• Radiation Oncology Journal
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• 제7권1호
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• pp.123-132
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• 1989

A radiation beam incident on an irregular or sloping surface produces the non-uniformity of absorded dose. The use of a tissue compensator can partially correct this dose inhomogeneity. The tissue compensator is designed based on the patient's three dimensional contour. After required compensator thickness was determined according to tissue deficit at $25cm\pm25cm$ field size, 10cm depth for 6MV x-rays, tissue deficit was mapped by isoheight technique using laser beam system. Compensator was constructed along the designed model using 0.8mm lead sheet or 5mm acryl plate. Dosimetric verification were peformed by film dosimetry using humanoid phantom. Dosimetric measurements were normalized to central axis full phantom readings for both compensated and non-compensated field. Without compensation, the percent differences in absorbed dose ranged as high as $12.1\%$ along transverse axis, $10.8\%$ along vertical axis. With the tissue compensators in place, the difference was reduced to $0\~43\%$ Therefore, it can be concluded that the compensator system constructed by isoheihnt technique can produce good dose distribution with acceptible inhomogeneity, and such compensator system can be effectively applied to clinical radiotherapy.

• Radiation Oncology Journal
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• 제11권1호
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• pp.127-132
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• 1993

Total of 53 patients of unresectable and recurrent rectal cancer treated with neutron beam during the period from Oct.1987 to Apr.1992 were analyzed. Dose fractionation for the neutron only group was 1.5 Gy per fraction,3 fraction per week,21 Gy/41/2 wks for 42 patients out of 53 ($76{\%}$). Neutron only but modified fractionation schedule ($10{\%}$ more or less of total dose) was applied for 9 patients, and mixed beam (neutron boost) was for 4 patients, Complete tumor response was obtained in 40 patients ($76{\%}$, response rate). Local control rate was 28 out of 53 ($53{\%}$). Statistically significant better prognostic factors for local control were age below 49 years old (15/22, $68{\%}$) than above 50 years old (13/31, $42{\%}$), male (20/32, $63{\%}$) than female (8/21, $38{\%}$), tumor size less than 5 cm and non-metastatic (16/24, $67{\%}$) than size more than 5 cm or metastatic (12/29, $41{\%}$). Major complication had developed in 7 patients ($13{\%}$). Two year overall survival rate by Kaplan-Meier method was $30{\%}$, but it was rised to, $47{\%}$ when the turner was less than 5 cm non-metastatic.

• Radiation Oncology Journal
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• 제12권2호
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• pp.191-199
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• 1994

Purpose : This study was undertaken to show the clinical results of combined radiotherapy and hyperthermia in primary hepatoma Materials and Methods : Between December 1989 and March 1993, 50 patients with hepatomas were treated by combined radiotherapy and hyperthermia. Among them, we analyzed retrospectively 33 patients who received the complete course of treatment. The ages of the patients ranged from 36 to 75(mean age: 55.5 years). Twenty-six patients ($78.8\%$) were men, and 7 ($21.2\%$ were women. According to Child's classification, nine patients ($27.3{\%}$) were A group, 9 ($27.3\%$) were B group, 15 ($45.4\%$) were C group. Radiation therapy was done by a 6 MV and 15 MV linear accelerator. Patients were treated with daily fractions of 150-180 cCy to doses of 2550 cGy -4950 cGy (median : 3000 cGy). Local hyperthermia was done by 8 MHZ RF capacitive heating device (Cancermia. Green Cross Co., Korea), 50-60 min/session, 1-2 sessions/wk, and 8.5 sessions (median number)/patient. We analyzed the prognostic factors including age, sex, tumor type, Child's classification, $\alpha$-fetoprotein, liver cirrhosis, ascites, portal vein invasion, esophageal varix, number of hyperthermia, chemotherapy, total bilirubin level, Karnofsky perfomance status. Results : The overall 1-year survival was $24.2\%$, with a mean survival of 10months. Of 33 patients, tumor regression (PR+MR) was seen in $30.4\%$, no response was seen in $52.2\%,\;17.4\%$ patient was progressed. In patients who had tumor regression, the overall 1-year survival was $42.1\%$ with a mean survival of 14 months. Factors influencing the survival were sex (p=0.05), tumor type (p=0.0248), Child's classification (p=0.0001), liver cirrhosis (p=0.0108), ascites (p=0.0009), and Karnofsky perfomance status (p=0.0028). Complications developed in 28 patients, including 18 hot pain,5 fat necrosis, 3 transient fever, 2 nausea and vomiting. Conclusion : In this study, the results suggests that combined radiotherauy and hyperthermia may improve the survival rate of hepatoma.

• 대한방사선치료학회지
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• 제1권1호
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• pp.37-42
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• 1985

Radiation Therapy(RT) has been used in the treatment of breast cancer for over 80 years. Technically, it should include a part or all of such areas as chest wall or breast, axilla, internal mammary nodes(IM) and supraclavicular nodes (SCL). Authors tried three-field technique for the treatment of breast cancer using 6 MV linear accelerator, exclusively the department of Radiology, Kang-Nam St. Mary's Hospital, at Catholic Medical College. The field junction was checked by a phantom study and radiation doses measured by film densitometry and TLD. The 3 fields we used in this study were two isocentric opposing tangential fields encompassing the breast, chest wall and occasionally IM and one single anterior field encompassing the axilla and SCL. Using appropriate beam blocks and blouses, we were able to avoid unwanted intrinsic divergency of photon beam. Blocking also enabled us to set-up precise radiation field with ease.

• 대한두경부종양학회지
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• 제6권1호
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• pp.40-45
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• 1990

Thirty five lesions of 35 patients with locally advanced malignant tumors of head and neck were received thermoradiotherapy with ultrasound and/or 915 MHz microwave. Most of all patients were failed with previous conventional therapeutic trial. Hyperthermia had been done immediately after radiotherapy, twice a week, $43^{\circ}C$ for one hour and radiotherapy had been done 5 fractions per week with a fraction size of 2 Gy up to total 30 to 60 Gy. Conclusions are as follows; 1) Total response rate (CR+PR) of thermoradiotherapy with microwave and ultrasound was 80%. 2) Tumor depth, minimum temperature of tumor center, number of heat fraction and irradiation dose were statistically significant factors affecting response. 3) Hyperthermia with microwave and ultrasound can be used efficiently to control locally advanced malignant tumors in head and neck whether previously received near tolerance dose of radiotherapy or not.

• Radiation Oncology Journal
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• 제6권1호
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• pp.75-80
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• 1988

Twenty seven lesions of 25 patients with locally advanced malignant tumors were treated with combined hyperthermia introduced by microwave and ultrasound and radiotherapy. Most of all patients were failed with previous conventional therapeutic trial. Hyperthermia had been done immediately after radiotherapy, twice a week, $43^{\circ}C$ for one hour and radiotherapy had been done 5 fractions per week with fraction size of 2Gy upto 30 to 60Gy. Conclusions are as follows. 1. Total response rate (PR+PR) to thermoradiotherapy with microwave and ultrasound was $81\%$. 2. Tumor depth, minimum temperature of tumor center, number of heat fraction and radiation dose were statistically significant factors affecting response. 3. Hyperthermia with microwave and ultrasound can be used efficiently to control locally advanced malignant disease whether previously received near tolerance dose of radiotherapy or not.

• Korean Journal of Radiology
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• 제25권2호
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• pp.199-209
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• 2024

Objective: This study aimed to compare therapeutic efficacy and technical outcomes between adjustable electrode (AE) and conventional fixed electrode (FE) for radiofrequency ablation (RFA) of benign thyroid nodules. Materials and Methods: Between 2013 and 2021, RFA was performed on histologically proven benign thyroid nodules. For the AE method, AE length ≥ 1 cm with higher power and < 1 cm with lower power were utilized for ablating feeding vessels and nodules, especially those near anatomical structures, respectively. The therapeutic efficacy (volume reduction rate [VRR], complication rate, and regrowth rate) and technical outcomes (total energy delivery, ablated volume/energy, RFA time, and ablated volume/time) of FE and AE were compared. Continuous parameters were compared using a two-sample t-test or Mann-Whitney U test, and categorical parameters were compared using a chi-squared test or Fisher's exact test. Results: A total of 182 nodules (FE: 92 vs. AE: 90) in 173 patients (mean age ± standard deviation, 47.0 ± 14.7 years; female, 90.8% [157/173]; median follow-up, 726 days [interquartile range, 441-1075 days]) were analyzed. The therapeutic efficacy was comparable, whereas technical outcomes were more favorable for AE. Both electrodes demonstrated comparable overall median VRR (FE: 92.4% vs. AE: 84.9%, P = 0.240) without immediate major complications. Overall regrowth rates were comparable between the two groups (FE: 2.2% [2/90] vs. AE: 1.1% [1/90], P > 0.99). AE demonstrated a shorter median RFA time (FE: 811 vs. AE: 627 seconds, P = 0.009). Both delivered comparable median energy (FE: 42.8 vs. AE: 29.2 kJ, P = 0.069), but AE demonstrated higher median ablated volume/energy and median ablated volume/time (FE: 0.2 vs. AE: 0.3 cc/kJ, P < 0.001; and FE: 0.7 vs. AE: 1.0 cc/min, P < 0.001, respectively). Conclusion: Therapeutic efficacy between FE and AE was comparable. AE demonstrated better technical outcomes than FE in terms of RFA time, ablated volume/energy, and ablated volume/time.

• Radiation Oncology Journal
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• 제4권1호
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• pp.75-80
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• 1986

관절주위 골형성은 고관절치환 성형술을 시행받은 환자의 $0.6\~61.7\%$에서 생친 수 있는 합병증이다. 저자들은 1981년 1월부터 1985년 5월까지 서울대학교병원 치료방사선과에서 고관절전치환 성형술 후 관절주위 골형성 예방을 위하여 방사선요법을 시행받은 4명의 환자(8개의 고관절)를 분석하였다. 방사선요법은 수술후 $6\~10$일이내 시작하였으며 2,000cGy를 10회 분할 조사하였다. Modified Brooker system에 의하여 7계의 고관절에서는 Grade(1개 의고관절에서는 Grade) 2의 결과를 얻었다. 저자들의 이번 연구결과 및 문헌조사에 의하면 고관절 성형술 후 관절주위 골형성 예방을 위하여 호발군에 있어서의 방사선요법은 효과적이라고 하겠다.

• 대한두경부종양학회:학술대회논문집
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• 대한두경부종양학회 1991년도 제8차 학술대회 연제순서 및 초록집
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• pp.18.1-18.1
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• 1991

• 대한두경부종양학회:학술대회논문집
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• 대한두경부종양학회 1989년도 제6차 학술대회 연제순서 및 초록집
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• pp.16.2-18
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• 1989