• Radiation Oncology Journal
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• v.19 no.3
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• pp.237-244
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• 2001

Purpose : To assess the tolerance, complete response rate, bladder preservation rate and survival rate in patients with muscle-invading bladder cancer treated with selective bladder preservation protocol. Method and Materials : From October 1990 to June 1998, twenty six patients with muscle-invading bladder cancer (clinical stage T2-4, N0-3, M0) were enrolled for the treatment protocol of bladder preservation. They were treated with maximal TURBT (transurethral resection of bladder tumor) and 2 cycles of MCV chemotherapy (methotrexate, crisplatin, and vinblastine) followed by $39.6\~45\;Gy$ pelvic irradiation with concomitant cisplatin. After complete urologic evaluation (biopsy or cytology), the patients who achieved complete response were planed for bladder preservation treatment and treated with consolidation cisplatin and radiotherapy (19.8 Gy). The patients who had incomplete response were planed to immediate radical cystectomy. If they refused radical cystectomy, they were treated either with TURBT followed by MCV or cisplatin chemotherapy and radiotherapy. The median follow-up duration is 49.5 months. Results : The Patients with stage T2-3a and T3b-4a underwent complete removal of tumor or gross tumor removal by TURBT, respectively. Twenty one out of 26 patients $(81\%)$ successfully completed the protocol of the planned chemo-radiotherapy. Seven patients had documented complete response. Six of them were treated with additional consolidation cisplatin and radiotherapy. One patient was treated with 2 cycles of MCV chemotherapy due to refusal of chemo-radiotherapy. Five of 7 complete responders had functioning tumor-free bladder. Fourteen patients of incomplete responders were further treated with one of the followings : radical cystectomy (1 patient), or TURBT and 2 cycles of MCV chemotherapy (3 patients), or cisplatin and radiotherapy (10 patients). Thirteen patients of them were not treated with planned radical cystectomy due to patients' refusal (9 patients) or underlying medical problems (4 patients). Among twenty one patients, 12 patients $(58\%)$ were alive with their preserved bladder, 8 patients died with the disease, 1 patient died of intercurrent disease. The 5 years actuarial survival rates according to CR and PR after MCV chemotherapy and cisplatin chemoradiotherapy were $80\%\;and\;14\%$, respectively (u=0.001). Conclusion : In selected patients with muscle-invading bladder cancer, the bladder preservation could be achieved by MCV chemotherapy and cisplatin chemo-radiotherapy. All patients tolerated well this bladder preservation protoco. The availability of complete TURBT and the responsibility of neoadjuvant chemotherapy and chemoradiotherapy were important predictors for bladder preservation and survival. The patients who had not achieved complete response after neoadjuvant chemotherapy and chemoradiotherapy should be immediate radical cystectomy. A randomized prospective trial might be essential to determine more accurate indications between cystectomy or bladder preservation.

• Radiation Oncology Journal
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• v.13 no.2
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• pp.149-156
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• 1995

Purpose : Since February 1991 a Prospective study for non-small cell lung cancer patients who underwent radical resection and had a risk factor of positive resection margin or regional lymph node metastasis has been conducted to evaluate the effect of MVP chemotherapy and radiotherapy on the pattern of failure, disease free and overall survival. and tolerance of combined treatment. Materials and Methods: Twenty nine patients were registered to this study until Sep. 1993; of these 26 received planned therapy Within 3 weeks after radical resection, two cycles of MVP(Mitomycin C $6mg/m^2,$ Vinblastin $6mg/m^2,$ Cisplatin $60mg/m^2$) chemotherapy was given with 4 weeks intervals. Radiotherapy (5040cGy tumor bed dose and 900cGy boost to high risk area) was started 3 to 4 weeks after chemotherapy. Results: One and two year overall survival rates were $76.5\%\;and\;58.6\%$ respectively. Locoregional failure developed in 6 patients$(23.1\%)$ and distant failure in 9 patients$(34.6\%)$ Number of involved lymph nodes, resection margin positivity showed some correlation with failure pattern but T-stage and N-stage showed no statistical significance. The group of patients who received chemotherapy within 2 weeks postoperatively and radiotherapy within 70 days showed lower incidence of distant metastasis. Postoperative combined therapy were well tolerated without definite increase of complication rate, and compliance rate in this study was $90\%$. Conclusion: 1) MVP chemotherapy showed no effect on locoregional recurrence, but appeared to decrease the distant metastasis rate and 2) combined treatments were well tolerated in all patients. 3) The group of patients who received chemotherapy within 2 weeks postoperatively and radiotherapy within 70days showed lower incidence of distant metastasis. 4) Addition of chemotherapy to radiotherapy failed to increase the overall or disease free survival.

• 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.

• Radiation Oncology Journal
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• v.26 no.2
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• pp.118-125
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• 2008

Purpose: On-line image guided radiation therapy(on-line IGRT) and(kV X-ray images or cone beam CT images) were obtained by an on-board imager(OBI) and cone beam CT(CBCT), respectively. The images were then compared with simulated images to evaluate the patient's setup and correct for deviations. The setup deviations between the simulated images(kV or CBCT images), were computed from 2D/2D match or 3D/3D match programs, respectively. We then investigated the correctness of the calculated deviations. Materials and Methods: After the simulation and treatment planning for the RANDO phantom, the phantom was positioned on the treatment table. The phantom setup process was performed with side wall lasers which standardized treatment setup of the phantom with the simulated images, after the establishment of tolerance limits for laser line thickness. After a known translation or rotation angle was applied to the phantom, the kV X-ray images and CBCT images were obtained. Next, 2D/2D match and 3D/3D match with simulation CT images were taken. Lastly, the results were analyzed for accuracy of positional correction. Results: In the case of the 2D/2D match using kV X-ray and simulation images, a setup correction within $0.06^{\circ}$ for rotation only, 1.8 mm for translation only, and 2.1 mm and $0.3^{\circ}$ for both rotation and translation, respectively, was possible. As for the 3D/3D match using CBCT images, a correction within $0.03^{\circ}$ for rotation only, 0.16 mm for translation only, and 1.5 mm for translation and $0.0^{\circ}$ for rotation, respectively, was possible. Conclusion: The use of OBI or CBCT for the on-line IGRT provides the ability to exactly reproduce the simulated images in the setup of a patient in the treatment room. The fast detection and correction of a patient's positional error is possible in two dimensions via kV X-ray images from OBI and in three dimensions via CBCT with a higher accuracy. Consequently, the on-line IGRT represents a promising and reliable treatment procedure.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.95-99
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• 2001

Purpose : To evaluate the effectiveness and tolerance of postoperative external radiotherapy for patients with intracranial meningiomas. Materials and Methods : The records of thirty three patients with intracranial meningiomas who were treated with postoperative external irradiation at our institution between Feb, 1988 and Nov, 1999 were retrospectively analyzed. Median age of patients at diagnosis was 53 years with range of 17 to 68 years. Sites of involvement were parasagital, cerebral convexity, sphenoid ridge, parasellar and tentorium cerebelli. Of 33 evaluated patients, 15 transitional, 10 meningotheliomatous, 4 hemangiopericytic, 3 atypical and 1 malignant meningioma were identified. Four patients underwent biopsy alone and remaining 29 patients underwent total tumor resection. A dose of 50 to 60 Gy was delivered in 28-35 daily fractions over a period of 5 to 7 weeks. Follow-up period ranged from 12 months to 8 years. Results : The actuarial survival rates at 5 and 7 years for entire group of patients were 78% and 67%, respectively. The corresponding disease free survival rates were 73% and 61%, respectively. The overall local control rate at 5 years was 83%. One out of 25 patients in benign group developed local failure, while 4 out of 8 patients in malignant group did local failure (p<0.05). Of 4 patients who underwent biopsy alone, 2 developed local failure. There was no significant difference in 5 year actuarial survival between patients who underwent total tumor resection and those who did biopsy alone. Patients whose age is under 60 showed slightly better survival than those whose age is 60 or older, although this was not statistically significant. There was no documented late complications in any patients. Conclusion : Based on our study, we might conclude that postoperative external beam radiotherapy tends to improve survival of patients with intracranial meningiomas comparing with surgery alone.

• Progress in Medical Physics
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• v.14 no.1
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• pp.8-14
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• 2003

The spinal cord dose is the one of the limiting factor for the radiation treatment of the head ＆ neck or the thorax region. It is not an easy task to maintain the spinal cord dose below tolerance and to keep the clinically acceptable dose to the PTV in this region. To overcome this problem, the spinal cord partial block technique (PBT) with the dynamic Multi-Leaf Collimator (dMLC) has been developed. This technique is an extension of the conventional treatment planning. In the beginning the beam directions are selected as same as the conventional treatment planning to encompass the PTV, then the partial block are designed to shield the spinal cord. The plan comparisons between the conventional therapy plan and the PTB plan were performed to evaluate the validity of this technique. The mean dose and the dose volume histogram (DVH) were used as the plan comparison indices. A series of quality assurance (QA) was performed to guarantee the reliable treatment. The QA consisted of the film dosimetry for the verification of the dose distribution and the point measurements. The PBT plan generated better results than the conventional treatment plan and it was proved to be useful for the H＆N region.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.2
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• pp.91-103
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• 1997

The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chemotherapy. For this study, cell surviving curves were obtained for human epidermoid carcinoma A-253 cell line using semiautomated MTT assay. 2,4,6,8,10 Gy were irradiated at a dose rate of 210 cGy/min using /sup 60/Co Irradiator ALDORADO 8. After irradiation, A-253 cell lines(2×10⁴cells/mil were exposed to bleomycin or cisplatin for 1 hour. The viable cells were determined for each radiation dose with/without 2 /lg/mi of drug at the 3rd day. And they were compared to control values. The results were obtained as follows : 1. The surviving curve with gentle slope was obtained after irradiation of 2, 4, 6, 8, 10 Gy on A-253 cell line. 2. The cytotoxicity of bleomycin or cisplatin at the concentration of 2㎍/ml was great on A-253 cell line. But, there was no significant difference between the cytotoxicity of bleomycin and that of cisplatin. 3. There were significant differences of surviving fractions after irradiation with 2㎍/mi of bleomycin compared with irradiation only on A-253 cell line. 4. There were significant differences of surviving fractions after irradiation with 2㎍/ml of cisplatin compared with irradiation only on A-253 cell line. 5. There were no significant differences of surviving fractions between the groups of irradiation with bleomycin and the groups of irradiation with cisplatin on A-253 cell line.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.157-164
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• 2017

In this research, the overlapped illumination model was used for designing a freeform LED lens with a uniform illuminance distribution on its illuminating plane, and their performances and tolerances were compared. And, the illuminations on a illumination plane was measures for change with average illuminance and illuminance uniformity. As a result of the tolerance analysis about z-axis direction change, thickness change in lens and tilt change of light emission and characteristic change in LED source, overlapped model and divergent illumination model are similar to the performance about Z-axis direction change of light emission in LED source. but the uniformity illumination value in this overlapped model is more remarkably value than it in divergent illumination model about thickness change in LED lens. Also, even though the lens based on a divergent illumination model showed good performance compare to the lens based on an overlapped illumination model, the latter was less the deviation to variation of LED beam radiation ability.

• KIEAE Journal
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• v.13 no.5
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• pp.89-96
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• 2013

Green roofs can reduce surface water runoff, provide a habitat for wildlife moderate the urban heat island effect, improve building insulation and energy efficiency, improve the air quality, create aesthetic and amenity value, and preserve the roof's waterproofing. Green roofs are mainly divided into three types : intensive, simple-intensive, and extensive. Especially, extensive roof environment is a harsh one for plant growth; limited water availability, wide temperature fluctuations, high exposure to wind and solar radiation create highly stressed environment. This study, aimed at extensive green roof, was carried out on the rooftop of the library at Seoul Women's Univ. from October to November, 2012 and from March to August, 2013. To suggest the most effective vegetation model for biodiversity and heat island mitigation, surface temperatures were monitored by each vegetation model. We found that herbaceous plants of Aster sphathulifolius, Aceriphyllum rossii and Belamcanda chinensis, shrub of Syringa patula 'Miss Kim', Thymus quinquecostatus var. japonica, Sedum species can mixing each other. Among them, the vegetation models including Sedum takesimense, Aster sphathulifolius, Thymus quinquecostatus var. japonica was more effective on the surface temperature mitigation, because the species have the tolerance and high ratio of covering, and also in water. Especially, in the treatment of bark mulching, they helped to increase the temperature of vegetation models. In the case of summer, temperature mitigation of vegetation models were no significant difference among vegetation types. Compared to surface temperature of June, July and August were apparent impact of temperature mitigation, it shows that temperature mitigation are strongly influenced by substrate water content.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.1
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• pp.13-20
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• 2003

Both MgO and $Sc_2O_3$ are shown to provide low interface state densities (in the $10^{11}{\;}eV^{-1}{\;}cm{\;}^{-2}$ range)on n-and p-GaN, making them useful for gate dielectrics for metal-oxide semiconductor(MOS) devices and also as surface passivation layers to mitigate current collapse in GaN/AlGaN high electron mobility transistors(HEMTs).Clear evidence of inversion has been demonstrated in gate-controlled MOS p-GaN diodes using both types of oxide. Charge pumping measurements on diodes undergoing a high temperature implant activation anneal show a total surface state density of $~3{\;}{\times}{\;}10^{12}{\;}cm^{-2}$. On HEMT structures, both oxides provide effective passivation of surface states and these devices show improved output power. The MgO/GaN structures are also found to be quite radiation-resistant, making them attractive for satellite and terrestrial communication systems requiring a high tolerance to high energy(40MeV) protons.