[en] Sarcoma originated in bone or soft tissue is relatively rare disease. ¹⁸F-FDG PET have been used in sarcoma for grading and predicting prognosis. In addition, FDG PET is expected to be useful in sarcoma for staging, detecting recurrence and monitoring therapy response in recent studies

[en] Nuclear cardiac imaging has been widely used to assess viable myocardium in patients with ischemic heart disease. The assessment of viable myocardium is important in selecting patients who will be benefit from revascularization. Although revascularization is indicated in patients with sufficient myocardium, patients with scar tissue should be treated medically. Nuclear imaging methods including myocardial perfusion SPECT and FDG PET have been shown to be effective modalities for identifying viable myocardium

[en] Various stem cells or progenitor cells are being used to treat cardiovascular disease. In ischemic heart disease, stem cell therapy is expected to regenerate damaged myocardium. To evaluate effects of stem cell treatment, the method to image stem cell location, distribution and differentiation is necessary. Optical imaging, MRI, nuclear imaging methods have been used for tracking stem cells. The methods and problems of each imaging technique are reviewed

[en] The prevalence of pancreas cancer is increasing. Due to difficulty in detecting early stage disease, the prognosis of pancreas cancer is known to be poor. Clinical use of FDG PET in pancreas has been reported. FDG PET showed good performance in diagnosing pancreas cancer, and is expected to be useful in staging and detecting recurrence

[en] A large number of major cardiovascular events occur in patients due to minimal or some lumen narrowing of the coronary artery. Recent biological studies have shown that the biological composition or vulnerability of the plaque is more critical for plaque rupture compared to the degree of stenosis. To overcome the limitations of anatomical images, molecular imaging techniques have been suggested as promising imaging tools in various fields. F-18 fluorodeoxyglucose (FDG), which is widely used in the field of oncology, is an example of molecular probes used in atherosclerotic plaque evaluation. FDG is a marker of plaque macrophage glucose utilization and inflammation, which is a prominent characteristic of vulnerable plaque. Recently, F-18 fluoride has been used to visualize vulnerable plaque in clinical studies. F-18 fluoride accumulates in regions of active microcalcification, which is normally observed during the early stages of plaque formation. More studies are warranted on the accumulation of F-18 fluoride and plaque formation/vulnerability; however, due to high specific accumulation, low background activity, and easy accessibility, F-18 fluoride is emerging as a promising non-invasive imaging probe to detect vulnerable plaque

[en] The purpose of this study was to evaluate the usefulness of whole body F-18 FDG PET scan for detecting postoperative recurrence of cancer. One hundred four cancer patients after operation were enrolled (14 brain tumor, 15 head and neck cancer, 23 gynecologic cancer, 16 gastrointestinal cancer, 16 thyroid cancer, and 20 other cancers). Besides conventional images (CI) including CT and MRI, F-18 FDG PET scan was obtained on ECAT EXACT 47 scanner (Siemens- CTI), beginning 60 minutes after injection of 370MBq(10mCi) of F-18 FDG. Regional scan was also obtained with emission image. Transmission images using Ge-68 were carried out for attenuation correction in both whole body and regional images. Findings of PET and CI were confirmed by pathology or clinical follow up. The sensitivity and specificity of PET for detecting recurrence were 94% and 92%, respectively. Contrarily, the sensitivity and specificity of CI were 78% and 68%. CI results were negative and PET results were positive in 11 cases. The biopsy or clinical follow-up of those cases confirmed recurrence of tumor. False negative cases of CI were frequent in patients with gynecologic cancers. Also we measured the serum concentration of tumor markers in patients with gynecologic cancer (CA125), thyroid cancer (thyroglobulin), and colorectal cancer (CEA). The sensitivity and specificity of tumor markers were 71% and 84%, respectively. We conclude that F-18 FDG PET can be used valuably in detecting recurrent foci of a wide variety of malignancy compared to conventional diagnostic methods

[en] F-18 fluorodeoxyglucose (FDG) uptake of myocardium is influenced by various factors. Increased glycolysis, and subsequent increased F-18 FDG uptake has been reported in ischemic cardiomyopathy. However, clinical significance of incidentally found myocardial F-18 FDG uptake has not been clarified. We retrospectively reviewed the degree and pattern of myocardial uptake in patients without history of ischemic heart disease who underwent torso F-18 FDG PET/CT for evaluation of neoplastic disease. From January 2005 to June 2009, 77 patients who underwent F-18 FDG PET/CT and Tc-99m sestamibi stress/rest SPECT within 3 months were enrolled. Of 77 patients, 55 (71.4%) showed increased F-18 FDG uptake in the myocardium. In this population, 40 showed uniform uptake pattern, while 15 showed focal uptake. In patients with uniform uptake, 17 showed decreased uptake in the septum without perfusion defect on myocardial SPECT. Remaining 23 patients showed uniform uptake, with 1 reversible perfusion defect and 1 fixed perfusion defect. In 15 patients with focal uptake, 9 showed increased F-18 FDG uptake in the base, and only 1 of them showed reversible perfusion defect on myocardial SPECT. In the remaining 6 focal uptake group, 4 had reversible perfusion defect in the corresponding wall, and 1 had apical hypertrophy. We demonstrated that septal defect pattern and basal uptake pattern in the myocardium may represent normal variants. Focal myocardial uptake other than normal variants on oncologic torso F-18 FDG PET/CT with routine fasting protocol may suggest ischemic heart disease, thus further evaluation is warranted

[en] The histopathological grade of differentiation is one of the significant prognostic factors in pancreatic adenocarcinoma. Especially in the patients with unresec-table pancreatic cancer, it is important to obtain the prognostic information non-invasively to avoid unnecessary invasive procedure. The aim of the study was to correlate ¹⁸F-fluorodeoxyglucose (FDG) uptake with pathologic grade of pancreatic cancer, furthermore, to evaluate prognostic value of standardized uptake value (SUV). FDG-PET scans of 102 patients with histologically proven pancreas adenocarcinoma were retrospectively reviewed. SUV of the primary tumor was calculated for quantification analysis. Pathological differentiation was graded into well-, moderately, and poorly differentiated groups. One-way analysis of variance is performed to test the correlation of the SUV and histopathologic grades. Patients were assigned into 3 categorical groups, using SUV cut-offs of 4 and 7, respectively. Survival functions of different histologic grade and assigned groups according to SUV were estimated by Kaplan-Meier estimator and compared by log-rank test. Multivariate analysis was performed using the Cox proportional hazard regression model. There was a significant correlation of SUVs and pathologic grades (F=4.97, p < 0.01). The mean SUV of well-, moderately and poorly differentiated groups was 4.93, 6.47 and 7.29, respectively. Tumor size, AJCC stage and treatment method were significantly related to the degree of FDG uptakes. SUV also shows a significant correlation with survival (p < 0.01), with better prognosis in lower SUV group. In multivariate analysis, the treatment method was the most strongly independent predictor (p < 0.01), followed by age (p=0.04) and tumor size (p=0.06). In moderately differentiated group, higher SUV showed significantly worse survival (p=0.02). SUV is related with histologic grade and might be competitive predictor for patients' survival Specifically, the prognosis of the patients with moderately differentiated pancreas adenocarcinoma could be stratified according to SUV. (author)

[en] The purpose of this study was to evaluate the usefulness of 18F-FDG PET/CT (PET/CT) in suspicious recurred thyroid cancer before high dose of radioactive iodine therapy (RAI therapy). PET/CT was performed after injecting 370-555MBq of 18F-FDG in 23 patients prior to RAI therapy. RAI therapy (212 58 mCi) was performed, and thyroglobulin (Tg) and anti-thyroglobulin antibody (anti-TG ab) during TSH stimulation was measured. The interval between PET/CT and RAI scan was 41 50 day. 15 patients were confirmed as recurred thyroid cancer (pathologic diagnosis: 10), whereas 8 patients were diagnosed as remission status (pathologic diagnosis: 3). PET/CT had 80.0% (12/15) of sensitivity and 75.0% (6/8) of specificity. TG and RAI scan had 80.0% (12/15) and 75% (6/8), 80% (12/15) and 37.5% (3/8) of sensitivity and specificity, respectively. Combination of PET/CT and TG increased the sensitivity (93.3%; 14/15) and specificity (87.5%; 7/8). There was 25 suspicious lesions (19 malignant lesion, 6 benign lesion) in lesion-based study. PET/CT had 84.5% and 83.3% of sensitivity and specificity but RAI scan had 89.5% and 16.7%, respectively. Five false positive sites of RAI scan were diagnosed as fungus ball of lung, calcified mediastinal LN, and post op induced change such as suture granuloma. PET/CT revealed 80% (3/5) of them as benign lesions. Even though PET/CT had similar sensitivity with high dose of RAI scan, it had a better discriminating nature to detect benign lesion. We could diminish the unnecessary high dose of RAI therapy using FDG PET/CT

[en] The aim of this study was to evaluate the adrenal FDG uptake in patients with lung cancer, and to assess the diagnostic performance. The aim of this study was to evaluate the adrenal FDG uptake in patients with lung cancer, and to assess the diagnostic performance of FDG PET in detecting adrenal metastasis. A total of 117 healthy subjects who underwent FDG PET/CT for cancer screening (M: F=74: 43, 50.011.3 yr) and 171 lung cancer patients who underwent FDG PET/CT for staging (M: F = 104: 67, age; 61.8 10.4 yr) were. The diagnosis of adrenal metastasis was confirmed by histology or radiologic follow-up. Maximal SUV of healthy subjects were 1.66 0.21 and 1.86 0.30 in right and left adrenal gland, and 2.77 0.37 in the liver. However, lung cancer patients had maximal SUV of 1.68 0.47, 1.64 0.39, and 2.15 0.49, respectively. SUV of liver was higher in healthy subjects group (p < 0.001). The ratio of adrenal gland to liver (AL ratio) in lung cancer were higher than that of normal subjects (0.61 0.10 vs. 0.78 0.14 in right adrenal gland, 0.68 0.12 vs. 0.78 0.14 in left adrenal gland; both of them: p < 0.001). From 24 adrenal masses of 22 lung cancer patients, 15 adrenal masses were proven as adrenal metastasis and the others were diagnosed as adrenal adenoma. We defined normal value of adrenal gland as mean + 2SD. The maximal SUV and AL ratio of lung cancer patients were 2.52 and 1.06, respectively. Both of them had a same sensitivity (86.7%) and specificity (88.9%). With ROC curves analysis, cut-off value of maxSUV and AL ratio on adrenal mass were 3.55 (area under curve = 0.900) and 1.21(area = 0.852). Sensitivity and specificity of maxSUV were 86.7% and 100% and AL ratio were 80.0% and 88.9%. Lung cancer patients had elevated adrenal FDG uptake than that of normal healthy subjects. Adrenal mass with maximal SUV over 3.55 could be considered as metastatic lesion in lung cancer patients