• Radiation Oncology Journal
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• v.12 no.2
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• pp.151-158
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• 1994

Since Jan. 1992, authors have conducted a pilot study to treat malignant glioma with multiple daily fractionated(MDF) radiation therapy and this paper presents the outcome compared MDF to conventional factionated(CF) radiation therapy Between Sep. 1989 and Jan. 1993, forty three patients with high grade glioma of brain except brain stem glioma were treated: nineteen patients were treated with CF radiation therapy and 24 patients were treated with MDF radiation therapy. In CF radiation therapy, total dose was 6300cGy/35fx in 7 weeks, which 5040cGy was delivered to the initial target volume and 1260cGy to reduced target volume. And in MDF radiation therapy, total dose was 6400cGy/40fx in 4 weeks, which 3200cGy was delivered to the initial target volume as 160cGy 2 times daily 6hr apart. All patients had histologically confirmed anaplastic astrocytoma(AA) of glioblastoma multiforme (GBM) with stereotactic biopsy or craniotomy for subtotal or gross tumor resection. The range of follow-up was 7 months to 4 years with a median follow-up of 9 months. The Median survival from surgery was 9 months for all patients. The median survival was 9 months and 10 months for MDF group and CF group and 10 months and 9.5 months for glioblastoma multiforme and anaplastic astrocytoma, respectively. In 36 patients with follow-up CT scan or MRI scan, disease status was evaluated according to treatment groups, Four patients(GBM:3, AA:1) of 21 patients in MDF group, were alive with no evidence of disease, while none of patient was alive with no evidence of disease in CF group. The progression of disease had occurred in 20 patients, 11 patients and 9 patients in MDF group and CF group, respectively All of these patients showed in-field progression of disease, Four of 11 patients($27\%$) in MDF group showed the new leasion outside of the treatment field, while 5 of 9 patients($56\%$) in CF group. In our study the prognosis was not influenced by age, KPS, grade, extent of surgery and different fractional scheduled radiation therapy. Authors concluded that MDF regimen was well tolerated and shortened the treatment period from 7 weeks to 4 weeks without compromising results. We believe that further follow-up is needed to assess the role of MDF.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2005.04a
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• pp.11-15
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• 2005

입체조형 및 세기조절 방사선치료가 보편화되어 가고 있는 현 시점에서, 치료율을 높이기 위해 종양처방선량은 증가시키는 반면 부작용은 최소화하고자 하는 요구가 증가하고 있다. 셋업오차 및 체내운동(internal motion)은 이러한 요구를 충족시키는데 대한 한계로 작용하고 있다. 4차원방사선치료(4-dimensional radiation therapy)는 체내운동을 최소화시키거나 또는 움직임을 추적하여 방사선치료를 시행함으로써 “종양선량최대화/정상조직선량최소화”라는 고정밀방사선치료의 요구에 부응할 수 있는 치료기술로 기대를 모으고 있다. 체내운동은 호흡에 의한 움직임과 같이 단기적으로 발생되는 조사분할내(intra-fraction)와 종양의 수축, 체중 변화 등과 같이 장기적으로 발생하는 조사분할간(inter-fraction)움직임으로 구분되는데, 본 연제에서는 주로 조사분할내 움직임, 즉 호흡에 의한 움직임에 대처하는 4차원방사선치료를 위한 동적영상 획득 및 방사선치료계획과정에 초점을 맞추어 소개하고자 한다.

• Radiation Oncology Journal
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• v.10 no.1
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• pp.15-20
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• 1992

A total of 20 patients (male: female=10:10, adult:children=8:12) with brainstem tumors had been received radiation therapy in the Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine between 1980 and 1990. Thirteen of 20 patients were treated with conventional radiation therapy (before 1989, 180~200 cGy per fraction, 5 days a week, total dose 4680~5400 cGy), and seven patients were treated with hyperfractionated radiation therapy (in 1990, 100 cGy per fraction, twice daily 10 fractions a week, total dose 7200 cGy). Median follow up Periods for conventional radiation therapy group and hyperfractionated radiation therapy group were 36 months and 10 months, respectively. Four of 20 Patients had histopathologic diagnosis prior to treatment; 3 cases were low grade astrocytoma and 1 case was high grade astrocytoma. Overall 2-year actuarial survival rate was 30%. The prognosis of patients with a longer duration of symptom and sign was better (60%, vs 12%), and the adult (52%) was better than children (14%). There was no significant difference between the focal (29%) and diffuse (26%) type. The initial clinical response was better in the hyperfractionated radiation therapy group. Because of the relatively small number of Patients and short follow up Period in hyperfractionated radiation therapy group, there was no comparison between two group.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.228-236
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• 2002

Purpose : Although high-dose-rate (HDR) brachytherapy regimens have been practiced with a variety of modalities and various degrees of success, few studies on the subject have been conducted. The purpose of this study was to compare the results of local control and late complication rate according to different HDR brachytherapy fractionation regimens in uterine cervical cancer patients. Methods and Materials : From November 1992 to March 1998, 224 patients with uterine conical cancer were treated with external beam irradiation and HDR brachytherapy. In external pelvic radiation therapy, the radiation dose was $45\~54\;Gy$ (median dose 54 Gy) with daily fraction size 1.8 Gy, five times per week. In HDR brachytherapy, 122 patients (Group A) were treated with three times weekly with 3 Gy to line-A (isodose line of 2 cm radius from source) and 102 patients (Group B) underwent the HDR brachytherapy twice weekly with 4 or 4.5 Gy to line-A after external beam irradiation. Iridium-192 was used as the source of HDR brachytherapy. Late complication was assessed from grade 1 to 5 using the RTOG morbidity grading system. Results : The local control rate (LCR) at 5 years was $80\%$ in group A and $84\%$ in group B (p=0.4523). In the patients treated with radiation therapy alone, LCR at 5 years was $60.9\%$ in group A and $76.9\%$ in group B (p=0.2557). In post-operative radiation therapy patients, LCR at 5 years was $92.6\%$ In group A and $91.6\%$ in group B (p=0.8867). The incidence of late complication was $18\%$ (22 patients) and $29.4\%$ (30 patients), of bladder complication was $9.8\%$ (12 patients) and $14.7\%$ (15 patients), and of rectal complication was $9.8\%$ (12 patients) and $21.6\%$ (22 patients), in group A and B, respectively. Lower fraction sized HDR brachytherapy was associated with decrease in late complication (p=0.0405) (rectal complication, p=0.0147; bladder complication, p=0.115). The same result was observed in postoperative radiation therapy patients (p=0.0860) and radiation only treated patients (0=0.0370). Conclusion : For radiation only treated patients, a greater number of itemized studies on the proper fraction size of HDR brachytherapy, with consideration for stages and prognostic factors, are required. In postoperative radiation therapy, the fraction size of HDR brachytherapy did not have much effect on local control, yet the incidence of late complication increased with the elevation in fraction size. We suggest that HDR brachytherapy three times weekly with 3 Gy could be an alternative method of therapy.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.3
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• pp.44-51
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• 2009

It is very important to verify generated setup errors in cancer therapy by using a high energy radiation and to perform the precise radiation therapy. Specially, the verification of treatment position is very crucial in special therapies like fractionated stereotatic radiotherapy (FSRT). The FSRT uses normally high-dose, small field size for treating small intracranial lesions. To estimate the developed FSRT system, the isocenter accuracy of gantry, couch and collimator were performed and a total of inaccuracy was less than ${\pm}1mm$. Precise beam targeting is crucial when using high-dose, small field size FSRT for treating small intracranial lesions. The EPID image of the 3mm lead ball mounted on the isocenter with a 25mm collimator cone was acquired and detected to the extent of one pixel (0.76mm) after comparing the difference between the center of a 25mm collimator cone and a 3 mm ball after processing the EPID image. In this paper, the radiation treatment efficiency can be improved by performing precise radiation therapy with a developed video based EPID and FSRT at near real time

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.11-15
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• 1999

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.38-42
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• 1999

• 대한방사선치료학회:학술대회논문집
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• 1999.05a
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• pp.15-16
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• 1999

• Radiation Oncology Journal
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• v.21 no.1
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• pp.10-18
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• 2003

Purpose : To evaluate the role of fractlonated sterotactic radiotherapy (FSRT) in the management of benign brain tumors, we reviewed the clinical, and radiographic responses of patients treated. Methods and Materials : Between March 1995 and March 2002, 36 patients with benign brain tumors were treated by FSRT. The pathological diagnoses consisted of pituitary adenomas (12 patients), cranio-pharyngiomas (5 patients), meningiomas (10 patients), and acoustic neurinomas (9 patients). Radiotherapy doses of 25 to 35 Gy (3~6 Gy/fraction, 5~10 fractions) were prescribed to the 85~90% isodose line, depending upon the location, size and volume of the tumors. The median clinical and radiographical follow up periods were 31 (range, 2~74) and 21 (range, 4~56) months, respectively. Results : In the 35 patients that could be evaluated for their clinical response, 13 (37.1%) were considered improved, 16 (45.7%) stable and 6 (17.2%) worse. Of the 33 patients who had radiographic studies, tumor shrinkage was noted in 17 (51.5%), tumor stabilization in 13 (39.4%), and tumor progression in 3 (9.1%). Of the 17 tumor shrinkage patients, 7 (21.2%) showed a complete response. Acute radiation-induced complications occurred iin 11 (30.6%) patients. Conclusions : FSRT is considered a safe and effective treatment method for begin brain tumors, but large numbers of patients, with relatively long follow-up periods are needed to assess the exact role or effect of FSRT.

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.94-99
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• 1999