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Drug-resistant temporal lobe epilepsy (TLE) is a potential candidate for surgery; however, nearly one-third subjects had a poor surgical prognosis. We studied the underlying neuromechanism related to the surgical prognosis using graph theory based on metabolic brain network. Sixty-four unilateral TLE subjects with preoperative 18F-fluorodeoxyglucose (FDG) PET scanning were retrospectively enrolled and divided into Ia (Engel class Ia, n = 32) and non-Ia (Engel class Ib-IV, n = 32) groups according to more than 3-year follow-up after unilateral anterior temporal lobectomy (ATL). The metabolic brain network was constructed and the changed metabolic connectivity of Ia and non-Ia was detected compared with 15 matched healthy controls (HCs). Further, the network properties, including small-worldness and global efficiency, were calculated and hub nodes were also identified for the 3 groups respectively. Non-Ia group exhibited increased connectivity between contralateral fusiform gyrus and contralateral lingual gyrus; while Ia showed decreased connectivity mainly among bilateral frontal, temporal and parietal cortex. Graph theoretical analysis revealed that non-Ia group showed increased small-worldness (35% L p (P = 0.05) compared to Ia group. Ia group showed reduced C p (55%

Purpose To compare the diagnostic performance of 18F-fluorodeoxyglucose-PET/MRI and MRI in the diagnosis of pelvic recurrence of rectal cancer. Methods All PET/MRIs of patients in the follow-up of rectal cancer performed between 2011 and 2018 at our institution were retrospectively reviewed. Recurrence was confirmed/excluded either by histopathology or imaging follow-up (> 4 months). Four groups of readers (groups 1/2: one radiologist each, groups 3/4: one radiologist/one nuclear medicine physician) independently interpreted MRI and PET/MRI. The likelihood of recurrence was scored on a 5-point-scale. Inter-reader agreement, sensitivity, specificity, PPV/NPV and accuracy were assessed. ROC curve analyses were performed. Results Fourty-one PET/MRIs of 40 patients (mean 61 years ± 10.9; 11 women, 29 men) were included. Sensitivity of PET/MRI in detecting recurrence was 94%, specificity 88%, PPV/NPV 97% and 78%, accuracy 93%. Sensitivity of MRI was 88%, specificity 75%, PPV/NPV 94% and 60%, accuracy 85%. ROC curve analyses showed an AUC of 0.97 for PET/MRI and 0.92 for MRI, but the difference was not statistically significant (p = 0.116). On MRI more cases were scored as equivocal (12% versus 5%). Inter-reader agreement was substantial for PET/MRI and MRI (0.723 and 0.656, respectively). Conclusion 18F-FDG-PET/MRI and MRI are accurate in the diagnosis of locally recurrent rectal cancer. Sensitivity, specificity, PPV, NPV and accuracy are comparable for both modalities, but PET/MRI increases readers’ confidence levels and reduces the number of equivocal cases. Graphic abstract

Imaging plays an important role in the diagnosis and treatment of women with uterine cervical and endometrial cancers. Quantitative imaging, through MRI, PET/CT, and hybrid PET/MRI, allows for characterization of primary tumors beyond anatomic and qualitative descriptors. MRI diffusion-weighted imaging (DWI) yields an apparent diffusion coefficient (ADC), which can be applied in both the pre-and post-treatment assessment of uterine tumors. PET/CT assesses metabolic activity, and measurement of tumor standardized uptake value (SUV) is a useful metric in the staging of uterine malignancies. Hybrid PET/MRI is an emerging modality that combines the soft tissue contrast of MRI with the molecular imaging capability of PET. This review provides an overview of these quantitative imaging modalities, and their current and potential roles in the assessment of uterine cervical and cancer.

Wilms' tumor also called as nephroblastoma is commonly seen extracranial solid tumor involving kidneys in children. Rarely, Wilms' tumor can arise from ectopic nephrogenic remnants located outside the kidneys. Extrarenal Wilms' tumor comprises 3% of total Wilms' tumor with its incidence even less common in adults. We report the staging and restaging fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of locally advanced metastatic extrarenal adult Wilms' tumor involving the retroperitoneum.

PURPOSE To determine if the correlation between different metabolic parameters along with clinical features can create an improved model of prognostication for diffuse large B-cell lymphoma (DLBCL) patients. METHODS We retrospectively evaluated 89 patients with DLBCL. All patients had a baseline and an interim 18F-FDG PET/CT. Seventy-nine also had an end-of-treatment PET/CT (EOT-PET). For each scan, we collected standardized uptake value (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUVmaxsum, SUVmeansum, MTVsum, and TLGsum. These metabolic parameters were combined with clinical features in order to identify a new prognostic model. The predictive value of interim PET and EOT-PET using Deauville score was also determined. RESULTS Baseline SUVmaxsum and SUVmeansum were significantly correlated to overall survival (OS) (P value = 0.012 and 0.011, respectively). The percentage change of MTV and TLG sum from baseline to EOT was predictive of progression-free survival (PFS) (P value = 0.003 and 0.022, respectively). The combination of either Deauville score at the EOT and SUVmaxsum at baseline significantly predicted OS (P value

Purpose This retrospective study aimed to analyzed the F-18 fluorodeoxyglucose PET/computed tomography (F-18 FDG PET/CT) features of pulmonary sclerosing pneumocytoma (PSP) to improve the understanding and preoperative diagnostic efficacy of this rare disorder. Methods FDG PET/CT images from 11 patients with 22 lesions (including one patient with 12 lesions) proven PSP in our hospital were reviewed. We summarized the PET/CT features of PSP and analyzed the correlation between FDG uptake and tumor size. Results PET/CT imaging revealed all tumors located in each lobe of the two lungs randomly. All 22 tumors were round or oval nodules; 15 had smooth margins, six were lobulated, six were calcified, and one had a ground-glass halo sign. The mean diameter of these tumors was 19.2 ± 7.8 mm (range: 8-34 mm); the mean maximum standardized uptake value (SUVmax) was 2.8 ± 1.3 (range: 1.1-7.4). Sixteen of the lesions exhibited mild to moderate FDG uptake (mean SUVmax 2.3 ± 0.6), and six of the lesions exhibited intense FDG uptake (mean SUVmax 4.3 ± 1.6). A positive correlation was observed between FDG uptake and tumor size (P Conclusion Single round or ovoid soft-tissue lesions with smooth margins, and mild to moderate FDG uptake on PET/CT images in middle-aged females, suggest a possible diagnosis of PSP. For some atypical cases with intense FDG uptake, a diagnosis of PSP also can be considered. A statistically significant positive correlation was found between SUVmax and PSP lesion size in our study.

PURPOSE The aim of the study was to assess the prognostic value of pretreatment PET/computed tomography (CT) scans in colorectal cancer (CRC) patients with unresectable metastasis. MATERIALS AND METHODS We retrospectively reviewed the pretreatment PET/CT images of 82 CRC patients with unresectable metastasis and their medical records. On PET/CT images, maximum standardized uptake value (SUVmax) of primary tumor, highest SUVmax of metastatic tumors and number of metastatic organs were identified. The patients were further divided into single and multiple organ metastases groups according to the extent of disease. Survival analysis was performed with the clinical variables and metabolic parameters from PET/CT. RESULTS In a total of 82 patients, the age of patients, highest SUVmax of metastatic tumors and number of metastatic organs were independent prognostic factors for overall survival (OS) (all P

PURPOSE To determine predictive models (PM) that could improve the accuracy for identifying metastatic regional nodes in non-small cell lung cancer based on both PET and CT findings seen on 18F-FDG PET CT. METHODS Three hundred thirty-nine biopsy-proven NSCLC patients who underwent surgical resection and had a staging 18F-FDG PET CT were enrolled. PET parameters obtained were (1) presence of visual PET positive nodes, (2) SUVmax of nodes (NSUV), (3) ratio of node to aorta SUVmax (N/A ratio) and (4) ratio of node to primary tumour SUVmax (N/T ratio). CT parameters obtained were (1) short-axis diameter and (2) Hounsfield units (HU) of PET-positive nodes. PET and CT parameters were correlated with nodal histopathology to find out the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy. Different PM combining these parameters were devised and the incremental improvement in accuracy was determined. RESULTS Visual PET positivity showed sensitivity, specificity, PPV, NPV and accuracy of 72.4, 76.1, 30.1, 95.1 and 75.6, respectively. PM2 which combined visual PET positivity, NSUV and HU appears more clinically relevant and showed sensitivity, specificity, PPV, NPV and accuracy of 53.5, 96.5, 68.9, 93.6 and 91.2, respectively. PM6 which combined visual PET positivity, NSUV, N/A ratio and HU showed the maximum PPV (80.0%), specificity (98.3%) and accuracy of (91.9%). CONCLUSION PM combining parameters like nodal SUVmax, N/A ratio, N/T ratio and HU values have shown to improve the PPV, specificity and overall accuracy of 18FDG PET CT in the preoperative diagnosis of nodal metastases.

Objectives The aim of the study was to evaluate the utility of 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the diagnosis, staging, restaging, and treatment response of childhood malignancies. Methods This study included 52 patients (32 boys, 20 girls) who were referred to our clinic between November 2008 and December 2018 with the diagnosis of malignancy. The patients were evaluated retrospectively. Median age of the patients was 13 years (range 2-17). 18F-FDG was given to the patients intravenously, and time of flight with PET/16 slice CT was performed 1 hour thereafter. The lowest dose was 2 mCi (74 MBq) and the highest dose was 10 mCi (370 MBq). Fasting blood sugars of all patients were found below 200 mg/dL (11.1 mmol/L). Results 18F-FDG PET/CT was performed to evaluate the response to treatment in 38 of 52 children, staging in 11 patients (staging and evaluation of the response to treatment in nine of them), restaging in 2 patients, restaging, and evaluation of the response to treatment in 1 patient. 18F-FDG PET/CT examination was reported as normal in 13 patients (5 girls, 8 boys). The pathological 18F-FDG uptake was detected in 39 patients (14 girls, 25 boys), which indicated metastasis and/or recurrence of the primary disease. Total number of deaths was 30 (13 girls, 17 boys). Conclusion 18F-FDG PET/CT has a significant role for staging, restaging, treatment response, and detection of metastatic disease but it is limited for the early diagnosis of childhood cancers.

BACKGROUND We aimed to evaluate the efficiency of dual time-point fluorodeoxyglucose (FDG) PET/computed tomography (CT) imaging in detecting primary and metastatic lesions in gastric cancer. METHODS Between May 2019 and January 2020, 52 patients with gastric carcinoma were prospectively involved in our study. And dual time-point FDG PET/CT imaging performed to the patients. Of detected primary and metastatic lesions, the ones that are better visualized or only appear in delayed imaging were visually identified. Also, maximum standardized uptake value (SUVmax) of the primary and metastatic lesions and the intact liver tissue were measured in early and delayed imaging. Acquired SUVmax values and SUVmax ratios were compared statistically. RESULTS In delayed images, lesions were better visualized in 32 patients (61.5%) and extra lesions were detected in 4 patients (7.7%). SUVmax of primary tumor, SUVmax of liver metastases, SUVmax of lymph node metastases, primary tumor SUVmax/liver SUVmax ratio and lymph node metastasis SUVmax/liver SUVmax ratio were significantly higher in delayed images (P

Aims: The aim of our study was to assess the correlations between apparent diffusion coefficient (ADC) values and standardized uptake values (SUVs) and their correlations with tumor size, tumor stage and histological grade in patients with head and neck squamous cell carcinomas (HNSSCs). Methods: This retrospective study included 36 patients with histologically confirmed HNSSCs visible on diffusion weighted imaging (DWI) and fluorodeoxyglucose (FDG) positron emission tomography (PET/CT). Correlations of minimum ADC (ADCmin), mean ADC (ADCmean), and minimum-mean ADC ratio (ADCmin/mean) with maximum SUV (SUVmax) and lean body mass SUVlbm (SUVlbm) were analyzed using the Spearman's correlation test. The Kruskal-Wallis one-way ANOVA test and Mann-Whitney U test were used to assess the correlations of ADC values and SUVs with tumor size, tumor stage and histological grade. Two experienced readers measured the ADC and SUVs independently, and intraclass correlation coefficient (ICC) was used to analyze the inter-observer agreement. Results: The mean ADCmin, ADCmean, and ADCmin/mean for HNSSCs were 0.68±0.17x10-3 mm2/s, 0.82±0.17x10-3 mm2/s, and 0.83±0.10, respectively. The mean SUVmax and SUVlbm were 14.65±5.5 and 10.96±5.1, respectively. The correlations between ADC values and SUVs did not reach statistical significance. There were no significant correlations of ADC values and SUVs with tumor size, tumor stage or histological grade. There was a tendency of SUVs to increase and ADC values to decrease with tumor dedifferentiation; however, the changes were not significant. Inter-observer agreement for tumor ADC values and SUVs was almost perfect (ICC>0.81). Conclusions: Pretreatment ADC values and SUVs in HNSSCs are reproducible and independent biomarkers. © 2020 Galenos Publishing House., received no financial support.

BACKGROUND The major challenge in diagnosing infective endocarditis using fluorine-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) is the high physiological myocardial F-FDG uptake, which may interfere with the detection of pathological uptake. Our aim was to retrospectively analyse the impact of a low-carbohydrate, high-protein, high-fat (LCHPHF) diet starting 72 h before the examination with classic overnight fasting. METHODS We included 92 patients (51 with LCHPHF diet 72 h before the examination and 41 with overnight fast only). Left ventricular (LV) myocardial F-FDG uptake was visually evaluated, to estimate the effect of LCHPHF on myocardial F-FDG uptake, we used a three-point visual scale: 0, negligible uptake and evaluable examination; 1, mild uptake and doubtful examination and 2, intense uptake and not evaluable examination. SUVmax and SUVmean were calculated putting a region of interest on LV myocardium at the level of the largest cardiac footprint and on the site of suspected lesion. Thus, a ratio between SUV of the suspect lesion and SUV of LV was calculated as SUV ratio. RESULTS By visual assessment, in LCHPHF diet group 46 patients (96.1%) had score 0, 3 patients (5.9%) had score 1 and nobody had score 2. In control group, 23 patients (56.1%) had a score 2, 12 (29.3%) patients obtained a score 1 with a doubtful examination and 6 patients (14.6%) were classified with a score 0 with reportable examination. CONCLUSION We demonstrated that an LCHPHF diet can adequately suppress the physiological myocardial uptake leading to a significant improvement in the interpretability and diagnostic accuracy of F-FDG PET/CT in infective endocarditis.

To explore the relationship between [18F]fluorodeoxyglucose (18F-FDG uptake) and PD-L1 expression and determine the usefulness of 18F-FDG PET/CT for evaluating the PD-L1 status in tumour cells (TCs) and tumour-infiltrating immune cells (TIICs) in patients with nasopharyngeal carcinoma (NPC). We retrospectively evaluated the records of 84 eligible patients who received an initial histopathological diagnosis of NPC between December 2016 and March 2019. All tissue specimens and PET/CT images were collected prior to treatment. High PD-L1 expression in TCs and TIICs was defined as ≥ 50% of stained cells. There was a significant difference in 18F-FDG uptake according to the PD-L1 status in TCs and TIICs. Univariate analysis showed that PD-L1 expression in TCs was associated with tumour maximum standardized uptake value (SUVmax) (P

18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) is a valuable tool in the diagnosis of endocarditis, especially in the setting of infection of prosthetic materials. Adequate knowledge of physiologic variants and possible confounders is key in the correct interpretation of FDG-PET/CT findings.

The increasing implementation of advanced imaging in the form of 18F-fluorodeoxyglucose (FDG) PET in patients with polymyalgia rheumatica has had a significant impact on the diagnostic work-up of this disorder. This article summarizes the role of FDG-PET imaging in polymyalgia rheumatica with a specific focus on findings, sensitivity and specificity, diagnosis and follow-up, assessment of concurrent large vessel vasculitis, and differential diagnosis.

Objective: This study aims to examine the association between 18F-fluorodeoxyglucose PET/CT (18F-FDG PET/CT) metabolic parameters of lymph node-positive and lymph node-negative breast carcinomas. Material and method: We included breast carcinomas patients who underwent 18F-FDG PET/CT imaging at our department between May 2018 and December 2019. A total of 108 female breast cancer patients were included (aged 48.8 ± 13.6years; range, 28-84 years). PET scanning was performed in 3D mode from the skull ceiling to the half of the thigh. According to pathology reports, we divided the patients into two groups: a lymph node-positive group of patients and a lymph node-negative group of patients. We calculated the sensitivity and specificity for determining the PET/CT pathological lymph node. Metabolic parameters like TLG (Total lesion glycolysis), MTV (Metabolic tumor volume), SUVmean, and SUVmax values were calculated. Result: The lymph node-positive group’s body weight and body mass index(BMI) were statistically higher than the lymph node-negative group (p=0,027,p=0,022 respectively). SUV max and SUV mean of the lymph node-positive group were statistically higher than the lymph node-negative group (p=0.008, p=0,009, respectively). Both TLG and MTV of the lymph node-positive group were statistically higher than the lymph node-negative group (p=0.01, P= 0.01, respectively). Ki-67(%) of the lymph node-positive group was not statistically different from the lymph node-negative group. We calculated the PET/CT’s sensitivity and specificity as 78,57% and 59,09%, respectively. For the positive predictive value of PET/CT, we found 55%, and for the negative predictive value, it was 81.25%. Conclusions: PET/CT metabolic parameters of patients with lymph node-positive breast cancer were higher than patients with lymph node-negative. High body weight and BMI appears to increase the possibility of metastases of lymph node. The sensitivity of PET/CT can be considered to be useful in determining the pathological lymph node, but the specificity of PET/CT is not very good.

OBJECTIVES To evaluate the impact of F-fluorodeoxyglucose PET/CT examinations on the management of patients with plasma cell disorders. METHODS This is a retrospective review of patients in a provincial database with PET/CT performed for plasma cell disorders between 2011 and 2018. The impact of PET/CT on actual patient management and outcome was assessed by two independent readers who compared planned pre-PET/CT management, documented at time of PET/CT requisition, to actual management received through linkages to administrative databases. PET/CT was considered of high impact if it altered the provision of active treatment, changed the modality of treatment or chemotherapy regimen. Change in management and the proportion of patients with high impact PET/CT were assessed. RESULTS There were 44 patients with plasma cell disorders, including multiple myeloma, solitary plasmacytoma, Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein, Skin changes syndrome, or monoclonal gammopathy of undetermined significance or biclonal gammopathy of undetermined significance. Management was altered after 38/56 (67.9%) PET/CT scans. Considering just the initial PET/CT scan in patients who underwent multiple scans, 31/44 (70.5%) patients had their management altered subsequent to PET/CT. CONCLUSION PET/CT resulted in a change in planned management in more than two-thirds of patients with plasma cell disorders in the current selected patient cohort. These results should be validated in a larger prospective trial.

PET using 18-fluorodeoxyglucose (FDG) has become an important part of the work-up for non-small cell lung cancer (NSCLC). This article summarizes advancements in using FDG-PET for patients with locally advanced NSCLC treated with definitive radiation therapy (RT). This article discusses prognostication of outcome based on pretreatment or midtreatment PET metrics, using textural image features to predict treatment outcomes, and using PET to define RT target volumes and inform RT dose modifications. The role of PET is evolving and is moving toward using quantitative image information, with the overarching goal of individualizing therapy to improve outcomes for patients with NSCLC.

In this prospective study, we sought to compare the clinical utility of fluorodeoxyglucose PET/MRI, MRI, and PET/CT in the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma (OHSCC). We examined 198 consecutive patients with biopsy-proven OHSCC who agreed to receive chemoradiation. All patients underwent pretreatment PET/MRI and PET/CT on the same day. Patients were followed-up for a minimum of 12 months or until death. The McNemar’s test and receiver-operating characteristic (ROC) curves were used to compare sensitivity/specificity and the diagnostic capabilities of PET/MRI, MRI, and PET/CT, respectively. We identified 55 patients (27.7%) who had synchronous cancers and/or distant metastases (number of involved sites: 83). The results of site-based analysis revealed that the sensitivity of PET/MRI was 15.7% higher than that of MRI (73.5% versus 57.8%, p

PET has become an essential tool for staging and response assessment in oncologic imaging. Over the past decade it has also evolved into a tool for image-guided interventions, specifically in the rapidly growing field of interventional oncology. PET-guided biopsies have greater sensitivity and diagnostic yield for fluorodeoxyglucose-avid lesions. Real-time PET imaging can also provide valuable image guidance during therapeutic minimally invasive procedures such as ablation of PET-avid tumors. The increasing use of PET in the assessment of therapeutic response results in earlier identification of disease that is amenable to image-guided therapies.

We aimed to evaluate the availability of fluorine-18-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in initial axillary lymph node (ALN) staging in breast cancer. The secondary objective is to evaluate the role of FDG PET/CT as a pretest in sentinel lymph node biopsy vs. axillary lymph node dissection when predicting disease aggressiveness.The study evaluated retrospectively 194 breast cancer patients who underwent preoperative 18F-FDG. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FDG PET/CT for ALN metastases were confirmed with histopathology as the gold standard.The value of the area under curve (AUC), sensitivity and specificity for ALN metastases were determined as 0.847, 78.8% and 92.6%, respectively. The cut-off value of the maximum standardized uptake value (SUVmax) for metastatic ALN detection was calculated as 1.79. PPV, NPV and the accuracy of 18F-FDG PET/CT were 0.933 (93.3%), 0.75 (75%) and 0.837 (83.7%), respectively. The SUVmax value of the primary lesion was significantly correlated with grade, estrogen receptor (ER) status, progesterone receptor (PR) status, SUVmax value of metastatic ALN, Her-2 status and Ki-67 level. Molecular subtypes revealed no statistically significant difference in terms of mean SUVmax value.High values of AUC, sensitivity, specificity, NPV and PPV encourage utilization of PET/CT for locoregional staging of nonmetastatic breast carcinoma. The significant correlation between the primary tumor SUVmax value and grade, ER status, PR status and Ki-67 level increases the prognostic predictive value of the preoperative PET/CT.

OBJECTIVE The aim of this study was to evaluate the association between intratumoral metabolic heterogeneity on F-fluorodeoxyglucose (F-FDG) PET imaging and the pathological type, differentiation and T stage of non-small cell lung cancer (NSCLC). METHODS Two hundred thirty-four consecutive patients who were performed pretreatment F-FDG PET/computed tomography and pathologically diagnosed as NSCLC were assessed retrospectively. Metabolic heterogeneity factor (MHF) derived from the volume-threshold function from 40 to 90% was calculated for primary lesions. The association between MHF and the pathological type, differentiation and T stage of NSCLC were analyzed, respectively. RESULTS The MHF values were statistically different among pathological types, differentiation and T stages (F = 17.611, 23.932 and 11.082, P all

Response to transarterial chemoembolization (TACE) in patients with liver cancer is commonly assessed on MRI or CT to quantify tumor necrosis and morphologic changes that occur gradually. However, the efficacy of embolotherapies remains limited because of local recurrence, as treated tumors demonstrate individual molecular characteristics that alter susceptibility and response to embolotherapies. Upregulation of cancer cell glycolysis can be detected by fluorine-18-fluorodeoxyglucose PET. Therefore, the combination of functional (PET) with commonly used cross-sectional imaging techniques (MRI, CT) can help characterize and monitor liver tumors with the potential to improve TACE toward becoming a more personalized and tumor microenvironment-directed therapy.

PURPOSE Fluorodeoxyglucose-PET/computed tomography (FDG-PET/CT) affects the management of patients with breast cancer. Our study aimed to determine the predictive ability of characteristics such as lymph node involvement or subtype and the prognostic value of pretreatment FDG-PET/CT in breast cancer. METHOD A total of 270 patients who were confirmed with breast cancer histopathologically and underwent pretreatment FDG-PET/CT were enrolled in the study. Nuclear medicine specialists obtained the readings and measured the maximum standardized uptake value (SUVmax) of the images. Tumor and lymph node SUVmax were evaluated according to lymph node metastasis and subtype status. Survival outcomes were analyzed by the Kaplan-Meier method. RESULTS The lymph node SUVmax and the lymph node/tumor SUVmax ratio were significantly higher in the subgroup of patients with lymph node metastasis than in those without lymph node metastasis. High cutoff lymph node SUVmax value and lymph node/tumor SUVmax ratio were confirmed as significant predictive factors in multivariate analysis. In a comparison of the tumor SUVmax values, the more biological aggressive subtype showed higher tumor SUVmax values. In survival analysis, tumor SUVmax and lymph node SUVmax were significant predisposing factors for disease-free survival in breast cancer. In subgroup analysis, tumor SUVmax was a more significant prognostic factor in patients who had breast cancer with tumor sizes of ≤2 cm. The lymph node SUVmax was more a significant prognostic factor in patients who had breast cancer with lymph node metastasis. CONCLUSION In this study, we showed that the SUVmax of FDG-PET/CT was a useful predictor of lymph node metastasis and breast cancer prognosis.

BackgroundDiagnostic and patients’ management modifications induced by whole-body 18F-FDG-PET/CT had not been evaluated so far in prosthetic valve (PV) or native valve (NV) infective endocarditis (IE)-suspected patients.MethodsIn sum, 140 consecutive patients in 8 tertiary care hospitals underwent 18F-FDG-PET/CT. ESC-2015-modified Duke criteria and patients’ management plan were established jointly by 2 experts before 18F-FDG-PET/CT. The same experts reestablished Duke classification and patients’ management plan immediately after qualitative interpretation of 18F-FDG-PET/CT. A 6-month final Duke classification was established.ResultsAmong the 70 PV and 70 NV patients, 34 and 46 were classified as definite IE before 18F-FDG-PET/CT. Abnormal perivalvular 18F-FDG uptake was recorded in 67.2% PV and 24.3% NV patients respectively (P < .001) and extracardiac uptake in 44.3% PV and 51.4% NV patients. IE classification was modified in 24.3% and 5.7% patients (P = .005) (net reclassification index 20% and 4.3%). Patients’ managements were modified in 21.4% PV and 31.4% NV patients (P = .25). It was mainly due to perivalvular uptake in PV patients and to extra-cardiac uptake in NV patients and consisted in surgery plan modifications in 7 patients, antibiotic plan modifications in 22 patients and both in 5 patients. Altogether, 18F-FDG-PET/CT modified classification and/or care in 40% of the patients (95% confidence interval: 32–48), which was most likely to occur in those with a noncontributing echocardiography (P < .001) or IE classified as possible at baseline (P = .04), while there was no difference between NV and PV.ConclusionsSystematic 18F-FDG-PET/CT did significantly and appropriately impact diagnostic classification and/or IE management in PV and NV-IE suspected patients.Clinical Trials RegistrationNCT02287792.

Purpose To evaluate the interrater reliability among radiologists examining posttreatment head and neck squamous cell carcinoma (HNSCC) fluorodeoxyglucose PET/contrast-enhanced CT (CECT) scans using Neck Imaging Reporting and Data System (NI-RADS). Materials and Methods In this retrospective study, images in 80 patients with HNSCC who underwent posttreatment surveillance PET/CECT and immediate prior comparison CECT or PET/CECT (from June 2014 to July 2016) were uploaded to the American College of Radiology's cloud-based website, Cortex. Eight radiologists from seven institutions with variable NI-RADS experience independently evaluated each case and assigned an appropriate prose description and NI-RADS category for the primary site and the neck site. Five of these individuals were experienced readers (> 5 years of experience), and three were novices (< 5 years of experience). In total, 640 lexicon-based and NI-RADS categories were assigned to lesions among the 80 included patients by the eight radiologists. Light generalization of Cohen κ for interrater reliability was performed. Results Of the 80 included patients (mean age, 63 years ± 10 [standard deviation]), there were 58 men (73%); 60 patients had stage IV HNSCC (75%), and the most common tumor location was oropharynx (n = 32; 40%). Light κ for lexicon was 0.30 (95% CI: 0.23, 0.36) at the primary site and 0.31 (95% CI: 0.24, 0.37) at the neck site. Light κ for NI-RADS category was 0.55 (95% CI: 0.46, 0.63) at the primary site and 0.60 (95% CI: 0.48, 0.69) at the neck site. Percent agreement between lexicon and correlative NI-RADS category was 84.4% (540 of 640) at the primary site and 92.6% (593 of 640) at the neck site. There was no significant difference in interobserver agreement among the experienced versus novice raters. Conclusion Moderate agreement was achieved among eight radiologists using NI-RADS at posttreatment HNSCC surveillance imaging. Keywords: CT, PET/CT, Head/Neck, Neck, Neoplasms-Primary, Observer Performance Supplemental material is available for this article. © RSNA, 2021.

F-18 fluorodeoxyglucose (F-18 FDG) PET/CT plays an increasing role in the diagnostic workup of large vessel vasculitis (LVV); however, information on the relationship between immunosuppressive drugs and vessel wall uptake is limited. In 94 patients with a confirmed diagnosis of LVV, the vessel wall-to-liver ratio (VLR) was assessed in eight vessel segments. Patients were grouped according to intake of immunomodulatory drugs (Group 1, prednisone; Group 2, prednisone + methotrexate; and Group 3, prednisone + others) and compared to treatment-naïve individuals. A total of 54/94 (57.4%) were treated with immunomodulatory drugs (Group 1, 29/49 (53.7%); Group 2, 9/54 (16.7%); Group 3, 11/54 (20.4%); and Group 4, 5/54 (9.3%)), whereas the remainder received no therapy (40/94 (42.6%)). The mean VLR of the arterial segments correlated significantly with the hematopoietic organs (r ≥ 0.22, p ≤ 0.05), c-reactive protein (r ≥ 0.25, p ≤ 0.05), and prednisone dosage (r ≥ −0.4, p ≤ 0.05). Relative to treatment-naïve patients, a significantly lower VLR was recorded in 5/8 (62.5%) of the investigated vessel segments in Group 1 (p ≤ 0.02), in 6/8 of the vessel segments in Group 2 (75.0%, p ≤ 0.006), and in 7/8 of the segments in Group 3 (87.5%, p ≤ 0.05). In LVV, the F-18 FDG uptake in vessel wall as a marker of inflammatory activity was attenuated by immunomodulatory drugs, which provides a foundation for future serial monitoring of treatment efficacy.

Fluorodeoxyglucose-PET/CT is a valuable tool for the work-up of patients with newly diagnosed and relapsed/refractory multiple myeloma, because it assesses bone damage with high sensitivity and specificity and detects extramedullary sites of proliferating clonal plasma cells (extramedullary diseases). PET/CT provides valuable prognostic data at diagnosis and at restaging during the course of the disease. Consistencies between independent studies confirm the negative prognostic value of extramedullary disease and greater than 3 focal lesions, whereas the role of standardized uptake value is more conflicting. Standardization of the technique is ongoing.

Supplemental Digital Content is available in the text, Objective: To investigate whether [18F]fluorothymidine (FLT) and/or [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) can differentiate growth in neurofibromatosis 2 (NF2) related vestibular schwannomas (VS) and to evaluate the importance of PET scanner spatial resolution on measured tumor uptake. Methods: Six NF2 patients with 11 VS (4 rapidly growing, 7 indolent), were scanned with FLT and FDG using a high-resolution research tomograph (HRRT, Siemens) and a Siemens Biograph TrueV PET-CT, with and without resolution modeling image reconstruction. Mean, maximum, and peak standardised uptake values (SUV) for each tumor were derived and the intertumor correlation between FDG and FLT uptake was compared. The ability of FDG and FLT SUV values to discriminate between rapidly growing and slow growing (indolent) tumors was assessed using receiver operator characteristic (ROC) analysis. Results: Tumor uptake was seen with both tracers, using both scanners, with and without resolution modeling. FDG and FLT uptake was correlated (R2 = 0.67–0.86, p

Esophageal carcinoma recurs within two years in approximately half of patients who receive curative treatment and is associated with poor survival. While 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a reliable method of detecting recurrent esophageal carcinoma, in most previous studies FDG PET/CT scans were performed when recurrence was suspected. The aim of this study was to evaluate FDG PET/CT as a surveillance modality to detect recurrence of esophageal carcinoma after curative treatment where clinical indications of recurrent disease are absent. A total of 782 consecutive FDG PET/CT studies from 375 patients with esophageal carcinoma after definitive treatment were reviewed. Abnormal lesions suggestive of recurrence on PET/CT scans were then evaluated. Recurrence was determined by pathologic confirmation or other clinical evidence within two months of the scan. If no clinical evidence for recurrence was found at least 6 months after the scan, the case was considered a true negative for recurrence. The diagnostic sensitivity and specificity of PET/CT for detecting recurrent esophageal carcinomas were 100% (64/64) and 94.0% (675/718), respectively. There were no significant differences in the diagnostic performance of PET/CT for detecting recurrence according to initial stage or time between PET/CT and curative treatments. Unexpected second primary cancers were detected by FDG PET/CT in seven patients. Surveillance FDG PET/CT is a useful imaging tool for detection of early recurrence or clinically unsuspected early second primary cancer in patients with curatively treated esophageal carcinoma but without clinical suspicion of recurrence.

BACKGROUND. Insulin resistance is routinely measured by homeostasis model assessment of insulin resistance (HOMA-IR).Positron emission tomography of 18F-fluorodeoxyglucose combined with computed tomography (18F-FDG PET/CT) is a valuable assessment tool for patients with cancer or staging tumors. 18F-FDG PET/CT imaging can also be utilised to detect the metabolic activity of glucose in the adipose tissue, liver and muscles. The aim of this study was to determine insulin sensitivity in the liver, muscle visceral adipose and subcutaneous adipose tissue separately via18F-FDG PET/CT. MATERIALS AND METHOD: Sixty three adult patients who underwent whole body 18F-FDG PET/CT scanning for clinical purposes (diagnosis or staging of cancer) between July and August of 2016 were included in the study. Patients were divided into two groups according to their BMI (Group 1: BMI25kg/m(2)). HOMA-IR,fasting glucose,insulin, triglycerides, total cholesterol, HDL levels were measured. We calculated SUV as the tissue activity of the ROI (MBq/g)/(injected dose [MBq]/ body weight [g]) on PET images and measured the maximum SUVs (SUVmax) of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT),liver and rectus muscle ROIs (2 cm). SUV corrected by blood glucose level (SUVgluc) was calculated as SUVmax×blood glucose level/100. Student-t test, Chi-square test and Pearson correlation test were used for statistical analysis. RESULTS: Mean glucose,insulin,HOMA-IR levels of the group-2 were statistically higher than of group-1. Muscle SUVmax and liver SUVmax of group-1 were statistically higher than of group-2. Muscle SUVgluc of group-1 was statistically higher than of group-2. HOMA-IR was negatively correlated with both SUVmax(r=-0.340, p=0.01) and muscle SUVmax(r=-0.373, p=0.005) CONCLUSION: 18F-FDG PET/CT has shown that the muscle tissue maximum FDG uptake was lower in the insulin resistance group. Therefore, 18-FDG PET/CT could be a valuable tool for diagnosing insulin resistance.

Aim 18F-Fluorodeoxyglucose (FDG) PET imaging may play an important role in the restaging of patients with small-cell lung cancer (SCLC),, nevertheless, a systematic review of literature was still missing in this setting. The aim of this review was to summarize the evidence on literature regarding the utility of 18F-FDG PET imaging in restaging patients with SCLC. Methods A literature search was performed to retrieve original studies using 18F-FDG PET or 18F-FDG PET/computed tomography (CT) in a minimum of 10 patients with SCLC at restaging. Results The selected literature (17 studies) was discussed in four sections: detection rate, impact on management, prediction of prognosis and evaluation of the response to therapy. According to the literature, PET imaging may result in discordance with conventional imaging, mainly contrast-enhanced CT (ceCT), and detect additional lesions in a certain proportion of cases, leading to upstaging or downstaging. A variable level of disagreement between PET and conventional imaging has been reported also in the evaluation of response to therapy. A positive PET study is associated with shorter survival, especially in the presence of distant metastases. According to some studies, semiquantitative parameters are also inversely associated with overall survival and progression-free survival. Although the retrieved articles proved the utility of 18F-FDG PET imaging in each clinical setting, literature is still limited. Conclusions This review encourages the use of 18F-FDG PET imaging, especially in conjunction with ceCT in recurrent SCLC patients. Further level I evidence is needed to further assess the diagnostic and prognostic capability of 18F-FDG PET/ceCT findings in SCLC.

Advances in molecular PET imaging of neurodegenerative parkinsonism are reviewed with focus on neuropharmacologic radiotracers depicting terminals of selectively vulnerable neurons in these conditions. Degeneration and losses of dopamine, norepinephrine, serotonin, and acetylcholine imaging markers thus far do not differentiate among the parkinsonian conditions. Recent studies performed with [18F]fluorodeoxyglucose PET are limited by the need for automated image analysis tools and by lack of routine coverage for this imaging indication in the United States. Ongoing research engages use of novel molecular modeling and in silico methods for design of imaging ligands targeting these specific proteinopathies.

To investigate diagnostic role of 18F-fluorodeoxyglucose PET/CT in patients with suspected vascular graft (VG) infection.A prospective analysis included data of 30 PET/CT examinations for suspected infection of aortic VG (PET/CT confirmed VG infection in 94% (17/18) and excluded in 50% (6/12) of cases. False PET/CT results were obtained in 23% (7/30) cases: false positive in 6 cases and false negative in 1 case. Thus, sensitivity, specificity and diagnostic accuracy of PET/CT were 94%, 50% and 77%, respectively; positive and negative predictive value - 74% and 86%. PET/CT results allowed correct reclassifying 33% (10/30) of cases. VG infection was confirmed in 73% (8/11) of patients with initially «possible» diagnosis and excluded in 17% (2/12) of patients with initially «rejected» infection. Moreover, whole body PET/CT revealed unknown inflammation foci outside VG in 73% (22/30) of cases. These data were applied to correct treatment approach in 80% (24/30) of cases.Our results showed high efficacy of 18F-fluorodeoxyglucose PET/CT in the diagnosis of VG infection. Despite low specificity, this technique has high sensitivity and accuracy that allowed reclassifying 33% of cases.Изучить диагностические возможности ПЭТ/КТ с 18F-фтордезоксиглюкозой у больных с подозрением на инфекцию сосудистых протезов (СП).В проспективный анализ включены результаты 30 ПЭТ/КТ-исследований, выполненных при подозрении на инфекцию СП в различные сроки (медиана 48 мес) после протезирования различных отделов аорты (Результаты ПЭТ/КТ позволили корректно диагностировать инфекционный процесс в зоне СП в 94% (17 из 18) случаев и исключить его наличие в 50% (6 из12) случаев. У 23% (7 из 30) пациентов получены ложные результаты — ложноположительные (Полученные данные свидетельствуют о высокой информативности ПЭТ/КТ с 18F-фтордезоксиглюкозой в диагностике инфекции СП: несмотря на низкую специфичность, метод обладает высокой чувствительностью и точностью, что позволило корректно реклассифицировать 33% случаев анализируемой группы.

Background: In the last decade, FDG-PET/CT has become routine practice in the management of lymphoma or autoimmune diseases. In the current study, we aimed to assess the usefulness of FDG-PET/CT as a potential diagnostic tool for detecting underlying systemic diseases (SD) in patients with orbital inflammatory disorders (OID).Methods: All consecutive patients managed for new-onset OID between 2011 and 2018 in a tertiary referral center for OID, who underwent FDG-PET/CT as part as the etiological diagnostic workup were enrolled. PET-FDG/CT scans were reviewed blindly and were considered as positive for SD detection if they showed lymphadenopathy and/or other visceral lesions with an uptake above blood pool background. We used the standard diagnostic workup (performed in all patients at presentation) as relevant comparator. To quantify the incremental value of FDG-PET/CT over the standard diagnostic workup, the Net Reclassification Index (NRI) and Integrated Discrimination Index (IDI) were used. The final diagnosis was based on international criteria for autoimmune diseases, or histological confirmation for lymphoma, xanthogranuloma, crystal storing histiocytosis (CSH), or idiopathic orbital inflammation syndrome (IOIS). Results: Among the 22 patients enrolled, 14 (63%) had underlying SD (granulomatosis with polyangiitis (GPA), n=1; IgG4-related disease (IgG4-RD), n=5; CSH, n=1; adult onset asthma and periocular xanthogranuloma (AAPOX), n=3; lymphoma, n=4) while the remaining 8 (37%) patients were diagnosed with IOIS. Eleven (50%) patients had a positive FDG-PET/CT. After clinicobiological evaluation, FDG-PET/CT correctly reclassified 29% of patients with SD (p=0.04) and 13% with IOIS (p=0.3), corresponding to an elevated NRI of 0.41±0.17 (p=0.03). The IDI test used to evaluate the improvement of FDG-PET/CT for SD detection was 0.38±0.08 (pConclusion: FDG-PET/CT enabled accurate reclassification of more than one quarter of patients with SD, suggesting its potential value for detecting SD (especially extraorbital lymphoma).

Myeloid sarcoma (MS) is a rare entity, and FDG PET/CT is a useful tool for staging at diagnosis and response assessment. We present a case of a 72-year-old woman diagnosed with multifocal extramedullary MS, using FDG PET/CT to guide palliative radiotherapy to 13 sites of disease over 2 separate relapses with complete and durable local responses and minimal toxicity. This case represents the largest reported burden of disease in MS successfully treated with FDG PET/CT-guided radiotherapy.

Purpose Nuclear medicine imaging can provide a noninvasive means of distinguishing inflammatory mass lesions from oncologic intraocular tumors. Observation We report a case of paraneoplastic ocular sarcoidosis with choroidal mass lesions that was initially concerning for choroidal metastasis of a primary carcinoid tumor. PET CT was utilized with two different tracers to characterize the choroidal mass as being FDG-avid, consistent with a sarcoid-like lesion, and lacking the Gallium (Ga-68) DOTATAE uptake of carcinoid tumor metastases. Conclusions and Importance Functional imaging is valuable to distinguish clinically similar inflammatory verses oncologic intraocular pathology.

Although fluorodeoxyglucose PET/MR imaging is a promising new modality, there is not yet enough data to support its routine use for staging or surveillance of children with lymphoma. PET/MR imaging protocols are still under development, and its availability globally is limited. The cost-benefit of using PET/MR imaging has not yet been established, especially because annual post-treatment surveillance imaging with fluorodeoxyglucose PET is not necessary in most patients with lymphoma. Further research into the use of PET/MR imaging in pediatric oncology patients is needed with continued collaborations among institutions.