• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.65-69
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• 2011

Purpose: Normal pancreas has low uptake rate in $^{18}F$-FDG PET scan. However, it is possible to diagnose malignancy of pancreatic cancer which has high uptake rate. Many studies approve a high prevalence of diabetes in pancreatic cancer and if the blood glucose level (BGL) is over the normal range, FDG uptake will be decreased and there will be inconvenience for patients from the delay time to reduce the high BGL or could cause difficulty to arrange the schedule. Therefore, we studied the relation of BGL and image quality in pancreatic cancer on PET. Materials and Methods: A hundred patients had PET scan. The prevalence of pancreatic cancer and diabetes were evaluated using SPSS ver. 17. The fasting BGL of patients were examined and sorted as diabetes mellitus (DM) group and Non-DM group. For the evaluation, patients were divided into 3 groups (Non-DM, DM; BGL${\geq}7.0mmol/L$, and DM; BGL<7.0 mmol/L). The ROI was drown on Liver and Lung for the PET imaging analysis. Results: Fifty three male and forty seven female were in the patients. The average age was $60.1{\pm}13.5$. There were 36 patients (male: 22, female: 14, 36%) who had pancreatic cancer with DM. There were 15 patients who showed over 7.0 mmol/L in their fasting BGL and 85 patients who showed under 7.0 mmol/L in their fasting BGL. Among the Non-DM, DM; BGL${\geq}7.0mmol/L$, and DM; BGL<7.0 mmol/L, there was not a statistical significance (p>0.05). Conclusion: The prevalence of pancreatic cancer was comparatively high in this study. If the fasting BGL was slightly over the normal BGL, we believe it will not give a severe disturbance when the patients have PET scan. Furthermore, the examination schedule doesn't need to change and the inconvenience from the delay of patients preparation will be reduced.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.45-50
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• 2011

Purpose: It appears the different value when the injection dose is calculating for patients on each PET/CT systems. It directly affects the technologists' radiation exposed dose. We studied the effect of the variable injection doses from several PET/CT systems to exposure dose for technologists. Materials and Methods: Six technologists have worked for 5 months through unit rotations with 3 PET/CT systems {Scanner 1 (S1): 0.15 mCi/kg, Scanner 2 (S2): 0.17 mCi/kg, Scanner 3 (S3): 0.12 mCi/kg}. Eighteen to 19 patients have had examinations per a day on each PET/CT systems. Examination parameters were adjusted to the same. TLDs were used for checking the exposure dose of technologists. Results: Each technologists' the monthly average exposure dose was as follows; S1: 0.76 mSv, S2: 0.93 mSv, S3: 0.47 mSv. The maximum exposure dose was 1.12 mSv, and minimum was 0.42 mSv. The results showed significance in the correlation between the PET/CT system and the exposure dose (p<0.005). Conclusion: When the amount of injection dose was small, the exposure dose was decreased not only the patients but also the technologists. The exposure dose was decreased by the individual proficiency of technologists. However, the low injection dose can highly reduce the exposure dose for technologist so that there will be needed to following studies.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3333-3338
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• 2015

Background: This study was conducted to analyze positron emission tomography (PET) / computed tomography (CT) and magnetic resonance imaging (MRI) performance with oropharyngeal non-Hodgkin's lymphoma (ONHL).Materials and Methods: The complete image data of 30 ONHL cases were analyzed, all patients were performed PET / CT and MRI examination before the treatment, with the time interval of these two inspections not exceeding 14 days. The distribution, morphology, MRI signal characteristics, enhancement feature, standardized uptake value (SUV) max value and lymph node metastasis way of the lesions were analyzed. Results: Among the 30 cases, 23 cases were derived from the B-cell (76.7%), 5 cases were derived from the peripheral T cells (16.7%) and 2 cases were derived from the NK/T cells (6.7%). 19 cases exhibited the palatine tonsil involvement (63.3%). As for the lesion appearance, 10 cases appeared as mass, 8 cases were the diffused type and 12 cases were the mixed type. 25 cases exhibited the SUVmax value of PET / CT primary lesions as 11 or more (83.3%). MRI showed that all patients exhibited various degrees of parapharyngeal side-compressed narrowing, but MRI still exhibited the high-signal fat, and the oropharyngeal mucosa was intact. 25 cases were associated with the neck lymph node metastasis, among who 22 cases had no necrosis in the metastatic lymph nodes, while the rest 3 cases exhibited the central necrosis in the metastatic lymph nodes. Conclusions: PET / CT and MRI have important value in diagnosing and determining the lesion extent of ONHL.

• The Korean Journal of Nuclear Medicine
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• v.36 no.1
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• pp.39-45
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• 2002

Clinical application of positron emission tomography (PET) is rapidly increasing for the defection and staging of cancer at whole-body studios performed with the glucose analogue tracer 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in the liver and the other abdominal organs, it is particularly useful for identification and characterization of the entire body simultaneously. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterizing of indeterminate soft-tissue masses. Most abdominal cancer requires surgical management. FDG PET can improve the selection of patients for surgical treatment and thereby reduce the morbidity and mortality associated with inappropriate surgery. FDG PET is also useful for the early detection of recurrence and the monitoring of therapeutic effect. The abdominal cancers, such as gastroesophageal cancer, colorectal cancer, liver cancer and pancreatic cancer, are common malignancies in Korea, and PET is one of the most promising and useful methodologies for the management of abdominal cancers.

• 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.42 no.2
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• pp.137-144
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• 2008

Positron emission tomography-computed tomography (PET/CT) provides both functional and anatomical images of high quality non-invasively with better precision in localization than PET alone. Increase in the use of PET/CT, coupled with increasing concerns about the quality of medical services accrued the demands for accurate evaluation of system performance and quality assurance. Thus, well designed programs for performance evaluation and quality assurance are needed. Widely used protocols for performance evaluation of PET are the methods proposed by National Electrical Manufacturers Association (NEMA) in 1994 and 2001. In addition, in order to maintain high quality of PET/CT images, quality assurance programs including periodic (daily, monthly, and yearly). Therefore, in this article, the methods and present state of performance evaluation and quality assurance of PET/CT are reviewed.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.700-704
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• 2010

Background: For staging primary lung cancer, integrated positron emission tomography/computed tomography (PET/CT) imaging is popular. The purpose of this study was to evaluate the accuracy of PET/CT scanning in lymph nodal staging of lung cancer. Material and Method: We studied 48 patients who had received CT, PET/CT and pulmonary resections due to primary non-small cell lung cancer in our hospital between January 2006 and August 2009. Mediastinal lymph nodes were classified as superior mediastinal nodes, aortic nodes, inferior mediastinal nodes, or N1 nodes. We compared the power of CT and PET/CT for diagnosing pulmonary lymph nodes for each of the four types of nodes. Result: PET/CT was more sensitive than CT for all groups except inferior mediastinal nodes. However, the differences were not significant (McNemar's test: superior mediastinal nodes, p=0.109; aortic nodes, p=1.000; inferior mediastinal nodes, p=0.625, N1 nodes, p=0.424). Conclusion: The accuracy of PET/CT is similar to that of CT alone for staging lymph nodes. The two imaging modalities might be used as complementary, cooperative tools. We expect that integrated PET/CT will be found to be significantly mmore sensitive after more trials are done and more data is accumulated.

• 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.41 no.3
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• pp.247-251
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• 2007

A 38-year-old man who was diagnosed with malignant paraganglioma underwent computed tomography (CT) and I-131 metaiodobenzylguanidine (MIBG) san. CT showed extensive lymph node enlargement in right iliac area and retroperitoneum with severe hydronephrosis and mass on posterior bladder wall. However, I-131 MIBG scan didn't showed abnormal uptake. He also underwent F-18 fluorodeoxyglucose (FDG) positron emisson tomography/CT for localizing accurate tumor site. F-18 FDG PET/CT showed multiple metastases of left supraclavicular, hilar, mediastinal para-aortic, inguinal, right iliac lymph nodes, lung, vertebrae, and pelvis. There are a few reports showing that the F-18 FDG PET/CT is helpful for staging and localizing tumor site of patients who are diagnosed with negative on the MIBG scans. Thus, we report a case with paraganglioma which showed negative I-131 MIBG scan, but revealed multiple intense hypermetabolic foci in F-18 FDG PET/CT.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10057-10059
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• 2015

Positron emission tomography (PET) as the functional component of current hybrid imaging (like PET/CT or PET/MRI) seems to dominate the horizon of medical imaging in coming decades. $^{18}$Flourodeoxyglucose ($^{18}FDG$) is the most commonly used probe in oncology and also in cardiology and neurology around the globe. However, the major capital cost and exorbitant running expenditure of low to medium energy cyclotrons (about 20 MeV) and radiochemistry units are the seminal reasons of low number of cyclotrons but mushroom growth pattern of PET scanners. This fact and longer half-life of $^{18}F$ (110 minutes) have paved the path of a centralized model in which $^{18}FDG$ is produced by commercial PET radiopharmacies and the finished product (multi-dose vial with tungsten shielding) is dispensed to customers having only PET scanners. This indeed reduced the cost but has limitations of dependence upon timely arrival of daily shipments as delay caused by any reason results in cancellation or rescheduling of the PET procedures. In recent years, industry and academia have taken a step forward by producing low energy, table top cyclotrons with compact and automated radiochemistry units (Lab-on-Chip). This decentralized strategy enables the users to produce on-demand doses of PET probe themselves at reasonably low cost using an automated and user-friendly technology. This technological development would indeed provide a real impetus to the availability of complete set up of PET based molecular imaging at an affordable cost to the developing countries.