• The Korean Journal of Nuclear Medicine
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• v.36 no.1
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• pp.8-18
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• 2002

Early and accurate diagnosis of tumors using positron omission tomography (PET) has been the focus of considerable interest due to its high metastasis and mortality rates at late detection. PET radiopharmaceuticals-which exhibit a high tumor-to-background uptake ratio, and appropriate metabolic characteristics, and pharmacokinetics-are attractive tools for tumor imaging. Tumor imaging by these radiopharmaceuticals are based on metabolic and receptor imaging. The former is based on accelerated metabolism in tumor tissue compared to normal tissue and the rate roughly corresponding to the rate of growth of tumors. Radiopharmaceuticals for this purpose include radiolabeled sugars, amino acids, and nucleosides which detect increased glucose utilization, protein synthesis, and DNA synthesis, respectively. Tumor receptor imaging is based on the proliferation of tumor cells regulated by many hormones and growth factors, which bind to the corresponding receptors and exhibit the biological responses Radiopharmaceuticals used to image the tumor receptor systems may be ligands for the specific receptors and antibodies for the growth factor receptors. Some antitumor agents have been labeled with radionuclides and used to study in vivo biodistribution and pharmacokinetics in humans. This overview describes typical PET radiopharmaceuticals used for tumor imaging based on their uptake mechanisms.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.45-51
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• 2003

Purpose: This study was designed to know the ability of thallium-201 scintigraphy to discriminate malignant bone tumor from benign by analysing the quantitative thallium uptake ratio. Materials and Methods: We took thallium-201 scintigraphy prospectively with other imaging studies in 82 bone tumor suspecting patients. The results of scintigraphy were read qualitatively and calculated quantitatively, and retention indexes were estimated. For the statistical analysis the patients were divided as four group; high grade malignant bone tumor, benign bone tumor, giant cell tumor and low grade malignant bone tumor. Results: The mean thallium uptake ratio was 4.14 in early phase and 2.26 in delayed phase in high grade malignant bone tumor group, 1.16 and 1.09 in benign bone tumor, 3.15 and 1.94 in giant cell tumor, and 1.41 and 1.31 in low grade malignant bone tumor. Retention indexes were 0.62, 0.97, 0.66, 0.93 in same order. The thallium uptake ratio and retention indexes were statistically correlated in high grade malignant bone tumor and benign bone tumor group(p<0.001). Conclusion: Thallium-201 scintigraphy proved as useful imaging study to discriminate malignant bone tumor from benign, but had exception in giant cell tumor and low grade malignant bone tumors.

• Natural Product Sciences
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• v.13 no.3
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• pp.234-240
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• 2007

The present study investigated the anti-tumor activity of ethyl acetate extract of Acanthospermum hispidum DC against daltons ascites lymphoma in mice. The extract was prepared by cold maceration with ethyl acetate for 3 - 7 days and evaporated in vacuum to dry. (Yield : 14.2 g, 1.42% w/w). The extract was fractionated by column chromatography by using gradient elution technique and the diterpenes fraction isolated (0.649 g). Both extract and the fraction were administered as oral suspension with tween 20 in water to tumor bearing mice (DAL) and changes in dead cell count, histopathology of tumor cells, hematological parameters and median survival time (MST) were examined and compared with that of tumor control or 5-Fluorouracil (5-FU). The results indicate that both ethyl acetate extract and fraction possess anti-tumor activity. The study suggests that Acanthospermum hispidum DC seems promising as a source of diterpenes for potential anti-tumor activity.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1422-1427
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• 1992

Askin tumor is rare malignant small round cell tumor that orgins from interconstal nerve of chest in children It was not until 1979 that Askin first reported that tumor. Although few sporadic reports had been reported, its incidence were too low to analize its clinical featurs. That tumors prognosis is so grave that no therapy would success to cure, but early diagnosis and enbloc excision with following combind chemotherapy and radiotherapy will prolong their survival. Other small round cell tumors of chest wall that must differentiate are Ewing`s sarcoma, rhabdomyosarcoma, lymphoma, neuroblastoma and pulmonary bla-stoma. The most prominant histologic charactersistics of this tumor is neuron specific eno-lase which is detected with immunohistochemistry technique, and neurosecretary electron dense granules within cytoplasm. We expirienced a case of Askin tumor occuring 12-year-old female who has huge right lower chest mass with dull chest pain. She have been underwent excision and postoperative radiotherapy. We are following her up for months and there is no evidence of local recurrence.

• The Journal of the Korean bone and joint tumor society
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• v.5 no.1
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• pp.63-69
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• 1999

Recently we experienced four cases of soft tissue Ewing sarcoma, developed in the calf muscles in two cases, and one case each in the foot and suprascapular region. We also found that the clinical course in all cases was rather rapid, because of local recurrence and metastatic lesions developing within a few months, followed by the patients' death in about 2 years after the primary tumor was excised. These cases were improperly treated initially as some kind of benign soft tissue tumor. The delay led to missed early accurate diagnosis and was thought to be one of the main causes for the rapid local recurrence and metastasis after tumor excision. The pulmonary metastasis was the most common cause of death.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.2
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• pp.142-145
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• 2007

Gastrointestinal stromal tumor (GIST) occurring outside the gastrointestinal tract is uncommon. When GIST is found outside the gastrointestinal tract, it has greater possibility to be diagnosed with metastatic lesion from other primary focus. But it rarely occurs in extragastrointestinal tract primarily, and then even outside abdomen. We experienced one case of GIST occurred from right buttock area of 25 year-old man. We could not find out the primary focus in abdomen. The tumor was developed inside gluteus medius and minimus and extended to pelvic inner area destroying iliac bone and adjacent sacrum. Here, we report the case of GIST with terminology of extragastrointestinal stromal tumor (EGIST).

• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.456-465
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• 2023

Cervical tumors represent a prevalent form of cancer affecting women worldwide; current treatment options involve surgery, radiotherapy, and chemotherapy. Angiogenesis, the process of new blood vessel formation, is a crucial factor in cervical tumor growth. The molecular mechanisms underlying the effects of the liver kinase B1 (LKB1/STK11) tumor suppressor protein on tumor angiogenesis have not been elucidated. Therefore, we investigated the role of LKB1 in cervical tumor angiogenesis both in vitro and in vivo in this study. Our results demonstrated that LKB1 inhibited cervical tumor angiogenesis by suppressing the expression of angiogenesis-related factors such as vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1α. LKB1 directly affected both carcinoma and vascular endothelial cells, resulting in a significant reduction in tumor growth and angiogenesis. Furthermore, LKB1 was found to bind to VEGF receptor 2 (VEGFR-2) and target the VEGFR-2-mediated protein kinase B/mechanistic target of rapamycin signaling pathway in endothelial cells, thereby reducing cervical tumor growth and angiogenesis. Our study provides new insights into the molecular mechanisms underlying the anti-tumor and anti-angiogenic effects of LKB1 in cervical cancer. These findings will help develop new therapeutic strategies for cervical cancer.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.267-273
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• 2011

In this paper, we proposed the method to detect brain tumor region in MR images. Our method is composed of 3 parts, detection of tumor slice, detection of tumor region and tumor boundary detection. In the tumor slice detection step, a slice which contains tumor regions is distinguished using symmetric analysis in 3D brain volume. The tumor region detection step is the process to segment the tumor region in the slice distinguished as a tumor slice. And tumor region is finally detected, using spatial feature and symmetric analysis based on the cluster information. The process for detecting tumor slice and tumor region have advantages which are robust for noise and requires less computational time, using the knowledge of the brain tumor and cluster-based on symmetric analysis. And we use the level set method with fast marching algorithm to detect the tumor boundary. It is performed to find the tumor boundary for all other slices using the initial seeds derived from the previous or later slice until the tumor region is vanished. It requires less computational time because every procedure is not performed for all slices.

• IMMUNE NETWORK
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• v.3 no.2
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• pp.96-102
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• 2003

Background: Granulocyte-macrophage colony-stimulating factor (GM-CSF) gene-transduced tumor cell vaccines induce very potent systemic anti-tumor immunity in preclinical and clinical models. Our previous phase I clinical trial in patients with metastatic renal cell carcinoma (RCC) has demonstrated both immune cell infiltration at vaccine sites and T cell-mediated delayed-type hypersensitivity (DTH) response to whole tumor cell vaccines. Methods: To investigate the immune responses to autologous genetically- modified tumor cell vaccines, tumor-specific $CD8^+$ T cell lines were generated from peripheral blood lymphocytes (PBL) of a RCC patient 1.24 by repeated in vitro stimulation with either B7.1-transduced autologous RCC tumor cells or B7.1-transduced autologous tumor cells treated with interferon gamma ($IFN{\gamma}$), and cloned by limiting dilution. Results: Among several RCC-specific cytotoxic T lymphocytes (CTLs), a $CD4^+/CD8^+$ double positive T cell clone (17/A2) appeared to recognize $IFN{\gamma}$-treated autologous RCC restricted by HLA-B39. The 17/A2 also recognized other HLA-B39 positive RCC tumor cells after $IFN{\gamma}$ treatment. Conclusion: These results demonstrate that autologous RCC vaccination successfully generates the tumor-specific CTL 17/A2, and suggest that the presentation and recognition of the tumor antigen by the 17/A2 might be upregulated by $IFN{\gamma}$.

• Journal of Yeungnam Medical Science
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• v.20 no.2
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• pp.117-128
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• 2003

Thallium-201 scintigraphy is used to discriminate the malignant bone tumor from the benign by qualitatively and quantitatively, and to predict the response of preoperative chemotherapy in osteosarcoma, by comparing the changes of thallium uptake ratio after chemotherapy to the tumor necrosis ratio. Thallium-201 scintigraphy scan should be done prior to surgical biopsy. PICKER Prism 2000 gamma camera with high resolution parallel hole collimator is usually used for scanning. The patient is injected with 2-3mCi of Tl-201 and the early phase is checked in 30 minutes and delayed phase in 3 hours. The scan images are visually evaluated by a blinded nuclear medicine physician. We could evaluate true positive, true negative, false positive and false negative by the comparison of results with those of biopsy, and calculate positive and negative predictive value(%), sensitivity(%), specificity(%) and diagnostic accuracy(%). For the quantitative analysis of thallium uptake, we drew the region of interest on the tumor side and contralateral normal side as mirror image, and calculated the uptake ratio with dividing the amount of gamma count in tumor side by normal side. We could calculate the percent changes of thallium uptake ratio in early and delayed phase, and compare them to the ratio of tumor necrosis. Thallium-201 scintigraphy proved as useful imaging study to discriminate malignant bone tumor from benign, but had exception in giant cell tumor and low grade malignant bone tumors. We can use T1-201 scan to differentiate the benign from the malignant tumor, and to evaluate the response of preoperative chemotherapy or radiotherapy, and to determine the residual tumor or local recurrence. For the better result, we need to have a more detail information about false positive cases and a more objective and quantitative reading technique.