• Journal of Radiation Industry
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• v.9 no.4
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• pp.193-198
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• 2015

Most of targeted therapies block the action of certain enzymes, proteins, or other molecules involved in the growth and spread of cancer cells to produce its cytotoxic effect. Either small molecule drugs or monoclonal antibodies are mostly used in targeted therapies. Unfortunately, targeted therapy has a certain degree of unwanted side effect like other cytotoxicity inducing chemotherapies. To overcome and to reduce unwanted side effects during a cancer therapy, recently radiopeptide therapies has got the worlds' attraction for the tumor targeting modalities due to its beneficial effect on less side effect compared to cytotoxic chemotherapies. Among radiopeptide therapies, $^{177}Lu$-DOTATATE is a major modality as an effective one invented so far in treating neuroendocrine tumor (NET) and it has been in clinical trials at least one decade. Although it does have rather effective therapeutic effect on NET, it has less effective in rather large solid tumor. There are many ways to improve or increase therapeutic effect of radiopeptide are a finding the potent small molecules to target the tumor site selectively, or a labeling with radioisotope of emitting high energy, or an improving its biological half-life by introducing different moieties to increase lipophilicity. Present study was focus to increase a biological half-life of radio somatostatin which will target the somatostatin receptor by altering the bifunctional chelator (BFCA) by introducing lipophilic moiety to the somatostatin, which would make the labeled peptide stay longer in the tumor site and thus it can intensify the therapeutic effect on tumor cell itself and around tissues.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.145-152
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• 2001

For the research of solar EUV (extreme ultraviolet) radiation, we have designed a small-sifted engineering model of solar EUV telescope, which is suitable for a Korean satellite. The EUV sole. telescope was designed to observe the sun at $584.3AA$(He I) and $629.7AA$(OV) The optical system is an f/8 Ritchey-Chr rien, and the effective diameter and focal length are 80mm and 640mm, respectively. The He I and 0V filters are loaded in a filter wheel. In the detection part, the MCP (Microchannel Plate) type is Z-stack, and the channel-to-diameter radio is 40:1. MCP and CCD are connected by fiber optic taper. A commercial optical design software is used for the analysis of the optical system design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.425-430
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• 2017

RFID is a technology that uses radio frequency to read information in tags attached to objects or people. Because it reads the information without contact when tracking the location using tags in a RFID system, there can be errors between the actual position and measured position. In this paper, three methods (the method of radiation pattern, the method of the median value, and the method using both the radiation pattern and median value) are proposed to identify the location of objects or people using the RFID technique. The location identification system based on RFID was constructed and tags were arranged in a square pattern. The real location and experimentally predicted location of an object containing a reader were compared to confirm the error. Instead of the existing papers that obtained the approximately location of a reader by calculating the center of gravity of all tags read by that reader, in this study, the predicted location was obtained by the median value and the radiation pattern. This study validated which method was the most efficient among the three methods proposed in this paper through the data of the read tags. As a result, the method of the median value had the smallest error among those assessed.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.97-106
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• 2015

Purpose : This study evaluate the thermal changes caused by use of the chemoport for drug administration and blood sampling during radiofrequency hyperthermia. Materials and Methods : 20cm size of the electrode radio frequency hyperthermia (EHY-2000, Oncotherm KFT, Hungary) was used. The materials of the chemoport in our hospital from currently being used therapy are plastics, metal-containing epoxy and titanium that were made of the diameter 20 cm, height 20 cm insertion of the self-made cylindrical Agar phantom to measure the temperature. Thermoscope(TM-100, Oncotherm Kft, Hungary) and Sim4Life (Ver2.0, Zurich, Switzerland) was compared to the actual measured temperature. Each of the electrode measurement position is the central axis and the central axis side 1.5 cm, 0 cm(surface), 0.5 cm, 1.8 cm, 2.8 cm in depth was respectively measured. The measured temperature is $24.5{\sim}25.5^{\circ}C$, humidity is 30% ~ 32%. In five-minute intervals to measure the output power of 100W, 60 min. Results : In the electrode central axis 2.8 cm depth, the maximum temperature of the case with the unused of the chemoport, plastic, epoxy and titanium were respectively $39.51^{\circ}C$, $39.11^{\circ}C$, $38.81^{\circ}C$, $40.64^{\circ}C$, simulated experimental data were $42.20^{\circ}C$, $41.50^{\circ}C$, $40.70^{\circ}C$, $42.50^{\circ}C$. And in the central axis electrode side 1.5 cm depth 2.8 cm, mesured data were $39.37^{\circ}C$, $39.32^{\circ}C$, $39.20^{\circ}C$, $39.46^{\circ}C$, the simulated experimental data were $42.00^{\circ}C$, $41.80^{\circ}C$, $41.20^{\circ}C$, $42.30^{\circ}C$. Conclusion : The thermal variations were caused by radiofrequency electromagnetic field surrounding the chemoport showed lower than in the case of unused in non-conductive plastic material and epoxy material, the titanum chemoport that made of conductor materials showed a slight differences. This is due to the metal contents in the chemoport and the geometry of the chemoport. And because it uses a low radio frequency bandwidth of the used equipment. That is, although use of the chemoport in this study do not significantly affect the surrounding tissue. That is, because the thermal change is insignificant, it is suggested that the hazard of the chemoport used in this study doesn't need to be considered.

• Radiation Oncology Journal
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• v.4 no.1
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• pp.35-43
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• 1986

Study patients with head and neck carcinoma were studied retrospectively to assess the impact of treatment on survival and local control rate by stage in the Dept of Radiation Therapy, Korea University Hae Wha Hospital between March 1981 and March 1986. Prior to definite radiotherapy, patients were evaluated by physical examination and radiologic studies including chest, laryngogram and CT scan and then these patients were grouped according to the American Joint Committee (AJC) staging system. They were treated with RT alone or postoperative irradiation to the dose of 7,200 cGy/8 weeks and 6,000 cGy/7 weeks respectively. The results were obtained and as follows; 1. Overall male to female sex ratio was 3.6:1. The peak age of patients with head and neck cancer was 6th decade. 2. In all patients treated by RT, the ratio of squamous cell 1 carcinoma to non-squamous cell carcinoma was 3.5:1 (60/77 patients). 3. The incidence according to the anatomic site of primary tumor was 22 cases in the larynx, 12 cases in PNS, 7 cases in nasopharynx, 6 cases in oropharynx, and 3 cases in hypopharynx. 4. According to AJC staging system,4 cases were Stage 1,7 in Stage II, 19 in Stage III and 27 in Stage IV. 5. The overall incidence of cervical lymph node metastases was $43\%$ and subdigatric and submaxillary triangle lymph nodes were the most frequent site of metastases. 6. Local control was achieved in $48\%$ of patients treated by radio-therapy. 7. The lung was the most common site for distant metastases, comprising 4 cases among 7 cases in which distant metastases occured. 8. The overall estimated 5-year survival rate was $43\%$ in the head and neck cancer treated with radiotherapy by life-table analysis.

• Journal of The Korean Astronomical Society
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• v.29 no.2
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• pp.223-243
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• 1996

We have constructed a line-by-line model of the A-X system of CO in order to analyze the CO bands appearing in the UV spectra of comets. The model includes electronic, rotational, vibrational transitions, excitations by solar UV radiation, and effects of neutral and electron collisions. The major bands of the A-X system occur in the $1200 - 1800{\AA}$ range where the temporal variation of solar irradiation is significant. The solar spectrum in this spectral range shows many emission lines, which cause a significant Swings effect. We derived fluorescence efficiencies of the bands as functions of heliocentric velocity and cometocentric distance using a high resolution spectrum of the sun. We compared our model with a spectrum of comet P/Halley obtained with the IUE, and estimated that the UV Swings effects are less than 20 fluorescence efficiencies for the most bands of the A-X system. We discuss the temporal variation of solar UV irradiation and its effects on the fluorescence efficiencies. The study of the A-X system also requites knowledge of vibrational and rotational fluorescent processes in the infrared and radio regions because the majority of CO molecules in the coma is in the ground rotational states. The solar infrared spectrum near 5 microns, where the fundamental band of CO occurs, contains strong absorption lines of the fundamental band and hot bands of CO and its isotopes. We derived fluorescence efficiencies of the infrared band as functions of heliocentric velocity and cometrocentric distance. The solar absorption lines near 5 microns cause a 20 reduction of the g-factor of the fundamental band at heliocentric velocities close to 0 km/sec. We discuss the effects of neutral and electron collisions on the fluorescence efficiencies of the infrared and UV bands.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.177-182
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• 2008

Digital imaging for general rediography has many advantages over the film/screen systems, including a wider dynamic range and the ability to manipulate the images produced. The wider range means that acceptable images may by acquired at a range of dose levels, and therefore repeat exposures can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency for images to be acquired at too high a dose. We investigated the actual exposure dose conditions on general radiography and a questionnaire survey was conducted with radiotechnologiest at medical institutions using digital radiology system. As a results, the dose of exposure was not controlled with patient's figure and dose optimization but was controlled by worker's convenience and image quality. Radio-technologiests often set up the exposure dose regardless of patient figure and body part to be examined. Many organizations, such as the International Commission on Radiological Protection, recommend to keep the dose as low as possible. In addition, they strongly recommend to keep the optimal but minimal dosage by proper training programs and constant quality control, including frequent patient dose evaluations and education.

• Radiation Oncology Journal
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• v.13 no.2
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• pp.163-171
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• 1995

Purpose: Primary radiation therapy following breast-conserving surgery has been an accepted alternative to mastectomy during the past 2 decades. In this country, however, the practice of conservative therapy for early invasive breast cancer has not been generalized yet. The purpose of this report was to evaluate the results and complications of breast conservation therapy in Korean Cancer Center Hospital(KCCH). Materials and Methods: From January 1987 to December 1989. 45 Patients with early breast cancer treated with conservative treatment in KCCH were studied retrospectively Median follow up was 54 months(range, 4 to 82 months) . All patients received partial mastectomy (biopsy, tumorectomy. or quadrantectomy) and radiation therapy. Twenty eight patients received axillary dissection The breast was treated with two opposing tangential fields (total 50 Gy or 50.4 Gy in 5 weeks with daily target dose of 2 Gy or 1.8 Gy) Thirty patients received chemotherapy before and after radio-therapy Eleven patients received hormonal therapy. Results: Five-year survival rate, 5-rear disease free survival rate and 5-year local control rate were 87.2%, 86.5% and 97.6%,$ respectively. Administration of systemic Therapy (chemotherapy or hormonal therapy) correlated with good prognosis but statistically not significant (0.05 < p < 0.1). The severe late complication rate was 8.9% Conclusion: Primary radiation therapy following breast-conserving surgery for early breast cancer is an alternative treatment comparing to radical treatment. Long term follow-up and more patients collection is needed to evaluate the Prognostic factor and cosmetic outcome.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1309-1315
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• 2000

Objectives : We performed an in vivo experiment to investigate the effect of $^{166}Holmium$ and $^{166}Holmium$-chitosan complex($^{166}Ho$-CHICO) on the normal brain of rats and to determine the sublethal dose of $^{166}Ho$-CHICO. Materials and Methods : $^{166}Ho$ is a beta and gamma ray emitter. $^{166}Ho$-CHICO is a novel radio-pharmaceutical complex with chitosan to facilitate the transport of $^{166}Ho$ obtained from Korea Atomic Energy Research Center(Taejon, Korea). It is in acidic form and becomes gel state at alkaline pH. One hundred and seventy consecutive rats were divided into four groups : $^{166}Ho$ treated(n＝50), $^{166}Ho$-CHICO treated(n＝57), saline treated(n＝5) and chitosan treated(n＝5) groups. $^{166}Ho$ and $^{166}Ho$-CHICO were injected into the rat brain stereotactically with various doses of 0.1mCi/$20{\mu}l$, 0.2mCi/$20{\mu}l$, 0.3mCi/$20{\mu}l$, and 0.4mCi/$20{\mu}l$ using an automated microinjector. Nuclear imaging, histopathological and hematological studies were performed in 10 rats in each group at 1 day, 3days, 7 days, 1 month and 3 months after the injections. Results : An infiltration of inflammatory cells and necrotic changes were noted in $^{166}Ho$ treated group at 1 week after the injection. A wedge-shaped tissue defect due to necrosis, lined with infiltrated glial cells in $^{166}Ho$ treated group and a cystic defect lined with reactive astroglial cells in $^{166}Holmium$-CHICO treated group at 3 months after the injection were observed. $^{166}Ho$ alone without chitosan leaked out and caused necrotic lesion on the cerebral surface but $^{166}Holmium$-CHICO treated group did not show this feature. As the dose of $^{166}Ho$ increased, the mortality rates were also increased. The mortality rate of the $^{166}Holmium$-CHICO group was higher than the $^{166}Ho$ treated group at a dose of 0.4mCi/$20{\mu}l$/300g. There was no detectable radioactivity due to the leakage or extravasation from the injected site of the brain on the scintigraphy performed at 1 hour, 24 hours and 48 hours after the injection. There was also no detectable activity of $^{166}Holmium$-CHICO in other organs including spleen, liver and kidney. Conclusions : $^{166}Ho$-CHICO did not leak out to the critical cortical surface of the brain from the injection site and induced radiation changes of the parenchyma around the injection site without cortical damage. The sublethal dose of $^{166}Ho$-CHICO for the normal brain in rats was determined to be 0.2mCi/$20{\mu}l$/300g.