In this study, we evaluated accuracy and usefulness of CyberKnife Respiratory Tracking System (SynchronyTM, Accuray, USA) about a moving during stereotactic radiosurgery. For this study, we used moving phantom that can move the target. We also used Respiratory Tracking System called Synchrony of the Cyberknife in order to track the moving target. For treatment planning of the moving target, we obtained an image using 4D-CT. To measure dose distribution and point dose at the moving target, ion chamber (0.62 cc) and gafchromic EBT film were used. We compared dose distribution (80% isodose line of prescription dose) of static target to that of moving target in order to evaluate the accuracy of Respiratory Tracking System. We also measured the point dose at the target. The mean difference of synchronization for TLS (target localization system) and Synchrony were 11.5+/-3.09 mm for desynchronization and 0.14+/-0.08 mm for synchronization. The mean difference between static target plan and moving target plan using 4D CT images was 0.18+/-0.06 mm. And, the accuracy of Respiratory Tracking System was less 1 mm. Estimation of usefulness in Respiratory Tracking System was 17.39+/-0.14 mm for inactivity and 1.37+/-0.11 mm for activity. The mean difference of absolute dose was 0.68+/-0.38% in static target and 1.31+/-0.81% in moving target. As a conclusion, when we treat about the moving target, we consider that it is important to use 4D-CT and the Respiratory Tracking System. In this study, we confirmed the accuracy and usefulness of Respiratory Tracking System in the Cyberknife.
Four-Dimensional Computed Tomography ; Prescriptions ; Radiosurgery ; Track and Field

In this study, we estimated inhomogeneity correction factor in small field. And, we evaluated accuracy of treatment planning and measurement data which applied inhomogeneity correction factor or not. We developed the Inhomogeneity Correction Phantom (ICP) for insertion of inhomogeneity materials. The inhomogeneity materials were 12 types in each different electron density. This phantom is able to adapt the EBT film and 0.125 cc ion chamber for measurement of dose distribution and point dose. We evaluated comparison of planning and measurement data using ICP. When we applied to inhomogeneity correction factor or not, the average difference was 1.63% and 10.05% in each plan and film measurement data. And, the average difference of dose distribution was 10.09% in each measurement film. And the average difference of point dose was 0.43% and 2.09% in each plan and measurement data. In conclusion, if we did not apply the inhomogeneity correction factor in small field, it shows more great difference in measurement data. The planning system using this study shows good result for correction of inhomogeneity materials. In radiosurgery using small field, we should be correct the inhomogeneity correction factor, more exactly.
Electrons ; Radiosurgery

PURPOSE: We evaluated whether Cyberknife radiosurgery is an effective and safe method of therapy for medically intractable trigeminal neuralgia (TN). MATERIALS AND METHODS: We retrospectively analyzed the outcome of 26 patients, who failed to surgery or were not suitable candidates for invasive intervention and were treated by Cyberknife radiosurgery between March 2004 and May 2005. Radiosurgery doses of 60~64 Gy were delivered to the 80% isodose line prescribed to an 6 mm length of the nerve, sparing the most proximal 3 mm away from the trigeminal nerve root entry zone (median dose: 64 Gy). RESULTS: Follow-up period was 3~15 months (median follow-up period: 9 months) Preliminary results from a cohort of 26 patients undergoing Cyberknife radiosurgery for TN showed that pain relief was achieved in 50% (13/26) of patients within the first 24 hrs after treatment. At last follow-up, 96.2% (25/26) of patients reported early pain relief within 7 days. Treatment failure developed in 2 of 26. Poor response occurred in one patient and relapse was observed in the other patient. 3 patients had hypoesthesia (11.5%), which was the only complication observed with any of our patients. CONCLUSION: With these results, authors assumed that Cyberknife radiosurgery for TN could be one of safe and effective therapeutic methods.
Cohort Studies ; Follow-Up Studies ; Humans ; Hypesthesia ; Radiosurgery* ; Recurrence ; Retrospective Studies ; Treatment Failure ; Trigeminal Nerve ; Trigeminal Neuralgia*

PURPOSE: Standardization quality assurance (QA) program of CyberKnife for suitable circumstances in Korea has not been established. In this research, we investigated the development of QA program for CyberKnife and evaluation of the feasibility under applications. MATERIALS AND METHODS: Considering the feature of constitution for systems and the therapeutic methodology of CyberKnife, the list of quality control (QC) was established and divided dependent on the each period of operations. And then all these developed QC lists were categorized into three groups such as basic QC, delivery specific QC, and patient specific QC based on the each purpose of QA. In order to verify the validity of the established QA program, this QC lists was applied to two CyberKnife centers. The acceptable tolerance was based on the undertaking inspection list from the CyberKnife manufacturer and the QC results during last three years of two CyberKnife centers in Korea. The acquired measurement results were evaluated for the analysis of the current QA status and the verification of the propriety for the developed QA program. RESULTS: The current QA status of two CyberKnife centers was evaluated from the accuracy of all measurements in relation with application of the established QA program. Each measurement result was verified having a good agreement within the acceptable tolerance limit of the developed QA program. CONCLUSION: It is considered that the developed QA program in this research could be established the standardization of QC methods for CyberKnife and confirmed the accuracy and stability for the image-guided stereotactic radiotherapy.
Constitution and Bylaws ; Humans ; Korea ; Mortuary Practice ; Quality Control ; Radiotherapy

In total body irradiation (TBI) for leukemia, we have a two methode. One is a AP (anterior-posterior) method and the other is a Lateral methode. Our hospital used lateral methode. TBI must consider about body contour, because of homogeneous dose distribution. For compensation about irregular body contour, we use compensator. For TBI treatment, we must be considered, accurate manufacture of compensator and accurate calculation of dose. We developed the automatic program for TBI. This program accomplished for compensator design and dose calculation for irregular body. This program was developed for uses to use in a windows environment using the IDL language. In this program, it use energy data for each energy: TMR, output factor, inverse square law, spoiler, field size factor. This program reduces the error to happen due to the manual. As a development of program, we could decrease the time of treatment plan and care the patient accurately.
Compensation and Redress ; Humans ; Jurisprudence ; Leukemia ; Whole-Body Irradiation*

PURPOSE: The changed expressions of TGF-beta1, as a key cytokine in the fibrotic process, due to melatonin with potent antioxidative effects, were investigated in the irradiated lung using fibrosis-sensitive C57BL/6 mice. MATERIALS AND METHODS: Female C57BL/6 mice were divided into control irradiation-only, and melatonin (300 mg/kg i.p. 1 hr before irradiation) pretreatment groups. The thoraces of the mice were irradiated with a single dose of 12 Gy. The mRNA expressions of TGF-beta1 in the lung tissue 2 and 4 weeks after irradiation were quantified using semiquantitive RT-PCR, and the cellular origin and expression levels of TGF-beta1 protein were identified using immunohistochemical staining. RESULTS: The relative mRNA expression levels in the irradiation-only and melatonin pretreatment groups 2 and 4 weeks after irradiation were 1.92- and 1.80-fold (p=0.064) and 2.38- and 1.94-fold (p=0.004) increased, respectively compared to those in the control group. Increased expressions of TGF-beta1 protein were prominently detected in regions of histopathological radiation injury, with alveolar macrophages and septal epithelial cells serving as important sources of TGF-beta1 expression. At 2 and 4 weeks after irradiation, the expression levels of protein were 15.8% vs. 16.9% (p=0.565) and 36.1% vs. 25.7% (p=0.009), respectively. CONCLUSION: The mRNA and protein expressions of TGF-beta1 in the lung tissue following thoracic irradiation with 12 Gy were significantly decreased by melatonin pretreatment at 4 weeks. These results indicate that melatonin may have a possible application as an antifibrotic agent in radiation-induced lung injury.
Animals ; Epithelial Cells ; Female ; Fibrosis ; Humans ; Lung Injury ; Lung* ; Macrophages, Alveolar ; Melatonin* ; Mice ; Radiation Injuries ; RNA, Messenger ; Thorax ; Transforming Growth Factor beta1* ; Transforming Growth Factors*

PURPOSE: The changed expressions of TGF-beta1, as a key cytokine in the fibrotic process, due to melatonin with potent antioxidative effects, were investigated in the irradiated lung using fibrosis-sensitive C57BL/6 mice. MATERIALS AND METHODS: Female C57BL/6 mice were divided into control irradiation-only, and melatonin (300 mg/kg i.p. 1 hr before irradiation) pretreatment groups. The thoraces of the mice were irradiated with a single dose of 12 Gy. The mRNA expressions of TGF-beta1 in the lung tissue 2 and 4 weeks after irradiation were quantified using semiquantitive RT-PCR, and the cellular origin and expression levels of TGF-beta1 protein were identified using immunohistochemical staining. RESULTS: The relative mRNA expression levels in the irradiation-only and melatonin pretreatment groups 2 and 4 weeks after irradiation were 1.92- and 1.80-fold (p=0.064) and 2.38- and 1.94-fold (p=0.004) increased, respectively compared to those in the control group. Increased expressions of TGF-beta1 protein were prominently detected in regions of histopathological radiation injury, with alveolar macrophages and septal epithelial cells serving as important sources of TGF-beta1 expression. At 2 and 4 weeks after irradiation, the expression levels of protein were 15.8% vs. 16.9% (p=0.565) and 36.1% vs. 25.7% (p=0.009), respectively. CONCLUSION: The mRNA and protein expressions of TGF-beta1 in the lung tissue following thoracic irradiation with 12 Gy were significantly decreased by melatonin pretreatment at 4 weeks. These results indicate that melatonin may have a possible application as an antifibrotic agent in radiation-induced lung injury.
Animals ; Epithelial Cells ; Female ; Fibrosis ; Humans ; Lung Injury ; Lung* ; Macrophages, Alveolar ; Melatonin* ; Mice ; Radiation Injuries ; RNA, Messenger ; Thorax ; Transforming Growth Factor beta1* ; Transforming Growth Factors*

PURPOSE: This retrospective study was conducted to compare early preliminary results of breast conservation therapy (BCT) with mastectomy in early breast cancer. MATERIALS AND MEHTODS: We evaluated 171 women with AJCC stage I and II breast cancer who had been treated at Kangnam St. Mary's Hospital from March 1989 to August 1996. Eighty-eight patients underwent mastectomy and 85 patients did conservative surgery with breast irradiation. In the BCT group, all patients received whole breast irradiation to a total dose of 45~50 Gy/5~6 wks, followed by a boost to the original tumor site at least 60 Gy. Chemotherapy was administered to 29 (34.1%) patients in BCT and 40 (45.5%) in mastectomy, with various sequencing of surgery and/or radiation. We compared survival rate, patterns of failure in each treatment group and the prognostic factors that had a significant effect on treatment failure. The median follow-up time was 63 months (19~111 months). Log rank test was used to estimate the prognostic factors for treatment failure. RESULTS: Overall survival, disease free survival, locoregional recurrence and distant metastasis rates were not significantly different between the two treatment groups. During the follow-up period, 11 patients (12.5%) in the mastectomy group and 10 patients (11.8%) in the BCT group were failed. Six local recurrences occurred after mastectomy and 5 after BCT. Five patients failed at distant site in mastectomy and 4 in BCT. Of the local recurrence cases, five of 6 mastectomy patients and 3 of 5 BCT patients were alive with no evidence of disease after salvage surgery and/or chemoirradiation. Our results indicated that the major influence on survival was distant metastasis. Unfortunately, control of distant metastasisis was not frequently achieved. Even with salvage systemic therapy or radiotherapy, most of distant metastasis patients died or had uncontrolled disease in both treatment groups: only one of 4 BCT patients and none of mastectomy patients were alive without disease. There was no apparent difference in the incidence rate of contralateral breast cancer and non-breast 2nd primary tumor between the two treatment groups. Univariate Log-rank test identified the N stage and the involved axillary LN number as distinct prognostic factors that were highly predictive of treatment failure in both treatment groups. Additionally, marginal status in BCT and histologic nuclear grade in the mastectomy group were risk factors for treatment failure (p<0.05). CONCLUSION: Although further careful follow-up is necessary to confirm the trends evident in this series, it would appear that patterns of failure and survival rate following conservative surgery and radiotherapy in early breast cancer are similar to those following mastectomy. The great majority of patients with local recurrence had an exellent salvage rate in both treatment groups. Therefore, these preliminary short term results support BCT as an equally effective management for early breast cancer as an alternative to mastectomy.
Breast Neoplasms* ; Breast* ; Disease-Free Survival ; Drug Therapy ; Female ; Follow-Up Studies ; Humans ; Incidence ; Mastectomy* ; Neoplasm Metastasis ; Radiotherapy ; Recurrence ; Retrospective Studies ; Risk Factors ; Survival Rate* ; Treatment Failure

PURPOSE: Current results of autologous stem cell transplantation (SCT) suggest that this procedure may prolong disease free survival in patients with acute myeloid leukemia (AML). Autologous SCT is increasingly used as treatment for AML in first remission. The aim of this study was to evaluate the outcome of autologous SCT for patients with AML in first remission treated by autologous SCT using cytarabine, melphalan and total body irradiation (TBI) as the conditioning regimen. MATERIALS AND METHODS: Between January 1995 and December 1999, 29 patients with AML in first remission underwent autologous SCT. The median age of patients was 33 years (range, 16 to 47). The conditioning regimen consisted of cytarabine (3.0 gm/m2 for 3 days), melphalan (100 mg/m2 for 1 day) and TBI (total 1000 cGy in five fractions over 3 days). RESULTS: The median follow up was 40 months with a range of 3 to 58 months. The 4-year cumulative probability of disease free survival was 69.0%, and median survival was 41.5 months. The 4-year relapse rate was 27.6%. The factor influencing disease free survival and relapse rate was the French-American-British (FAB) classification (M3 group vs. other groups; p=0.048, p=0.043). One patient died from treatment-related toxicity. CONCLUSION: Although the small number of patients does not allow us to draw any firm conclusion, our results were encouraging and suggest that the association of cytarabine, melphalan and TBI as a conditioning regimen for autologous SCT for AML in first remission appears to be safe and effective.
Classification ; Cytarabine* ; Disease-Free Survival ; Follow-Up Studies ; Humans ; Leukemia, Myeloid, Acute ; Melphalan* ; Recurrence ; Stem Cell Transplantation* ; Stem Cells* ; Whole-Body Irradiation*

PURPOSE: One of the most controversial aspects of surgery for esophageal cancer is the appropriate extent of lymphadenectomy to achieve the best outcome. The purpose of this study was to clarify the effects of an extended lymphadenectomy (complete 2-field lymphadenectomy; complete 2-FL or 3-field lymphadenectomy; 3-FL) in esophageal cancer surgery. MATERIALS AND METHODS: In order to prevent a local recurrence and improve the long-term survival following surgery, an extended lymphadenectomy has systematically been performed at four hospitals of the Catholic University College of Medicine since 1995. And since that time, until the end of 2001, a total of 98 patients have undergone the procedure. Their clinical results were compared with those of 54 esophageal cancer patients who received an incomplete 2-field lymphadenectomy (incomplete 2-FL), between 1990 and 1994, at the same hospitals. RESULTS: After an extended lymphadenectomy a recurrence was noted in 41 cases (44.6%), a local recurrence occurred in 23 cases (25.0%) and a metastatic recurrence in 18 (19.6%), with the 5-year survival rate improved to 39.5%, than the 29% of the incomplete 2-FL. There was no difference in the morbidity of the fatal complications and the mortality between the two groups. CONCLUSION: The long survival rate was improved with an extended lymphadenectomy, but the morbidity and mortality rate had not increased.
Esophageal Neoplasms* ; Humans ; Lymph Node Excision ; Mortality ; Recurrence ; Survival Rate