Positron Emission Tomography(PET) is a new imaging modality to make biochemical metabolic images. Because biochemical changes precede anatomical changes in most of diseases including cancer, PET can detect earlier changes of diseases than conventional anatomical imaging modalities. PET can also characterize biochemical property of diseases. A PET center is composed of a medical cyclotron, synthesis system of radiopharmaceuticals and scanner. For PET oncology, several positron-emitting radiopharmaceuticals have been developed. Among them, F-18-fluorodeoxyglucose (FDG) is most frequently used. Higher rate of glucose metabolism has been observed in cancer cells. Like glucose, FDG is transported into the cancer cells and converted to FDG-6-phosphate by hexokinase. FDG-6-phosphate is trapped in the cytoplasm, and emits gamma rays to make PET images. The current application of FDG PET in oncology is in detection, differentiation, and staging of the primary tumors, grading malignancy, monitoring therapeutic response, and early detection of recurrence. Nowadays, PET is an established procedure for staging the diseases and detecting the recurrence in many cancers, especially the lung, colorectal, and head and neck cancers, melanoma, and lymphoma. PET is a regular part of medical insurance reimbursement in many developed countries, and becomes a valuable research tool in oncology as well as an important imaging modality in managing cancer patients.
Cyclotrons ; Cytoplasm ; Developed Countries ; Electrons* ; Gamma Rays ; Glucose ; Head ; Hexokinase ; Humans ; Insurance ; Lung ; Lymphoma ; Melanoma ; Metabolism ; Neck ; Radiopharmaceuticals ; Recurrence

No abstract available.
Brain Neoplasms* ; Brain*

No abstract available.
Brain Neoplasms* ; Brain*

No abstract available.
Thyroid Gland* ; Thyroid Neoplasms*

Cancer cells are known to show increased rates of glycolysis metabolism. Based on this, PET studies using F-18-fluorodeoxyglucose have been used for the detection of primary and metastatic tumors. To account for this increased glucose uptake, a variety of mechanisms has been proposed. Glucose influx across the cell membrane is mediated by a family of structurally related proteins known as glucose transporters (Gluts). Among 6 isoforms of Gluts, Glut-1 and/or Glut-3 have been reported to show increased expression in various tumors. Increased level of Glut mRNA transcription is supposed to be the basic mechanism of Glut overexpression at the protein level. Some oncogens such as src or ras intensely stimulate Glut-1 by means of increased Glut-1 mRNA levels. Hexokinase activity is another important factor in glucose uptake in cancer cells. Especially hexokinase type II is considered to be involved in glycolysis of cancer cells. Much of the hexokinase of tumor cells is bound to outer membrane of mitochondria by the porin, a hexokinase receptor. Through this interaction, hexokinase may gain preferred access to ATP synthesized via oxidative phosphorylation in the inner mitochondria compartment. Other biologic factors such as tumor blood flow, blood volume, hypoxia, and infiltrating cells in tumor tissue are involved. Relative hypoxia may activate the anaerobic glycolytic pathway. Surrounding macrophages and newly formed granulation tisssue in tumor showed greater glucose uptake than did viable cancer cells. To expand the application of FDG PET in oncology, it is important for nuclear medicine physicians to understand the related mechanisms of glucose uptake in cancer tissue.
Adenosine Triphosphate ; Anoxia ; Biological Factors ; Blood Volume ; Carcinogens ; Cell Membrane ; Glucose* ; Glycolysis ; Hexokinase ; Humans ; Macrophages ; Membranes ; Metabolism ; Mitochondria ; Nuclear Medicine ; Oxidative Phosphorylation ; Protein Isoforms ; RNA, Messenger

No abstract available.
Electrons* ; Positron-Emission Tomography*

No abstract available.
Animals ; Dopamine* ; Nucleus Accumbens* ; Panax* ; Rats* ; Saponins*

PURPOSE: For the purpose of using Re-188 as a therapeutic radionuclide, we performed the quality control of the W-188/Re-188 generation system. MATERIALS AND METHODS: Several quality control tests of the Re-188 eluate from generator were carried out of about 300 days. After elution of Re-188 with normal saline (20 ml), chromatogram and gamma-ray spectrum of Re-188 eluate were obtained. The presence of aluminum which was derived from the elumina bed of the generator was detected by using aluminum ion indicator kit. Re-188 eluate was allowed to decay for several days, and then W-188 breakthrough in the Re-188 eluate was measured by detecting gamma-ray at 227 keV and 290 keV. The pH and the pyrogenicity of the eluate were checked. The Re-188 eluate from the generator was 67.4+/-7.0% of W-188 during 270 days, and it was hightest at third day after previous elution. Radiochemical purity of Re-188 eluate obtained from chromatogram was higher than 99%. Gamma-ray spectrum of Re-188 eluate showed a peak at 155 keV. Aluminum ion and W-188 contamination were not detected. The pH of Re-188 eluate was 3 and the concentration yield was 85%. CONCLUSION: Our experiments and results on quality control tests of Re-188 eluate from W-188/Re-188 generator may be useful for setting W-188/Re-188 generator in hospitals.
Aluminum ; Hydrogen-Ion Concentration ; Quality Control*

PURPOSE: For the purpose of using Re-188 as a therapeutic radionuclide, we performed the quality control of the W-188/Re-188 generation system. MATERIALS AND METHODS: Several quality control tests of the Re-188 eluate from generator were carried out of about 300 days. After elution of Re-188 with normal saline (20 ml), chromatogram and gamma-ray spectrum of Re-188 eluate were obtained. The presence of aluminum which was derived from the elumina bed of the generator was detected by using aluminum ion indicator kit. Re-188 eluate was allowed to decay for several days, and then W-188 breakthrough in the Re-188 eluate was measured by detecting gamma-ray at 227 keV and 290 keV. The pH and the pyrogenicity of the eluate were checked. The Re-188 eluate from the generator was 67.4+/-7.0% of W-188 during 270 days, and it was hightest at third day after previous elution. Radiochemical purity of Re-188 eluate obtained from chromatogram was higher than 99%. Gamma-ray spectrum of Re-188 eluate showed a peak at 155 keV. Aluminum ion and W-188 contamination were not detected. The pH of Re-188 eluate was 3 and the concentration yield was 85%. CONCLUSION: Our experiments and results on quality control tests of Re-188 eluate from W-188/Re-188 generator may be useful for setting W-188/Re-188 generator in hospitals.
Aluminum ; Hydrogen-Ion Concentration ; Quality Control*

Coronary artery disease is on the rise over the world. Myocardial perfusion SPECT is a well established technique to detect coronary artery disease and to assess left ventricular function. In addition, it has the unique ability to predict the prognosis of the patients. Moreover, the application of ECG-gated images provided the quantitatve data and improved the accuracy. This approach has been proved to be cost-effective and suitable for the emerging economies as well as developed countries. However, the utilization of nuclear cardiology procedures vary widely considering the different countries and region of the world. Korea exits 2-3 times less utilization than Japan, and 20 times than the United States. Recently, with the emerging of new technology, namely cardiac CT, cardiac MR and stress echocardiography, the clinical usefulness of nuclear cardiology has been called in question and its role has been redefined. For the proper promotion of nuclear cardiology, special educations should be conducted since the nuclear cardiology has the contact points between nuclear medicine and cardiology. Several innovations are in horizon which will impact the diagnostic accuracy as well as imaging time and cost savings. Development of new tracers, gamma camera technology and hybrid systems will open the new avenue in cardiac imaging. The future of nuclear cardiology based on molecular imaging is very exciting. The newly defined biologic targets involving atherosclerosis and vascular vulnerability will allow the answers for the key clinical questions. Hybrid techniques including SPECT/CT indicate the direction in which clinical nuclear cardiology may be headed in the immediate future. To what extent nuclear cardiology will be passively absorbed by other modalities, or will actively incorporate other modalities, is up to the present and next generation of nuclear cardiologists.
Arteries ; Atherosclerosis ; Cardiology ; Chimera ; Coronary Artery Disease ; Cost Savings ; Developed Countries ; Echocardiography, Stress ; Education, Special ; Gamma Cameras ; Head ; Humans ; Japan ; Korea ; Molecular Imaging ; Nuclear Medicine ; Perfusion ; Prognosis ; Tomography, Emission-Computed, Single-Photon ; Ventricular Function, Left