• Journal of radiological science and technology
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• v.29 no.3
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• pp.125-132
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• 2006

The PET/CT scanner is an evolution in image technology. The two modalities are complementary with CT and PET images. The PET scan images are well known as low resolution anatomic landmak, but such problems may help with interpretation detailed anatomic framework such as that provided by CT scan. PET/CT offers some advantages-improved lesion localization and identification, more accurate tumor staging. etc. Conventional PET employs tranmission scan require around 4 min./bed position and 30 min. for whole body scan. But PET/CT scanner can reduced by 50% in whole body scan. Especially nowadays PET scanner LSO scintillator-based from BGO without septa and operate in 3-D acquisition mode with multidetectors CT. PET/CT scanner fusion problems solved through hardware rather than software. Such device provides with the capability to acquire accurately aligned anatomic and functional images from single scan. It is very important to effective detection from gamma ray source in PETdetector. And can be offer high quality diagnostic images. So we have study about detection processing of PET detector and high quality imaging process.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.100-103
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• 2004

Experiments and simulation were done to study the impact of contrast agent when CT scan was used to attenuation correction for PET images in PET/CT system. Whole body phantom was imaged with various concentration of iodine-based contrast agent using CT. Mathematical emission and transmission density map with liver were made to simulate for whole body FDG imaging. Various transmission density maps was generated with non-uniform enhancement of contrast agent, hypo-attenuating of contrast agent for tumor, different concentration of contrast agent, and so on. Attenuation correction was done with all transmission maps. In the experiments, we confirmed that attenuation coefficient was changed by concentration of contrast agent. From the simulation data, image quality of attenuation corrected images was affected by contrast agent and artifact was produced by contrast agent. These results indicated that the contrast agent should be used with a full understanding of its potential problem in PET/CT system.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.205-209
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• 2001

Purpose: Most cases of primary hyperparathyroidism are due to parathyroid adenoma or parathyroid hyperplasia. Parathyroid carcinoma is a very rare cause of hyperparathyroidism. Although the diagnosis of parathyroid carcinoma is usually established by pathologic criteria especially of vascular or capsular invasion, some clinical and biochemical features differentiate it from benign forms of hyperparathyroidism. We under-took a retrospective study in 6 patients with parathyroid carcinoma, with the aim of conveying experience from management for this rare cause of hyperparathyroidism. Methods: Clinical symptoms, biochemical laboratory, radiologic, and intraoperative findings, local recurrence and distant metastasis were analyzed in 6 patients diagnosed pathologically as a parathyroid carcinoma after operation from 1992 to 2001. Results: Mean age was 50.2 years (33.0-60.0 years) and male to female ratio was 1:1. Neck mass was found in 5 patients, multiple bone pain in 3 patients and renal stone in 1 patient. One case has suffered from chronic renal failure for 19 years. Although preoperative laboratory evaluations showed the aspects of hyperparathyroidism in all cases, mean serum calcium level was 11.2mg/dl(10.5-12.1mg/dl), slightly elevated. Laboratory values after surgery were within the normal range in 5 cases. However, in one case with chronic renal failure, serum PTH levels, serially checked, were above the normal range. Any of imaging methods failed to suggest a parathyroid carcinoma preoperatively. Parathyroid adenoma was suspected in 3 cases, thyroid cancer in the other cases before surgery. The extent of resection was radical resection of parathyroid lesion with more than unilateral thyroid lobectomy and central compartment neck node dissection and in 2 cases, the resection of recurrent laryngeal nerve or strap muscles was added. During follow-up period, any local or systemic recurrence were not evident in all the cases. Conclusion: Although parathyroid carcinoma is a rare disease and its preoperative diagnosis, in our experience, could not easily be made, the understanding of characteristic clinical and biochemical feature could help diagnosis at first surgery. Radical resection without remaining residual tumor is most important for the management of the parathyroid cancer.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1316-1321
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• 2000

Objectives : The authors analyzed the surgical series of Cushing's disease to evaluate the proper treatment policy and to verify the possible prognostic factors. Material and Methods : Of 50 patients diagnosed as Cushing's disease and operated at Department of Neurosurgery of our institute between 1988 and 1999, 48 patients with available medical records were analyzed retrospectively. Mean follow-up period was 48 months(3 to 109 months). Preoperative diagnosis was made after evaluating the patients with multiple-stage endocrinological studies and 31 selective patients were evaluated with inferior petrosal sinus sampling(IPSS). Magnetic resonance imaging(MRI) and/or high resolution computerized tomography(CT) was done in all patients. A total of 51 transsphenoidal adenomectomy(TSA) were performed including 3 revision for initial surgical failure cases. Remission was decided on the basis of both endocrinological criteria and clinical status. Radiation and/or ketoconazole therapy were applied to failed cases. For the verification of prognostic factors, the authors evaluated the statistical significance of multiple variables over remission rate by chi-square test. Result : Sensitivity of IPSS for central localization was 93.5% which was better than that of MRI(87.5%). But for lateralization, it was 72.4% for IPSS versus MRI 90.5%. Success rate of TSA was 82%(42/51) and recurrence rate was 9%(4/48). When including adjuvant treatments for surgically failed cases, overall success rate was 89.6% and all of 3 reoperated cases(TSA) due to recurrence were successful. Significant complication occurred in 7.8%(4/51) after TSA including hypopituitarism, diabetes insipidus, and visual loss. Non-existence of tumor in MRI and prolonged symptom duration(>3 years) were significant prognostic factors. Conclusion : TSA can be considered as initial treatment for Cushing's disease. In surgically failed cases, multiple treatment modality may improve the overall outcome and repeated TSA for recurrent cases seem to provide similar success.

• Radiation Oncology Journal
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• v.29 no.3
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• pp.147-155
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• 2011

Purpose: This study was designed to determine the influencing factors and clinical course of pathologically proven cases of radiation-induced brain injury (RIBI). Materials and Methods: The pathologic records of twelve patients were reviewed; these patients underwent surgery following radiotherapy due to disease progression found by follow-up imaging. However, they were finally diagnosed with RIBI. All patients had been treated with 3-dimensional conventional fractionated radiotherapy and/or radiosurgery for primary or metastatic brain tumors with or without chemotherapy. The histological distribution was as follows: two falx meningioma, six glioblastoma multiform (GBM), two anaplastic oligodendroglioma, one low grade oligodendroglioma, and one small cell lung cancer with brain metastasis. Results: Radiation necrosis was noted in eight patients and the remaining four were diagnosed with radiation change. Gender (p = 0.061) and biologically equivalent dose $(BED)_3$ (p = 0.084) were the only marginally influencing factors of radiation necrosis. Median time to RIBI was 7.3 months (range, 0.5 to 61 months). Three prolonged survivors with GBM were observed. In the subgroup analysis of high grade gliomas, RIBI that developed <6 months after radiotherapy was associated with inferior overall survival rates compared to cases of RIBI that occurred ${\geq}6$ months (p = 0.085). Conclusion: Our study demonstrated that RIBI could occur in early periods after conventional fractionated brain radiotherapy within normal tolerable dose ranges. Studies with a larger number of patients are required to identify the strong influencing factors for RIBI development.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4071-4075
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• 2016

Background: FDG PET/CT is at an equivocal stage to recommend for staging of colorectal cancer as compared to contrast-enhanced CT (ceCT). This study was intended to evaluate the value of FDG PET/ceCT in colorectal cancer staging as compared to ceCT alone. Materials and Methods: PET/ceCT was performed for 61 colorectal cancer patients who were prospectively enrolled in the study. Three patients were excluded due to loss to follow-up. PET/ceCT findings and ceCT results alone were read separately. The treatment planning was then determined by tumor board consensus. The criteria for T staging were determined by the findings of ceCT. Nodal positive by PET/ceCT imaging was determined by visual analysis of FDG uptake greater than regional background blood pool activity. The diagnostic accuracy of T and N staging was determined only in patients who received surgery without any neoadjuvant treatment. Results: Of 58 patients, there were 40 with colon cancers including sigmoid cancers and 18 with rectal cancers. PET/ceCT in pre-operative staging detected bone metastasis and metastatic inguinal lymph nodes (M1a) that were undepicted on CT in 2 patients (3%), clearly defined 19 equivocal lesions on ceCT in 18 patients (31%) and excluded 6 metastatic lesions diagnosed by ceCT in 6 patients (10%). These resulted in alteration of management plan in 15 out of the 58 cases (26%) i.e. changing from chemotherapy to surgery (4), changing extent of surgery (9) and avoidance of futile surgery (2). Forty four patients underwent surgery within 45 days after PET/CT. The diagnostic accuracy for N staging with PET/ceCT and ceCT alone was 66% and 48% with false positive rates of 24% (6/25) and 76% (19/25) and false negative rates of 47% (9/19) and 21% (4/19), respectively. All of the false negative lymph nodes from PET/ceCT were less than a centimeter in size and located in peri-lesional regions. The diagnostic accuracy for T staging was 82%. The sensitivity of the peri-lesional fat stranding sign in determining T3 stage was 94% and the specificity was 54%. Conclusions: Our study suggested promising roles of PET/ceCT in initial staging of colorectal cancer with better diagnostic accuracy facilitating management planning.

• Tuberculosis and Respiratory Diseases
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• v.54 no.2
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• pp.230-235
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• 2003

A primary pulmonary artery sarcoma is a rare malignant tumor derived from the intimal layer of the pulmonary artery. Its clinical presentation can lead to a misdiagnosis of more common diseases such as thromboembolic disease. It is known to have a very poor prognosis. Therefore, the correct diagnosis of a primary pulmonary artery sarcoma is difficult and often delayed. We experienced a case of primary pulmonary artery sarcoma mimicking a pulmonary thromboembolism. The patient was admitted as a result of progressive dyspnea and coughing. The lung perfusion scan showed a large perfusion defect involving almost the entire right lung and suspicious small perfusion defects in the left upper lobe. Magnetic resonance imaging of the chest showed an enhancing nodule within the thrombus in the right pulmonary artery. The mass was removed completely by surgery, but the patient died as a result of shock.

• Tuberculosis and Respiratory Diseases
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• v.70 no.5
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• pp.423-427
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• 2011

Epithelioid sarcomas are rare soft tissue sarcomas with a high tumor grade and high local recurrence and metastasis rates. Although the lung is the most common site of metastasis, endobronchial metastasis hasn't been reported yet. We now report a case of epithelioid sarcoma with endobronchial metastasis. A 28-year-old man had recurrent pneumothorax and underwent wedge resection. He presented at our hospital with hemoptysis, dyspnea, and chest pain. Chest computed tomography revealed left pneumothorax, multiple lung nodules and endobronchial lesions at the right lower basal lobe. Bronchoscopy showed a hemorrhagic mass obstructing the bronchus of the right lower basal lobe. Magnetic resonance imaging revealed multiple nodular lesions in the left thigh muscles. The bronchoscopic biopsy of the endobronchial lesion and the muscle biopsy of the thigh showed the same feature epithelioid sarcoma. This is the first case report of an epithelioid sarcoma with endobronchial metastasis that was diagnosed by bronchoscopic biopsy.

• Journal of Life Science
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• v.30 no.6
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• pp.563-569
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• 2020

Oncoplastic surgery (OPS) combines oncologically safe tumor resection with aesthetically satisfying reconstruction of defects using established plastic surgery techniques. OPS is characterized by initial excision as extensive as is beneficial for oncological safety, and, once sufficient resection is complete, displacement or replacement techniques are selected based on remnant volume. The size of the lesion and the individual patient are important factors when considering the appropriate approach, and when pre-operative imaging, including MRI, is used to determine the technique, the complete removal of cancer cells by permanent pathology is essential. A frozen section is used during the operation to reduce the reoperation rate, but it is difficult to cover the entire margin surface theoretically and even harder in practice. A recent report about adequate margins has empowered OPS in its oncological safety. Considering the patients to whom each modality could be applied, basic breast volume is an important factor, and this is influenced by ethnic differences. In Europe or the US, for example, the average breast size is 36D (600 ㎤) and reduction mammoplasty is predominantly used. However, the average size of patients in our institution is 33A (300 ㎤), and so quite different approaches are selected in most cases. New techniques involving radiofrequency and fluorescence have been proposed as safe and easily accessible ways of reducing complications.

• The Korean Journal of Nuclear Medicine
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• v.31 no.4
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• pp.440-451
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• 1997

This study was designed to prospect the $^{111}In$-labelled paclitaxel as tumor imaging agent. In order to provide a taxol molecule with a functional group which is able to chelate In-111, taxol-DTPA conjugate and 2'-hemisuccinyltaxol were synthesized by esterification of taxol at C-2'on C-13 carbon with DTPA anhydride and succinic anhydride, respectively. Synthesis yield of the taxol derivatives was 34% for taxol-DTPA and 80% for 2'-hemisuccinyltaxol. Cytotoxicity of the taxol derivatives were measured by MTT method toward cell lines HT29, B16, P388, and CT26. The cytotoxic activities of the taxol derivatives were maintained, although less active than taxol. Radiolabelling of the taxol derivatives were proceeded directly with $^{111}InCl_3$ or indirectly with $^{111}In$-citrate(ligand-exchange method). The ligand-exchange method was not suitable because some precipitates appeared during the reaction. On the contrary, by direct radiolabelling method, we were able to obtain taxol-DTPA-$^{111}In$ in 100% radiochemical yield. However, 2'-hemisuccinyltaxol was not labelled by both methods. Yield and radiochemical purity of the radiolabelled com-pound were determined by HPLC, paper chromatography and instant thin layer chromatography. Taxol-DTPA-$^{111}In$ was characterized to be hydrophilic by lipophilicity test, and nearly non-adhesive to HT29, B16, P388, and CT26 by cell binding affinity test. Binding affinity of the taxol-DTPA-$^{111}In$ complex to serum proteins was also examined by protein precipitation with 30% trichloroacetic acid. The results showed that 30% of the taxol-DTPA-$^{111}In$ complex binds with serum proteins.