and tolerance of the postoperative radiation therapy for patients with Stage III thymoma and to define the optimal radiotherapeutic regimen Materials and Methods : We retrospectively analyzed the records of 24 patients with Stage III thymoma who were referred for postoperative radiation therapy in our institution from June, 1987 to May, 1999. Surgical therapy consisted of total resection in one patient, subtotal resection in seventeen, and biopsy alone in six patients. Age of the patients was ranged from 20 to 62 years with mean age of 47 years. Male to female ratio was 14 to 10. Radiation therapy was delivered with linear accelerator producing either 6 MeV or 10 MeV photons. The irradiated volume included anterior mediastinum and known residual disease. The supraclavicular fossae were not irradiated. The delivered total dose was ranged from 30 to 56 Gy. One patient received 30 Gy and eighteen patients received minimum of 50 Gy. Follow up period was ranged from 12 months to 8 years with median follow up of 40 months. Results : The overall local control rate for entire group of patients was $67\%$ at 5 years. The cumulative local failure rates at one, three and five year were $18\%,\;28\%\;and\;33\%$, respectively. In patients treated with subtotal resection and biopsy alone, local control rate was $76\%\;and\;33\%$, respectively. The actuarial observed survival rate at 5 years was $57\%$, and actuarial adjusted survival at 5 years was $72\%$. The difference between 5 year survival rates for patients treated with subtotal resection and biopsy alone was not statistically significant $(62\%\;vs\;30\%)$. Conclusion : We might conclude that postoperative radiation therapy was safe and effective treatment for patients with Stage III thymoma. Postoperative radiation therapy is recommended in cases where tumor margin is close or incomplete resection is accomplished.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.173-180
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• 2009

Purpose: To investigate the role of radiotherapy for squamous cell carcinomas of the external auditory canal and middle ear. Materials and Methods: A series of 35 patients who were treated at a single institution from 1981 through 2007 were retrospectively analyzed. Thirteen patients were treated by radiotherapy alone; four by surgery only and 18 by a combination of surgery and radiotherapy. The total radiation dose ranged from 39~70 Gy (median, 66 Gy) in 13~35 fractions for radiotherapy alone and 44~70 Gy (median, 61.2 Gy) in 22~37 fractions for the combined therapy. Clinical end-points were the cause of specific survival (CSS) and local relapse-free survival (LRFS). The median follow-up time was 2.8 years (range, 0.2~14.6 years). Results: The 3-year CSS and LRFS rate was 80% and 63%, respectively. Based on a univariate analysis, performance status and residual disease after treatment had a significant impact on CSS; performance status and histologic grade for LRFS. Patients treated by radiotherapy alone had more residual disease following the course of treatment compared to patients treated with the combined therapy; 69% vs. 28%, respectively. Conclusion: Our results suggest that radiation alone was not an inferior treatment modality for CSS compared to the combined therapy for squamous cell carcinoma of the external auditory canal and middle ear. However, local failure after radiotherapy is the main issue that will require further improvement to gain optimal local control.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.145-152
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• 2009

Purpose: We retrospectively studied the outcomes and prognostic factors of patients with locally advanced, unresectable pancreatic cancer who were treated with concurrent chemoradiotherapy (CCRT) or radiotherapy only. Materials and Methods: Fifty-one patients with locally advanced, unresectable pancreatic cancer (stage IIA~III) who recevied radiotherapy ($\geq$30 Gy) between January 1994 and August 2008 were reviewed retrospectively. The median radiation dose was 39 Gy. Chemotherapy consisted of gemcitabine, cisplatin, or 5-FU alone or in various combinations, and was administered concurrently with radiotherapy in 38 patients. Results: The follow-up period ranged from 2~40 months (median, 8 months). The median survival, and the 1-and 2-year overall survival (OS) rates were 7 months, 15.7%, and 5.9%, respectively. Based on univariate analysis, the baseline CA19-9, performance status, and chemotherapy regimen were significant prognostic factors. The median survival was 8 months for CCRT, and 6 months for radiotherapy alone. The patients treated with gemcitabine-containing regimens had longer survival (median, 10 months) than the patients treated with radiotherapy alone (p=0.027). Twenty-three patients were available to evaluate the patterns of failure. Distant metastases (DM) occured in 18 patients and regional recurrences were demonstrated in 4 patients. Local progression developed in 14 patients. We analyzed the association between the time-to-DM and the baseline CA19-9 levels for 18 evaluable patients. The median time-to-DM was 20 months for patients with normal baseline CA19-9 levels and 2 months for patients with baseline CA19-9 levels $\geq$200 U/ml. Conclusion: CCRT with gemcitabine-based regimens was effective in improving OS in patients with locally advanced, unresectable pancreatic cancer. We suggest that the baseline CA19-9 level is valuable in determining the treatment strategy for patients with locally advanced, unresectable pancreatic cancer.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.219-226
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• 2007

Purpose: The aim of this retrospective analysis was to analyze the results of radiotherapy administered to patients with neck node metastases from an unknown primary cancer, with or without neck dissection. Materials and Methods: From January 1986 to December 2005, 88 patients with neck node metastases from an unknown primary cancer were treated with curative intent. The age of the patients ranged from 35 to 74 years (median age, 59 years). There were 74 male and 14 female patients. Distribution of patients by N status was as follows: N1, 4 patients; N2a, 10 patients; N2b, 48 patients; N2c, 8 patients; N3, 18 patients. Fifty-one patients underwent neck dissection and 37 patients had only a biopsy (31 patients had fine-needle aspiration and 6 patients had an excisional biopsy). All patients received radiotherapy. The follow-up time ranged from 1 to 154 months, with a median time of 32 months. Results: The overall survival (OS) and disease-free survival (DFS) rate at 5 years were 43.9% and 41.7%, respectively. The factors associated with the OS rate were neck dissection, and a subsequent primary tumor. Factors associated with the DFS rate were N stage, neck dissection, and a subsequent primary tumor. Neck failure was noted in 15 patients, distant metastases in 18 patients, and a subsequent primary tumor in 8 patients. Conclusion: With comprehensive radiotherapy given to the bilateral neck and the potential mucosal sites, good survival rates can be obtained in patients with neck node metastases from an unknown primary cancer. However, considering the side effects, a randomized trial is required to determine the optimal radiotherapy volume.

• Radiation Oncology Journal
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• v.26 no.1
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• pp.17-23
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• 2008

Purpose: The best treatment for advanced esophageal cancer is chemoradiotherapy followed by surgery. In spite of the advance of multimodality therapy, most patients with esophageal cancer are treated with radiation therapy alone. This study reports the outcome of the use of conventional external beam radiotherapy alone for the treatment of esophageal cancer. Materials and Methods: Between January 1998 and December 2005, 30 patients with squamous cell carcinoma of the esophagus were treated with external beam radiotherapy using a total dose exceeding 40 Gy. Radiotherapy was delivered with a total dose of 44-60 Gy(median dose, 57.2 Gy) over $36{\sim}115$ days(median time, 45 days). Thirteen patients(43.3%) had a history of disorders such as diabetes, hypertension, tuberculosis, lye stricture, asthma, cerebral infarct, and cancers. Four patients metachronously had double primary cancers. The most common location of a tumor was the mid-thoracic portion of the esophagus(56.7%). Tumor lengths ranged from 2 cm to 11 cm, with a median length of 6 cm. For AJCC staging, stage III was the most common (63.3%). Five patients had metastases at diagnosis. Results: The median overall survival was 8.3 months. The survival rates at 1-year and 2-years were 33.3% and 18.7%, respectively. The complete response rate $1{\sim}3$ months after radiotherapy was 20%(6/30) and the partial response rate was 70%(21/30). Sixteen patients(53.3%) had an improved symptom of dysphagia. Significant prognostic factors were age, tumor length, stage, degree of dysphagia at the time of diagnosis and tumor response. Cox regression analysis revealed the aim of treatment, clinical tumor response and tumor length as independent prognostic factors for overall survival. Twenty-eight patients had local failure and another four patients had metastases. Three patients were detected with double primary cancers in this analysis. A complication of esophageal stricture was observed in three patients(10%), and radiation pneumonitis occurred in two patients(6.7%). Conclusion: The prognosis of esophageal cancer remains poor, in spite of advances in radiotherapy techniques. Radiotherapy is one of the main treatment modalities for the relief of dysphagia and treatment related complications are minimal. It is expected that the addition of chemotherapy or another systemic modality to radiotherapy will improve tumor control and increase the survival rate in advanced esophageal cancer.

• Journal of Veterinary Clinics
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• v.26 no.2
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• pp.138-143
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• 2009

Ischemia/reperfusion injury(I/RI) is the major cause of acute renal failure and delayed graft function(DGF) unavoidable in renal transplantation. Enormous studies on ischemia damage playing a role in activating graft rejection factors, such as T cells or macrophages, are being reported. Present study was performed to determine whether ischemia time would play an important role in activating rejection-related factors or not in rat models of I/RI. Male Sprague-Dawley rats were submitted to 30, 45, and 60 minutes of warm renal ischemia with nephrectomy or control animals underwent sham operation(unilateral nephrectomy). Renal function and survival rates were evaluated on day 0, 1, 2, 3, 5 and 7. Immunofluorescence staining of dendritic cells(DCs), natural killer(NK) cells, macrophages, B cells, CD4+ and CD8+ T cells were measured on day 1 and 7 after renal I/RI. Survival rates dropped below 50% after day 3 in 45 minutes ischemia. Histologic analysis of ischemic kidneys revealed a significant loss of tubular architecture and infiltration of inflammatory cells. DCs, NK cells, macrophages, CD4+ and CD8+ T cells were infiltrated from a day after I/RI depending on ischemia time. Antigen presenting cells(DCs, NK cells or macrophages) and even T cells were infiltrated 24 hours post-I/RI, which is at the time of acute tubular necrosis. During the regeneration phase, not only these cells increased but B cells also appeared in more than 45 minutes ischemia. The numbers of the innate and the adaptive immune cells increased depending on ischemia as well as reperfusion time. These changes of infiltrating cells resulting from each I/RI model show that ischemic time plays a role in activating rejection related immune factors and have consequences on progression of renal disease in transplanted and native kidneys.

• The Korean Society of Law and Medicine
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• v.8 no.1
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• pp.107-135
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• 2007

In preparation of the medical examination records, the failure to correctly write the taken medical behaviors on the medical examination records, is subject to criminal conviction due to the breach of the Article 21-1. The false or overstated writings on the medical examination records is subject to the same punishment due to the Article 21-1, which $\underline{additionally}$ may lead to the administrative measures such as the suspension of license according to Article 53-1. The interpretation is considered as proper in light of the function of the medical examination records, hazard to the patients, and the doctors' ethics. In light of the attitude of The Supreme Court for the preparation obligation of the medical examination records specified in the medical law Article 21-1(Purport : The doctors may continue to use their opinions on the patient's status and treatment process on the medical examination records, may provide the proper information to other medical staff, and ought to specify the details enough to decide the appropriateness of such medical behaviors after the recent treatment.), the false writings of the doctors on the medical examination records of the non-treated patient as faithfully treated one during the entire period before the present hospitalization, will be regarded as the fulfillment obligation of the preparation of the medical examination records in the medical law Article 21-1.