• Title/Summary/Keyword: 방사선 선량 분포

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Microbiological Characteristics of Gamma Irradiated and Low-Salted Fermented Squid (감마선 조사된 저염 오징어젓갈 발효의 미생물균총 특성)

  • Kim, Dong-Ho;Kim, Jae-Hun;Yook, Hong-Sun;Ahn, Hyun-Joo;Kim, Jung-Ok;Sohn, Cheon-Bae;Byun, Myung-Woo
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1619-1627
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    • 1999
  • Microbiological characteristics of gamma irradiated low salt squid Jeot-gal were examined. Following the fermentation periods, total bacterial cell, Lactobacillus spp., Staphylococcus spp., Streptococcus spp., Pseudomonas spp. and yeast cell number were counted on their selective media and some acid forming bacteria and Pseudomonas spp. were identified. As the gamma irradiation dose increased, the microbial density of early fermentation phase was reduced and the growth rate was delayed. The repression effects on microbiological growth by gamma irradiation were to be higher as salt concentration increased. Adequate conditions of salt concentration and gamma irradiation for low-salt squid Jeot-gal preparation were 10% and 10 kGy, respectively. Lactobacillus sp. 2, Micrococcus varians and Streptococcus sp. I were isolated from 5% salt containing squid Jeot-gal, and Micrococcus morrhuae was from 20% only while Lactobacillus plantarum and Lactobacillus brevis were widespread. Lactobacillus brevis, Pediococcus halophilus and Pseudomonas diminuta were sensitive and Lactobacillus plantarum, Micrococcus morrhuae and Pseudomonas sp. 3 were resistant to gamma irradiation. The diversity of microflora decreased as salt concentration decreased and gamma irradiation dose increased.

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Analysis of the Radiation Therapy Outcomes and Prognostic Factors of Thymoma (흉선종에 대한 방사선치료 성적 및 예후인자분석)

  • Lee, Seok-Ho;Lee, Kyu-Chan;Choi, Jin-Ho;Lee, Jae-Ik;Sym, Sun-Jin;Cho, Eun-Kyung
    • Radiation Oncology Journal
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    • v.28 no.1
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    • pp.1-8
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    • 2010
  • Purpose: This retrospective study was performed to evaluate the efficacy of radiation therapy (RT) and to investigate the prognostic factors for thymoma when treated with RT. Materials and Methods: We analyzed 21 patients with thymoma and also received RT from March 2002 to January 2008. The median follow-up time was 37 months (range, 3 to 89 months). The median patient age was 57 years (range, 24 to 77 years) and the gender ratio of males to females was 4:3. Of the 21 patients, complete resections (trans-sternal thymectomy) and R2 resections were performed in 14 and 1 patient, respectively. A biopsy was performed in 6 patients (28.7%). The WHO cell types in the 21 patients were as follows: 1 patient (4.8%) had type A, 10 patients (47.6%) had type B1-3, and 10 patients (47.6%) had type C. Based on Masaoka staging, 10 patients (47.6%) were stage II, 7 patients (33.3%) were stage III, and 4 patients (19.1%) were stage IVa. Three-dimensional RT was adminstered to the tumor volume (planned target volume), including the anterior mediastinum and the residual disease. The total RT dose ranged from 52.0 to 70.2 Gy (median dose, 54 Gy). Consistent with the WHO criteria, the response rate was only analyzed for the 6 patients who received a biopsy only. The prognostic factors analyzed for an estimate of survival included age, gender, tumor size, tumor pathology, Masaoka stage, the possibility of treatment by performing surgery, the presence of myasthenia gravis, and RT dose. Results: The 3-year overall survival rate (OS) and the progression free survival rate (PFS) were 80.7% and 78.2%, respectively. Among the 10 patients with WHO cell type C, 3 of 4 patients (75%) who underwent a complete resection and 3 of 6 patients (50%) who underwent a biopsy survived. Distant metastasis developed in 4 patients (19.1%). The overall response rate in the 6 patients who received biopsy only were as follows: partial remission in 4 patients (66.7%), stable disease in 1 patient (16.6%), and progressive disease in 1 patient (16.6%). Acute RTOG radiation pneumonitis occurred in 1 patient (4.8%), grade 2 occurred in 2 patients (9.5%), grade 3 occurred in 1 patient (4.8%), and grade 4 occurred in 1 patient (4.8%). A univariate analysis revealed that the significant prognostic factors for OS were age (${\geq}60$, 58.3%; <60, 100%; p=0.0194), pathology (WHO cell type A-B3, 100%; C, 58.3%; p=0.0194) and, whether the patient underwent surgery (yes, 93.3%; no, 50%; p=0.0096). Conclusion: For the 15 patients who received surgery, there was no local failure within the radiation field. In patients with WHO cell type C, surgical procedures could have resulted in a more favorable outcome than biopsy alone. We report here our clinical experience in 21 patients with thymoma who were treated by radiation therapy.

Once vs. Twice Daily Thoracic Irradiation in Limited Stage Small Cell Lung Cancer (국한성 병기 소세포폐암의 방사선치료시 분할 조사방식에 따른 치료성적)

  • Kim, Jun-Sang;Kim, Jae-Sung;Kim, Ju-Ock;Kim, Sun-Young;Cho, Moon-June
    • Radiation Oncology Journal
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    • v.16 no.3
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    • pp.291-301
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    • 1998
  • Purpose : A retrospective study was conducted comparing single daily fraction (SDF) thoracic radiotherapy (TRT) with twice daily (BID) TRT to determine the potential benefit of BID TRT in limited-stage small cell lung cancer (SCLC). Endpoints of the study were response. survival, pattern of failure, and acute toxicity. Materials and Methods : Between November 1989 to December 1996, 78 patients with histologically proven limited-stage SCLC were treated at the Department of Therapeutic Radiology, Chungnam National University Hospital. Of these, 9 were irradiated for palliative intent, and 1 had recurrent disease. Remaining 68 patients were enrolled in this study. There were 26 patients with a median age of 58 years, and 22 (85$\%$) ECOG performance score of less than 1 in SDF TRT. There were 42 patients with a median age of 57 years, and 36 (86$\%$) ECOG performance score of less than 1 in BID TRT By radiation fractionation regimen, there were 26 in SDF TRT and 42 in BID TRT. SDF TRT consisted of 180 cGy, 5 days a week. BID TRT consisted of 150 cGy BID, 5 days a week in 13 of 42 and 120 cGy BID, in 29 of 42. And the twice daily fractions were separated by at least 4 hours. Total radiotherapy doses were between 5040 and 6940 cGy (median, 5040 cGy) in SDF TRT and was between 4320 and 5100 cGy (median, 4560 cGy) in BID TRT. Prophylactic cranial irradiation (PCI) was recommended for patients who achieved a CR. The recommended PCI dose was 2500 cGy/10 fractions. Chemotherapy consisted of CAV (cytoxan 1000 mg/$m^2$, adriamycin 40 mg/$m^2$, vincristine 1 mg/$m^2$) alternating with VPP (cisplatin 60 mg/$m^2$, etoposide 100 mg/$m^2$) every 3 weeks in 25 (96$\%$) of SDF TRT and in 40 (95$\%$) of BID TRT. Median cycle of chemotherapy was six in both group. Timing for chemotherapy was sequential in 23 of SDF TRT and in 3 BID TRT, and concurrent in 3 of SDF TRT and in 39 of BID TRT Follow-up ranged from 2 to 99 months (median, 14 months) in both groups. Results : Of the 26 SDF TRT, 9 (35$\%$) achieved a complete response (CR) and 14 (54$\%$) experienced a partial response (PR). Of the 42 BID TRT, 18 (43$\%$) achieved a CR and 23 (55$\%$) experienced a PR. There was no significant response difference between the two arms (p=0.119). Overall median and 2-year survival were 15 months and 26.8$\%$, respectively. The 2-year survivals were 26.9$\%$ and 28$\%$ in both arm, respectively (p=0.51). The 2-rear survivals were 35$\%$ in CR and 24.2$\%$ in PR, respectively. The grade 2 to 3 esophageal toxicities and grade 2 to 4 neutropenias were more common in BID TRT (p=0.028 0.003). There was no difference in locoregional and distant metastasis between the two arms (p=0 125 and 0.335, respectively). The most common site of distant metastasis was the brain. Conclusion : The median survival and 2-year survival were 17 months and 20.9$\%$ in SDF TRT with sequential chemotherapy, and 15 months and 28$\%$ in BID TRT with concurrent chemotherapy, respectively. We did not observe a substantial improvement of long-term survival in the BID TRT with concurrent chemotherapy compared with standard schedules of SDF TRT with sequential chemotherapy. The grade 2 to 3 esophageal toxicities and glade 2 to 4 neutropenias were more common in BID TRT with concurrent chemotherapy. Although the acute toxicities were more common in BID TRT with concurrent chemotherapy than SDF TRT with sequential chemotherapy, a concurrent chemotherapy and twice daily TRT was feasible. However further patient accrual and long-term follow up are needed to determine the potential benefits of BID TRT in limited-stage SCLC.

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The Role of Postoperative External Irradiation for the Incompletely Resected Meningiomas (불완전절제된 수막종에서 수술 후 방사선치료의 역할)

  • Kim Tae-Hyun;Yang Dae-Sik;Kim Chul-Young;Choi Myung-Sun
    • Radiation Oncology Journal
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    • v.18 no.2
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    • pp.85-91
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    • 2000
  • Purpose : The aim of this study is to look for the possible efficacy of postoperative external irradiation for incompletely resected meningiomas. Methods and Materials : From August 198: to January 1997, forty-four patients with intracranial meningioma were treated by postoperative external irradiation. Of the 44 meningiomas, 18 transitional, 13 meningotheliomatous, 6 hemangiopericytic, 4 atypical, 2 fibroblastic and 1 malignant meningioma were identified. We classified all patients into two groups by the histology. The benign group was consisted of the meningotheliomatous, transitional and fibroblastic types. The malignant group was consisted of the atypical, hemangiopericytic and malignat types. In the means of surgery, 37 patients were resected incompletely and 7 patients were managed by biopsy only. After surgery, all patients were received postoperative external irradiation. Radiotherapy was deliverd using Co-60 or 4 MV photon beam to a total dose of 50 to 65 Gy (mean dose 57.4 Gy) with a 1.8 to 2 Gy per fraction. The median follow-up was 48 months (range : 21 $\~$ 101 months). Multivariate analysis of the Influence by age, sex, location, histology and radiation dose on local control has been done using Cox's proportional hazard model. Results : 5-year local control rate was 93.8$\%$ for the benign histology and 51.8$\%$ for the malignant histology (p=0.0110) and overall local control rate at 5 years was 87.4$\%$. The analysis of the prognostic factors, such as age, sex, location, and radiation dose were not significant except for the histology. Conclusion : Adjuvant postoperative external irradiation appears to be significantly improved local control in the patients with incompletely resected meningiomas.

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Radiation Therapy for Carcinoma of the Oropharynx (구인두암의 방사선치료)

  • Park, In-Kyu;Kim, Jae-Choel
    • Radiation Oncology Journal
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    • v.14 no.2
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    • pp.95-103
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    • 1996
  • Purpose : A retrospective analysis for patients with oropharyngeal carcinoma who were treated with radiation was performed to assess the results of treatment and patterns of failure, and to identify the factors that might influence survival. materials and methods : From March 1985 through June 1993, 53 patients with oropharyngeal carcinoma were treated with either radiation therapy alone or combination of neoadjuvant chemotherapy and radiation therapy at the Department of Radiation Oncology, Kyungpook National University Hospital. Patients' ages ranged from 31 to 73 years with a median age of 54 years. There were 47 men and 6 women, Forty-two Patients ($79.2\%$) had squamous cell carcinoma, 10 patients ($18.9\%$) had undifferentiated carcinoma and 1 patient ($19\%$) had adenoid cystic carcinoma. There were 2 patients with stage I, 12 patients with stage II, 12 Patients with stage III and 27 patients with stage IV. According to the TNM classification, patients were distributed as follows: T1 7, T2 28, T3 10, T4 7, TX 1, and N0 17, Nl 13, N2 21, N3 2. The primary tumor sites were tonsillar region in 36 patients ($67.9\%$), base of the tongue in 12 patients ($22.6\%$), and soft palate in 5 patients ($9.4\%$). Twenty-five patients were treated with radiation therapy alone and twenty-eight Patients were treated with one to three courses of chemotherapy followed by radiation therapy. Chemotherapeutic regimens used were either CF (cisplatin and 5-fluorouracil) or CVB (cisplatin, vincristine and bleomycin). Radiation therapy was delivered 180-200 cGy daily, five times a week using 6 MV X-ray with or without 8-10 MeV electron beams A tumor dose ranged from 4500 cGy to 7740 cGy with a median dose of 7100 cGy. The follow-up time ranged from 4 months to 99 months with a median of 21 months. Results : Thirty-seven patients ($69.8\%$) achieved a CR (complete response) and PR (partial response) in 16 patients ($30.2\%$) after radiation therapy. The overall survival rates were $47\%$ at 2 years and $42\%$ at 3 years, respectively. The median survival time was 23 months. Overall stage (p=0.02) and response to radiation therapy (p=0.004) were significant prognostic factors for overall survival. The 2-year disease-free survival rate was $45.5\%$. T-stage (p=0.03), N-stage (p=0.04) and overall stage (P=0.04) were significant prognostic factors for disease-free survival. Age, sex, histology, primary site of the tumor, radiation dose, combination of chemotherapy were not significantly associated with disease-free survival. Among evaluable 32 Patients with CR to radiation therapy, 12 patients were considered to have failed Among these, 8 patients failed locoregionally and 4 Patients failed distantly. Conclusion : T-stage, N-stage and overall stage were significant prognostic factors for disease-free survival in the treatment of oropharyngeal cancer Since locoregional failure was the predominant pattern of relapse, potential methods to improve locoregional control with radiation therapy should be attempted. More controlled clinical, trials should be completed before acceptance of chemotherapy as a part of treatment of oropharyngeal carcinoma.

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Induction Chemotherapy and Radiotherapy in Locally Advanced Non-Small Cell Lung Cancer (NSCLC) (국소 진행된 비소세포성 폐암에서 유도 화학요법 및 방사선치료)

  • Yun, Sang-Mo;Kim, Jae-Cheol;Park, In-Kyu
    • Radiation Oncology Journal
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    • v.17 no.3
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    • pp.195-202
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    • 1999
  • Purpose : We peformed this study to evaluate the prognostic factors and the effect of induction chemotherapy in locally advanced non-small cell lung cancer (NSCLC). Materials and Methods : A retrospective analysis was done for 130 patients with locally advanced NSCLC treated with curative radiotherapy alone or induction chemo-radiotherapy from January 1986 to October 1996. Eighty-five patients were treated with radiotherapy alone, forty-five with induction chemotherapy and radiotherapy. Age, sex, performance status, histopathologic type, and stage were evenly distributed in both groups. The patients were treated with 6 MV or 10 MV X-ray. Conventional fractionation with daily fraction size 1$.8\~2.0$ Gy was done. Of the patients, 129 patients received total dose above 59.6 Gy ($56\~66$ Gy, median 60 Gy). Induction chemotherapy regimen were CAP (Cyclo-phosphamide, Adriamycin, Cisplatin) in 6 patients, MVP (Mitomycin, Vinblastine, Cisplatin) in 9 patients, MIC (Mitomycin, Ifosfamide Cisplatin) in 13 patients, and EP (Etoposide, Cisplatin) in 17 patients. Chemotherapy was done in $2\~5$ cycles (median 2). Results : Overall 1-, 2-, and 3-year survival rate (YSR) for all patients were $41.5\%,{\;}13.7\%,{\;}and{\;}7\%$, respectively (median survival time 11 months). According to treatment modality, median survival time, overall 1-, 2-, and 3-YSR were 9 months, $32.9\%,{\;}10.\5%,{\;}6\%$ for radiotherapy alone group, and 14 months, $57.8\%,{\;}20\%,{\;}7.6\%$ for induction chemotherapy group, respectively (f=0.0005). Complete response (CR) to overall treatments was $25\%$ (21/84) in radiotherapy alone and $40.5\%$ (17/42) in induction chemotherapy group (p=0.09). The Prognostic factors affecting overall survival were hemoglobin level (p=0.04), NSE (neuron-specific enolase) level (p=0.004), and respense to overall treatment(p=0.004). According to treatment modalities, NSE (neuron-specific enolase) (p=0.006) and response to overall treatment (p=0.003) were associated with overall survival in radiotherapy alone group, and response to overall treatment (p=0.007) in induction chemotherapy group. The failure Pattern analysis revealed no significant difference between treatment modalities. But, in patients with CR to overall treatment, distant metastasis were found in 11/19 patients with radiotherapy alone, and 3/13 patients with induction chemotherapy and radiotherapy (p=0.07). Locoregional failure patterns were not different between two groups (10/19 vs 6/13). Conclusion : Induction chemotherapy and radiotherapy achieved increased 2YSR compared to radiotherapy alone, At least in CR patients, there was decreased tendency in distant metastasis with induction chemotherapy. But, locoregional failures and long-term survival were not improved. Thus, there is need of more effort to increasing local control and further decreasing distant metastasis.

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Development and Testing of CdZnTe Detector for Pocket Surveymeter (CdZnTe 검출기를 이용한 개인용 Pocket Surveymeter의 제작 및 특성)

  • Lee, Hong-Kyu;Kang, Young-Il;Choi, Myung-Jin;Wang, Jin-Suk;Kim, Byung-Taik
    • Journal of Radiation Protection and Research
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    • v.21 no.1
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    • pp.1-7
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    • 1996
  • In this paper, we discussed the fabrication and characterization of bulk type CdZnTe detector for pocket surveymeter. The resistivity of CdZnTe single crystal grown by the High Pressure Bridgman method is in the mid of $10^9$ ohm-cm. The detector structure is Au/CdZnTe/Au and gold electrode is formed by electroless deposition method. Resolutions of 4.8keV and 2.2keV were observed at 22.2keV line of $^{109}Cd$ and 59.6keV line of $^{241}Am$ at room temperature, respectively. We also constructed the small size pocket surveymeter using home made CdZnTe detector. It shows the good linearity over a range from 1mR/hr to 10R/hr with deviation less than 5%. The sensitivity of the surveymeter developed is $2.2{\times}10^3 cps/Rad\;hr^{-1}$ for the 662keV of $^{l37}Cs\;{\gamma}-ray$.

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Results of Radiation Therapy and Extrafascial Hysterectomy in Bulky Stage IB, IIA-B Carcinoma of the Uterine Cervix (종괴가 큰 병기 IB, IIA-B 자궁경부암에서 방사선치료와 Extrafascial Hysterectomy의 결과)

  • Kim Jin Hee;Lee Ho Jun;Choi Tae Jin;Do Cha Soon;Lee Tae Sung;Kim Ok Bae
    • Radiation Oncology Journal
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    • v.17 no.1
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    • pp.23-29
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    • 1999
  • Purpose : To evaluate the efficacy of radiation therapy and extrafascial hysterectomy in bulky stage IB, IIA-B uterine cervix cancers. Methods and Materials : Twenty four patients with bulky stage IB and IIA-B carcinoma of the uterine cervix were treated with extrafascial hysterectomy following radiation therapy due to doubts of residual disease at Department of therapeutic radiology, Keimyung University, Dongsan Hospital, from April 1986 to December 1997 According to FIGO staging system, there were 7 patients with stage IB, 9 patients with IIA and 8 patients with IIB stage whose median age was 45. Pathologic distribution showed 16 patients with squamous cell carcinoma and 8 patients with adenocarcinoma. Seven patients had tumors that are less than 5cm in size and 17 patients had tumors with larger than 5cm. The mean interval between radiation therapy and extrafascial hysterectomy was 57 days. The radiation therapy consisted of external irradition to the whole pelvis (180 cGy/fraction, mean 4100 cGy) and parametrial boost (for a mean total dose of 5000 cGy) with midline shield (4H 10 cm), followed by intracavitary irradiation up to 7500 cGy to point A (maximum 8500 cGy). The maximum follow up duration was 107 months and mean follow up duration was 42 months. Results :Ten out of 24 patients (41.7%) had residual disease found at the time of extrafascial hysterectomies. Five year overall survival rate (5Y OSR) and five year disease free survival rate (5Y DFSR) were 63.6% and 62.5% respectively. Five year overall survival rate for stage IB and IIA was 71.4% and 50% for stage IIB. There was a significant difference in 5Y OSR and 5Y DFSR between patients with and those without residual disease (negative vs positive, 83.3% vs. 40% (P=0.01), 83.3% vs 36% (P=0.01) respectively). There was a notable tendency of better survival with adenocarcinoma than with squamous cell carcinoma (adenocarcinoma vs squamous cell carcinoma, 85.7% vs. 53.3% (P=0.1), 85.7% vs. 50.9% (P=0.1) of 5Y OSR and 5Y DFS respectivey). Total dose to A point did not make a significant difference in survival rate or the existence of residual lesion (< 7500 cGy, ${\geq}$ 7500 cOy). It was also noted that significantly more frequent local failures have occurred in patients with positive residual disease compared with negative residual disease (5/10 vs. 0/14, p=0.003), There was no death related to the treatment. Conclusion : There was no improvement of residual disease and to the overall survival rate in spite of increased total dose to point A. We conclude that there is a possible beneficial effect of radiation therapy followed by extrafaseial hysterectomy in survival for adenocarcinoma of bulky stage IB and IIA-B uterine cervix. We need to confirm this with longer follow up and with large number of patients.

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A Retrospective Study of the Radiotherapy Care Patterns for Patients with Laryngeal Cancer and Comparison of Different Korean Hospitals Treated from 1998 through 1999 (한국인 후두암 환자의 방사선치료 과정 및 내용에 관한 분석 (1998~1999년도))

  • Chung, Woong-Ki;Kim, Il-Han;Yoon, Mee-Sun;Ahn, Sung-Ja;Nam, Taek-Keun;Song, Ju-Young;Chung, Jae-Uk;Nah, Byung-Sik;Lee, Joon-Kyoo;Wu, Hong-Gyun;Lee, Chang-Geol;Lee, Sang-Wook;Park, Won;Ahn, Yong-Chan;Kang, Ki-Moon;Kim, Jung-Soo;Oh, Yoon-Kyeong;Cho, Moon-June;Park, Woo-Yoon;Kim, Jin-Hee;Choi, Doo-Ho;Yun, Hyong-Geun;Kim, Woo-Cheol;Yang, Dae-Sik;Sohn, Seung-Chang;Suh, Hyun-Suk;Ahn, Ki-Jung;Chun, Mi-Son;Lee, Kyu-Chan;Choi, Young-Min;Jeung, Tae-Sik;Kang, Jin-Oh
    • Radiation Oncology Journal
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    • v.27 no.4
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    • pp.201-209
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    • 2009
  • Purpose: To investigate the care patterns for radiation therapy and to determine inter-hospital differences for patients with laryngeal carcinoma in Korea. Materials and Methods: A total of 237 cases of laryngeal carcinoma (glottis, 144; supraglottis, 93) assembled from 23 hospitals, who underwent irradiation in the year of 1998 and 1999, were retrospectively analyzed to investigate inter-hospital differences with respect to radiotherapy treatment. We grouped the 23 hospitals based on the number of new patients annually irradiated in 1998; and designated them as group A (${\geq}$900 patients), group B (${\geq}$400 patients and <900 patients), and group C (<400 patients). Results: The median age of the 237 patients was 62 years (range, 25 to 88 years), of which 216 were male and 21 were female. The clinical stages were distributed as follows: for glottis cancer, I; 61.8%, II; 21.5%, III; 4.2%, IVa; 11.1%, IVb; 1.4%, and in supraglottic cancer, I; 4.3%, II; 19.4%, III; 28.0%, IVa; 43.0%, IVb; 5.4%, respectively. Some differences were observed among the 3 groups with respect to the dose calculation method, radiation energy, field arrangement, and use of an immobilization device. No significant difference among 3 hospital groups was observed with respect to treatment modality, irradiation volume, and median total dose delivered to the primary site. Conclusion: This study revealed that radiotherapy process and patterns of care are relatively uniform in laryngeal cancer patients in Korean hospitals, and we hope this nationwide data can be used as a basis for the standardization of radiotherapy for the treatment of laryngeal cancer.

An Experimental Study on the Effect of Combined X-ray and Microwave Hyperthermia on the Rectum and Urinary Bladder of Rats (흰쥐의 직장과 방광에 X-선 조사와 마이크로파 온열요법의 효과에 관한 실험적 연구)

  • Lee, Kyung-Ja;Rhee, Chung-Sik
    • Radiation Oncology Journal
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    • v.4 no.2
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    • pp.115-128
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    • 1986
  • Hyperthermia can enhance the radiation effect as a synergistic reaction in combined X-ray irradiation and hyperthermia; hyperthermia sensitize radioresistant S-phase cells and inhibit cellular recovery from sublethal damage. We fabricated 100 watts, 2450 MHz microwave applicator for hyperthermia and planned the method and condition of heating and measured the temperature by using Agar phantom as a preliminary test. For biological examination, 102 rats were divided into 4 groups as hyperthermia, X-ray irradiation (6Gy-15Gy), combined X-ray and hyperthermia, and normal control groups. Microscopic examination of the rectum and bladder was done and the results were as followings: 1. The microwave generator with 100 watts, 2450MHz magnetron could be heating up to $40^{\circ}{\sim}50^{\circ}C$ for one hour in living tissue. 2. The thermal distribution in tissue equivalent phantom with microwave can be maintained at $40^{\circ}{\sim}44^{\circ}C$ in area of 3cm in depth and 2-10cm in diameter. 3. In Hyperthermia alone group, there was submucosal edema of the rectum but no histologic change in the urinary bladder was seen. 4. The minimal necrosis of the mucosa was appeared in the rectum and bladder after 15 days of 6 Gy and 8 Gy irradiation respectively. The minimal necrosis of the muscle layer of rectum and bladder was appeared after 15 days of 8Gy and 60days of 10Gy irradiation respectively. 5. In combined group of radiation and hyperthermia, thermal enhancement ratio (calculated at necrosis of mucosa and muscle layer) of rectum and bladder was 1.0, and it suggest that there is no change of tolerance dose of normal rectum and bladder.

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