• Nuclear Medicine and Molecular Imaging
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• v.41 no.5
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• pp.377-379
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• 2007

• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.574-577
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• 2007

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.120-128
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• 2009

Purpose: Early detection of recurrence is an important factor for long term survival of patients with colorectal cancer. Measurement of serum levels of CEA, CA 19-9, CT and PET/CT has been commonly used in the postoperative surveillance of colorectal cancer. The purpose of this study was to compare the diagnostic ability of PET/CT, tumor marker and CT for recurrence in colorectal cancer patients after treatment. Materials and Methods: F-18 FDG PET/CT imaging was performed in 189 colorectal cancer patients who underwent curative surgical resection and/or chemotherapy. Measurement of serum levels of CEA, CA 19-9 and CT imaging were performed within 2 months of PET/CT examination. Final diagnosis of recurrence was made by biopsy, radiologic studies or clinical follow-up for 6 months after each study. Results: Overall sensitivity, specificity of PET/CT was 94.7%, 91.1%, while those of serum CEA were 44.7% and 97.3%, respectively. Sensitivity and specificity were 94.2%, 90.4% for PET/CT and better than those of combined CEA and CA 19-9 measurement(52.1%, 88.5%) in 174 patients measured available both CEA and CA 19-9 data. In 115 patients with both tumor markers and CT images available, PET/CT showed similar sensitivity but higher specificity(92.9%, 91.3%) compared to combination of tumor markers and CT images(92.9%, 74.1%). Conclusion: PET/CT was superior for detection of recurred colorectal cancer patients compared with both CEA, CA 19-9, and even with combination of both tumor markers and CT. Therefore PET/CT could be used as a routine surveillance examination to detect recurrence or metastasis of colorectal cancer.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.411-420
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• 2009

Purpose: The aim of this study was to investigate the usefulness of $^{18}F$-FDG PET/CT with neck ultrasonography (neck US) in patients with recurrent, papillary thyroid cancer. Material and methods: This retrospective study (December 2006 to April 2008) enrolled sixty-one patients (ninety-one lesions) who underwent high-dose $^{131}I$-ablation therapy after total thyroidectomy, and evaluated recurred papillary thyroid cancer. All lesions were confirmed by histopathology and compared histopathologic findings to PET, PET/CT, and neck US findings. Results: In sixty-one patients (57 women, 4 men; age range, 24-81 years, mean 49 years; 61 papillary carcinomas), the sensitivity, specificity, accuracy of $^{18}F$-FDG PET/CT was 87.2%, 64.0%, 78.1% on a patient basis and 92.3%, 66.7%, 80.9% on a lesion basis, respectively. The sensitivity, specificity, accuracy of $^{18}F$-FDG PET was 71.8% (p=0.03), 59.0% (p=1.00), 67.2% (p=0.03) on a patient basis and 78.8% (p<0.01), 64.1% (p=1.00), 72.5% (p=0.02) on a lesion basis, respectively. The sensitivity, specificity, accuracy of neck US was 71.1% (p=0.07), 52.2% (p=0.75), 63.9% (p=0.05) on a patient basis and 71.2% (p<0.01), 61.5% (p=1.00), 67.0% (p=0.06) on a lesion basis, respectively. Combined $^{18}F$-FDG PET/CT with neck US improved the sensitivity, specificity, accuracy to 94.7% (p=0.50), 82.6% (p=0.13), 90.2% (p=0.03) on a patient basis and 96.2% (p=0.50), 89.7% (p<0.01), 93.4% (p<0.01) on a lesion basis, respectively. Conclusion: $^{18}F$-FDG PET/CT demonstrated significantly higher sensitivity than neck US for the detection of recurred papillary thyroid cancer lesions. Furthermore, combined $^{18}F$-FDG PET/CT with neck US showed more improved sensitivity, specificity, accuracy for diagnosis of recurrent papillary thyroid cancer.

• The Korean Journal of Nuclear Medicine
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• v.36 no.6
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• pp.368-380
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• 2002

Purpose: Liver transplantation (LT), one of the therapeutic options of primary liver cancer has been suffering from recurrence caused by metastasis in 8-54% of patients. This study was performed to investigate whether FDG-PET is useful for detecting hidden metastasis in LT candidates. Materials and Methods: Twenty-six patients (male:female=23:3, mean age 55.7 years) underwent FDG-PET. Their previous conventional diagnostic studies (CDS) like abdomen US and CT, chest x-ray and CT, and bone scan were negative (n=22) or equivocal (n=4) for metastasis. Positive FDG-PET findings were confirmed by biopsy or clinical follow-up. Results: Among 4 patients with equivocal metastatic lesions on CDS, 3 had 6 hypermetabolic lesions on FDG-PET, which were confirmed as metastasis and subsequently LTs were cancelled. Of these, 5 lesions were initially negative on CDS. Remained 1 patient underwent LT with a negative FDG-PET result. Among 22 patients without metastasis on CDS, 5 had 7 hypermetabolic lesions on FDG-PET. One of these patients proved to have 2 metastatic lesions, and LT was cancelled. The other 4 patients had S hypermetabolic lesions on FDG-PET, which were confirmed as benign lesions, and 3 patients of them underwent LT. In summary, FDG-PET was useful in avoiding 4 unwarranted LT by detecting unsuspected metastatic lesions on CDS. A total of 17 patients underwent LT. In comparison with pathology, the sensitivity and specificity of FDG-PET for detecting viable primary liver cancer were 55.6% (5/9) and 87.5% (7/8), respectively. Conclusion: FDG-PET can detect additional hidden metastasis and contribute to reducing unwarranted LT in the patients with primary liver cancer.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.286-287
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• 2001

A 44 year-old male patient was undergoing diagnosis and therapy for acute myelogenous leukemia (AML, M2). On physical examination a thyroid mass was palpated in the left lower lobe. He had palpitation and intolerance to heat. Thyroid function tests revealed hyperthyroidism; T3: 150ng/dl (N:60-90), fT4: 2.26 ng/dl (N:0.70-1.80), TSH: 0.01 ulU/ml (N:0.25-5.00). Ultrasonography demonstrated a hypoechoic mass with scattered calcifications measuring 2.55 2.03 3.64 cm in size. F-18 FDG camera-based PET scan performed as a follow-up study of AML revealed a focal increased uptake in the left neck, where an autonomous nodule was detected on Tc-99m thyroid scan. After the diagnosis of toxic autonomous nodule, Goetz disease, he underwent surgical nodulectomy. Microscopically, the nodule contained follicular proliferation with degenerative change but without evidence of thyroid carcinoma. Focal uptake in autonomous thyroid nodules is due to increased glycolysis within the nodules.

• Journal of radiological science and technology
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• v.42 no.2
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• pp.119-130
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• 2019

Positron emission tomography (PET) is widely used imaging modality for effective and accurate functional testing and medical diagnosis using radioactive isotopes. However, PET has difficulties in acquiring images with high image quality due to constraints such as the amount of radioactive isotopes injected into the patient, the detection time, the characteristics of the detector, and the patient's motion. In order to overcome this problem, we have succeeded to improve the image quality by using the dynamic image reconstruction method based on singular value decomposition. However, there is still some question about the characteristics of the proposed technique. In this study, the characteristics of reconstruction method based on singular value decomposition was estimated over computational simulation. As a result, we confirmed that the singular value decomposition based reconstruction technique distinguishes the images well when the signal - to - noise ratio of the input image is more than 20 decibels and the feature vector angle is more than 60 degrees. In addition, the proposed methode to estimate the characteristics of reconstruction technique can be applied to other spatio-temporal feature based dynamic image reconstruction techniques. The deduced conclusion of this study can be useful guideline to apply medical image into SVD based dynamic image reconstruction technique to improve the accuracy of medical diagnosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9879-9884
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• 2014

Aim: The purpose of the current study was to conduct a systematic review of the published literature to evaluate the diagnostic accuracy of FDG-PET, PTE/CT, MRI and scintigraphy for multiple myeloma related bone disease. Methods: Through a search of PubMed, EMBASE, and the Cochrane Library, two reviewers independently assessed the methodological quality of each study. We estimated pooled sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR), and two sample Z-tests were conducted to evaluate for differences in sensitivity, specificity, area under the curve (AUC), and the $Q^*$ index between any two diagnostic modalities. Results: A total of 17 studies were reviewed. The MRI had a pooled sensitivity of 0.88, specificity of 0.68, AUC of 0.897, and $Q^*$ index of 0.828, whereas for MIBI, the corresponding values were 0.98, 0.90, 0.991, and 0.962, respectively, and for bone scan, they were 066, 0.83, 0.805, and 0.740, respectively. The corresponding values of MIBI were 0.98, 0.90, 0.991, and 0.962, respectively. For PET and PET/CT, the values were 0.91, 0.69, 0.927 and 0.861, respectively. Statistically significant differences were not found in the sensitivity, specificity, AUC, and $Q^*$ index between MRI, scintigraphy, FDG-PET and PET/CT. Conclusions: On the condition that X ray is taken as a reference in our study, we suggested that FDG-PET, PTE/CT, MRI and scintigraphy are all associated with high detection rate of bone disease in patients with MM. Thus, in clinical practice, it is recommended that we could choose these tests according to the condition of the patient.

• Progress in Medical Physics
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• v.24 no.3
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• pp.176-182
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• 2013

Through this research, we measure the data for several SUVs such as SUVLBM, SUVBW, and SUVBSA using volume of interest in order to enhance the diagnostic level in whole-body image for healthy examinees via F-18 FDG PET/CT. Maximum value, mean value, standard deviation, and threshold value for each SUVs are shown. The measurement of SUVs are carried out with 31 examinees who have taken whole-body examination with F-18 FDG PET/CT from July, 2012 to August, 2012. To secure the preciseness of measurement, we selected 26 healthy examinees as a subject of measurement according to diagnostic view of a nuclear-medical doctor. We see from the measurement of SUVs of PET/CT that the value of SUVBW is hightest and followed by SUVLBM and SUVBSA in turn regardless of the use of contrast media. By comparing the SUVLBM-maximum data for the group used contrast media with those for the group used no contrast media, there found a trend that the measured values increase when the contrast media are used. Among them, liver, aorta, lumbar-5, and Cerebellum exhibit significant difference (p<0.05). We conclude that our data for SUVs would be basic references in overall image interpretation, and hope that the research using VOI would be active.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.176-180
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• 2008

Department of Nuclear Medicine in Seoul National University Hospital (SNUH) had developed $^{18}F$-Flumazenil as Benzodiazepine receptor imaging agent for PET diagnosis of Epilepsy. But production Activity of $^{18}F$-Flumazenil is decreased owing to this method has difficult synthesis procedures and pretty long synthesis time. In this study, we can modify synthesizing method to have more simple procedure and less spend time and help to increase production Activity. Old method: Radioactivity was produced by cyclotron was captured by QMA cartridge that was activated. Captured radioactivity was eluted into the reaction vial by using kryptofix solution and delivered. After evaporation of eluent, the azeotrophic drying step repeated two times. tosylflumazenil in anhydrous Acetonitrile was added to a reaction vial while bubbling. The reaction mixture was evaporated until the mixture volume was 0.5 mL. Reaction vial washed with 20 % Acetonitrile and that solution went into the reaction vial. The reaction mixture was loaded to the HPLC loop by hand and purified $^{18}F$-Flumazenil by HPLC column. New method: We used $TBAHCO_3$ solution as a eluent. After the eluent was evaporated, tosylflumazenil in anhydrous acetonitrile was added to a reaction vial and the reaction mixture was bubbled for 15 minutes. It was evaporated until the mixture volume became 0.5 mL. It was loaded to the HPLC loop. In old method, $^{18}F$-Flumazenil was synthesized via 6 steps synthesis procedures in 105 minutes with 30~35% synthesizing yield (non-decay correction) and specific activity was about $0.5{\sim}2{\times}10^5$ Ci/mole. In new method, It had 3 steps synthesis procedures in 53 minutes with 40~45% synthesizing yield and specific activity was about $3{\sim}8{\times}10^5$ Ci/mole. This method leads to improve of minimizing synthesis time, increasing synthesis yield and specific activity. While we can load reaction mixture to the HPLC loop, we can expose high radiation field thanks to used by hand.