PURPOSE: The purpose of this study was to establish optimal imaging acquisition conditions for the GE Advance(TM) PET imaging system by performing the acceptance tests designed by National Electrical Manufacturers Association (NEMA) protocol and General Electric Medical Systems (GEMS) test procedures. MATERIALS AND METHODS: Performance tests were carried out with 18FDG radioactivity source and phantoms by using a standard acquisition mode. Transaxial resolution and scatter fraction tests were performed with a line source and axial resolution with a point source, respectively. A cylindrical phantom made of polymethylmethacrylate (PMMA) was used to measure sensitivity, count rate losses and randoms, uniformity correction, and attenuation inserts were added to measure remaining tests. The test results were acquired in a diagnostic acquisition mode and analyzed mainly on high sensitivity mode. RESULTS: Transaxial resolution and axial resolution were measured as average of 4.65 mm and 3.98 mm at 0 cm, and 6.02 mm and 6.71 mm at 20 cm on high sensitivity mode, respectively. Average scatter fraction was 9.87%, and sensitivity was 225.8 kcps/micronCi/cc of trues. Activity at 50% deadtime was 4.6 Ci/cc, and the error of count rate correction at that activity was from 1.49% to 3.83%. Average nonuniformity for total slice was 8.37%. The accuracy of scatter correction was -0.95%. The accuracies of attenuation correction were 5.68% for air, 0.04% for water and -6.51% for polytetrafluoroethylene (PTFE). CONCLUSION: The results satisfied most acceptance criteria, indicating that the GE AdvanceTM PET system can be optimally used for clinical applications.
Electrons* ; Fluorodeoxyglucose F18 ; Polymethyl Methacrylate ; Polytetrafluoroethylene ; Positron-Emission Tomography* ; Radioactivity ; Water

BACKGROUND: One quarter to one third of patients with NSCLC present with primary tumors that although confined to the thorax are too extensive for surgical resection. Until resently standard treatment for these patients had been thoracic radiation, which produces tumor regression in most patients but few cures and dismal 5-year survival rate. The fact that death for most patients with stage III tumors is caused by distant metastases has promped a reevaluation of combined modality treatment approaches that include systemic chemotherapy. Therefore, we report the results observed in a study to evaluate the effect of multimodality treatment in locally advanced non-small cell lung cancer from 1/91 to 8/93 in CNUH. METHOD: We grouped the patients according to the treatment modalities and evaluated response rate, median survival and the effect of prognostic variables. Among 67 patients evaluated, twenty seven patients classified with group A, received cisplatin and etoposide containing combination chemotherapy alone, eighteen patients, classified with group B, received chemotherapy and radiotherapy, fifteen patients, group C, received neoadjuvant or adjuvant chemotherapy and surgery with/without radiation therapy, seven patients, group D, received only supportive care. RESULT: The major response rate for group A and B was 37% and 61% respectively. There was no statistically significant difference in response rate between A and B groups(p=0.97). The analysis of prognostic factors showed that differences of age, sex, pathology, blood type, smoking year, stage and ECOG performance did not related to improvement in survival. Median survival time was 8.6 months for group A, 13.4 months for group B, 19.2 months for group C, and 5.4 months for group D, respectively and there was statistically significant difference(p=0.003), suggesting that multimodality therapy was associated with signigicant improvement in survival. Subset survival analysis showed a significant therapeutic effect for earlier stage and good performance state(p=0.007, 0.009, respectively). A possible survival advantages were observed for major response groups. CONCLUSION: It was suggested that multimodality therapy for the management of patients who had stage III disease, has yielded good median survival and long survival for seleted patients. But, it is necessory to validate above result with further investigation in large scale and in prospective randomized trials.
Carcinoma, Non-Small-Cell Lung* ; Chemotherapy, Adjuvant ; Cisplatin ; Drug Therapy ; Drug Therapy, Combination ; Etoposide ; Humans ; Neoplasm Metastasis ; Pathology ; Prospective Studies ; Radiotherapy ; Smoke ; Smoking ; Survival Rate ; Thorax

Background: Psoriasis is a chronic disease that can have accompanying comorbidities including arthritis, metabolic syndrome, and cardiovascular diseases. Patients with psoriasis tend to frequently visit medical institutions, and their economic burden for medical services is high. Objective: To investigate the economic burden of psoriasis in Korea. Methods: The Korean Society for Psoriasis conducted a multi-center field survey of the patients and analyzed the national insurance claim data. Also, we discussed the medical environment of psoriasis in Korea based on the results. Results: The economic burden of psoriasis patients is substantial and varied by the type of medical institute. Patients also paid the indirect and intangible medical costs. Biological agents, which is used in patients with severe psoriasis, led to an increase in the cost. Conclusion This is the first study to estimate the economic burden of psoriasis in Korea comprehensively. To improve the medical environment of psoriasis and alleviate the burden of patients, discussion on the more efficient health policy and medical insurance criteria for psoriasis would be needed.

Background: Psoriasis is a chronic disease that can have accompanying comorbidities including arthritis, metabolic syndrome, and cardiovascular diseases. Patients with psoriasis tend to frequently visit medical institutions, and their economic burden for medical services is high. Objective: To investigate the economic burden of psoriasis in Korea. Methods: The Korean Society for Psoriasis conducted a multi-center field survey of the patients and analyzed the national insurance claim data. Also, we discussed the medical environment of psoriasis in Korea based on the results. Results: The economic burden of psoriasis patients is substantial and varied by the type of medical institute. Patients also paid the indirect and intangible medical costs. Biological agents, which is used in patients with severe psoriasis, led to an increase in the cost. Conclusion This is the first study to estimate the economic burden of psoriasis in Korea comprehensively. To improve the medical environment of psoriasis and alleviate the burden of patients, discussion on the more efficient health policy and medical insurance criteria for psoriasis would be needed.

PURPOSE: The objective of the present study was to predict the gestational age at preterm birth using artificial neural networks for singleton pregnancy. METHODS: Artificial neural networks (ANNs) were used as a tool for the prediction of gestational age at birth. ANNs trained using obstetrical data of 125 cases, including 56 preterm and 69 non-preterm deliveries. Using a 36-variable obstetrical input set, gestational weeks at delivery were predicted by 89 cases of training sets, 18 cases of validating sets, and 18 cases of testing sets (total: 125 cases). After training, we validated the model by another 12 cases containing data of preterm deliveries. RESULTS: To define the accuracy of the developed model, we confirmed the correlation coefficient (R) and mean square error of the model. For validating sets, the correlation coefficient was 0.839, but R of testing sets was 0.892, and R of total 125 cases was 0.959. The neural networks were well trained, and the model predictions were relatively good. Furthermore, the model was validated with another dataset of 12 cases, and the correlation coefficient was 0.709. The error days were 11.58±13.73. CONCLUSION: In the present study, we trained the ANNs and developed the predictive model for gestational age at delivery. Although the prediction for gestational age at birth in singleton preterm birth was feasible, further studies with larger data, including detailed risk variables of preterm birth and other obstetrical outcomes, are needed.
Dataset ; Gestational Age ; Parturition ; Pregnancy ; Premature Birth