• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.16-37
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• 2018

In this study, difference in chemical composition of $PM_{2.5}$ observed between the year 2013 and 2015 at six air quality intensive monitoring stations (Bangryenogdo (BR), Seoul (SL), Daejeon (DJ), Gwangju (GJ), Ulsan (US), and Jeju (JJ)) was investigated and the possible factors causing their difference were also discussed. $PM_{2.5}$, organic and elemental carbon (OC and EC), and water-soluble ionic species concentrations were observed on a hourly basis in the six stations. The difference in chemical composition by regions was examined based on emissions of gaseous criteria pollutants (CO, $SO_2$, and $NO_2$), meteorological parameters (wind speed, temperature, and relative humidity), and origins and transport pathways of air masses. For the years 2013 and 2014, annual average $PM_{2.5}$ was in the order of SL ($${\sim_=}DJ$$)>GJ>BR>US>JJ, but the highest concentration in 2015 was found at DJ, following by GJ ($${\sim_=}SJ$$)>BR>US>JJ. Similar patterns were found in $SO{_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$. Lower $PM_{2.5}$ at SL than at DJ and GJ was resulted from low concentrations of secondary ionic species. Annual average concentrations of OC and EC by regions had no big difference among the years, but their patterns were distinct from the $PM_{2.5}$, $SO{_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$ concentrations by regions. 4-day air mass backward trajectory calculations indicated that in the event of daily average $PM_{2.5}$ exceeding the monthly average values, >70% of the air masses reaching the all stations were coming from northeastern Chinese polluted regions, indicating the long-range transportation (LTP) was an important contributor to $PM_{2.5}$ and its chemical composition at the stations. Lower concentrations of secondary ionic species and $PM_{2.5}$ at SL in 2015 than those at DJ and GJ sites were due to the decrease in impact by LTP from polluted Chinese regions, rather than the difference in local emissions of criteria gas pollutants ($SO_2$, $NO_2$, and $NH_3$) among the SL, DJ, and GJ sites. The difference in annual average $SO{_4}^{2-}$ by regions was resulted from combination of the difference in local $SO_2$ emissions and chemical conversion of $SO_2$ to $SO{_4}^{2-}$, and LTP from China. However, the $SO{_4}^{2-}$ at the sites were more influenced by LTP than the formation by chemical transformation of locally emitted $SO_2$. The $NO_3{^-}$ increase was closely associated with the increase in local emissions of nitrogen oxides at four urban sites except for the BR and JJ, as well as the LTP with a small contribution. Among the meterological parameters (wind speed, temperature, and relative humidity), the ambient temperature was most important factor to control the variation of $PM_{2.5}$ and its major chemical components concentrations. In other words, as the average temperature increases, the $PM_{2.5}$, OC, EC, and $NO_3{^-}$ concentrations showed a decreasing tendency, especially with a prominent feature in $NO_3{^-}$. Results from a case study that examined the $PM_{2.5}$ and its major chemical data observed between February 19 and March 2, 2014 at the all stations suggest that ambient $SO{_4}^{2-}$ and $NO_3{^-}$ concentrations are not necessarily proportional to the concentrations of their precursor emissions because the rates at which they form and their gas/particle partitioning may be controlled by factors (e.g., long range transportation) other than the concentration of the precursor gases.

• Radiation Oncology Journal
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• v.14 no.1
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• pp.1-8
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• 1996

Purpose: We tried to evaluate the role of conventional radiotherapy alone or with neoadjuvant chemotherapy in oropharyngeal cancer in terms of survival rates and to identify prognostic factors affecting survival by retrospective analysis. Materials and Methods: Forty seven patients of oropharyngeal cancer were treated by conventional radiotherapy in our hospital from Nov. 1985 to APr. 1993. Of these, twenty six patients were treated by conventional radio-therapy alone, and 21 patients with neoadjuvant chemotherapy of mostly two or more cycles of cisplatin and pepleomycin. The Patient characteristics of radiotherapy alone group and neoadjuvant chemotherapy group were not different generally. Radiotherapy was performed by 6MV-LINAC and the total radiation doses of Primary tumors were 54.0-79.2 Gy and cervical lymph nodes were 55.8-90.0 Gy with a fraction size of 1.8 or 2.0 Gy per day. The range of follow-up periods was 3-102 months and median was 20 months. The range of a9e was 33-79 years old and median was 58 years old. Results : Overall 3-year actuarial survival rate (3YSR) of all patients was $39\%$. The 3YSRS of stage I (n=5), II (n=11), III (n=12) and IV (n=19) were 60, 55, 33 and $32\%$, respectively The 3YSRS of Tl+2, T3+4 and No, N+ were 55, $18\%$ (p=0.005) and 43, $36\%$ (p>0.1), respectively. There was no difference in 3YSRS between radiotherapy alone group and neoadjuvant chemotherapy group (38 vs $43\%$, p>0.1). According to the original site of primary tumor, the 3YSRS of tonsil (n=32), base of tongue (n=8), soft palate or uvula (n=6) and pharyngeal wall (n=1) were 36 38, 67 and $0\%$, respectively The Patients of soft palate or uvular cancer had longer survival than other primaries but the difference was not significant statistically (p>0.1). Of 32 patients of tonsillar cancer, 22 Patients who had primary extension to adjacent tissue showed inferior survival rate to the ones who had not Primary extension, but the difference was marginally significant statistically (24 vs $60\%$, p=0.08). On Cox multivariate analysis in entire patients with variables of age, T stage, N stage, total duration of radiotherapy, the site of primary tumor and the use of neoadjuvant chemotherapy, only T stage was a significant Prognostic factor affecting 3YSR. Conclusion : The difference of 3YASRS of conventional radiotherapy alone group and neoadjuvant chemotherapy group was not significant statistically. These treatments could be effective in oropharyngeal cancer of early stage, especially such as soft palate, uvular or tonsillar cancer which did not extend to adjacent tissue. But in order to improve the survival of patients of most advanced oropharyngeal cancer, other altered fractionated radiotherapy such as hyperfractionation rather than conventional fractionation or multi-modal approach combining radiotherapy and accessible surgery or concurrent chemotherapy might be beneficial.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.181-188
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• 2009

Purpose: The aim of this study was to evaluate the results of postoperative radiotherapy in a case of perihilar cholagiocarcinoma by analyzing overall survival rate, patterns of failure, prognostic factors for overall survival, and toxicity. Materials and Methods: Between January 1998 and March 2008, 38 patients with perihilar cholangiocarcinoma underwent a surgical resection and adjuvant radiotherapy. The median patient age was 59 years (range, 28 to 72 years), which included 23 men and 15 women. The extent of surgery was complete resection in 9 patients, microscopically positive margins in 25 patients, and a subtotal resection in 4 patients. The tumor bed and regional lymphatics initially received 45 Gy or 50 Gy, but was subsequently boosted to a total dose of 59.4 Gy or 60 Gy in incompletely resected patients. The median radiotherapy dose was 59.4 Gy. Concurrent chemotherapy was administered in 30 patients. The median follow-up period was 14 months (range, 6 to 45 months). Results: The 3-year overall survival and 3-year progression free survival rates were 30% and 8%, respectively. The median survival time was 28 months. A multivariate analysis showed that differentiation was the only significant factor for overall survival. The 3-year overall survival was 34% in R0 patients and 20% in R1 patients. No statistically significant differences in survival were found between the 2 groups (p=0.3067). The first site of failure was local in 18 patients (47%). No patient experienced grade 3 or higher acute toxicity and duodenal bleeding developed in 2 patients. Conclusion: Our results suggest that adjuvant RT might be a significant factor in patients with a positive margin following a radical resection. However, there was still a high locoregional recurrence rate following surgery and postoperative radiotherapy. Further study is necessary to enhance the effect of the adjuvant radiotherapy.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.2
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• pp.156-162
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• 2009

Purpose: The aim of this study was to investigate the clinical usefulness of upper gastrointestinal (GI) endoscopy in children with Henoch-Sch$\"{o}$nlein purpura (HSP). Methods: We retrospectively analyzed the clinical, endoscopic, and histopathologic records of children with HSP who had been admitted to the Department of Pediatrics of Gil Hospital and underwent upper GI endoscopy between January 2002 and June 2009. Patients were classified into the following two groups for statistical analysis: duodenal involvement (+) and duodenal involvement (-). Results: Fifty-one children with HSP underwent upper GI endoscopy; the mean age was 7.2${\pm}$2.9 years. The upper GI endoscopy showed abnormalities of the duodenum in 38 cases (74.5%), 22 of which had duodenal ulcers. Among the biopsy specimens obtained from the duodenum of 37 cases, 13 cases (35.1%) had leukocytoclastic vasculitis, neutrophil debri, and/or extravasation of RBCs. Steroid use was more frequent in the duodenal involvement (+) group (86.8%) than the duodenal involvement (-) group (53.8%; p=0.02). The mean length of hospitalization was 13.9${\pm}$8.43 days in the duodenal involvement (+) group and 8.1${\pm}$4.62 days in the duodenal involvement (-) group (p=0.003). The recurrence rate was significantly higher in the duodenal involvement (-) group than the duodenal involvement (+) group (p=0.027), whereas none of the other study parameters, such as the age of onset, renal involvement, and steroid use, led to significantly higher or lower recurrence rates. Conclusion: These results suggest that duodenal involvement can influence the clinical course and prognosis of HSP in children.

• Journal of the Korean Society of Food Culture
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• v.1 no.2
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• pp.116-126
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• 1986

This study was designed to be a link in the chain of the investigation on daily life and consciousness of longevous people in Korea, and to investigate the regional feature of longevity areas. The daily life and consciousness were investigated on 379 subjects(male 121, female 258) of the aged who were above 80 years of age, from June to November in 1985. This paper is to report the results investigated the longevity rate, distribution, classification and weather of longevity districts, and also the actual conditions such as the functions of daily life and educational degree of longevous people. 1. The number of longevous people in Korea was 171,449 (male 42,842, female 128,607), and the average longevity rate was 0.46% against total population in Korea(male 0.23%, female 0.69%). 2. Of the longevity rates of shi and/or do in Korea, Cheju(1.03%) was the highest among these districts, and decreased in the order of Chonnam(0.79%), Chonbuk(0.66%), Kyongbuk(0.65%) and Kyongnam(0.61%), whereas the large cities such as Inchon(0.22%), Seoul(0.23%), Pusan(0.23%) and Taegu(0.28%) were remarkably lower than districts in seasides and mountains. 3. The districts above 1.0% of longevity rate in Korea showed 17-guns, and the distribution of these districts was 10-guns of Chonnam, 2-guns of Kyongbuk and Kyongnam, and 1-gun of Kyonggi, Cho-nbuk and Cheju, respectively. 4. Of these districts, Pukcheju(1.65%) was the highest, and decreased in the order of Namhae(1.56%), Sungju(1.24%), Posong(1.22%) and Koksong(1.20%). The highest figure(male 0.71%, female 2.51%) was observed in Pukcheju as contrasted with 0.23%(male) and 0.69%(female) of the average longevity rate in Korea. 5. The sex ratio of longevous people in Korea showed the female/male ratio of 3.0. It is, therefore, believed that the longevity rate of female was 3 times higher than that of male. 6. The longevity districts were classified into seven districts in seasides, three districts in isolated islands, and seven rural districts in mountains. 7. The situation of weather in longevity districts was in the range of 11.2 to $14.8^{\circ}C$ at annual average temperature, and 878.5 to 1585.9mm at annual average rainfall. 8. Of the educational degree of longevous people, uneducated(71.5%) was the highest, and followed by the order of village school(15.8%) and above elementary school(4.8%). 9. In the functions of daily life, the aged moving actively(53.0%) was the highest among these longevous people, followed by the aged moving a little(23.5%). Therefore, it is believed that health degree of these longevous peoples by the functions of daily life was very gratifying.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.109-120
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• 2010

The purpose of this study was first to analyze the utilization of dental examination through questionnaire to develop a diagnostic reference level of patient doses for dental radiography in korea. 77 dental institutions were classified into three groups: A group for the dental hospitals of the college of dentistry (11 institutions), B group for dental hospitals (30 institutions) and C group for dental clinics (36 institutions). The results were as follows : The mean numbers of unit chairs and medical staffs were 140.2, 15.3 and 5.8 sets, 112.6, 7.3 and 1.7 dentists, 3.1, 0.5 and no one radiologic technologists, and 19.7, 12.5 and 3.3 dental hygienists in A, B and C groups, respectively. The mean numbers of dental X-ray equipments were 14.64, 3.21 and 2.19 in A, B and C groups, respectively. Intraoral dental X-ray unit was used the most, the following equipments were panoramic, cephalometric, and cone-beam CT units. The most used X-ray imaging system was also digital system (above 50%) in all three groups. Insight dental film (Kodak, USA) having high sensitivity was routinely used for periapical radiography. The automatic processor was not used in many dental institutions, but the film-holding device was used in many dental institutions. The utilization rates of PACS in A, B and C groups were 90.9%, 83.3% and 16.7% respectively, and the PACS software program was used the most PiView STAR (Infinitt, Korea). The annual mean number of radiographic cases in one dental institution in 2008 for A group was 6.8 times and 21.2 times more than those for B and C groups, and periapical and panoramic radiographs were taken mostly. Tube voltage (kVp) and tube current (mA) for periapical radiography were similar in all three groups, but exposure time in C group was 12.0 times and 3.5 times longer than those in B and C groups. The amount of radiation exposure in C group, in which dental hygienists take dental radiographs, was more than those in other groups. The exposure parameters for panoramic radiography were similar in all three groups. In conclusion, the exposure parameters in dental radiography should be determined with reference level, not past experiences. Use of automatic processor and film-holding devices reduces the radiation exposure in film system. The quality assurance of dental equipments are necessary for the reduction of the patient dose and the improvement of X-ray image quality.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.316-322
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• 2002

Objective : A retrospective study was peformed to evaluate whether postoperative adjuvant radiotherapy can improve survival and decrease recurrence as compared with surgery alone in resected esophageal cancer. Materials and Methods : From Jan. 1985 to Dec. 1993, among 94 esophageal cancer Patients treated with surgery, fifty-one patients were included in this study. Transthoracic esophagectomy was peformed in 35 patients and transhiatal esophagectomy in 16. Postoperative adjuvant radiotherapy was peformed 4 weeks after surgery in 26 among 38 patients in stage II and III. A total dose of $30\~60\;Gy$ in 1.8 Gy daily fraction, median 54 Gy over 6 weeks, was delivered in the mediastinum+both supraclavicular lymph nodes or celiac lymph nodes according to the tumor location. Forty-seven patients$(92\%)$ had squamous histology. The median follow-up period was 38 months. Results : The overall 2-year and 5-year survival and median survival were $56.4\%,\;36.8\%$ and 45 months. Two-year and 5-year survival and median survival by stage were $92\%,\;60.3\%$ for stage I, $63\%,\;42\%$ and 51 months for stage II and $34\%,\;23\%$ and 19 months for stage III (p=0.04). For stage II and III patients, 5-year survival and median survival were $22.8\%$, 45 months for the surgery alone group and $37.8\%$, 22 months for the postoperative RT group (p=0.89). For stage III patients, 2-year survival and median survival were $0\%$, 11 months for the surgery alone group and $36.5\%$, 20 months for the postoperative RT group (p=0.14). Local and distant failure rates for stage II and III were $50\%,\;16\%$ for the surgery alone and $39\%,\;31\%$ for the postoperative RT group. For N1 patients, local failure rate was $71\%$ for the surgery alone group and $37\%$ for the postoperative RT group (p=0.19). Among 10 local failures in the postoperative RT group, in-field failures were 2, marginal failures 1, out-field 5 and anastomotic site failures 2. Conclusion : There were no statistically significant differences in either the overall survival or the patterns of failure between the surgery alone group and the postoperative RT group for resected stage II and III esophageal cancer. But this study showed a tendency of survival improvement and decrease in local failure when postoperative RT was peformed for stage III or N1 though statistically not significant. To decrease local failure, a more generous radiation field encompassing the supraclavicular, mediastinal, and celiac lymph nodes and anastomotic site in postoperative adjuvant treatment should be considered.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.323-327
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• 2002

Purpose : To evaluate the outcome of early stage non-small cell lung cancer patients who were treated with radiation therapy alone and define the optimal radiotherapeutic regimen for these patients. Materials and Methods : A retrospective review was peformed on patients with sage I or II non-small cell carcinoma of the lung that were treated at our institution between June, 1987 and May, 2000. A total of 21 patients treated definitively with radiation therapy alone were included in this study. The age of the patients ranged from 53 to 81 years with a median of 66 years. All the patients were male. The medical reasons for inoperability were lack of pulmonary reserve, cardiovascular disease, poor performance status, old age, and patient refusal in the decreasing order. Pathological evidence was not adequate to characterize the non-small cell subtype in two patients. Of the remaining 19 patients, 16 had squamous cell carcinoma and 3 had adenocarcinoma. Treatment was given with conventional fractionation, once a day, five times a week. The doses to the primary site ranged from 56 Gy to 59 Gy. No patients were lost to follow-up. Results : The overall survival rates for the entire group at 2, 3 and 5 years were 41, 30 and $21\%$, respectively. The cause specific survivals at 2, 3 and 5 years were 55, 36 and $25\%$, respectively. An intercurrent disease was the cause of death in two patients. The cumulative local failure rate at 5 years was $43\%$. Nine of the 21 patients had treatment failures after the curative radiotherapy was attempted. Local recurrences as the first site of failure were documented in 7 patients. Therefore, local failure alone represented $78\%$ of the total failures. Those patients whose tumor sizes were less than 4 cm had a significantly better 5 year disease free survival than those with tumors greater than 4 cm $(0\%\;vs\;36\%)$. Those patients with a Karnofsky performance status less than 70 did not differ significantly with respect to actuarial survival when compared to those with a status greater than 70 $(25\%\;vs\;26\%,\;p>0.05)$. Conclusion : Radiation therapy 리one is an effective and safe treatment for early stage non-small ceil lung cancer patients who are medically inoperable or refuse surgery. Also we believe that a higher radiation dose to the primary site could improve the local control rate, and ultimately the overall survival rate.

• Radiation Oncology Journal
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• v.15 no.4
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• pp.349-356
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• 1997

Purpose : To evaluate the efficacy of hyperfractionated radiation therapy in carcinoma of the cervix, especially on huge exophytic and endophytic stage Ib, IIa and IIb Materials and Materials : Fourty one patients with carcinoma of the cervix treated with hyperfractionated radiation therapy at the Department of Therapeutic Radiology, Dongsan Hospital, Keimyung University. School of Medicine from Jul, 1991 to Apr, 1994. According to FIGO s1aging system, therewere stage Ib (3 patients) IIa (6 patients) with exophytic ($\geq$5cm in dinmeter) and huge endophytic mass. and IIb (32 patients) with median age of 55 yeavs old. Radiation therapy consisted of hyperfractionated external irradition to the whole pelvis (120cGy/fraction, 2 fraction/day (minimum interval of 6 hours), 3600-5520cGy) and boost parametrial doses (for a total of 4480-6480cGy) with midline shield $(4\times10cm)$, and combined with intracavitary irradiation (up to 7480-8520cGy in Ib, IIa and 8480-9980cGy in IIb to point A). The maximum and mean follow up durations were 70 and 47 months respectively . Results : Five year local control rate was $78\%$ and the actuarial overall five year survival rate was $66.1\%$ for all patients, $44.4\%$ for stage Ib, IIa and $71.4\%$ for stage IIb. In bulky IIb (above 5cm in tumor size, 11 patients) five year local control rate and five rear survival rate was $88.9\%,\;73\%$ respectively Pelvic lymph node status (negative : $74\%,\;positive:25\%$, p=0.0015) was significant Prognostic factor affecting to five rear survival rate. There was marginally significant survival difference by total dose to A point ($>84Gy\;:\;70\%,\;>84Gy\;:\;42.8\%$, p=0.1). We consider that the difference of total dose to A point by stage (mean Ib,IIa : 79Gy. IIb 89Gy P=0.001) is one of the causes in worse local control and survival of Ib,IIa than IIb The overall recurrence rate was $39\%$ (16/41). The rates of local failure alone. distant failure alone. and combined local and distant failure were $9.7\%,\;19.5\%,\;and\;9.7\%$, respectively. Two Patients developed leukopenia ($\geq$ grade 3) and Three patients develoued grade 3 gastrointestinal complication. Above grade 3 complication was not noted. There was no treatment related death noted. Conclusion : We thought that it may be necessary to increase A point dose to more than 85Gy in hyperfractionated radiotherapy of huge exophytic and endophvtic stage Ib,IIa. We considered that hyperfractionated radiation therapy may be tolerable in huge exophytic and endophytic stage IIb cervical carcinoma with acceptable morbidity and possible survival gain but this was results in small patient group and will be confirmed by long term follow up in many patients.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.295-301
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• 1993

Since Jan. 1991 a prospective randomized study for Stage III unresectable non small cell lung cancer (NSCLC) has been conducted to evaluate the response rate and tolerance of induction chemotherapy with MVP followed by hyperfractionated radiotherapy and evaluate the efficacy of maintenance chemotherapy in Asan Medical Center. All patients in this study were treated with hyperfractionated radiotherapy (120 cGy/fx BID, 6480 cGy/54 fx) following 3 cycles of induction chemotherapy, MVP (Mitomycin C 6 $mg/m^2,$ Vinblastin 6 $mg/m^2,$ Cisplatin 60 $mg/m^2$) and then the partial and complete responders from induction chemotherapy were randomized to 3 cycles of adjuvant MVP chemotherapy group and observation group. 48 patients were registered to this study until December 1992; among 48 patients 3 refused further treatment after induction chemotherapy and 6 received incomplete radiation therapy because of patient's refusal, 39 completed planned therapy. Twenty-three $(58\%)$ patients including 2 complete responders showed response from induction chemotherapy. Among the 21 patients who achieved a partial response after induction chemotherapy,1 patient rendered complete clearance of disease and 10 patients showed further regression of tumor following hyperfractionated radiotherapy. Remaining 10 patients showed stable disease or progression after radiotherapy. Of the sixteen patients judged to have stable disease or progression after induction chemotherapy, seven showed more than partial remission after radiotherapy but nine showed no response in spite of radiotherapy. Of the 39 patients who completed induction chemotherapy and radiotherapy, 25 patients $(64\%)$ including 3 complete responders showed more than partial remission. Nineteen patients were randomized after radio-therapy. Nine Patients were allocated to adjuvant chemotherapy group and 4/9 showed further regression of tumor after adjuvant chemotherapy. For the time being, there is no suggestion of a difference between the adjuvant chemotherapy group and observation group in distant metastasis rate and survival. Median survival time was 13 months. Actuarial survival rates at 6,12 and 18 months of 39 patients who completed this study were $84.6\%,\;53.7\%\;and\;40.3\%,$ respectively. The partial and complete responders from induction chemotherapy showed significantly better survival than non-responders (p=0.028). Incidence of radiation pneumonitis in this study group was less than that in historical control group inspite of induction chemotherapy. All patients tolerated hypertractionated radiotherapy without definite increase of acute complications compared with conventional radiotherapy group. The longer follow up is needed to evaluate the efficacies of induction and maintenance chemotherapy and survival advantage by hyperfractionated radiotherapy but authors are encouraged with an excellent tolerance, higher response rate and improvement of one year survival rate in patients of this study.