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The purpose of this study was to evaluate the predictive features of baseline F-18-fluorodeoxy-D-glucose positron emission tomography (18F-FDG PET)/computed tomography (CT) parameters in patients with dedifferentiated liposarcomas (DDLPSs) and well-differentiated liposarcomas (WDLPSs) receiving systemic treatment. A total of 24 patients with liposarcoma who underwent longitudinal 18F-FDG PET/CT in systemic therapy were included. All volumetric segmentation of each tumor section and semiquantitative imaging parameters were extracted from the axial field of view from both PET and CT images. Maximum, mean, and minimum standardized uptake values (SUVmax, SUVmean, and SUVmin), Hounsfield units (HUs), and their respective changes from baseline and posttreatment were calculated. The voxel values from unenhanced CT images were correlated with PET-derived parameters. The 18F-FDG uptake decreased by more than 56% on average in responders for both SUVmax and SUVmean in DDLPS. There was a decrease in HUmax in DDLPS among responders. Using AUC > 0.8 as a reasonable predictor, we found that the ratios of SUVmaxD/HUmean, SUVmaxD/HUmedian, and SUVmeanD/HUmedian at baseline were significant indicators of the response to treatment in patients with liposarcoma. The changes in SUVmean and not just SUVmax parameters could be considered as accurate tumor response indicators. For the first time, we introduced baseline SUV/HU ratios as a valuable diagnostic tool in predicting liposarcoma treatment outcomes. This ability was not revealed by classic semiquantitative PET or CT parameters at baseline. [ABSTRACT FROM AUTHOR]

Malignancy may lead to sarcoidosis, which is referred to as sarcoid reaction. This reaction is believed to be a host immune response to the release of soluble antigens from cancer cells. Studies have shown strong 2′-deoxy-2′-[F-18]fluoro-D-glucose (F-18 FDG) uptake in sarcoid reaction and in true sarcoidosis. Therefore, in patients with malignancy, sarcoid reactions can mimic metastasis or recurrence on F-18 FDG positron emission tomography/computed tomography (PET/CT). Herein, we report the case of a 58-year-old woman with a history of left breast cancer whose FDG PET/CT evaluated at 3 months after adjuvant chemotherapy presented hypermetabolic lymphadenopathy in the right supraclavicular and right mediastinal areas. We interpreted these as metastases because the involved lymph nodes were intensely hypermetabolic and appeared newly. Pathologic evaluation of the excised lymph node revealed noncaseating chronic granulomas without malignant cells, indicating a sarcoid reaction. After appropriate steroid therapy, both the size and metabolic activity of the lymphadenopathy substantially decreased. Most sarcoid reactions present as bilateral hilar and peribronchial lymphadenopathies. Our patient presents an atypical example that a sarcoid reaction can also present in a unilateral pattern, making its diagnosis challenging. When interpreting FDG PET/CT images, considering that the sarcoid reaction pattern can vary is crucial.

The aim of the current meta-analysis was to evaluate diagnostic accuracies of preoperative F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) for prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) patients. The scientific database such as PubMed, Cochrane, and Embase database were searched for studies evaluating diagnostic accuracies of preoperative F-18 FDG PET or PET/CT for prediction of MVI in HCC patients up to November 30, 2020. Fourteen eligible studies (1276 patients) were enrolled. The pooled sensitivity for F-18 FDG PET or PET/CT was 0.67 (95% CI; 0.57–0.76) with heterogeneity and a pooled specificity of 0.80 (95% CI; 0.74–0.85) with heterogeneity. Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 3.3 (95% CI; 2.5–4.5) and negative likelihood ratio (LR−) of 0.41 (95% CI; 0.31–0.55). The pooled diagnostic odds ratio (DOR) was 8 (95% CI; 5–14). Summary receiver operating characteristic (ROC) curve indicates that the area under the curve was 0.81 (95% CI; 0.78–0.84). The current meta-analysis showed a low sensitivity and moderate specificity of F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients. F-18 FDG PET or PET/CT might not be useful for the preoperative prediction of MVI in HCC patients and should not be used to exclude MVI. Therefore, cautious application and interpretation should be paid to the F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients preoperatively. • Predictive value of F-18 FDG PET/CT for MVI in HCC was assessed. • F-18 FDG PET/CT showed moderate diagnostic value for MVI in HCC patients. • F-18 FDG PET/CT might not be useful for prediction of MVI in HCC patients. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the current study was to compare the diagnostic accuracies of F-18 FDG PET/CT and MRI for prediction of pathologic responses to neoadjuvant treatment (NAT) in locally advanced rectal cancer (LARC) patients based on a systematic review and meta-analyses. Methods: The PubMed, Cochrane, and Embase databases were searched to identify studies that conducted direct comparisons of the diagnostic performance of F-18 FDG PET/CT and MRI for the prediction of pathologic response to NAT in patients with LARC from the earliest available date of indexing up to July 31, 2020. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR + and LR −), and we constructed summary receiver operating characteristic curves. Results: In nine studies (427 patients), the pooled sensitivity of F-18 FDG PET/CT was 0.79 (95% CI 0.71–0.86) and the pooled specificity was 0.74 (95% CI 0.60–0.84). LR syntheses yielded an overall LR + of 3.1 (95% CI 1.9–5.0) and an LR − of 0.28 (95% CI 0.18–0.43). The pooled diagnostic odds ratio (DOR) was 11 (95% CI 5–26). The pooled sensitivity of MRI was 0.89 (95% CI 0.77–0.95) and the pooled specificity was 0.66 (95% CI 0.55–0.76). LR syntheses yielded an overall LR + of 2.6 (95% CI 1.9–3.6) and an LR − of 0.17 (95% CI 0.08–0.37). The pooled DOR was 15 (95% CI 6–42). In meta-regression analysis, no variable was identified as the source of the study heterogeneity. Conclusion: F-18 FDG PET/CT and MRI showed similar diagnostic performances for the prediction of pathologic responses to NAT in patients with LARC. However, each modality can be a complement to other rather than being used singly. [ABSTRACT FROM AUTHOR]

Introduction:Elastofibroma dorsi (ED) is a rare, benign and slowly growing connective tissue tumor that is frequently observed in the subscapular region in elderly people. It can be detected with various imaging modalities, such as computed tomography (CT), magnetic resonance imaging, ultrasonography and positron emission tomography (PET). In this retrospective study, the clinical features of EDs detected in PET/CT examinations performed for malignant or nonmalignant causes were evaluated.Methods:In this retrospective study, PET/CT examinations performed between May 2014 and December 2017 in a single institution for oncological and non-oncological diseases were evaluated retrospectively. Anatomical dimensions of the lesions were evaluated on axial CT sections. The metabolic activities or receptor expression status of the lesions were evaluated according to the SUVmax values obtained from the region of interests drawn on the lesions detected in PET scans.Results:A total of 7300 PET/CT reports were searched for term “ED” and the images of patients with ED were re-evaluated. ED was detected in 174 scans of 131 patients (97 female and 34 male; mean age: 62.13±8.6 years). The prevalence of ED was 1.79%. Bilateral ED was detected in 116 patients (88.5%) and 15 patients (11.5%) had unilateral ED. The mean diameter was 2.6x4.9±1.1x1.9 cm, and mean SUVmax value was 2.46±0.74. There were statistically significant differences regarding SUVmax values and measured dimensions (p=0.001).Conclusion:In this study, the prevalence and demographic patterns of ED were demonstrated with F-18 fluorodeoxyglucose and Ga-68 DOTATATE PET-CT. Knowledge of the distribution and uptake patterns of PET agents and their physiological uptake sites will prevent unnecessary procedures and interventions.

Introduction:F-18 radioisotope has higher photon energy when compared with other radioisotopes that are preferred in conventional imaging procedures in nuclear medicine. The aim of this study was to measure external radiation dose rate from patients injected with F-18 fluorodeoxyglucose (FDG) and to determine appropriate discharge time after F-18 FDG positron emission tomography/computed tomography (PET/CT) procedure.Methods:Our study included 29 (M/F=9/20) patients who were referred to nuclear medicine department for F-18 FDG PET/CT imaging. Dose rates were measured at a distance of 0, 0.5, 1, 1.5 and 2 m from patients via Geiger-Müller probe at 3 different time points: 1) Just after the intravenous injection of F-18 FDG, 2) before PET/CT imaging and 3) just before discharge of patients from PET/CT department. Statistical analysis was performed to evaluate the differences between measurements.Results:Patients were injected 291±62 megabecquerel (MBq) (range: 226-440 MBq) F-18 FDG via IV route. The patients stayed in nuclear medicine department for 70.3±13.8 min (range: 53 min-100 min) after injection of F-18 FDG. Radiation dose velocity measurements taken at a distance of 1 meter were 39.7±11.9 μSv/h just after the injection, 21.1±4.5 μSv/h before PET/CT examination and 14.3±2.9 μSv/h just before discharge.Conclusion:Although F-18 has high photon energy, its halflife is relatively short and this makes F-18 FDG an ideal radiopharmaceutical for PET/CT imaging. When the PET/CT scan is terminated, the dose rate measurements of the patients at a distance of 1 m are appropriate for discharge according to Turkish Atomic Energy Authority regulations. Therefore, patients can be safely discharged by explaining the necessary radiation safety measures after completing F-18 FDG PET/CT imaging.

Abstract Background The low sensitivity of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the evaluation of metastatic lymph nodes (LNs) is mainly due to the partial volume effect in patients with rectal cancer. This retrospective study evaluated the diagnostic accuracy of F-18 FDG PET/CT with optimal cut-off values of the maximum standardized uptake value (SUVmax), according to LN size, for the evaluation of regional LN in rectal cancer patients. Methods This study included 176 patients with rectal cancer who underwent F-18 FDG PET/CT for initial staging. Patients were classified based on the long-axis diameter of the regional LN on CT images as small (≤ 7 mm; n = 118) and large (> 7 mm; n = 58) LN groups. The optimal cut-off value of SUVmax was determined for each group, using receiver operating characteristic curve analysis. Areas under the curve (AUC) were compared by C-statistics using two methods: the cut-off value of SUVmax optimized according to LN size, and a fixed SUVmax cut-off value of 2.5. Results The optimal cut-off values of SUVmax for the small and large LN groups were 1.1, and 2.1, respectively. The sensitivity, specificity, and accuracy of F-18 FDG PET/CT using the optimal cut-off values were 90.6, 70.9, and 76.3% in the small LN group, and 68.6, 78.3, and 72.4% in the large LN group. The sensitivity, specificity, and accuracy of F-18 FDG PET/CT using the fixed cut-off value were 18.8, 100, and 78.0% in the small LN group, and 51.4, 87.0, and 65.5% in the large LN group. The AUC was significantly higher using the optimal cut-off values than the fixed cut-off value (0.808 vs. 0.594, p = 0.005) in the small LN group, but not in the large LN group (0.734 vs. 0.692, p = 0.429). Conclusions Application of the lower cut-off value of SUVmax improves the diagnostic performance of F-18 FDG PET/CT for the evaluation of small regional LNs in patients with rectal cancer.

Objective: The purpose of the current study was to investigate the diagnostic performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for diagnosis of cardiac sarcoidosis (CS) through a systematic review and meta-analysis. Methods: The PubMed and EMBASE database, from the earliest available date of indexing through 31 March 31, 2018, were searched for studies evaluating the diagnostic performance of F-18 FDG PET or PET/CT for CS. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR−), and constructed summary receiver operating characteristic (SROC) curves. Results: Across 17 studies (891 patients), the pooled sensitivity was 0.84 [95% confidence interval (95% CI) 0.71-0.91] with heterogeneity (I2 = 77.5) and a pooled specificity of 0.83 (95% CI 0.74-0.89) with heterogeneity (I2 = 80.0). Likelihood ratio (LR) syntheses gave an overall LR+ of 4.9 (95% CI 3.3-7.3) and LR− of 0.2 (95% CI 0.11-0.35). The pooled diagnostic odds ratio was 27 (95% CI 14-55). Hierarchical SROC curve indicates that the area under the curve was 0.90 (95% CI 0.87-0.92). Meta-regression showed that combined myocardial perfusion imaging was the source of heterogeneity. Conclusion: The current meta-analysis showed the moderate sensitivity and specificity of F-18 FDG PET or PET/CT for diagnosis of CS. The presence of combined myocardial perfusion imaging could improve diagnostic accuracy of F-18 FDG PET or PET/CT for diagnosis of CS. At present, the literature regarding the use of F-18 FDG PET for detection of CS remains limited; thus, further large multicenter studies would be necessary to substantiate the diagnostic accuracy of F-18 FDG PET for diagnosis of CS. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to investigate the diagnostic performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the differentiation of benign and malignant vertebral compression fractures (VCFxs) through a systematic review and meta-analysis. MEDLINE via PubMed, Cochrane, Scopus, and Embase database, from the earliest available date of indexing through September 30, 2019, were searched for studies evaluating the diagnostic performance of F-18 FDG PET or PET/CT for the differentiation of malignant VCFxs. We determined the sensitivities and specificities across the studies, calculated the positive and negative likelihood ratios (LR+ and LR−, respectively), and constructed summary receiver operating characteristic curves. For the 5 studies (274 patients), the pooled sensitivity was 0.96 (95% confidence interval [CI], 0.82–0.99) without heterogeneity (I 2, 50.6) and 0.77 (95% CI, 0.56–0.89) with heterogeneity (I 2, 76.1). LR syntheses gave an overall LR+ of 4.1 (95% CI, 2.1–8.0) and LR− of 0.05 (95% CI, 0.01–0.23). The pooled diagnostic odds ratio (DOR) was 78 (95% CI, 19–316). The hierarchical summary receiver operating characteristic curve indicates that the areas under the curve was 0.94 (95% CI, 0.92–0.96). The results of the present meta-analysis have shown high sensitivity and moderate specificity for F-18 FDG PET and PET/CT for differentiation of malignant VCFxs. At present, the reported data regarding the use of F-18 FDG PET for differentiation of malignant VCFxs remain limited; thus, further large multicenter studies are necessary to substantiate the diagnostic accuracy of F-18 FDG PET for the differentiation of malignant VCFxs. [ABSTRACT FROM AUTHOR]

Objective: Langerhans cell histiocytosis (LCH) is a very rare disease. The use of F-18 FDG PET/CT in LCH has recently become widespread. In this study, we aimed to investigate the role of F-18 FDG PET/CT in LCH cases. Material-Method: Eleven patients (mean age 23.09±19.02 (1-56); 6 males, 5 females) who underwent F-18 FDG PET/CT histopathologically diagnosed as LCH between 2014-2019 were included in the study. A total of 27 F-18 FDG PET/CT images were evaluated. SUVmax values of hypermetabolic lesions were calculated automatically. F-18 FDG PET/CT findings and other imaging methods (bone scintigraphy, computed tomography and magnetic resonance imaging) were compared. Results: F-18 FDG PET/CT was positive in 8/11 patients. The SUVmax mean value was calculated as 5.80±1.97. Seven (63.6%) patients were in single system (SS) and 4 (36.4%) were in multiple system-risk organ (MS-R) group. No statistically significant difference was observed between the single system-single lesion (SS-SL) and single systemmultiple lesion (SS-ML)/ML-R subgroups in terms of SUVmax values of the lesions (4.67±1.34 and 6.48±2,09, p=0.23). F-18 FDG PET/CT shows bone, bone marrow, skin, lymph node, lung, pituitary, kidney and pancreas involvement. While F-18 FDG PET/CT was concordant with other imaging methods in 5/11 patients, F-18 FDG PET/CT was found to be superior to other imaging methods in 4/11 patients. F-18 FDG PET/CT was also false negative in 2/11 patients. Partial/complete metabolic response was detected in 6 patients who underwent F-18 FDG PET/CT after treatment, and reactivation was detected in 2 patients. Conclusions: F-18 FDG PET/CT can be used for staging, response to treatment and reactivation in LCH patients. In particular, it is superior to other imaging modalities except for small and cystic lung lesions in the differentiation of active/inactive lesions. [ABSTRACT FROM AUTHOR]

Eccrine carcinoma is an extremely rare malignant skin cancer arising from eccrine sweat glands with a high metastatic potential. It mainly occurs in the elderly, with equal incidence in both sexes. It usually spreads to regional lymph nodes, with liver, lungs, and bones being the most common sites of distant metastasis. Because of tumor rarity, little is known about the value of F18- FDG PET/CT in evaluating this disease. Our case report aims to increase current knowledge of F18- FDG PET/CT in eccrine sweat gland carcinoma as a noninvasive imaging tool for assessing the extension of the disease and detecting distant metastases. We reported a -96year-old man who presented with as lowly progressive, ill-margined erythematous papules and nodules with a crusted and eroded involving multiple sites of groin, scrotum, penis, left pelvic wall, left hip and left thigh for >3 years, which became extensive in the past 2 months. The histologic investigation confirmed the diagnosis of an eccrine carcinoma. He was performed F18- FDG PET/CT to further evaluate the lesions. FDG PET/ CT imaging revealed FDG uptake at the extensive skin lesion, involvement of lymph nodes, and multiple FDG-avid of liver, skeletal and lung metastases.

Copyright of Istanbul Medical Journal is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: The purpose of the current study was to investigate the diagnostic performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the prediction of v-Ki-ras-2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation in colorectal cancer (CRC) patients through a systematic review and meta-analysis. Methods: The PubMed and EMBASE database, from the earliest available date of indexing through April 30, 2018, were searched for studies evaluating the diagnostic performance of F-18 FDG PET/CT for prediction of KRAS mutation in CRC patients. Results: Across 9 studies (804 patients), the pooled sensitivity for F-18 FDG PET/CT was 0.66 (95% CI 0.60–0.73) without heterogeneity (I2 = 34.1, p = 0.14) and a pooled specificity of 0.67 (95% CI 0.62–0.72) without heterogeneity (I2 = 1.63, p = 0.42). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 2.0 (95% CI 1.7–2.4) and negative likelihood ratio (LR−) of 0.5 (95% CI 0.41–0.61). The pooled diagnostic odds ratio (DOR) was 4 (95% CI 3–6). Hierarchical summary receiver operating characteristic (ROC) curve indicates that the areas under the curve were 0.69 (95% CI 0.65–0.73). Conclusion: The current meta-analysis showed the low sensitivity and specificity of F-18 FDG PET/CT for prediction of KRAS mutation in CRC patients. The DOR was very low and the likelihood ratio scatter-gram indicated that F-18 FDG PET/CT might not be useful for prediction of KRAS mutation and not for its exclusion. Therefore, cautious application and interpretation should be paid to the F-18 FDG PET/CT for prediction of KRAS mutation in CRC patients. [ABSTRACT FROM AUTHOR]

Copyright of Istanbul Medical Journal is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A 77‐year‐old woman underwent F‐18 FDG PET/CT for evaluation of fever focus. Diffuse and intense hepatosplenic uptake was noted and lymphoma or tuberculosis was proposed. Liver biopsy revealed chronic granulomatous inflammation with Langerhans‐type giant cells and necrosis. A follow‐up PET/CT after anti‐tuberculosis treatment revealed that the hepatosplenic uptake had resolved. [ABSTRACT FROM AUTHOR]

Combined positron emission tomography (PET) and computed tomography (CT) scans are widely used in the staging and monitoring of most malignancies. The differential for PET-positive cutaneous lesions includes primary skin cancers, infections, cutaneous metastases from distant malignancies, and benign neoplasms. In dermatology, PET/CT scans have been most widely studied in patients with melanoma and Merkel cell carcinoma. The role of PET/CT scans in the management of other cutaneous malignancies is less clear, but it has shown great promise in the management of patients with squamous cell carcinoma and cutaneous lymphoma. This review seeks to address the usefulness of PET/CT scans in nonmelanoma skin cancer and to provide guidance regarding the management of patients with incidental PET-positive nodules. Currently, there is limited experience with PET/CT scans for staging and monitoring of non-head and neck metastatic basal cell and squamous cell carcinomas, and results show limited sensitivity and specificity. We also address the evidence for management of an incidental PET-positive cutaneous nodule and recommend obtaining a biopsy specimen in patients with a known noncutaneous malignancy, a history of primary skin cancer, or a high risk of either cutaneous or noncutaneous malignancy. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the correlation of primary tumor FDG uptake to clinicopathological prognostic factors in invasive ductal carcinoma of the breast. Methods: We retrospectively reviewed 136 of 215 female patients with pathologically proven invasive ductal breast cancer from January 2008 to December 2011 who underwent F-18 FDG PET/CT for initial staging and follow-up after curative treatment with analysis of estrogen receptor (ER), progesterone receptor (PR) and human epithelial growth factor receptor 2 (HER2). The maximum standardized uptake value (SUVmax) of the primary breast tumor was measured and compared with hormonal receptor and HER2 overexpression status. Results: The high SUVmax of primary breast tumors is significantly correlated with the clinicopathological factors: tumor size, histologic grade, TNM stage, negativity of ER, negativity of PR, HER2 overexpression and triple negativity. The recurrent group with non-triple negative cancer had a higher SUVmax compared with the non-recurrent group, though no significant difference in FDG uptake was noted between the recurrence and non-recurrent groups in subjects with triple-negative cancer. Lymph node involvement was the independent risk factor for cancer recurrence in the multivariate analysis. Conclusions: In conclusion, high FDG uptake in primary breast tumors is significantly correlated with clinicopathological factors, such as tumor size, histologic grade, TNM stage, negativity of the hormonal receptor, HER2 overexpression and triple negativity. Therefore, FDG PET/CT is a helpful prognostic tool to direct the further management of patients with breast cancer. [ABSTRACT FROM AUTHOR]

F-18 fluorodeoxyglucose (FDG) is a highly influential radiotracer that provides valuable information in many cancer types. However, the normal biodistribution of F-18 FDG is often variable and can be altered by intrinsic or iatrogenic factors. We report a case of diffuse symmetrically increased skeletal muscle uptake and relatively decreased hepatic uptake on F-18 FDG PET/CT in a 57-year-old female with pulmonary adenocarcinoma. Detailed clinical evaluation and retrospective radiologic evaluation revealed that she had been diagnosed with subacute thyroiditis 2 weeks ago. After 6 weeks, F-18 FDG distribution was normalized at the follow-up PET/CT study. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the clinical impact of the preoperative F-FDG PET/CT in the initial workup of breast cancer with clinically negative axillary nodes. Whether the status of the clinical axillary nodal involvement can be considered a parameter for making a decision to omit the preoperative F-FDG PET/CT in the situation reported herein was also determined. A total of 178 patients who had newly diagnosed breast cancer and for whom the conventional diagnostic modalities showed no sign of axillary node metastasis were retrospectively enrolled in this study. All the patients underwent preoperative F-FDG PET/CT. The images and histologic results that were obtained were analyzed. F-FDG PET/CT detected primary lesions in 156 of the 178 patients, with an overall sensitivity of 87.6 %, and false negative results were obtained for 22 patients (12.4 %). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of F-FDG PET/CT in the detection of axillary nodes were 20.8, 86.9, 37.0, 74.8, and 69.1 %, respectively. Extra-axillary node metastasis was identified in two patients (1.1 %) who had internal mammary nodes. There was no distant metastasis, but coexisting primary tumor was detected in five patients (2.8 %). In total, the therapeutic plan was changed based on F-FDG PET/CT in seven (3.9 %) of the 178 patients, but considering only the cases confined to breast cancer, the change occurred in only two patients (1.1 %). F-FDG PET/CT almost did not affect the initial staging and treatment plan in breast cancer with clinically negative axillary node. If the axillary node is clinically negative in the preoperative workup of breast cancer, then F-FDG PET/CT can be omitted. [ABSTRACT FROM AUTHOR]

The contribution that F-18 fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18 FDG) PET/CT makes to the diagnosis of malignancy in patients with hemophagocytic lymphohistiocytosis (HLH) is still uncertain. The aim of this study was to evaluate the diagnostic performance of F-18 FDG PET/CT for the detection of underlying malignancy, to investigate the correlation between PET and laboratory parameters, and to identify prognosis-related factors in patients with secondary HLH. We enrolled 14 patients who were diagnosed with HLH and referred for F-18 FDG PET/CT to exclude malignancy. The diagnostic performance of F-18 FDG PET/CT for malignancy detection was assessed. The correlations between PET and laboratory parameters were determined. The prognostic significance of the following factors was evaluated: PET and laboratory parameters, age in years, presence of underlying malignancy, and fever and splenomegaly. Six of the 14 patients had malignancies (four with lymphoma, one with multiple myeloma, and one with colonic malignancy). Sensitivity, specificity, and diagnostic accuracy of F-18 FDG PET/CT for malignancy detection were 83, 62.5, and 71.4 %, respectively. F-18 FDG uptake in the bone marrow and spleen was positively correlated with neutrophil count and C-reactive protein. All of the PET parameters, but none of the clinical or laboratory parameters, were significantly associated with patient outcome, as determined by univariate analysis. Given the small sample size, F-18 FDG PET/CT was useful for detecting underlying malignancy, and PET parameters correlated with laboratory parameters that reflected inflammatory status. F-18 FDG PET/CT might provide prognostic information for the management of patients with secondary HLH. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the characteristics of PET and CT features of mediastinal metastatic lymph nodes on F-18 FDG PET/CT and to determine the diagnostic criteria in nodal staging of non-small cell lung cancer. Methods: One hundred four non-small cell lung cancer patients who had preoperative F-18 FDG PET/CT were included. For quantitative analysis, the maximum SUV of the primary tumor, maximum SUV of the lymph nodes (SUVmax), size of the lymph nodes, and average Hounsfield units (aHUs) and maximum Hounsfield units (mHUs) of the lymph nodes were measured. The SUVmax, SUV ratio of the lymph node to blood pool (LN SUV/blood pool SUV), SUV ratio of the lymph node to primary tumor (LN SUV/primary tumor SUV), size, aHU, and mHU were compared between the benign and malignant lymph nodes. Results: Among 372 dissected lymph node stations that were pathologically diagnosed after surgery, 49 node stations were malignant and 323 node stations benign. SUVmax, LN SUV/blood pool SUV, and size were significantly different between the malignant and benign lymph node stations ( P < 0.0001). However, there was no significant difference in LN SUV/primary tumor SUV ( P = 0.18), mHU ( P = 0.42), and aHU ( P = 0.98). Using receiver-operating characteristic curve analyses, there was no significant difference among these three variables (SUVmax, LN SUV/blood pool SUV, and size). The optimal cutoff values were 2.9 for SUVmax, 1.4 for LN SUV/blood pool SUV, and 5 mm for size. When the cutoff value of SUVmax ≥2.9 and size ≥5 mm were used in combination, the positive predictive value was 44.2 %, and the negative predictive value was 90.9 %. When we evaluated the results based on the histology of the primary tumor, the negative predictive value was 92.3 % in adenocarcinoma (cutoff values of SUVmax ≥2.3 and size ≥5 mm) and 97.2 % in squamous cell carcinoma (cutoff values of SUVmax ≥3.6 and size ≥8 mm), separately. Conclusions: In the lymph node staging of non-small cell lung cancer, SUVmax, LN SUV/blood pool SUV, and size show statistically significant differences between malignant and benign lymph nodes. These variables can be used to differentiate malignant from benign lymph nodes. The combination of the SUVmax and size of lymph node might have a good negative predictive value. [ABSTRACT FROM AUTHOR]

Uterine epithelioid angiosarcoma can have conventional imaging characteristics similar to those of other uterine tumors, such as leiomyoma, leiomyosarcomas or hemangioendothelioma. Uterine epithelioid angiosarcoma exhibiting increased fluorine-18 fluorodeoxyglucose (F-18 FDG) activity can be misdiagnosed. A 61-year-old woman who was diagnosed with uterine epithelioid angiosarcoma underwent F-18 FDG positron emission tomography/computed tomography (PET/CT) as a part of the pretreatment work up for surgery. F-18 FDG PET/CT showed an intense F-18 FDG uptake in the uterus in addition to increased F-18 FDG uptake at the paraaortic and aortocaval lymph nodes. To our knowledge, this is the first case report of intense F-18 FDG uptake in uterine epithelioid angiosarcoma in Korea. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the value of gated F-18 FDG PET/CT on left ventricular (LV) dyssynchrony assessment in comparison with gated Tc-99m sestamibi SPECT in patients with coronary artery disease (CAD). Methods: The data of 100 consecutive CAD patients who underwent both gated myocardial Tc-99m sestamibi SPECT and F-18 FDG PET/CT imaging were analyzed. Phase standard deviation (SD) and histogram bandwidth (BW) were derived from phase analysis using Cedars software package. The correlation and agreement of SD and BW between Tc-99m sestamibi SPECT and F-18 FDG PET/CT were examined. Myocardial viability and the site of latest activation assessed by the two imaging methods were compared as well. Results: A moderate correlation for SD ( r = 0.58, p < 0.0001) and BW ( r = 0.60, p < 0.0001) was found between gated SPECT and gated F-18 FDG PET/CT. Bland-Altman analysis revealed an overestimation of SD and BW (6.4° ± 14.3° and 22.0° ± 46.8°) by gated F-18 FDG PET/CT. Multivariate logistic regression analysis identified that significant LV remodeling on SPECT imaging, LV functional parameters and F-18 FDG uptake ratio of myocardium to blood pool (SUV) were associated with the overestimation. Myocardial SPECT and F-18 FDG PET/CT had a 67.1 % identity in determining the latest activation site and 5.2 % more viable myocardium was detected by F-18 FDG PET/CT than SPECT. Conclusion: Gated F-18 FDG PET/CT moderately correlated with gated Tc-99m sestamibi SPECT in assessing LV dyssynchrony. Gated F-18 FDG PET/CT phase analysis should be cautiously applied in CAD patients with significant LV remodeling on SPECT imaging, severe LV functional impairment or poor myocardial F-18 FDG uptake. [ABSTRACT FROM AUTHOR]

Objective: Langerhans cell histiocytosis (LCH) has a wide spectrum of clinical manifestations, ranging from spontaneous resolution to rapid progression or death, with the risk of permanent consequences. F-18 FDG PET/CT has been used for assessment of LCH patients. However, its clinical implication has not been well elucidated, mainly due to very low incidence of LCH. The aim of this study was to evaluate the clinical usefulness of F-18 FDG PET/CT in LCH patients. Methods: A database of 12 patients (mean age 17.8 ± 17.9 years; 7 children, 5 adults) who were diagnosed histopathologically as LCH was retrospectively reviewed. Two patients underwent F-18 FDG PET/CT before and after therapy, 6 patients underwent only before therapy and 4 patients underwent only after therapy. Results: Nine (75.0 %) and 3 patients (25.0 %) had single-system (single site and multiple sites) and multisystem involvements, respectively. Pretreatment SUV of patients with multisystem or multiple site involvement of a single-system was significantly higher than that of patients with single site involvement of a single-system (3.29 ± 2.52 vs. 1.63 ± 0.52, p = 0.025). One patient showed multisystem risk organs (lung and bone marrow) involvement. In 2 patients, F-18 FDG PET/CT detected additional active LCH lesions not identified on conventional imaging modalities. In follow-up F-18 FDG PET/CT scans, complete resolution was identified in 2 patients and reactivation in another 2 patients. Conclusions: Results of this study suggest that F-18 FDG PET/CT is useful for identification of active lesions, stratification of disease stages, monitoring of therapeutic response, and detection of reactivation in LCH patients. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the usefulness of F-18 fluorodeoxyglucose (FDG) dual-time-point (DTP) positron emission tomography (PET)/computed tomography (CT) with semiquantitative analyses for the initial staging in patients with malignant lymphoma. Methods: Forty-three patients had DTP PET/CT, with 60-min and 2-h scan [ n = 8, Hodgkin's lymphoma (HL); n = 12, indolent non-Hodgkin lymphoma (NHL); n = 23, aggressive NHL]. Results: A total of 524 lesions were evaluated (406 lymph nodes and 118 extra-nodal lesions). The maximum standardized uptake value (SUV) on 2-h delayed scan (SUV) was significantly higher than those on 1-h early scan (SUV) for all groups ( P < 0.0001 for HL; P < 0.0001 for indolent NHL; P < 0.0001 for aggressive NHL). Significant differences were detected between HL and indolent NHL, between indolent NHL and the aggressive NHL for both SUV and SUV (each P < 0.0001). No significant differences were detected between HL and aggressive NHL for both SUV and SUV ( P = 0.6891 for SUV; P = 0.8828 for SUV); however, significant differences were detected for the retention index of SUV between these groups ( P = 0.0238). Conclusions: DTP F-18 FDG PET/CT with a semiquantitative technique may have the potential to provide the more accurate diagnoses for the staging of malignant lymphoma and the more important role in predicting the histological grades of malignancy compared with single-time-point F-18 FDG-PET scan. [ABSTRACT FROM AUTHOR]

Background. Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cutaneous lymphomas, accounting for less than 1% of cases of non-Hodgkin's lymphoma. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positronemission tomography/computed tomography (PET/CT) findings of SPTCL before and after treatment were rarely reported. Case report. We report a case of SPTCL in which F-18 FDG PET/CT showed increased FDG accumulations in numerous subcutaneous nodules without extracutaneous disease. Contrast-enhanced CT during F-18 FDG PET/CT showed multiple minimally enhancing nodules with an infiltrative pattern in the subcutaneous layer throughout the body. Follow-up F-18 FDG PET/CT after three cycles of CHOP chemotherapy showed a complete metabolic remission of the lesions. Conclusions. F-18 FDG PET/CT is suggested to be useful in assessing the disease activity, extent and treatment response in SPTCL. [ABSTRACT FROM AUTHOR]

The aim of this retrospective analysis was to describe our clinical experience for fluorine-18 (18F) fluorodeoxglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with soft tissue and osseous sarcoma. Total of 26 18F-FDG PET/CT scans were evaluated in 17 patients (7 osteosarcoma, 5 Ewing's sarcoma, 3 uterine sarcoma and 2 rhabdomyosarcoma) in different stages of disease. 18F-FDG PET/CT was applied on postoperative period except for one patient. The results of 18F-FDG PET/CT, conventional imaging modalities (CT and/or MRI) and clinical follow-up data were reviewed retrospectively. The range of the period between conventional imaging modalities and 18F-FDG PET/CT was 1-6 months. The mean follow-up period was 3.8±0.2 years. The findings of CT and/or MRI and 18F-FDG PET/CT were compared on the patient basis. Concordance was seen in 7 of 17 patients and discordance in 10 of 17 patients. In the concordant group, results were normal in 4 of 7 patients. Local recurrence or distant metastases did not seen in these patients during the follow-up period. In one patient who had undergone 18F-FDG PET/CT for preoperative staging, both of 18F-FDG PET/CT and CT examinations showed the primary lesion on the clavicula. Distant metastases (liver, lung, lymph nodes) were defined with the 18F-FDG PET/CT and conventional imaging modalities in two patients. In the discordant group, 18F-FDG PET/CT scans were normal in 4 patients who had multiple nodules on the both lungs in CT. These patients were followed up in remission. Local recurrence and distant metastases (bone, peritonium, lymph nodes) which could not be detected by conventional imaging modalities were seen in three patients, respectively. In this retrospective analysis we concluded that 18F-FDG PET/CT is a functional imaging modality which can be used successfully in addition to conventional imaging modalities in soft tissue and osseous sarcomas. [ABSTRACT FROM AUTHOR]

Cardiac hemangiomas are extremely rare, benign tumors, which can occur anywhere in the heart. Symptoms are variable according to the size, extension and tumor location, but most cases are asymptomatic and are detected incidentally. They may grow, remain stable and regress; therefore, the natural course of the tumors is unpredictable. Diagnosis mainly depends upon echocardiography, CT, MRI and angiography. Reports of detection by F-18 FDG PET/CT are very limited. We report a case of cardiac hemangioma attached to the right ventricle, compressing the ventricle. It was revealed incidentally on F-18 FDG PET/CT for routine evaluation of thyroid cancer. During two serial F-18 FDG PET/CTs, it grew from 2.8 cm to 4.0 cm with mild FDG uptake. After surgery, the patient remained stable without any complications. [ABSTRACT FROM AUTHOR]

Intraductal papillary neoplasm of the bile duct (IPN-B) has been recently proposed as the biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas. Histologically, IPN-B can be classified into adenoma, borderline, carcinoma in situ, and invasive carcinoma. Two patients with suspected intraductal tumor underwent fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography. One patient showed an FDG-avid tumor in the right liver with SUV of 9.4 in early images and 11.3 in delayed images. The patient underwent complete tumor resection. Adenoma with high-grade dysplasia was confirmed by pathology. The other patient showed an FDG-avid polypoid lesion at the distal common bile duct with SUV of 5.4. The lesion was endoscopically resected. Histopathologic findings showed adenoma with low-grade dysplasia. These two cases highlight that IPN-B should be included in the differential diagnosis of abnormal biliary intraductal FDG accumulation along with carcinoma, and inflammatory and infectious processes. [ABSTRACT FROM AUTHOR]

Purpose: This retrospective study investigated the usefulness of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after interventional therapy for hepatocellular carcinoma (HCC). Methods: Between March 2007 and November 2010, 31 patients (24 men, 7 women; mean age, 61.8 ± 11.0 years) with 45 lesions underwent PET/CT within 1 month after interventional therapy for HCC. Twenty-six patients with 40 lesions underwent transcatheter arterial chemoembolization (TACE), two patients with 2 lesions underwent radiofrequency ablation (RFA), and three patients with 3 lesions underwent percutaneous ethanol injection therapy (PEIT). Patients with a history of previous interventional therapy were excluded. Visual analysis was graded as positive when FDG was observed as an eccentric, nodular, or infiltrative pattern, and negative in case of isometabolic, hypometabolic, or rim-shaped uptake. For quantitative analysis, the standardized uptake value (SUV) was measured by region of interest technique. Maximum SUV (SUVmax) was assessed, and the ratio of SUVmax of tumor to mean SUV of normal liver (TNR) was calculated. The patients were divided into two groups, with and without residual tumor, based on 6-month clinical follow-up with serum alpha-fetoprotein and contrast-enhanced abdominal CT. Results: Of the 45 lesions, 24 were classified in the residual tumor group and the other 21 lesions in the no residual tumor group. No residual tumor was detected after RFA or PEIT. By visual analysis, the respective values for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.5, 71.4, 77.8, 83.3, and 80.0 %. However, there were no significant differences in the SUVmax and TNR between the two groups. Conclusions: It is suggested that FDG PET/CT may play a role in the evaluation of early treatment response after interventional therapy for HCC. The results indicate that FDG PET/CT visual analysis may be more useful than quantitative analysis. Further prospective studies with a large number of patients and established protocol are needed to substantiate our results. [ABSTRACT FROM AUTHOR]

We present the pattern of metabolic brain abnormalities detected in patients undergoing whole body (WB) F-18 flurodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) examination for noncentral nervous system (CNS) malignancies. Knowledge of the PET/CT appearance of various intracranial metabolic abnormalities enables correct interpretation of PET scans in oncological patients where differentiation of metastasis from benign intracranial pathologies is important and improves specificity of the PET study. A complete clinical history and correlation with CT and MRI greatly helps in arriving at a correct imaging diagnosis. [ABSTRACT FROM AUTHOR]

We report a case of relapsing polychondritis for which fluorodeoxyglucose (FDG) positron-emission tomography/computed tomography (PET/CT) showed increased FDG accumulation in all rib cartilages, as well as in the larynx, trachea, and major bronchi. Contrast-enhanced CT during PET/CT showed smooth tracheal and bronchial wall thickening with calcification and airway narrowing. After steroid therapy, clinical symptoms and laboratory data were improved and cartilaginous FDG accumulation had completely disappeared. FDG PET/CT is considered to be a powerful radiological tool to assess the disease activity of relapsing polychondritis. [ABSTRACT FROM AUTHOR]

Abstract: We report a case of amyloid pulmonary nodules with positive FDG uptake that mimic multiple lung metastases. A 54-year-old female patient was referred for the evaluation of multiple lung nodules. A PET/CT scan revealed mild FDG uptake in various sized pulmonary nodules. Resected nodules contained amorphous eosinophilic proteineous material with focal calcification, consistent with amyloidosis. Pulmonary amyloidosis should be added to the differential diagnosis for cases of multiple pulmonary nodules that show positive FDG uptake. [Copyright &y& Elsevier]

Abstract: Purpose: The aim of the current study was to investigate the role of F-18 FDG PET/CT in the detection and prediction of local recurrence of maxillary sinus cancer. Methods: Retrospectively, we analyzed F-18 FDG PET/CT images of maxillary sinus cancer patients for the surveillance after treatment. Twenty-two consecutive patients with maxillary sinus cancer, who underwent maxillectomy followed by adjuvant radiation treatment, were included in the study. F-18 FDG PET/CT images were analyzed visually and quantitatively. Results: The median age of the patients included in the current study population was 54.5 years (range, 35–78). Seven patients (29.1%) had local recurrent diseases. Recurrent diseases show statistically significant higher values in SUVmax (recurrent: 5.09 ± 3.3, non-recurrent; 3.05 ± 0.7, p < 0.05), L/NL (recurrent: 2.95 ± 0.9, non-recurrent; 1.86 ± 0.5, p < 0.05), L/Ao (recurrent: 3.37 ± 2.1: non-recurrent; 1.88 ± 0.4, p < 0.05), and L/Cbr (recurrent: 1.06 ± 0.7: non-recurrent; 0.46 ± 0.1, p < 0.05) than those of non-recurrent disease of maxillary sinus cancer. There were no statistical differences between visual assessment and quantitative indices for the detection of local recurrence. The visual assessment was the potent predictor by logistic regression analysis for prediction of local recurrence. Conclusion: The visual assessment of F-18 FDG uptake pattern was potential predictor for local recurrence of maxillary sinus cancer. However, the diagnostic performances were similar between visual assessment and quantitative indices. Further studies are needed to confirm these results and improve statistical accuracy. [Copyright &y& Elsevier]

Abstract: This study aims to investigate the usefulness of F-18 FDG PET/CT in differentiated thyroid cancer (DTC) with elevated serum thyroglobulin (Tg) but negative iodine-123 (I-123) scan. Methods: Twenty patients with histopathologically proven DTC, negative diagnostic I-123 scan, and elevated serum Tg levels were prospectively submitted to F-18 FDG PET/CT evaluation. The histopathologic findings consisted of 19 papillary thyroid cancers, 1 follicular thyroid cancer. Results: F-18 FDG PET/CT identified lesions in 18 out of 20 patients, giving a sensitivity of 90%. Thirteen of the 18 patients revealed limited loco-regional disease. Remaining 5 patients showed distant metastases, consisting of 4 patients with lung metastases and 1 patient with bone metastasis. Two patients revealed negative F-18 FDG PET/CT findings. Conclusion: F-18 FDG PET/CT is suitable for the detection and precise localization of loco-regional recurrences and distant metastases of DTC in patients with elevated serum Tg but negative I-123 whole body scan. [Copyright &y& Elsevier]

Positron emission tomography (PET) using the glucose analogue F-18 fluorodeoxyglucose (FDG) enables the visualisation of increased glucose metabolism in cancer. Whole-body FDG-PET can be used for staging patients with breast cancer to identify metastatic disease. The metabolic information from FDG-PET is more sensitive than conventional structural imaging for the detection of loco-regional and distant metastases. FDG-PET is superior in detecting tumour-involved lymph nodes, particularly those which are normal in size radiologically and is superior in characterising enlarged lymph nodes as positive or negative. The overall sensitivity for bone scintigraphy and FDG-PET have been reported as comparable, but bone scintigraphy seems to be superior in the detection of osteoblastic disease and FDG-PET in osteolytic metastases, suggesting a complementary role for both imaging procedures. Due to its ability to more accurately stage patients with locally advanced breast cancer, FDG-PET may have a significant impact on patient management especially in combination with computed tomography (CT). Combined FDG-PET/CT provides both metabolic information from FDG-PET and the anatomical information from CT. FDG-PET/CT could potentially replace currently used imaging modalities and consolidate the diagnostic work-up of breast cancer patients with locally advanced or suspected locally recurrent or metastatic disease. [ABSTRACT FROM AUTHOR]

• A systematic review identified 7 eligible studies, 1265 patients, of F-18 FDG PET/CT in pediatric HL. • Pooled diagnostic yield was 95% of sensitivity and 97% of specificity. • F-18 FDG PET/CT has high sensitivity and specificity for detection of BMI in pediatric HL patients. • F-18 FDG PET/CT is appropriate for detection of BMI in pediatric HL. The present study aimed to investigate the diagnostic performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the detection of bone marrow involvement (BMI) in paediatric Hodgkin lymphoma (HL) through a systematic review and meta-analysis. PubMed, Cochrane, and EMBASE databases were searched from the earliest available date of indexing till March 31, 2020 for studies evaluating the diagnostic performance of F-18 FDG PET/CT in the detection of BMI in paediatric HL. Across seven studies (1265 patients), the pooled sensitivity of F-18 FDG PET or PET/CT was 0.95 (95% confidence interval [CI]: 0.87–0.98) with heterogeneity (I 2 = 86.2, p < 0.001), and the pooled specificity was 0.97 (95% CI: 0.84–1.00) with heterogeneity (I 2 = 97.2, p < 0.001). Likelihood ratio syntheses provided an overall positive likelihood ratio of 37.8 (95% CI: 5.2–274.9) and a negative likelihood ratio of 0.05 (95% CI: 0.02–0.14). The pooled diagnostic odds ratio was 732 (95% CI: 55–9806). The area under the summary receiver operating characteristic curve was 0.98 (95% CI: 0.97–0.99). The present meta-analysis revealed high sensitivity and specificity of F-18 FDG PET/CT for the detection of BMI in paediatric HL. Currently, the literature regarding the use of F-18 FDG PET/CT for the detection of BMI in paediatric HL is limited. Large multicentre studies are necessary to substantiate the diagnostic accuracy of F-18 FDG PET/CT in the detection of BMI in paediatric HL. Through a meta-analysis, this study provided a more reliable assessment of the diagnostic utility of F-18 FDG PET/CT, which exhibited good diagnostic accuracy in the detection of BMI in paediatric HL. [ABSTRACT FROM AUTHOR]

Fronto-temporal lobar degeneration (FTLD) is a clinically and pathologically heterogeneous syndrome, characterized by progressive decline in behavior or language associated with degeneration of the frontal and anterior temporal lobes. Three distinct clinical variants of FTLD have been described. Despite the difficulties, accurate diagnosis is critical because the clinical management differs for Alzheimer's disease (AD) and FTLD. Positron emission tomography with fluro-deoxy-glucose (FDG-PET) typically shows sufficient abnormalities that can be used to improve the accuracy of distinguishing AD from FTLD in individual cases. Though temporo-parietal hypometabolism is sensitive in diagnosis of AD, it is less specific. The importance of evaluating the cingulate and anterior temporal cortices for arriving at a diagnosis of FTLD is stressed. [ABSTRACT FROM AUTHOR]

We present a case of poorly differentiated muscle invasive transitional cell carcinoma in a 64-year-old male diagnosed with FDG-avid mass in the urinary bladder wall and multiple skeletal muscles visualised on F-18 FDG PET/CT. [ABSTRACT FROM AUTHOR]

• The current study meta-analysis to compare the accuracies of F-18 FDG PET or PET/CT and MRI for bone marrow involvement in lymphoma. • The accuracy was 0.90 of F-18 FDG PET or PET/CT and 0.89 of MRI for detection of bone marrow involvement. • F-18 FDG PET or PET/CT and MRI had similar diagnostic performances for the detection of bone marrow involvement. The purpose of the current study was to compare the diagnostic accuracies of F-18 FDG PET or PET/CT and MRI for detection of bone marrow involvement (BMI) in lymphoma patients through a systematic review and meta-analysis. The PubMed, Cochrane database, and EMBASE database, from the earliest available date of indexing through July 31, 2020, were searched for studies evaluating direct comparison of diagnostic performance of F-18 FDG PET or PET/CT and MRI for BMI in lymphoma patients. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR + and LR-), and constructed summary receiver operating characteristic curves. Across 5 studies (212 patients), the pooled sensitivity of F-18 FDG PET or PET/CT was 0.65 (95 % CI; 0.42−0.82) a pooled specificity of 0.90 (95 % CI; 0.85−0.94). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 6.4 (95 % CI; 3.3–12.4) and negative likelihood ratio (LR-) of 0.39 (95 % CI; 0.21−0.73). The pooled DOR was 16 (95 % CI; 5–56). The pooled sensitivity of MRI was 0.78 (95 % CI; 0.55−0.91) and a pooled specificity of 0.86 (95 % CI; 0.67−0.95). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 5.6 (95 % CI; 1.8–17.0) and negative likelihood ratio (LR-) of 0.26 (95 % CI; 0.1−0.65). The pooled DOR was 22 (95 % CI; 3–149). In meta-regression analysis, no variable was the source of the study heterogeneity. F-18 FDG PET or PET/CT and MRI showed similar diagnostic performances for the detection of BMI in lymphoma patients. Further large multicenter studies would be necessary to substantiate the diagnostic accuracy of F-18 FDG PET or PET/CT and MRI for the diagnosis of BMI in lymphoma patients. [ABSTRACT FROM AUTHOR]