• Radiation Oncology Journal
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• v.6 no.2
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• pp.203-209
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• 1988

Thirty eight women with recurrent breast carcinoma involving chest wall and/or regional lymph nodes after surgery with or without systemic therapy were treated with radiation between 1979 and 1986. Among them, 5 patients were excluded from analysis because of incomplete treatment. The median follow up of survivors was 30 months (randged 1-79 months). Fifteen (45%)patients had their disease confined to the chest wall and eighteen patients had lymph node involvement as some of their locoregional recurrent disease. Within 36 months after the initial treatment, 87% of recurrences manifested themselves. All patients had radiotherapy to at least the site of involvement. In 8 patients, recurrent tumors were treated with complete excision followed by radiation. Of the remaining 25 patients,18 (72%) had complete response (CR) following radiotherapy. The actuarial 3-year survival of all patients following locoregional recurrence was 50% Three year survival was 24% in those 25 patients who had recurrences within 24 months of the initial treatment. For those 8 patients whose recurrences occurred after more than 24 month disease free interval, the 3-year survival was 100%. For those patients with recurrences confined to chest wall alone, 3-year survival was 57% The patients who had lymph node involvement as part of their locoregional recurrences had a 43% 3-year survival. The majority of them developed distant metastases. Those patients who had a CR showed 63% 3-year survival. On the other hand, 1 year survival was only 33% for those patients who had a less than CR. Three patients developed carcinoma of the contralateral breast following radiotherapy. Three year survival following locoregional recurrence was 40% for patients whose initial treatment for their primary breast carcinoma was surgery and adjuvant systemic therapy. For those patients whose primary breast carcinoma was treated by surgery alone, the 3-year survival following locoregional recurrence was 71%. In patients who had subsequent recurrence after radiotherapy, the actuarial survival was 25% at 2 years.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.36-41
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• 1999

Purpose : We reviewed the treatment results for the patients with locally recurrent rectal carcinoma. The object was to evaluate the treatment outcome and to identify the prognostic factors influencing the survival. Methods and Materials: Twenty-eight patients with locally recurrent rectal carcinoma treated principally with external-beam radiation therapy between 1982 to 1996 in the Department of Radiation Oncology at Paik and Hanyang Hospital were reviewed retrospectively Of these, 17 patients had initially abdominoperineal resection, 9 had low anterior resection, and 2 had local excision. No patients had received adjuvant radiation therapy for the primary disease. There were 14 men and 14 women whose ages ranged from 31 to 72 years (median age:54.5). Median time from initial surgery to the start of radiation therapy for local recurrence was 11 months (4~47 months). Radiation therapy was given with total doses ranging from 27 to 64.8 Gy (median=51.2 Gy). Results : The median survival was 16.7 months. The 2-year and 5-year survival rates were 20.1%, 4.1% respectively. Upon multivariate analysis, overall survival was positively correlated with duration of intervals from initial surgery to local recurrence (P=0.039). Relief of pelvic symptoms was achieved in 17 of 28 patients (60.7%). Pain and bleeding responded in 40% and 100% of patients, respectively Conclusions : Patients with locally recurrent rectal carcinoma treated with radiotherapy have benefited symptomatically, and might have increased survivals with a small chance of cure. But, patient were rarely cured (median survival : 10 months, 5-year survival : less than 5%). Overall survival was positively correlated with long intervals from initial surgery to local recurrence. Future efforts should be directed to the use of effective therapy for patients with locally recurrent rectal carcinoma and adjuvant therapy for patients with rectal cancer to reduce the incidence of pelvic recurrence.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.1-8
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• 1994

When cells are exposed to low doses of a mutagenic or clastogenic agents. they often become less sensitive to the effects of a higher dose administered subsequently. Such adaptive responses were first described in Escherichia coli and mammalian cells to low doses of an alkylating agent. Since most of the studies have been carried out with human lymphocytes, it is urgently necessary to study this effect in different cellular systems. Its relation with inherent cellular radiosensitivity and underlying mechanism also remain to be answered. In this study, adaptive response by 1 cGy of gamma rays was investigated in three human lymphoblastoid cell lines which were derived from ataxia telangiectasia homozygote, ataxia telangiectasia heterozygote, and normal individual. Experiments were carried out by delivering 1 cGy followed by 50 cGy of gamma radiation and chromatid breaks were scored as an endpoint. The results indicate that prior exposure to 1 cGy of gamma rays reduces the number of chromatid breaks induced by subsequent higher dose (50 cGy), The expression of this adaptive response was similar among three cell lines despite of their different radiosensitivity. When 3-aminobenzamide, an inhibitor of poly (ADP-ribose) polymerase, was added after 50 cGy, adaptive responses were abolished in all the tested cell lines. Therefore it is suggested that the adaptive response can be observed in human lymphoblastoid cell lines, which was first documented through this study. The expression of adaptive response was similar among the cell lines regardless of their radiosensitivity. The elimination of the adaptive response by 3-aminobenzamide is consistent with the proposal that this adaptive response is the result of the induction of a certain chromosomal repair mechanism.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.247-253
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• 2004

Purpose: Hypopharyngeal cancer is diagnosed at the advanced stage in most cases, which the prognosis known to be poor. Thus, the efficacy of induction chemotherapy followed by radiotherapy, with regards to the response and survival rate for stage IV hypopharyngeal cancer patients, was examined. Materials and Methods: From July 1998 to February 2000, 18 cases were diagnosedas AJCC stage IV hypopharyngeal cancer without distant metastasis. These patients were treated with induction chemotherapy followed by radiotherapy, and the results retrospectively analyzed. The regimen of the induction chemotherapy was the 5-FU and cisplatincombination, at 3-week intervals for, 2 cycles. The total radiation dose for the primary lesion and metastatic lymph nodes was $68.4\~72.0$Gy (median: 70.2 Gy). Results: The: The median follow up period was 28 months, ranging from 7 to 99 months. The 3-year overall survival and disease-free survival rate were 41.7 and $31.1\%$, respectively. In 6 cases ($33.3\%$), conservation of the larynx for over 3 years was possible. After the induction chemotherapy there were 16 partial responses ($88.8\%$), 1 complete response and 1 with no response ($5.6\%$ each), therefore, 17 of the 18 cases ($94.6\%$) showed responses. After the completion of the induction chemotherapy and radiotherapy, a complete response was noted in 13 cases ($72.2\%$), a partial response in 5 ($27.8\%$), with an overall response rate of $100\%$. In the analysis of the prognostic factors influencing the survival rate, the 3-year and disease-free survival rates for the complete and partial response groups were 43.1, and $20.0\%$, and 39.6, and $20.0\%$, respectively (p=0.0003, p=0.002). Only the final response after treatment completion was statistically significant. Conclusion: For stage IV hypopharyngeal cancer, induction chemotherapy followed by radiotherapy was an effective treatment, with no severe side effects.

• Radiation Oncology Journal
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• v.28 no.2
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• pp.79-84
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• 2010

Purpose: We retrospectively analyzed the long-term results of radical surgery and intraoperative radiation therapy (IORT) in patients with stomach cancer. Materials and Methods: From 1988 to 1994, 51 patients were treated with curative surgery and IORT. Postoperative external beam radiotherapy (EBRT) was administered to 30 patients, while adjuvant chemotherapy was administered to 35 patients. A dose of 15 Gy was irradiated with a 9 MeV electron beam as the IORT and a median dose of EBRT was 43.2 Gy (range, 7.2 to 45 Gy). The follow-up period ranged from 1~254 months, with a median follow-up period of 64 months. Results: The median age of all the patients was 58 years (range, 30 to 71 years). The distribution of pathologic stage (American Joint Committee on Cancer [AJCC] 2002 tumor-note-metastasis [TNM]) was as follows: 13 stage I (25.5%), 10 stage II (19.6%), 25 stage III (49.0%), and 3 stage IV (5.9%). Distant metastases occurred in 11 patients (10 in the peritoneum and 1 in bone), including one patient with concurrent local recurrence (anastomosis site). The 5-year locoregional control, disease free survival and overall survival rates were 94.7%, 66.5%, and 51.7%, respectively. For the multivariate analysis, age, TNM stage, and EBRT were significant prognostic factors for overall survival, and only TNM stage for disease free survival. Conclusion: We could have achieved a high loco-regional control rate in patients with locally advanced stomach cancer by adding IORT to radical surgery. However, the benefit of IORT on survival remains to be elucidated.

• Radiation Oncology Journal
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• v.28 no.2
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• pp.71-78
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• 2010

Purpose: To evaluate the result of neoadjuvant chemotherapy, surgery, and radiation therapy in locally advanced breast cancer as well as analyze the prognostic factors affecting survival. Materials and Methods: One hundred fifty-nine patients with breast cancer were treated by neoadjuvant chemotherapy between April 1995 and November 2006 at the Samsung Medical Center. Among these patients, we retrospectively reviewed 105 patients treated with neoadjuvant chemotherapy followed by surgery and radiation therapy for a cure with an initial tumor size >5 cm or clinically positive lymph nodes. All patients received anthracycline based chemotherapy except for 2 patients. According to clinical tumor stage, 3 patients (3%) were cT1, 26 (25%) were cT2, 39 (37%) were T3 and 37 (35%) were T4. Initially, 98 patients (93%) showed axillary lymph node metastasis. The follow-up periods ranged from 7~142 months (median, 41 months) after the beginning of neoadjuvant chemotherapy. Results: Locoregional failure free survival rate and distant metastasis free survival rate at 5 years were 82.1% and 69.9%, respectively. Disease free survival rate and overall survival rate at 5 years were 66.1% and 77.1%, respectively. The results of a univariate analysis indicate that clinical tumor stage, pathologic tumor stage, pathologic nodal stage and pathologic TNM stage were statistically significant factors for disease free survival rate and overall survival rate. Whereas, a multivariate analysis indicated that only hormone therapy was a statistically significant factor for survival. Conclusion: The current study results were comparable to other published studies for neoadjuvant chemotherapy for breast cancer. Hormone therapy was a statistically significant prognostic factor. The patients with early clinical or pathologic stage had a tendency to improve their survival rate.

• Progress in Medical Physics
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• v.18 no.3
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• pp.126-133
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• 2007

A head-and-neck phantom was designed in order to evaluate remotely the quality of the delivery dose of intensity modulated radiation therapy (IMRT) in each institution. The phantom is homogeneous or inhomogeneous by interchanging the phantom material with the substructure like an air or bone plug. Monte Carlo simulations were executed for one beam and three beams to the phantom and compared with ion chamber and thermoluminescent dosimeter (TLD) measurements of which readings were from two independent institutions. For single beam, the ion chamber results and the MC simulations agreed to within about 2% TLDs agreed with the MC results to within 2% or 7% according to which institution read the TLDs. For three beams, the ion chamber results showed -5% maximum discrepancy and those of TLDs were $+2{\sim}+3%$. The accuracy of the TLD leadings should be increased for the remote dose monitoring. MC simulations are a valuable tool to acquire the reliability of the measurements in developing a new phantom.

• Progress in Medical Physics
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• v.9 no.1
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• pp.55-64
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• 1998

In recent, the demand of development of the high dose rate brachytherapy source increased for substitute for Co-60 source by iridium source, since the supplying Co-60 source is very depressed and the high dose rate brachytherapy sources are entirely imported from the abroad. This study investigated the exposure rates and isotropic dose distributions for the Ir-192 source produced from $\^$191/Ir(n,r)$\^$192/Ir by nuclear reactor in Korea Atomic Energy Research Institute. The activity of source was obtained an 1.012 Ci (the initial activity without encapsulation was 2,87Ci) by measurement with encapsuled stainless steel. The exposure rate of provided Ir-192 source was determined on 6.36 ${\pm}$ 0.147 Rm$^2$/h-GBq (2.350 ${\pm}$ 0.054 Rcm$^2$/mCi-hr) within ${\pm}$ 2.2% discrepancy with IC-10 ion chamber (0.14 cc) which was mounted on the acrylic jig to 5, 10 and 20 cm from the center of source. The calculated doses with 22 most significant spectrum lines were corrected with intrinsic efficiency of the germanium detector were compared to measured exposure dose rates within ${\pm}$3.8 % discrepancy. The authors confirmed the high dose rate Ir-192 source could be replaced the long decayed Co-60 source via investigation of the isotropic dose distributions in lateral, source axis and diagonal direction of source center are very closed to within 3% uncertainties. Especially, this exposure rate constant and isotropic dose distribution will be fundamental to build the high dose rate source and develop the computed therapy planning system.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.3
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• pp.151-158
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• 2019

Patients with disabilities from various reasons such as disasters, injuries or chronic illness or elderly with limited body motion range due to aging are recommended to participate in rehabilitation programs at hospitals. But typically, it's not as simple for them to commute without help as they have limited access outside of the home. Also, regarding the perspectives of hospitals, having to maintain the workforce and have them take care of the rehabilitation sessions leads them to more expenses in cost aspects. For those reasons, in this paper, a home-based remote rehabilitation system using motion recognition is developed without needing help from others. This system can be executed by a personal computer and a stereo camera at home, the real-time user motion status is monitored using motion recognition feature. The system tracks the joint range of motion(Joint ROM) of particular body parts of users to check the body function improvement. For demonstration, total of 4 subjects with various ages and health conditions participated in this project. Their motion data were collected during all 3 exercise sessions, and each session was repeated 9 times per person and was compared in the results.

• Radiation Oncology Journal
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• v.14 no.1
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• pp.17-23
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• 1996

Purpose : To evaluate the role of combination therapy of external radio-therapy and chemotherapy in the management of advanced esophageal cancer as a primary treatment compared with radiation therapy alone. Materials and Methods : A retrospective review of evaluable 55 esophageal cancer patients referred to the Department of Therapeutic Radiology, Paik Hospital for the external radiotherapy between Jul, 1983 and Dec. 1994 was undertaken. Combined therapy patients (A group) were 30 and radiation alone patients (B group) were 25. Median age was 60 years old in A group (ranges : 42-81) and 65 years old in B group (ranges : 50-81). The male patients were 53. The fifty patients had squamous cell carcinomas. Radiation doses of 2520-6480c0y were delivered over a period of 4-7weeks, using 4MV LINAC. Chemotherapy was administered in bolus injection before, after, or during the course of external radiotherapy. The local control rate and patterns of failure according to both treatment modalities and 1, 2 year survival rates according to prognostic factors (stage, tumor length, radiation dose etc.) were analysed. Resuts : Median follow up Period was 7 months (range : 2-73 months). Median survival was 7.5 months (20 days-29 months) in A group and 5 months (20 days-73 months) in B group. The 1, 2 YSRs were $26.7\%$, $8.9\%$ in A group, $12.7\%$, $4.3\%$ in B group (p>0.05), respectively. The 1, 2 YSRs according to stage(II/III), tumor length (5cm more or less). radiation dose (5000cGymore or less) of A and B group were analyzed and the differences of survival rates of both treatments were not statistically significant. But among group B, patients who received 5000cGy or more showed significant survival benefits (p<0.05). The treatment response rates of A and B group were $43.8\%$. $25.0\%$, respectively. Complete response rate of $25.0\%$ in A and $8.3\%$ in B were achieved. The local failure and distant metastsis were $52.4\%$. $23.8\%$ in A group, $64.3\%$, $14.3\%$ in 8 group, respectively. The combination therapy revealed more frequent leukopenia and nausea/vomiting than radiation alone group, but degree of side effects was only mild to moderate. Conclusion : The combined external radiotherapy and chemotherapy for advanced esophageal cancer appears to improve the response rate, local control rate and survival rate, but the improvement was not statistically significant. The side effects of combined modalities were mild to moderate without significant morbidity. Therefore it may be worthwhile to continue the present combined external radiotherapy and chemotherapy in the management of advanced esophageal cancer to confirm our result.