• Journal of Radiation Protection and Research
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• v.27 no.1
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• pp.37-49
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• 2002

The accuracy of radiation dose delivery to target volume is one of the most important factors for good local control and less treatment complication. In vivo dosimetry is an essential QA procedure to confirm the radiation dose delivered to the patients. Transmission dose measurement is a useful method of in vivo dosimetry and it's advantages are non-invasiveness, simplicity and no additional efforts needed for dosimetry. In our department, in vivo dosimetry system using measurement of transmission dose was manufactured and algorithms for estimation of transmission dose were developed and tested with phantom in various conditions successfully. This system was applied in clinic to test stability, reproducibility and applicability to daily treatment and the accuracy of the algorithm. Transmission dose measurement was performed over three weeks. To test the reproducibility of this system, X-tay output was measured before daily treatment and then every hour during treatment time in reference condition(field size; $10 cm{\times} 10 cm$, 100 MU). Data of 11 patients whose pelvis were treated more than three times were analyzed. The reproducibility of the dosimetry system was acceptable with variations of measurement during each day and over 3 week period within ${\pm}2.0%$. On anterior- posterior and posterior fields, mean errors were between -5.20% and +2.20% without bone correction and between -0.62% and +3.32% with bone correction. On right and left lateral fields, mean errors were between -10.80% and +3.46% without bone correction and between -0.55% and +3.50% with bone correction. As the results, we could confirm the reproducibility and stability of our dosimetry system and its applicability in daily radiation treatment. We could also find that inhomogeneity correction for bone is essential and the estimated transmission doses are relatively accurate.

• Journal of Chest Surgery
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• v.41 no.4
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• pp.447-456
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• 2008

Background: Caspase-3 is a cysteine protease that plays a major role in the process of apoptotic cell death. The dysregulated expression of c-myc contributes to the tumorigenesis in a variety of human cancers. The aim of this study was to investigate the expressions of caspase-3 and c-myc and their significances as prognosis markers in patients with completely resected non-small cell lung cancer (NSCLC). Material and Method: A total 130 consecutive patients who had undergone complete resection without pre-operative radio-therapy or chemotherapy between May 1996 and December 2003 for NSCLC were retrospectively reviewed. The median follow-up period of the patients was 50 months (range: $3{\sim}128$ months). The expressions of caspase-3 and c-myc were immuno-histochemically examined, and these were correlated with the clinico-pathologic data. Result: The prevalence of caspase-3 and c-myc expressions in the patients was 68% (88/130) and 59% (77/130), respectively. Significant association was found between the frequency of the expressions of caspase-3 and c-myc (p=0.025). The caspase-3 and c-myc expressions were not significantly associated with the prognosis in all the patients. However, according to stages, a positive caspase-3 expression was significantly correlated with a favorable prognosis for patients with stage IIIa disease (median survival period: 35 months vs. 10 months, p=0.021). Multivariate analysis showed the pathologic stage to be significantly correlated with a good prognosis in all the patients (p=0.024), and with a positive caspase-3 expression, well differentiated tumor and negative neuronal invasion in the patients with stage llla disease (p=0.005, p=0.003, p=0.004, respectively). Conclusion: Caspase-3 and c-myc were frequently expressed in NSCLC, suggesting its possible involvement in tumor development. The caspase-3 expression, as determined with performing immunohistochemical staining, may be a favorable prognostic indicator in patients with completely resected NSCLC an advanced stage (IIIa).

• Journal of Gastric Cancer
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• v.7 no.2
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• pp.82-87
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• 2007

Purpose: In gastric cancer patients with gastric outlet obstruction, there are several complications such as malnutrition and vomiting. Palliative enteral stenting is a less invasive procedure as compared with a gastrojejunostomy. The aim of this study was to determine whether there was a significant difference between patients that undergone palliative enteral slanting and patients that had received a bypass gastrojejunostomy. Materials and Methods: One hundred patients underwent palliative entering stenting and 3f patients were subjected to a surgical bypass gastrojejunostomy. We reviewed the medical records of the patients with gastric outlet obstruction secondary to far advanced gastric cancer that were diagnosed using a gastrofibroscope, UGI and abdominal CT, and were admitted to our institution between January 2000 and August 2006. The outcome of stent placement for gastric outlet obstruction was compared with palliative gastrojejunostomy during the same period. We excluded patients with recurrent gastric cancer and double cancer from this study. Results: There were significant differences between the group of patients that underwent slanting and the group of patients that received a gastrojejunostomy regarding the age of patients ($67{\pm}12$ vs. $57{\pm}9$, P<0.001) but not between the sex of the patients (M : F, 2 : 1 vs. 2 :1, P=0.637). The most common complication of stenting was tumor ingrowth (16/100, 16%) and the second most common complication was stent migration (14/100). Failure of the procedure occurred in only three patients. Twenty-three patients underwent re-slanting and one patient required open conversion with a gastrojejunostomy. The median time to the first meal was $4{\pm}2$ days in the stent group of patients and $6{\pm}2$ days in the gastrojejunostomy group of patients (P=0.001). The median postoperative hospital stays were 9 days in the stent group of patients and 15 days in the gastrojejunostomy group of patients (P=0.003). The mean survival periods were 11 months in the stent group of patients and 10 months in the gastrojejunostomy group of patients (P=0.937). Conclusion: There were no significant differences In the mean survival rates. An earlier first meal and a shorter hospitalization stay were found in the slanting group of patients compared to the bypass gastrojejunostomy group of patients. However, re-slanting was a concern due to tumor ingrowth and stent migration.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.267-275
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• 1993

Eighty five patients of oral cavity cancer, treated with radiation at the Department of Therapeutic Radiology, Korea Cancer Center Hospital, during the period from March 1985 to September 1990 were analyzed retrospectively. Among 85 patients, 37 patients were treated with radiation only and 48 patients were treated with radiation following surgery. And 70 patients received external irradiation only by $^{60}Co$ with or without electron, the others were 7 patients for external irradiation plus interstitial implantation and 8 patients for external irradiation plus oral cone electron therapy. Primary sites were mobile tongue for 40 patients, mouth floor for 17 patients, palate for 12 patients, gingiva including retromolar trigone for 10 patients, buccal mucosa for 5 patients, and lip for 1 patient. According to pathologic classification, squamous cell carcinoma was the most common (77 patients). According to AJC TNM stage, stage I + II were 28 patients and stage III+IV were 57 patients. Acturial overall survival rate at 3 years was $43.9\%,$ 3 year survival rates were $60.9\%$ for stage I + II, and $23.1\%$ for stage III+IV, respectively. As a prognostic factor, primary T stage was a significant factor (p<0.01). The others, age, location, lymph node metastasis, surgery, radiation dose, and cell differentiation were not statistically significant. Among those factors, radiation plus surgery was more effective than radiation only in T3+T4 or in any N stage although it was not statistically sufficient (p<0.1). From those results, it was conclusive that definitive radiotherapy was more effective than surgery especially In the view of pertainig of anatomical integrity and function in early stage, and radiation plus surgery was considered to be better therapeutic tool in advanced stage.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• Radiation Oncology Journal
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• v.14 no.1
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• pp.1-8
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• 1996

Purpose: We tried to evaluate the role of conventional radiotherapy alone or with neoadjuvant chemotherapy in oropharyngeal cancer in terms of survival rates and to identify prognostic factors affecting survival by retrospective analysis. Materials and Methods: Forty seven patients of oropharyngeal cancer were treated by conventional radiotherapy in our hospital from Nov. 1985 to APr. 1993. Of these, twenty six patients were treated by conventional radio-therapy alone, and 21 patients with neoadjuvant chemotherapy of mostly two or more cycles of cisplatin and pepleomycin. The Patient characteristics of radiotherapy alone group and neoadjuvant chemotherapy group were not different generally. Radiotherapy was performed by 6MV-LINAC and the total radiation doses of Primary tumors were 54.0-79.2 Gy and cervical lymph nodes were 55.8-90.0 Gy with a fraction size of 1.8 or 2.0 Gy per day. The range of follow-up periods was 3-102 months and median was 20 months. The range of a9e was 33-79 years old and median was 58 years old. Results : Overall 3-year actuarial survival rate (3YSR) of all patients was $39\%$. The 3YSRS of stage I (n=5), II (n=11), III (n=12) and IV (n=19) were 60, 55, 33 and $32\%$, respectively The 3YSRS of Tl+2, T3+4 and No, N+ were 55, $18\%$ (p=0.005) and 43, $36\%$ (p>0.1), respectively. There was no difference in 3YSRS between radiotherapy alone group and neoadjuvant chemotherapy group (38 vs $43\%$, p>0.1). According to the original site of primary tumor, the 3YSRS of tonsil (n=32), base of tongue (n=8), soft palate or uvula (n=6) and pharyngeal wall (n=1) were 36 38, 67 and $0\%$, respectively The Patients of soft palate or uvular cancer had longer survival than other primaries but the difference was not significant statistically (p>0.1). Of 32 patients of tonsillar cancer, 22 Patients who had primary extension to adjacent tissue showed inferior survival rate to the ones who had not Primary extension, but the difference was marginally significant statistically (24 vs $60\%$, p=0.08). On Cox multivariate analysis in entire patients with variables of age, T stage, N stage, total duration of radiotherapy, the site of primary tumor and the use of neoadjuvant chemotherapy, only T stage was a significant Prognostic factor affecting 3YSR. Conclusion : The difference of 3YASRS of conventional radiotherapy alone group and neoadjuvant chemotherapy group was not significant statistically. These treatments could be effective in oropharyngeal cancer of early stage, especially such as soft palate, uvular or tonsillar cancer which did not extend to adjacent tissue. But in order to improve the survival of patients of most advanced oropharyngeal cancer, other altered fractionated radiotherapy such as hyperfractionation rather than conventional fractionation or multi-modal approach combining radiotherapy and accessible surgery or concurrent chemotherapy might be beneficial.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.4
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• pp.218-227
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• 2006

Purpose: The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. Materials and Methods: Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with $K[^{18}F]/K2.2.2.$ in acetonitrile using N2-monomethoxytrityl-9-14-(tosyl)-3-monomethoxytritylmethylbutyl]guanine as a precursor, followed by deprotection with 1 N HCl. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of $[^{18}F]FHBG$ were performed, and was analyzed correlation between $[^{18}F]FHBG$ uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor bearing Balb/c-nude mouse model. Results: $[^{18}F]FHBG$ was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiothemical yield was about 20-25%) (corrected for decay), radiochemical purity was >95% and specific activity was around >55.5 $GBq/{\mu}\;mol$. Specific accumulation of $[^{18}F]FHBG$ was observed in HSV1-tk gene transduced MCA-tk cells but not in MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked $[^{18}F]FHBG$ was retained inside of cells. The uptake of $[^{18}F]FHBG$ was showed a highly significant linear correlation ($R^2=0.995$) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. Conclusion: $[^{18}F]FHBG$ appears to be a useful as non-invasive PET imaging substrate in HSV1-tk expressing hepatoma model.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.899-906
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• 1997

Background : The percutaneous pleural needle biopsy have been regarded as cornerstone in the diagnosis of lymphocyte dominant pleural effusions of which acid fast bacilli smear and cytologic exam was negative. However, the complications of percutaneous pleural needle biopsy is not rare and its diagnostic efficacy is not always satisfactory. Recently, pleural fluid adenosine deaminase (ADA) and carcinoembryonic antigen (CEA) are widely accepted as markers of tuberculous pleurisy and malignant pleural effusion respectively. We designed this study to re-evaluate the role of percutaneous pleural needle biopsy in the diagnosis of lymphocyte dominant exudative pleural effusions whose AFB smear, cytologic exam was negative. Method : Retrospective analysis of 73 cases of percutaneous pleural needle biopsy in case of lymphocyte dominant exudative pleural effusions whose AFB smear and cytoloic exam was negative from Jan 1994 to Feb 1996 was done. Result : In 35 cases, specific diagnosis was obtained(all cases were tuberculous pleurisy), and in 30 cases specific diagnosis was not obtained in spite of getting adequate pleural tissues, and in the other 8 cases, percutaneous pleural biopsy failed to get pleural tissues. In 9 cases, complications were combined including pneuomothorax and hemothorax. All 49 cases of pleural effusions whose ADA value was higher than 40IU/L and satisfying other categories were finally diagnosed as tuberculous pleurisy, however, the pleural biopsy confirmed only 28 cases as tuberculous pleurisy. In 6 cases of pleural effusions of which CEA value is higher than 10ng/ml, the pleural biopsy made specific diagnosis in no case. Final diagnosis of above 6 cases consisted of 4 malignant effusions, 1 malignancy associated effusion and 1 tuberculous pleurisy. Conclusion : In the diagnosis of 73 cases of lymphocyte dominant pleural effusions of which acid fast bacilli smear and cytologic exam was negative, percutaneous pleural biopsy diagnosed only in 35 cases. In the diagnosis of tuberculous pleurisy, the positive predictive value of higher ADA than 40 IU/L in lymphocyte dominant pleural effusion with negative AFB smear and negative cytologic exam was 100%. And the diagnostic efficacy of pleural biopsy was 57%. In cases of effusions with high CEA than 10ng/ml 83% and 0% respectively. Finally, we concluded that percutaneous pleural needle biopsy in the diagnosis of AFB smear negative and cytologic exam negative lymphocyte dominant exudative pleural effusion was not obligatory. especially in effusions with high ADA and low CEA value.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.201-205
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• 2009

Background: Cryosurgery has been used to treat primary malignant pulmonary tumors at our institute since November 2004. In this study we analyzed our treatment results and complication rates. Material and Method: A retrospective study using medical charts and imaging data was conducted involving 17 patients with a total of 17 malignant pulmonary tumors who were treated between November 2004 and March 2007. Fourteen patients were males and 3 were females. The median age of the patients was 64 years (range, $54{\sim}77$ years). The average size of the tumors was 48.8mm (range, $36{\sim}111mm$) in diameter. The patients were followed with chest CT scans 7 days, 1 month, 3 months, and 6 months postoperatively. PET scans were obtained between 6 and 9 months postoperatively. The treatment response was analyzed according to the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Result: Six months after treatment, 6 tumors (35.3%) showed a complete response, 4 (23.5%) had a partial response, 3 (17.6%) had stable disease, and 4 (23.5%) showed disease progression. In tumors <4 cm in diameter, a complete response was reported in 50% of the tumors. A $x^2$-test showed that in tumors <4 cm in diameter, the p-value for results better than a partial response was 0.034. With respect to procedural complications, there was 1 case of blood-tinged sputum which resolved spontaneously within 1 or 2 days, a spontaneously relieved case of subcutaneous emphysema, and 1 patient with a fever. There were no mortalities and the average hospital stay was 6.3 days. Conclusion: The effects of cryosurgery on primary lung cancer is greatest in patients with small tumors. Considering the facts that cryosurgery is minimally invasive, has a low complication rate, and can be performed repetitively, we believe that it may play an important role in the treatment of high risk lung cancer patients.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.585-590
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• 2004

Bronchogenic cyst is a rare and benign disease. Because of its complication or associated disease, Bronchogenic cyst requires surgical treatment. Recently, with the development of diagnostic methods, its incidence has increased. So we reviewed our results from the past 30 years. Material and Method: We reviewed 27 cases surgically treated from March 1971 to March 2003. This investigation is designed to illustrate the peak age incidence, sex ratio, symptoms, anatomic location, radiologic imagings, associated diseases, operative methods, postoperative pathologic findings and postoperative complications. Result: The peak age incidence laid in the 1st to 3rd decade and the ratio of male and female was 1 : 1.5. The most common complaints were cough and dyspnea, but some had hemoptysis. There were 22 cases (81%) of Intrapulmonary bronchogenic cysts and 5 cases(19%) of mediastinal bronchogenic cysts. Thirteen cases (48.1%) showed cystic lesion in simple chest X-ray. Ten cases showed cystic lesion among 13 cases that had taken computed tomography. We found associated disease in 15cases (56%). The inflammatory diseases from infection were many in intrapulmonary bronchogenic cysts and especially, one case showed carcinosarcoma. Mitral regurgitation and Bronchial obstruction could be seen in mediastinal bronchogenic cysts. The 13 cases (48%) were managed by lobectomy, and cystectomy, pneumonectomy, and segemental resection were done in 7 cases (26%), 4 cases (15%), 3 cases (11%) respectively. Cystic contents were mucus in 9 cases, pus in 9 cases, blood in 2 cases, and carcinosarcoma in 1 case. Bronchotracheal communications were in 13 cases (48%). Five cases showed Postoperative complications, which were pneumothorax, empyema, bleeding. Postoperative death could not be found. Conclusion: Almost all patients had clinical symptoms. Severe complications could be associated with bronchogenic cysts. Recently, With the development of diagnostic methods, preoperatively accurate diagnosis is possible; therefore, invasive study has decreased. Bronchogenic cyst is a benign disease. However, because of its clinical symptoms, complications, and possibility of malignant change, immediate surgical treatment is needed.