• The Journal of Korean Society for Radiation Therapy
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• v.21 no.2
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• pp.75-82
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• 2009

Purpose: Measure the ozone level in the treatment room while treating a patient so want to know the degree of contamination caused by ozone occurrence. Materials and Methods: Use the linear accelerator (Clinac 21EX, Varian, USA) with the ozone meter (series-200, aeroQual, New Zealand) and water phantom (Wellhofer, IBA, Germany) is irradiated the radiation so that measured the ozone generation level according to MU, dose-rate, SSD, field size, energy, delay time and put the ozone meter in the treatment room actually while treating a patient so measured the daily ozone level variation. Results: While irradiating the radiation, degree of ozone contamination wasn't affected by the energy but mostly in case of electron beam, ozone level was higher than photon beam. The higher dose-rate (0.016~0.025 ppm/hr), the farther SSD (0.018~0.030 ppm/hr), the wider field sizes (0.016~0.025 ppm/hr), the more MU (0.018~0.046 ppm/hr), it occurred high ozone level. Ozone decrement according to delay time changed the background level (0.016 ppm/hr) after elapsed time of 10 minutes from irradiating radiation. And daily ozone occurrence level in the treatment room was below ozone standard level 0.1 ppm/hr (average:0.06 ppm/8 hr) but it could confirm that ozone generation level was included the level (max:0.038 ppm/hr) above 0.02 ppm/hr which patient could perceive. Conclusion: Through ozone level according to variation of certain conditions, actually in the treatment room ozone generation level didn't damaged to patients or workers. Commonly peoples think that ozone was harmful gas but it thought that small amount of ozone generation level while treating a patient was beneficial in the treatment room through air purge action of pathogenic germ or virus sterilization.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.125-131
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• 2005

Purpose : For stereotactic radiosurgery (SRS) of a tumor in the region whose movement due to respiration is significant, like Lung lower lobe, the gated therapy, which delivers radiation dose to the selected respiratory phases when tumor motion is small, was performed using the Respiratory gating system and its clinical effectiveness was evaluated. Materials and Methods : For two SRS patients with a tumor in Lung lower lobe, a marker block (infrared reflector) was attached on the abdomen. While patient' respiratory cycle was monitored with Real-time Position Management (RPM, Varian, USA), 4D CT was performed (10 phases per a cycle). Phases in which tumor motion did not change rapidly were decided as treatment phases. The treatment volume was contoured on the CT images for selected treatment phases using maximum intensity projection (MIP) method. In order to verify setup reproducibility and positional variation, 4D CT was repeated. Results : Gross tumor volume (GTV) showed maximum movement in superior-inferior direction. For patient #1, motion of GTV was reduced to 2.6 mm in treatment phases ($30{\sim}60%$), while that was 9.4 mm in full phases ($0{\sim}90%$) and for patient #2, it was reduced to 2.3 mm in treatment phases ($30{\sim}70%$), while it was 11.7 mm in full phases ($0{\sim}90%$). When comparing two sets of CT images, setup errors in all the directions were within 3 mm. Conclusion : Since tumor motion was reduced less than 5 mm, the Respiratory gating system for SRS of Lung lower lobe is useful.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.133-140
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• 2005

Purpose : This test is designed to identify the validity of treatment plan by implementing real-time dosimetry by means of dose that is absorbed into PTV and OAR when preparing doses of 3D and POP plans. Materials and Methods : In treatment. error can be calculated be comparing Exp. Dose with the actual dose, which has been converted from 'the reading value obtained by placing diode detector on the area to be measured'. Same test can be repeated using Alderson-Rando phantom. Results : Errors were found: A patient(POP plan): 197.6/199=-1.2%, B patient(3D-plan): 199.9/198.7=+0.6%, C patient: 196/200=-1.5%. In addition, considering the resulted value of measuring OAR besides target-dose for C patient showed 96/200, representing does of 47%, the purpose of protection was judged to be duly accomplished. Also it was acknowledged the resulted value of -3.7% met the targeted dose within the range of ${\pm}5%$. Conclusion : Aimed for identifying the usefulness of pre-treatment dose measurement using diode detector, this test was useful to evaluate the validity of curing because it resulted in the identification of category to be protected as well as t dose. Moreover, it is thought to have great advantage in ascertaining the dose of target, dose of which is not calculated yet. Similar to L-gram before treatment, this test is thought to be very effective so that it can bring great advantages in the aspects such as validity of curing method and post-treatment plan as well.

• Radiation Oncology Journal
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• v.17 no.4
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• pp.307-313
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• 1999

Purpose : To investigate the Presence of adaptive response by low dose radiation in murine tumors in relation to radiation induced apoptosis as well as related mechanism. Materials and Methods : Syngeneic murine tumors, OCa-I and HCa-l, were given 0.05 Gy pretreatment followed by therapeutic dose of 25 Gy radiation. Induction of apoptosis was analyzed for each treatment group. Regulating molecules of apoptosis, p53, Bcl-2, Bax, Bcl-X, were also analyzed by Western blotting. Results : In 0.05 Gy pretreatment group of OCa-I, 25 Gy-induced apoptosis per 1000 cells was 229, which was estimated at $30\%$ lower level than the expected (p<0.05). In contrast, this reduction in radiation induced apoptosis was not seen in HCa-l. In the expression of apoptosis regulating molecules, p53 increased in both tumors in response to radiation. Bcl-2 and Bax did not show significant change in both tumors however, the expression of Bcl-2 surpassed that of Bax in 0.05 Gy pretreatment group of OCa-l. Bcl-X was not expressed in OCa-l. In HCa-l, Bcl-X showed increased expression even with 0.05 Gy. Conclusion : Adaptive response by low dose radiation Is shown in one murine tumor, OCa-l, in relation to radiation induced apoptosis. Apoptosis regulating molecules including Bcl-2/Bax and Bcl-X, appear to related. This study shows an evidence that adaptive response is present, but not a generalized phenomenon in vivo.

• Journal of the Korea Concrete Institute
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• v.21 no.1
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• pp.85-92
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• 2009

A concrete is considered unfriendly-environmental material because it uses cement which emits much $CO_2$ during producing process. However, a concrete absorbs $CO_2$ through carbonation process during service life. In this paper how much concrete absorbs $CO_2$ through carbonation was calculated using 1) concentration of carbonatable substances in concrete, 2) carbonated volume of concrete, 3) molecular weight of $CO_2$ based on references and the method was proposed. $CO_2$ emission from producing $1m^3$ concrete was calculated based on $CO_2$ emission datum of materials used in concrete. From using these methods that calculate $CO_2$ emission and absorption of concrete, assessment of $CO_2$ emission-absorption against a real apartment was conducted by subtracting absorption $CO_2$ according to service life from $CO_2$ emission in the process of making concrete. As a result, a ratio of absorption over emission of $CO_2$ through concrete carbonation according to service life 40, 60, 80 years was assessed about 3.65, 4.47, 5.18%. An objective of this study is to propose how to calculate emission - absorption of $CO_2$ from producing and using concrete. Although the result value, emission - absorption of $CO_2$, is 5.18% very low when the service life of an apartment is 80years, the value can be improved by reducing emission from using blended cement such as blast furnace slag or increasing replacement ratio of cement and increasing carbonated volume of concrete from expanding service life of a building. This study may be useful when $CO_2$ emission - absorption of concrete is evaluated in the further study.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.153-160
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• 2008

Purpose : To evaluate if at the time of diagnosis of Legg-Calve-Perthes disease, MR imaging is superior to radiographs for identifying patients with a favorable long term prognosis as determined by maintenance of a spherical configuration of the femoral head epiphysis on follow-up radiographs. Materials and Methods : We retrospectively analyzed plain radiographs and MR images of 48 femoral heads in 41 patients with Legg-Calve-Perthes disease at time of diagnosis. Femoral head involvement was estimated on initial plain radiographs and MR images using the Catterall classification. Prognosis as determined by maximum femoral head deformity was determined on follow-up radiographs evaluated according to Stulberg classification. Results: Catterall classification of greater than 1 at MR imaging had 100% sensitivity (14/14) for detecting patients with a poor prognosis as indicated by deformity of the femoral head on follow-up radiographs (Stulberg class > 2). Initial radiographs had a lower sensitivity of 57% (8/14) for detecting patients with poor prognosis. Specificity for MR imaging was 21% (7/34) which was not significantly different from 32% (11/34) specificity for initial radiographs. Conclusion: Catterall group 1 at initial MR imaging indicates favorable prognosis for Legg-Calve-Perthes disease. Patients with more extensive involvement of the femoral head can have a good outcome, however they are at risk for loss of spherical configuration of the femoral head and subsequent osteoarthritis in adulthood. MR imaging may be superior to radiographs for identifying a subgroup of patients with favorable prognosis.

• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.211-216
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• 2008

Purpose: The frequency of foreign body in the knee joint is not as high, but it sometimes required wide or multiple arthrotomy in order to remove, which can baffle the surgeon in some ways. Our study is to evaluate for effectiveness of arthroscopic retrieval for intra-articular foreign body in the knee joint. Materials and Methods: The 22 patients(16 males, 6 females) had received arthroscopic foreign body retrieval in the knee joint from March 1983 to September 2006. The causes of foreign bodies of the knee joint were 7 of trauma (31.9%) related cases, 13 of surgery related cases (59.0%), 2 found during follow up after operation (8.1%) in pathologies of foreign body. Results: There were 15 of metal showed the most percentage (68.1%), 7 of non-metal (31.9%) in types of foreign bodies, and others included bullet, suture material, pencil lead, broken wire etc. All cases were used by arthroscopic techniques. All foreign bodies were removed easily and were showed no complication such as postoperative joint stiffness. Conclusion: Arthroscopic foreign body retrieval in the knee joint is effective surgery in terms of easy access to foreign body and less postoperative complication.

• Journal of the Korean Arthroscopy Society
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• v.15 no.2
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• pp.99-107
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• 2011

Purpose: The purpose of this study was to investigate the clinical results after a anatomical double bundle ACL reconstruction using a longitudinally split tibialis anterior allograft. Materials and Methods: We evaluated 24 patients with a minimum follow-up of 12 months who had undergone anatomical double bundle ACL reconstructions. The grafts utilized in all cases were tibialis anterior allografts which were longitudinally split into two strands. A standard rehabilitation protocol was applied in all patients. The pre- and post-operative data including Lysholm scores, International Knee Documentation Committee (IKDC) scores, Lachman test, pivot shift test and the side-to-side differences of anterior laxity measured by KT-2000 arthrometer were analyzed by use of a statistical method Results: The mean side-to-side instrumented laxity measured by the KT-2000 arthrometer significantly improved to a mean of $1.04{\pm}0.80\;mm$ (P < 0.001). The Lysholm knee scores also improved from $58.34{\pm}15.32$ to $86.25{\pm}6.48$ after surgery (P < 0.001). The patients exhibited improved IKDC scores (A: 15 cases, B; 9 cases) at the final follow-up, compared to preoperative scores (B: 5, C: 10, D: 9). Conclusion: Our data demonstrated that clinical results of anatomical double bundle ACL reconstruction with a split tibialis anterior allograft are encouraging with excellent side-to side laxity, significantly improved Lysholm knee score, IKDC score, Lachman and pivot shift data.

• Korean Journal of Environmental Agriculture
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• v.33 no.2
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• pp.103-110
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• 2014

BACKGROUND: Azadirachta indica has been widely used as environment-friendly organic materials because of its insecticidal properties. This study was carried out to investigate the acute toxicity and the subacute toxicity of Azadirachta indica extract(AIE) in rats. METHODS AND RESULTS: For the oral acute toxicity test, Sprague-Dawley rats were gavaged with 2.0 g/Kg bw of AIE. The $LD_{50}$ value was greater than 2.0 g/Kg bw for both male and female rats. For the subacute toxicity study, rats were treated with AIE at doses of 0.5, 1.0, 2.0 mg/Kg bw once a day for 4 weeks(n=10 animals per each group). There were no significant changes in body weight, food intake and water consumption observed during the experimental duration. In addition, no difference of relative kidney weight was observed among all treated groups. Serum creatinine level in the AIE 2.0 g/Kg group increased significantly compared with that of control group in male rats, but serum blood urea nitrogen was significantly decreased in a dose-dependent manner (p<0.05). Significant increase of serum cholesterol levels were observed in all AIE groups, compared with the control group, in the female rats (p<0.05). However, histopathological examination of the kidney did not reveal any significant lesions in all groups. CONCLUSION: On the basis of results, it could be concluded that oral administration AIE didn't cause any toxic response in kidney, except the increased serum cholesterol.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.24-27
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• 2010

Purpose: Early diagnosis of breast is of the utmost importance to improve prognosis. We have a limitation for mammography and sonography detecting small cancer. Clinical importance of Breast Specific Gamma Imaging (BSGI) has improved for that reason. So We studied performance evaluation test of count rate and resolution with high sensitivity to the low dose of BSGI. Materials and Methods: BSGI of Dilon 6800, point source of $^{99m}Tc$ from 1.85~148 MBq (0.05~4 mCi) at the intervals of 1.85~37 MBq (0.05~1 mCi) was used for the test. Performance evaluation method was performed for measuring deadtime for choosing at the 5 different point in the useful field of view (UFOV), acquired image for 60 seconds. Compared with reference of clinical uptake distribution of breast, activity increased according to the distance change 10, 20, 30, 40, 50 mm in the useful field of view. Results: Counting curve increased according to the activity from 1.85 MBq (0.05 mCi) to the 74 MBq (2 mCi), and it change flat shape over 74 MBq (2 mCi). The variation of the full width of half maximum (FWHM) to the distance is 4.05, 4.73, 5.77, 6.90, 8.00, 9.32 mm in 1.85 MBq (0.05 mCi), 4.30, 4.80, 5.90, 7.00, 8.10, 9.07 mm in 3.7 MBq (0.1 mCi), 4.90, 5.60, 6.20, 7.20, 8.20, 9.10 mm in 5.55 MBq (0.15 mCi), 5.30, 6.10, 6.60, 7.00, 7.90, 8.70 mm in 7.40 MBq (0.2 mCi). Conclusion: Distortions of image would be acquired because of the deadtime in BSGI. We found out the fact that specification of $^{99m}Tc$ reaction under 74 MBq (2 mCi) for BSGI. Second, FWHM distribution change from varied distance from the detector, clearly distinguished the location of the lesion.