• Radiation Oncology Journal
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• v.21 no.3
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• pp.207-215
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• 2003

Purpose: Extracellular signal-regulated kinase (ERK), which is part of the mitogen-activated protin kinase cascade, opposes initiation of the apoptotic cell death which is programmed by diverse cytotoxic stimuli. In this regard, the inhibition of ERK may be useful in improving the therapeutic efficacy of established anticancer agents. Materials and Methods: Murine hepatocarcinoma, HCa-I is known to be highly radioresistant with a TCD50 (radiation dose yield in $50\%$ cure) of more than 80 Gy. Various anticancer drugs have been found to enhance the radioresponse of this particular tumor but none were successful. The objective of this study was to explore whether the selective inhibition of MEK could potentiate the antitumor efficacy of radiation in vivo, particularly in the case on radioresistant tumor. C3H/HeJ mice hearing $7.5\~8\;mm$ HCa-I, were treated with PD98059(intratumoral injection of $0.16\;\mug/50\;\mul$). Results: Downregulation on ERK by PD98059 was most prominent 1h after the treatment. In the tumor growth delay assay, the drug was found to Increase the effect of the tumor radioresponse with an enhancement factor (EF) of 1.6 and 1.87. Combined treatment of 25 Gy radiation with PD98059 significantly increased radiation induced apoptosis. The peak apoptotic index (number on apoptotic nuclei in 1000 nuclei X100) was $1.2\%$ in the case of radiation treatment alone, $0.9\%$ in the case of drug treatment alone and $4.9\%,\;5.3\%$ in the combination treatment group. An analysis of apoptosis regulating molecules with Western blotting showed upregulation of p53, p$p21^{WAF1/CIP1}\;and\;Bcl-X_s$ in the combination treatment group as compared to their levels in either the radiation alone or drug alone treatment groups. The level of other molecules such as $Bcl-X_L4, Bax and Bcl-2 were changed to a lesser extent. Conclusion: The selective inhibition of MEK in combination with radiation therapy may have potential benefit in cancer treatment.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.1
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• pp.41-44
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• 2006

Purpose: To evaluate the short-term results of arthroscopic ACL reconstruction using fresh frozen Achilles allograft Materials & Methods: From March 2002 to March 2004, arthroscopic ACL reconstructions using fresh frozen Achilles allograft were performed in 25 knees of 25 patients. The average age at operation was 30.1 years (range, 18-50 years) and the average follow-up was 17 months (range, 12 to 27months). Preoperative and follow-up clinical results were evaluated using the Lysholm knee score, IKDC knee rating system, physical examination and KT-2000 arthrometer. Results: The Lachman test was positive in 25 patients preoperatively and 18 patients(72%) had negative results at latest follow-up. The average side-to-side differences of anterior tibial translation using KT-2000 arthrometer under loading of 301b were improved from $7.9{\pm}2.4mm\;to\;2.6{\pm}1.6mm$. The average Lysholm score was improved from $61.1{\pm}13.9\;to\;93.5{\pm}5.3$ points. The IKDC grade was abnormal(C) or severely abnormal(D) in 25 cases preoperatively They improved 22(88%) of normal(A) or nearly normal(B) and 3(12%) of abnormal. Conclusion: Short term results of ACL reconstruction using Achilles allograft was acceptable. Achilles allograft can be a reasonable graft alternative to autograft for ACL reconstruction.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.145-149
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• 2010

Purpose: Recently, $^{18}F$-FDG Fusion PET which has a high sensitivity for diagnosing cancer is being used for purpose of health examination. This study is to demonstrate that $^{18}F$-FDG fusion PET study is useful for diagnosing an early stage cancer. Materials and Methods: This research has been conducted with 2790 patients visited Seoul National University Hospital Healthcare System (SNUHHS) for $^{18}F$-FDG fusion PET study for a health examination from February, 2004 to December 2008. PET/CT images were acquired from skull base to femur after 1 hour from injecting $^{18}F$-FDG 0.14 mCi/kg to the patients. GEMINI GS (Philips, Netherlands) was used for scanning. Results: From February 2004 to December 2008, $^{18}F$-FDG Fusion PET study was performed for 99,009 patients among all patients who visited SNUHHS and 2,790 patients was performed. Diagnostic rate for malignant cancer was 0.95% for the patients who were not examined by $^{18}F$-FDG Fusion PET study. 1.94% was for the patients who were. The rate of malignant tumor was showed 10% and benign tumor was 90% among 542 patients who showed abnormality in the PET/CT images. Types and rates of malignant tumor showed thyroid cancer: 31.5%, lung cancer: 14.8%, stomach cancer: 9.3%, rectum cancer: 3.7%, breast cancer: 3.7%, metastasis cancer: 16.7%. Nonspecific lymph node in the mediastinum, physiologic uptake in the colon, diffuse mild hypermetabolism in bilateral thyroid gland were shown as a benign tumor. Conclusion: The diagnostic rate of malignant tumor with $^{18}F$-FDG Fusion PET for a purpose of health examination was relatively higher than general medical examination. Consequently, it is superior and useful for applying $^{18}F$-FDG Fusion PET study for health examination.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.132-136
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• 2005

Purpose: The purpose of this study was to compare the clinical results of the arthroscopic anterior cruciate ligament reconstruction used by Bone-Patella tendon-Bone autograft and Achilles tendon allograft. Materials and Methods: We reviewed the results of patients who had been managed with arthroscopic anterior cruciate ligament reconstruction using different graft such as Bone-Patella tendon-Bone autograft and Achilles les tendon allograft. 60patients (average age, 33.5 years)were retrospectively evaluated. The one group(average age, 33.4 years) was 32 patient who had been managed with arthroscopic anterior cruciate ligament reconstruction using Bone-Patella tendon-Bone autograft. The other group(average age, 32.1 years) was 28 patient who had been managed with arthroscopic anterior cruciate ligament reconstruction using Achilles tendon allograft. 2 groups were evaluated subjectively by Lysholm knee scoring scale and objectively by KT-2000 arthrometer. The follow-up period was more than a year(average, 18 month). An early rehabilitation protocol was instituted. Results: On Lysholm knee scoring scale, the final evaluation was nearly normal in all patients. We could not find statistical difference among the two groups by KT-2000TM arthrometer. Conclusion: The use of allografts may be an acceptable choice for ACL reconstruction.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.156-158
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• 2009

Purpose: Since radiopharmaceuticals are intended for human administration, it is imperative that we should undergo quality control very strictly. Now almost all the PET laboratories have adopted Bacterial Endotoxin Test as the stand quality control method to monitor whether pyrogen is free or not in the product vial containing crude solution. The aim of this study is to find out the reason why false positive result is observed when using commercially available test vial. Materials and Methods: For this experiment, we used commercially available single test kit (Associates of Cape Code. Inc. USA) and we made pH samples by mixing each buffer whose pH ranges are 1.0 to 12.0. Otherwise we made Ethanol samples diluted with distilled water. After making test samples, it added 0.2 mL to the test vial. Assay mixture in the test vial was incubated in a water bath (Chang Shin Co. KOR) for 60 min at $35{\pm}2^{\circ}C$. Results: After incubation period ($60{\pm}1^{\circ}C$), we inverted the test vial about $180^{\circ}$ To know what pH and how many percentage of Ethanol (Fisher Scientific Korea. Ltd) will affect the reaction. With pH buffer, false positive result was observed at pH 1.0 to 5.0 and 7.7 to 12.6 but at pH 5.2 to.7.5, the test results show negative. It's very strange that we couldn't observe negative test result with Tris buffer at pH 8.4, 8.6, 8.8, 9.0. in other case Ethanol, the test result was seen with 5 to 10% Ethanol. But to my surprise we could see very thick gel formation with 100% Ethanol. Conclusions: In this study, we could notice that pH which is too much acidic or alkalic or high concentrated Ethanol would affect Bacterial Endotoxin Test result. As you know, LAL test is sensitive and very reliable method. Therefore, we are needed to elicit the accurate test result as possible as we can.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.135-141
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• 1997

Purpose: To assess the usefulness of breath-hold fast MR imaging of liver with fat suppression (FS) by application of chemical saturation technique in the diagnosis of regional fatty changes suspected in sonography. Materials and Methods: Thirteen patients who had focal lesions with diffuse, homogeneous signal changes after FS through chemical saturation technique without additional changes of imaging parameter during MR imaging of liver were selected. T1-weighted fast low-angle shot and T2-weighted turbo spin-echo sequences were obtained with or without FS during each single breath-holding session. Subjective changes of signal intensity between the pre-FS and the FS images were compared with the sonographic findings in each lesion. Results: Seven lesions of decreased signal intensity after FS on T1 or T2-weighted images, including three lesions only at FS T1 images, were regarded as focal fat infiltration. All seven lesions had compatible sonographic findings as homogenously echogenic areas. Another six lesions of subjectively increased signal intensity including two lesions only at FS T2 images were regarded as focal fat sparing. All six lesions had sonographic findings as homogenous echo poor areas suggesting focal fat sparing. In cases regarded as fat infiltration, score changes were more prominent at FS T1 images than FS T2 images(p=0.0002). In cases regarded as fat sparing, score changes were more prominent at FS T2 images than FS T1 images(p=0.042). Conclusion: Breath-hold fast T1 and T2-weighted MR imaging with and without chemical saturation pre-pulse may be sufficient for characterization of regional fatty changes in the differential diagnosis of focal hepatic lesion found at sonography.

• Radiation Oncology Journal
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• v.12 no.2
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• pp.233-241
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• 1994

Purpose : This study was performed to verify dose distribution with the tissue compensator which is used for uniform dose distribution in total body irradiation(TBI). Materials and methods : The compensators were made of lead(0.8mm thickness) and aluminum(1mm or 5mm thickness) plates. The humanoid phantom of adult size was made of paraffin as a real treatment position for bilateral total body technique. The humanoid phantom was set at 360cm of source-axis distance(SAD) and irradiated with geographical field size(FS) $144{\times}144cm^2(40{\times}40cm^2$ at SAD 100cm) which covered the entire phantom. Irradiation was done with 10MV X-ray(CLINAC 1800, Varian Co., USA) of linear accelerator set at Department of Therapeutic Radiology, Chonnam University Hospital. The midline absorbed dose was checked at the various regions such as head, mouth, mid-neck, sternal notch, mid-mediastinum, xiphoid, umbilicus, pelvis, knee and ankle with or without compensator, respectively. We used exposure/exposure rate meter(model 192, Capintec Inc., USA) with ionization chamber(PR 05) for dosimetry, For the dosimetry of thorax region TLD rods of $1x1x6mm^3$ in volume(LiF, Harshaw Co., Netherland) was used at the commercially available humanoid phantom. Results : The absorbed dose of each point without tissue compensator revealed significant difference(from $-11.8\%\;to\;21.1\%$) compared with the umbilicus dose which is a dose prescription point in TBI. The absorbed dose without compensator at sternal notch including shoulder was $11.8\%$ less than the dose of umbilicus. With lead compensator the absorbed doses ranged from $+1.3\%\;to\;-5.3\%$ except mid-neck which revealed over-compensation($-7.9\%$). In case of aluminum compensator the absorbed doses were measured with less difference(from $-2.6{\%}\;to\;5.3\%$) compared with umbilicus dose. Conclusion : Both of lead and aluminum compensators applied to the skull or lower leg revealed a good compensation effect. It was recognized that boost irradiation or choosing reference point of dose prescription at sternal notch according to the lateral thickness of patient in TBI should be considered.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.49-55
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• 2013

Purpose: Respiratory Gated Radiation Therapy (RGRT) has been carried out using RPM (Real-time Position Management) Respiratory Gating System (version 1.7.5, varian, USA) in Asan Medical Center. This study was to analyze and evaluate the accuracy of Respiratory Gated Radiation Therapy (RGRT) according to variation of respiration. Materials and Methods: Making variation of respiration using Motion Phantom:QUASAR Programmable Respiratory Motion Phantom (Moudus Medical Device Inc. CANADA) able to adjust respiration pattern randomly was varying period, amplitude and baseline by analyze 50 patient's respiration of lung and liver cancer. One of the variations of respiration is baseline shift gradually downward per 0.01 cm, 0.03 cm, 0.05 cm. The other variation of respiration is baseline shift accidently downward per 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm. Experiments were performed in the same way that is used RPM Respiratory Gating System (phase gating, usually 30~70% gating) in Asan Medical Center. Results: It was all exposed radiation under one of the conditions of baseline shift gradually downward per 0.01 cm, 0.03 cm, 0.05 cm. Under the other condition of baseline shift accidently downward per 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm equally radiation was exposed. Conclusion: The variations of baseline shifts didn't accurately reflect on phase gating in RPM Respiratory Gating System. This inexactitude makes serious uncertainty in Respiratory Gated Radiation Therapy. So, Must be stabilized breathing of patient before conducting Respiratory Gated Radiation Therapy. also must be monitored breathing of patient in the middle of treatment. If you observe considerable changes of breathing when conducting Respiratory Gated Radiation Therapy. Stopping treatment immediately and then must be need to recheck treatment site using fluoroscopy. If patient's respiration rechecked using fluoroscopy restabilize, it is possible to restart Respiratory Gated Radiation Therapy.

• Journal of Gastric Cancer
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• v.8 no.3
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• pp.154-159
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• 2008

Purpose: Although most surgeons generally administer prophylactic antibiotics for more than three days, the optimal duration of antimicrobial prophylaxis in elective gastric surgery is still open to debate. The aim of this study was to determine if the duration of prophylactic antibiotic use can affect the recovery of patients after elective gastric surgery. Materials and Methods: A total of 93 patients with gastric cancer were enrolled in this study, between January 2007 and December 2007. Patients were excluded if they had an infection at the time of surgery or they underwent an emergency operation. The first antibiotics were commonly given from just prior to the operation. The patients were divided into three groups according to the operation periods: those who received antibiotics only on the day of operation (arm A), those who received antibiotics for up to 3 days (arm B), and those who received antibiotics for more than 5 days postoperatively (arm C). The antibiotic that was used was second generation cephalosporin. Results: The rate of surgical site infection was 12.9% (n=4) in arm A, 16.1% (n=5) in arm B and 19.4% (n=6) in arm C, respectively (P=0.788). No relationship was observed between the duration of prophylaxis and the rate of fever or the neutrophil counts during postoperative 7 days (P=0.119, P=0.855). Conclusion: The prophylactic effect of antibiotics on recovery, with the antibiotics being received only on the day of the operation, is as effective as receiving antibiotics for a longer duration after gastric cancer surgery.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.147-154
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• 2002

Purpose : Gingko biloba extract (GBE), a natural product extracted from Gingko leaves, is known to increase the radiosensitivity of tumors. This radiosensitization probably arises from the increase in the peripheral blood flow by decreasing the blood viscosity and relaxing the vasospasm. The influence of a GBE on the metabolic status in fibrosarcoma II (FSall) of a C3H mouse was investigated using $^{31}P$ magnetic resonance spectroscopy (MRS). Materials and Methods : Eighteen C3H mice with fibrosarcoma II $(from\;100\;mm^3\;to\;130\;mm^3)$ were prepared for this experiment. The mice were divided into 2 groups; one (9 mice) without a priming dose, and the other (9 mice) with a priming dose of GBE. The GBE priming dose (100 mg/kg) was administered by an intraperitoneal (i.p.) injection 24 hours prior to the measurement. First $^{31}P$ MRS spectra were measured in the mice from each group as a baseline and test dose of GBE (100 mg/kg) was then administered to each group. One hour later, the $^{31}P$ MRS spectra were measured again to evaluate the change in the energy metabolic status. Results : In the group without the priming dose, the mean pH, PCr/Pi, PME/ATP, Pi/ATP, PCr/(Pi+PME) values 1 hour after the test dose were not changed significantly compared to the values at the baseline. However, in the group with the priming dose, the mean PCr/Pi, Pi/ATP, PCr/(Pi+PME) values 1 hour after the test dose changed from the baseline values of 0.49, 0.77, 0.17 to 0.74, 0.57, 0.28 respectively. According to the paired t-test, the differences were statistically significant. Conclusion : The above findings suggest that the metabolic status is significantly improved after administering GBE if the priming dose is given 24 hours earlier. This shows that the radiosensitizing effect of GBE is based on the increase of tumor blood flow and the improvement in the metabolic status.