• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.126-129
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• 2008

Renal cell carcinoma is the most common histological type of renal malignancy, predominant in men and the primary treatment modality of this tumor is surgery. The role of diagnostic imaging in the management of this tumor is the evaluation of extent of disease as well as the detection and characterization of renal mass. US has long been a routine screening tool for kidney but tomographic imaging modalities such as CT and MRI begin to be also commonly used these days. On the other hand, the sensitivity of $^{18}F-FDG-PET$ in detection of renal mass is relatively low because of inherent limitation caused by FDG excretion pathway despite avid uptake of FDG to tumor cell per se. Many studies revealed FDG PET scan could play an important role in detection of metastatic lesions although the sensitivity for the detection of primary lesion is not so high. Furthermore, development of PET/CT scanner will make it possible to expand the indication of FDG PET scan in this malignancy.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.184-191
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• 2008

Purpose: To evaluate the degree of malignancy of incident thyroid lesion found in $^{18}F$-FDG PET/CT findings and the usefulness of the method suggested in this study, we applicate the Delay Scan Method that differentiate a false positive benign tumor, inflammation and malignancy, as well as make the criteria of SUV. Materials and Methods: A retrograde study was conducted of 800 patients who were admitted in E hospital to receive $^{18}F$-FDG PET/CT examination. One patient who was diagnosed as primary thyroid cancer and received $^{18}F$-FDG PET/CT examination was excluded. The number of final patients of this study was 799, the reasons of $^{18}F$-FDG PET/CT examination of these patients were follow-up of old cancer or suspicious tumorous lesion in 696 and disease screening in 103. $^{18}F$-FDG PET/CT image photographing was taken in Biograph-Duo made by SIEMENS, after taking normal $^{18}F$-FDG PET/CT image (1 hr) and then 1 hr later we took the thyroid 1 bed-delayed image for the patients who showed abnormal thyroid $^{18}F$-FDG uptake and above 2.0 SUV for 2 minutes every 1 bed. For the patients who showed abnormal thyroid uptake and above 2.0 SUV, 1 hr later, we took a 1 bed-delayed image and then made a comparative study between measured $SUV_{max}$ of 1 hr-abnormal uptake image and that of 2 hr-delayed image. Results and Conclusion: In this $^{18}F$-FDG PET/CT study among the patients who showed incidental $^{18}F$-FDG thyroidal uptake the number of thyroid incidentaloma was 5 (0.63%), all of then showed benign findings. And in the case of incidental $^{18}F$-FDG uptake in thyroid, $SUV_{max}$ variance obtained from 2 hr delayed image can be a indirect criteria in differentiating benign tumor from malignancy and decrease finding error. In the cases found thyroid incidentaloma when 1) $SUV_{max}$ of focal thyroid lesion is above 5.0 and 2) $SUV_{max}$ variance between normal $^{18}F$-FDG PET/CT exam and 2 hr delayed is $1.0{\pm}0.5$, they are suspected as malignancy and confirming biopsy is to be followed. Otherwise, I also think that distinct follow-up PET or CT image study is a reasonable diagnostic method.

• Journal of Gastric Cancer
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• v.18 no.3
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• pp.218-229
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• 2018

Purpose: This study investigated whether the metabolic avidity of primary tumors and/or metastatic lymph nodes (LNs) measured by $^{18}F$-fluorodeoxyglucose ($^{18}F-FDG$) positron emission tomography/computed tomography (PET/CT) was related to survival after surgery in patients with advanced gastric cancer (AGC). Materials and Methods: One hundred sixty-eight patients with AGC who underwent preoperative $^{18}F-FDG$ PET/CT and curative resection were included. The $^{18}F-FDG$ avidity of the primary gastric tumor and LNs was determined quantitatively and qualitatively. The diagnostic performance of $^{18}F-FDG$ PET/CT was calculated, and the prognostic significance of $^{18}F-FDG$ avidity for recurrence-free survival (RFS) and overall survival (OS) was assessed. Results: In all, 51 (30.4%) patients experienced recurrence, and 32 (19.0%) died during follow-up (median follow-up duration, 35 months; range, 3-81 months); 119 (70.8%) and 33 (19.6%) patients showed $^{18}F-FDG$-avid primary tumors and LNs, respectively. $^{18}F-FDG$ PET/CT showed high sensitivity (73.8%) for the detection of advanced pathologic T ($pT{\geq}3$) stage and high specificity (92.2%) for the detection of advanced pN (${\geq}2$) stage. $^{18}F-FDG$ avidity of LNs was significantly associated with RFS (P=0.012), whereas that of primary tumors did not show significance (P=0.532). Univariate and multivariate analyses revealed that $^{18}F-FDG$ avidity of LNs was an independent prognostic factor for RFS (hazard ratio=2.068; P=0.029). Conclusions: $^{18}F-FDG$ avidity of LNs is an independent prognostic factor for predicting RFS. Preoperative $^{18}F-FDG$ PET/CT can be used to determine the risk and prognosis of patients with AGC after curative resection.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.328-332
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• 2008

Simple bone cyst (SBC) is very rare in adult ribs. The diagnosis basically relies on conventional radiography and occasionally on a. There has been no earlier publication on PET/CT diagnosis of SBC. We report a case of adult costal SBC diagnosed by positive $^{18}F$-fluorodeoxyglucose (FDG) uptake. Histology showed the FDG uptake to be associated with reactive woven bone formation and nonspecific chronic inflammation. Correlation of PET, CT, plain radiography and sonography are also described.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.395-401
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• 2009

Purpose: We evaluated $^{18}F$-FDG PET/CT findings in initially diagnosed adenoid cystic carcinoma (ACC) of the head and neck in association with pathological subtype, staging, uptake comparison with squamous cell carcinoma (SqCC) and prognosis. Materials and Methods: The subjects were 16 patients with initially diagnosed ACC of head and neck who underwent pretreatment $^{18}F$-FDG PET/CT. Histological subtype (solid pattern vs. tubular/cribriform pattern), $SUV_{max}$ of size-matched SqCC of the head and neck as control group, disease-free survival (DFS) were compared with the $SUV_{max}$ of ACC of the head and neck. Results: Of total 16 patients, 6 had solid pattern and the remaining 10 had tubular/cribriform pattern. The $SUV_{max}$ were significantly higher in solid pattern group than in tubular/cribriform pattern group ($6.7{\pm}3.2$ vs. $4.2{\pm}0.9$, p=0.03). PET/CT found unexpected distant metastasis in 18.7% of patients (3/16) and changed the therapeutic plan in those patients. The $SUV_{max}$ of ACC was significantly lower than that of size-matched SqCC ($5.1{\pm}2.4$ vs. $13.6{\pm}6.0$, p<0.001). DFS was not significantly different according to the histological subtype. In contrast, patients with high $^{18}F$-FDG uptake ($SUV_{max}$ ${\geq}$6.0) had significantly shorter DFS than those with low $^{18}F$-FDG uptake ($SUV_{max}$ <6.0). Conclusion: $^{18}F$-FDG uptake of ACC of the head and neck is significantly associated with histological subtype and DFS. $^{18}F$-FDG PET/CT may be useful for detecting unexpected metastasis. Since $^{18}F$-FDG uptake of tubular/cribriform ACC compared with SqCC is relatively low, it is necessary to interpret PET images carefully in patients without alleged ACC.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.1
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• pp.42-48
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• 2007

Purpose: The purpose of this study is to image metastaic lung melanoma model with optimal pre-conditions for animal handling by using $[^{18}F]FDG$ small animal PET and clinical CT. Materials and Methods: The pre-conditions for lung region tumor imaging were 16-22 h fasting and warming temperature at $30^{\circ}C$. Small animal PET image was obtained at 60 min postinjection of 7.4 MBq $[^{18}F]FDG$ and compared pattern of $[^{18}F]FDG$ uptake and glucose standard uptake value (SUVG) of lung region between Ketamine/Xylazine (Ke/Xy) and Isoflurane (Iso) anesthetized group in normal mice. Metastasis tumor mouse model to lung was established by intravenous injection of B16-F10 cells in C57BL/6 mice. In lung metastasis tumor model, $[^{18}F]FDG$ image was obtained and fused with anatomical clinical CT image. Results: Average blood glucose concentration in normal mice were $128.0{\pm}23.87$ and $86.0{\pm}21.65\;mg/dL$ in Ke/Xy group and Iso group, respectively. Ke/Xy group showed 1.5 fold higher blood glucose concentration than Iso group. Lung to Background ratio (L/B) in SUVG image was $8.6{\pm}0.48$ and $12.1{\pm}0.63$ in Ke/Xy group and Iso group, respectively. In tumor detection in lung region, $[^{18}F]FDG$ image of Iso group was better than that of Ke/Xy group, because of high L/B ratio. Metastatic tumor location in $[^{18}F]FDG$ small animal PET image was confirmed by fusion image using clinical CT. Conclusion: Tumor imaging in small animal lung region with $[^{18}F]FDG$ small animal PET should be considered pre-conditions which fasting, warming and an anesthesia during $[^{18}F]FDG$ uptake. Fused imaging with small animal PET and CT image could be useful for the detection of metastatic tumor in lung region.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.352-356
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• 2009

Intravascular large B-cell lymphoma (IVLBCL) is a subtype of diffuse large cell lymphoma, characterized by proliferation of lymphoid cells in the intravascular space of various organs without causing a mass effect. Although $^{18}$F-FDG PET is a powerful imaging tool in lymphoma, the usefulness of $^{18}$F-FDG PET in the assessment of IVLBCL is still controversial. $^{99m}$Tc-MIBI, a tumor imaging radiopharmaceutical with a different mechanism from that of $^{18}$F-FDG, has been reported to be also effective in lymphoma. However, there is nearly no report on the efficacy of $^{99m}$Tc-MIBI in the assessment of IVLBCL. We present one case of IVLBCL that showed $^{99m}$Tc-MIBI accumulation in the involved bone marrow as an incidental finding, which was discrepant from that of $^{18}$F-FDG PET.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.570-573
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• 2007

We present a case of infected abdominal aortic aneurysm due to salmonella enteritidis. F-18 FDG PET/CT was performed to diagnosis and during follow-up after antibiotic treatment. Computed tomography (CT) is considered to be the best diagnostic imaging modality in infected aortic lesions. In this case, a combination of CT and FDG PET/CT provided accurate information for the diagnosis of infected abdominal aortic aneurysm. Moreover, FDG PET/CT made an important contribution to monitoring disease activity during antibiotic treatment.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.538-545
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• 2007

Purpose: We evaluated correlation of $^{18}F$-FDG uptakes, therapeutic response and relapse in pre-treatment $^{18}F$-FDG PET/CT in patients with SCLC. Materials and methods: We included 26 patients with pathologically proven small cell lung cancer. Total 102 lesions (26 lungs, 69 lymph nodes and 8 metastatic lesions) were evaluated. All patients underwent $^{18}F$-FDG PET/CT for staging. The maxSUV was used as a parameter of $^{18}F$-FDG uptake. The patients were divided into responders and non-responders according to response criteria on chest CT scan after 3 cycles of chemotherapy. We compared maxSUV between two groups by using independent t-test. To access correlation with $^{18}F$-FDG uptake and relapse, maxSUV and interval time to relapse was analyzed by correlation analysis. The cutoff value of maxSUV was evaluated by ROC curve. Results: Twelve-one patients (81%) were responders and five patients were non-responders on follow-up chest CT scan. The mean maxSUV of main lung lesions in responders and non-responders were $14.15{\pm}3.72$ and $9.17{\pm}2.15$, respectively. The maxSUV in the responders was significantly lower than that in non-responders (p<0.05). According to ROC curve, point of cut that predicts therapeutic response was 8.98 with 100% sensitivity and 57% specificity. The correlation analysis between $^{18}F$-FDG uptakes and interval time to relapse showed a significant negative correlation (p<0.05, r=-0.757). Conclusion: The pre-treatment $^{18}F$-FDG uptake of responders was significantly lower than that of non-responders. Patients with high $^{18}F$-FDG uptake in pre-treatment $^{18}F$-FDG PET/CT relapse earlier.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.150-153
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• 2009

Xanthogranulomatous pyelonephritis is an uncommon chronic renal infection, which is usually found on middle-aged women and is rare in infant. Sometimes it forms focal mass like lesion of kidney with pathologically characteristic lipid-laden macrophage. A 1-month female infant was admitted for fever and moaning sound. On work-up of urinary tract infection, abdomen ultrasonography and computed tomography revealed a large mass on the upper portion of right kidney and PET/CT showed homogeneously increased $^{18}F$-FDG uptake. The radical nephrectomy of right kidney was performed and histology revealed a focal xanthogranulomatous pyelonephritis. To our knowledge, this is the first report presenting the finding of $^{18}F$-FDG PET/CT in the childhood xanthogranulomatous pyelonephritis.