• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.333-336
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• 2008

A 52-year-old woman with a history of general weakness, fatigue, weight loss, elevated serum levels of liver transaminase enzyme for three months underwent an F-18 FDG PET/CT scan to evaluate a cause of the hepatosplenomegaly found on abdominal ultrasonography. Initial PET/CT revealed markedly enlarged liver and spleen with intense FDG uptake. Otherwise, there were no areas of abnormal FDG uptake in whole body image. Histological evaluation by a hepatic needle biopsy demonstrated diffuse large B cell type lymphoma and final diagnosis for this patient was hepatosplenic B-cell lymphoma. She received five cycles of CHOP chemotherapy, and second PET/CT scan was followed after then. Follow-up PET-CT revealed normal sized liver with disappearance of abnormal FDG uptake. Hepatosplenic B-cell lymphoma is relatively rare and mostly presents as single or multiple nodules.1,2 Diffuse type hepatosplenic lymphoma is extremely rare and poorly recognized entity.3 The diagnosis is very difficult and complicated by the presence of misleading symptoms.4 In this rare hepatosplenic B-cell lymphoma case, F-18 FDG PET/CT scan provided a initial diagnostic clue of hepatosplenic lymphoma and an accurate chemotherapy response.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.52-61
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• 2004

Purpose: Cervical lymph node metastasis is the most important factor of the prognosis and therapeutic planning in head and neck cancer. With increasing interest of minimally invasive neck surgery, more accurate preoperative assessment of cervical lymph node becomes more essential. We evaluated the diagnostic accuracy of $^{18}F$ FDG-PET in the assessment of lymph node metastasis in patients with primary head and neck cancer and compared the results with those of CT/MRI. Materials and Methods: Thirty-two patients (M/F=27/5, $56{\pm}10yr$) with biopsy proven head and neck cancer (16 supraglottic cancer, 9 tongue cancer, 7 others) underwent FDG-PET and CT/MRI (25/7) within 1 month before neck dissection. Based on lymph node level, the diagnostic sensitivity and specificity of FDG PET and CT/MRI for the metastasis of cervical lymph node were compared. Results: Of 153 lymph node levels dissected in 32 patients, 32 lymph node levels of 19 patients were positive for metastasis by histopatholologic examination. The overall sensitivity and specificity of FDG-PET were 88% (28/32) and 93% (113/121), whereas those of CT/MRI were 56% (18/32) (p=0.002) and 92% (112/121), respectively. The diagnostic sensitivity and specificity of FDG-PET were different according to location of lymph node levels, and those of ipsilateral level 11 were lower than those of other levels. Conclusion: FDG-PET is more sensitive in detecting metastatic cervical lymph node in head and neck cancer than CT/MRI. FDG-PET might be useful in guiding the extent of neck dissection.

• The Korean Journal of Nuclear Medicine
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• v.39 no.4
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• pp.263-265
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• 2005

A 25 years old male patient with Hodgkin's disease, considered as complete remission, underwent $^{18}F$-FDG whole body PET/CT. $^{18}F$-FDG whule body PET/CT showed unexpected hypermetabolic nodule in left quadratus femoris muscle suggesting local recurrence. Subsequent MRI also revealed well-enhancing nodular lesion with intermediate and high signal intensity on T1WI and T2WI, respectively. The lesion was confirmed as nodular fasciitis by pathologic examination of the excited specimen.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.1
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• pp.26-34
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• 2009

Purpose: The purpose of this study was to find out what clinicopathologic or immunohistochemical parameter that may affect FDG uptake of primary tumor in PET/CT scan of the gastric carcinoma patient. Materials and Methods: Eighty-nine patients with stomach cancer who underwent pre-operative FDG PET/CT scans were included. In cases with perceptible FDG uptake in primary tumor, the maximum standardized uptake value (SUVmax) was calculated. The clinicopathologic results such as depth of invasion (T stage), tumor size, lymph node metastasis, tumor differentiation and Lauren's classification and immunohistochemical markers such as Ki-67 index, expression of p53, EGFR, Cathepsin D, c-erb-B2 and COX-2 were reviewed. Results: Nineteen out of 89 gastric carcinomas showed imperceptible FDG uptake on PET/CT images. In cases with perceptible FDG uptake in primary tumor, SUVmax was significantly higher in T2, T3 and T4 tumors than T1 tumors ($5.8{\pm}3.1$ vs. $3.7{\pm}2.1$, p=0.002). SUVmax of large tumors (above or equal to 3 cm) was also significantly higher than SUVmax of small ones (less than 3 cm) ($5.7{\pm}3.2$ vs. $3.7{\pm}2.0$, p=0.002). The intestinal types of gastric carcinomas according to Lauren showed higher FDG uptake compared to the non-intestinal types ($5.4{\pm}2.8$ vs. $3.7{\pm}1.3$, p=0.003). SUVmax between p53 positive group and negative group was significantly different ($6.0{\pm}2.8$ vs. $4.4{\pm}3.0$, p=0.035). No significant difference was found in presence of LN metastasis, tumor differentiation, Ki-67 index, and expression of EGFR, Cathepsin D, c-erb-B2 and COX-2. Conclusion: T stage of gastric carcinoma influenced the detectability of gastric cancer on FDG PET PET/CT scan. When gastric carcinoma was perceptible on PET/CT scan, T stage, size of primary tumor, Lauren's classification and p53 expression were related to degree of FDG uptake in primary tumor.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.157-161
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• 2008

Malignant pleural mesothelioma (MPM) has a poor prognosis and a strong association with exposure to asbestos. Although there are not generally accepted guidelines for treatment of MPM, recent reports suggest that multi modality therapy combining chemotherapy, radiotherapy, and surgery can improve the survival of patients with MPM. Therefore exact staging is required to decide the best treatment option. However, it is well known that there are many difficulties in determining precise preoperative stage, predicting prognosis, and monitoring response to therapy with conventional imaging modalities such as CT and MRI in MPM. Recently PET with $^{18}F-FDG$ comes into the spotlight as an important staging method. There is increasing evidence that PET is superior to other conventional imaging modalities in diagnosis and staging of MPM. Particularly PET/CT improves the diagnostic and staging accuracy over PET or CT alone in MPM because it provides anatomic imaging data as well as functional information. PET and PET/CT are also useful for monitoring response to therapy and SUV is reported as a prognostic factor in MPM.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.499-504
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• 2009

F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET/CT) plays an important role in diagnosis of malignant tumors and adds to conventional imaging in the staging of pertoneal carcinomatosis. However, false positive cases resulting from benign disease such as tuberculosis may occur. We report two cases of peritoneal tuberculosis on F-18 FDG PET/CT which showed multiple hypermetabolic foci in the mesentery and peritoneum with increased serum cancer antigen 125 (CA 125). Subsequent F-18 FDG PET/CT showed a disappearance of pathologic uptake following treatment with anti-tuberculosis drugs.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.1
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• pp.49-53
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• 2007

Purpose: It was reported that CT-based measured attenuation correction (CT-MAC) produced radioactivity concentration values significantly higher than $^{68}Ge$-based segmented attenuation correction (Ge-SAC) in PET images. However, it was unknown whether the radioactivity concentration difference resulted from different sources (CT vs. Ge) or types (MAC vs. SAC) of attenuation correction (AC). We evaluated the influences of the source and type of AC on the radioactivity concentration differences between reconstructed PET images in normal subjects and patients. Material and Methods: Five normal subjects and 35 patients with a known or suspected cancer underwent $^{18}F-FDG$ PET/CT. In each subject, attenuation corrected PET images using OSEM algorithm (28 subsets, 2 iterations) were reconstructed by 4 methods: CT-MAC, CT-SAC, Ge-MAC, and Ge-SAC. The physiological uptake in normal subjects and pathological uptake in patients were quantitatively compared between the PET images according to the source and type of AC. Results: The SUVs of physiological uptake measured in CT-MAC PET images were significantly higher than other 3 differently corrected PET images. Maximum SUVs of the 145 foci with abnormal FDG uptake in CT-MAC images were significantly highest among 4 differently corrected PET images with a difference of 2.4% to 5.1% (p<0.001). The SUVs of pathological uptake in Ge-MAC images were significantly higher than those in CT-SAC and Ge-MAC PET images (p<0.001). Conclusion: Quantitative radioactivity values were highest in CT-MAC PET images. The adoption of MAC may make a more contribution than the adoption of CT attenuation map to such differences.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.110-112
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• 2008

Endometrial carcinoma is one of the most common gynecologic malignancies and which is predominant in postmenopausal women. Clinically many patients are hospitalized in early stage due to clinical sign and symptom such as vaginal bleeding and in this case, patient's prognosis is known to be good. However, considerable number of patients with advanced and relapsed disease reveal poor prognosis. Therefore, exact staging work up is essential for proper treatment as is primary lesion detection. $^{18}F-FDG-PET$ has been widely used for the evaluation of gynecologic malignancies such as cervical carcinoma and ovarian cancer. In contrast, FDG PET application to endometrial carcinoma is limited until now and there is no sufficient data to validate the usefulness of FDG PET for this disease yet. However, several studies showed promising results that FDG PET is sensitive and specific in detection of recurrent or metastatic lesions. Therefore further active investigation in this field can facilitate the use of FDG PET for endometrial carcinoma.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.116-120
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• 2008

Prostate cancer is the second leading cause of cancer death of men in western countries and the death related to this disease in Korea is also getting increased. Although anatomic imaging tools such as transrectal US or MRI have been playing a great role in detection of primary prostate lesion, the evaluation of regional lymph node or distant organ metastasis using these modalities is not successful. $^{18}F-FDG-PET$ scan is emerging diagnostic tool for various malignancies. Considering the usual characteristics of prostate cancer such as slow growing and osteoblastic metastasis, the application of FDG PET scan to this disease might be limited. However, in advanced prostate cancer refractory to chemotherapy, FDG PET scan show strong FDG uptake and SUV changes in serial PET scan can be a good indicator of treatment response. Although FDG PET can be useful only in limited cases of prostate cancer, its indication can be widened in future owing to rapid technical improvement and accumulated experiences in this field.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.41-47
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• 2013

Purpose: To evaluate the usefulness of Integrated PET/CT and compare the gloss tumor volume (GTV) identified on CT, PET, PET/CT to that obtained from fluorodeoxyglucose (FDG). Materials and Methods: This experimental study was obtained using GE Discovery 690 (General Electric Healthcare, Milwaukee, MI, USA) PET/CT simulator with Gammex Laser System for five non-small cell lung cancer (NSCLC) patients. In order to increase the reproducibility of the patient setup, We have to fixed to patients using the Extended Wing Board. GTV delineation was painted using the EclipseTM ver.10 contouring program for CT, PET, PET/CT images. And then, We were to compare the changes in the GTV. Results: These results are drawn from 5 patients who have atelectasis or pneumonitis. Compared to CT defined GTV, PET was decreased by 10.5%, 11.8% and increased by 67.9%, 220%, 19.4%. PET/CT was decreased by 7.7%, 6.7%, 28% and increased by 232%, 24%. Conclusion: We were able to determine the usefulness of PET/CT simulator for NSCLC. PET/CT simulator in radiation therapy is useful to define the target volume and It is possible to delineate Objective and accurate target volume. It seems to be applicable to other areas in the near future.