Spleen SUVmean Research Articles

Exploring the predictive potential of programmed death ligand 1 expression in healthy organs and lymph nodes as measured by 18F-BMS-986192 PET: pooled analysis of data from four solid tumor types

IntroductionImmune checkpoint inhibitors (ICIs) can elicit anticancer immune responses, but predictive biomarkers are needed. We measured programmed death ligand 1 (PD-L1) expression in organs and lymph nodes using 18F-BMS-986192 positron...

Fluorine-18 fluorodeoxyglucose uptake change in liver, mediastinal blood pool, and lymphoid cell-rich organs during programmed cell death-1 immunotherapy in lymphoma.

The aim of this study was to evaluate metabolism change in reference organs (liver and mediastinum) and lymphoid cell-rich organs (spleen and bone marrow) during programmed cell death-1 immunotherapy in relapsed or refractory lymphoma patients. A total of 66 patients with baseline and serial monitoring fluorodeoxyglucose (FDG) PET/computed tomography scans were retrospectively enrolled. Mean standardized uptake value (SUV) and maximum SUV of evaluated organs were obtained by two reviewers, and their association with tumor burden and clinical response were evaluated. Immune-related adverse events detected by FDG PET/computed tomography were also recorded. The SUV values of reference organs and lymphoid cell-rich organs did not change significantly during the immunotherapy process. The intersubject variability of these values ranged from 13.0 to 28.5%. Meanwhile, metabolism of reference organs was affected by neither the tumor burden nor clinical response. SUV change of lymphoid cell-rich organs was associated with clinical response to immunotherapy. Responders showed decreased metabolism, while nonresponders showed a reverse trend (spleen SUV max : -0.30 ± 0.47 vs. 0.18 ± 0.39, P = 0.001, spleen SUV mean : -0.24 ± 0.39 vs. 0.14 ± 0.31, P = 0.001; and bone marrow SUV max : -0.14 ± 0.37 vs. 0.07 ± 0.46, P = 0.042, respectively). The influence of immune-related adverse events on the SUV change in evaluated organs was not significant. During programmed cell death-1 immunotherapy, metabolism change of reference organs is influenced neither by tumor burden nor by clinical response, while FDG uptake change of lymphoid cell-rich organs is significantly associated with clinical response.

Baseline [18F]FDG PET features are associated with survival and toxicity in patients treated with CAR T cells for large B cell lymphoma.

Chimeric antigen receptor (CAR) T cells have established themselves as an effective treatment for refractory or relapsed large B cell lymphoma (LBCL). Recently, the sDmax, which corresponds to the distance separating the two farthest lesions standardized by the patient's body surface area, has appeared as a prognostic factor in LBCL. This study aimed to identify [18F]FDG-PET biomarkers associated with prognosis and predictive of adverse events in patients treated with CAR T cells. Patients were retrospectively included from two different university hospitals. They were being treated with CAR T cells for LBCL and underwent [18F]FDG-PET just before CAR T cell infusion. Lesions were segmented semi-automatically with a threshold of 41% of the maximal uptake. In addition to clinico-biological features, sDmax, total metabolic tumor volume (TMTV), SUVmax, and uptake intensity of healthy lymphoid organs and liver were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The occurrence of adverse events, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), was reported. Fifty-six patients were included. The median follow-up was 9.7 months. Multivariate analysis showed that TMTV (cut-off of 36 mL) was an independent prognostic factor for PFS (p < 0.001) and that sDmax (cut-off of 0.15 m-1) was an independent prognostic factor for OS (p = 0.008). Concerning the occurrence of adverse events, a C-reactive protein level > 35 mg/L (p = 0.006) and a liver SUVmean > 2.5 (p = 0.027) before CAR T cells were associated with grade 2 to 4 CRS and a spleen SUVmean > 1.9 with grade 2 to 4 ICANS. TMTV and sDmax had independent prognostic values, respectively, on PFS and OS. Regarding adverse events, the mean liver and spleen uptakes were associated with the occurrence of grade 2 to 4 CRS and ICANS, respectively. Integrating these biomarkers into the clinical workflow could be useful for early adaptation of patients management.

New criteria for the diagnosis of infective endocarditis using 18F-FDG PET/CT imaging

The purpose of this study was to examine a qualitative scoring system and a semi-quantitative method of FDG-PET/CT imaging in the diagnosis of infective endocarditis (IE). We retrospectively included 108 patients who underwent 18F-FDG-PET/CT for suspected IE. PET/CT scans were interpreted using a 4-point score (0 = no uptake; 1 = cardiac uptake &lt; blood-pool activity; 2 = blood-pool &lt; uptake &lt; liver activity; 3 = uptake &gt; liver) and semi-quantitatively using SUVmax and SUVmean of the suspected valve lesion, liver, spleen, and of the bone marrow (BM). BM and spleen SUVmean were normalized to the liver, and hypermetabolism (HSBM) was defined as a BM or spleen-to-liver ratio &gt; 1. Comparing the score criteria results with the clinical final diagnosis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of qualitative criteria were 93%, 81%, 84%, 91%, and 87%, respectively. A definite IE was documented in 83% of patients showing HSBM and abnormal cardiac uptake, 44% with abnormal cardiac uptake, 28% with HSBM, and 10% with neither one. The qualitative scoring system is helpful in the diagnosis of IE. The HSBM is an additional, reliable indirect sign of IE.

Preoperative Body Composition Combined with Tumor Metabolism Analysis by PET/CT Is Associated with Disease-Free Survival in Patients with NSCLC.

Objective To evaluate the relationship between preoperative primary tumor metabolism and body composition in patients with NSCLC and analyze their effects on DFS. Method A retrospective study was conducted on 154 patients with NSCLC. All patients were scanned by baseline 18F-FDG PET/CT. SUVmax (maximum standard uptake value) of primary tumor, liver SUVmean (mean standard uptake value), and spleen SUVmean were measured by AW workstation. The skeletal muscle area (SMA), skeletal muscle mass index (SMI), skeletal muscle radiation density (SMD), visceral fat area (VFA), visceral adipose tissue index (VATI), and skeletal muscle visceral fat ratio (SVR) were measured by ImageJ software. Kaplan–Meier survival analysis was used to evaluate the impact of the above parameters on DFS. Results Compared with the low SUVmax group of primary tumors, the mean values of SMA, VFA, and VATI in the high SUVmax group were significantly higher. In addition, there were obvious differences in histopathological type, pathological differentiation, AJCC stage, and T stage between the two groups. Univariate analysis of DFS showed that VFA, VATI, pathological differentiation, tumor SUVmax, AJCC stage, tumor T stage, and N stage all affected the DFS of patients except for the parameters reflecting skeletal muscle content. Multivariate regression analysis showed that only VFA and SUVmax were associated with DFS. Kaplan–Meier survival analysis showed that high SUVmax, low VFA, high T stage, and high N stage were related to the decrease of DFS. Conclusion：Preoperative 18F-FDG PET/CT could comprehensively evaluate the primary tumor SUVmax, skeletal muscle, and visceral fat in patients with NSCLC. The combination of primary tumor SUVmax and visceral fat area can well evaluate the prognosis of patients with NSCLC.

Clinical Value of 18F-FDG PET/CT Scan and Cytokine Profiles in Secondary Hemophagocytic Lymphohistiocytosis in Idiopathic Inflammatory Myopathy Patients: A Pilot Study.

BackgroundSecondary hemophagocytic lymphohistiocytosis (sHLH) is a rare but fatal complication in idiopathic inflammatory myopathy (IIM) patients. The clinical value of radiological manifestations and serum cytokines remain unknown in this systemic crisis. This study aims to investigate the clinical value of PET/CT scan and cytokine profiles in predicting and understanding sHLH in IIM patients.MethodsAdult IIM patients who were admitted to the four divisions of the First Affiliated Hospital, Zhejiang University School of Medicine (FAHZJU) from January 1, 2017 to December 31, 2020 were reviewed. PET/CT scan, cytokine profiles, and other factors of patients who met the inclusion and exclusion criteria were collected and analyzed.ResultsSixty-nine out of 352 IIM patients were finally enrolled into the study. Ten patients developed sHLH and 70.0% of them died within 6 months. After false discovery rate (FDR) correction and multivariate logistic regression analysis, increased serum interferon (IFN)-γ level (p = 0.017), higher spleen mean standard uptake value (SUVmean, p = 0.035), and positivity of anti-MDA5 antibody (p = 0.049) were found to be significantly correlated with development of sHLH in IIM patients. The combination of serum IFN-γ, spleen SUVmean, and anti-MDA5 antibody found a balanced and satisfying predictor with a cutoff value of 0.047 and AUC of 0.946. A moderate correlation was identified between ferritin and spleen SUVmean (p = 0.001, r = 0.380) as well as serum IFN-γ(p = 0.001, r = 0.398). Before FDR correction, higher bilateral lung SUVmean (p = 0.034) and higher colon/rectum SUVmean (p = 0.013) were also observed in IIM patients who developed sHLH. By narrowing down to IIM patients with sHLH, anti-MDA5-antibody-positive DM patients tended to suffer from unfavorable outcome (p = 0.004) in Kaplan–Meier survival analysis.ConclusionIncreased serum level of IFN-γ, elevated splenic FDG uptake, and positivity of anti-MDA5 antibody were significantly correlated with development of sHLH in IIM patients. Lung and lower digestive tract might also be affected due to systemic immune activation in IIM patients with sHLH. In addition, splenic FDG uptake, in combination with serum IFN-γand anti-MDA5 antibody, was found valuable in predicting development of sHLH in IIM patients. Among IIM patients with sHLH, anti-MDA5-antibody-positive DM patients showed higher tendency for unfavorable outcome.

Glucose Metabolism Reprogramming of Primary Tumor and the Liver Is Associated With Disease-Free Survival in Patients With Early NSCLC.

PurposeTumor promote disease progression by reprogramming their metabolism and that of distal organs, so it is of great clinical significance to study the changes in glucose metabolism at different tumor stages and their effect on glucose metabolism in other organs.MethodsA retrospective single-centre study was conducted on 253 NSCLC (non-small cell lung cancer) patients with negative lymph nodes and no distant metastasis. According to the AJCC criteria, the patients were divided into different groups based on tumor size: stage IA, less than 3 cm (group 1, n = 121); stage IB, greater than 3-4 cm (group 2, n = 64); stage IIA, greater than 4-5 cm (group 3, n = 36); and stage IIB, greater than 5-7 cm (group 4, n = 32). All of the patients underwent baseline 18F-FDG PET/CT scans, and the primary lesion SUVmax (maximum standardized uptake value), liver SUVmean (mean standardized uptake value), spleen SUVmean, TLR (Tumor-to-liver SUV ratio) and TSR (Tumor-to-spleen SUV ratio) were included in the study, combined with clinical examination indicators to evaluate DFS (disease free survival).ResultsIn NSCLC patients, with the increase in the maximum diameter of the tumor, the SUVmax of the primary lesion gradually increased, and the SUVmean of the liver gradually decreased. The primary lesion SUVmax, liver SUVmean, TLR and TSR were related to disease recurrence or death. The best predictive parameters were different when the tumor size differed. SUVmax had the highest efficiency when the tumor size was less than 4 cm (AUC:0.707 (95% CI, 0.430-0.984) tumor size < 3 cm), (AUC:0.726 (95% CI, 0.539-0.912) tumor size 3-4 cm), liver SUVmean had the highest efficiency when the tumor size was 4-5 cm (AUC:0.712 (95% CI, 0.535-0.889)), and TLR had the highest efficiency when the tumor size was 5-7 cm [AUC:0.925 (95%CI, 0.820-1.000)].ConclusionsIn patients with early NSCLC, glucose metabolism reprogramming occurs in the primary lesion and liver. With the increase in tumor size, different metabolic parameters should be selected to evaluate the prognosis of patients.

The lungs were on fire: a pilot study of 18F-FDG PET/CT in idiopathic-inflammatory-myopathy-related interstitial lung disease

BackgroundInterstitial lung disease (ILD) and its rapid progression (RP) are the main contributors to unfavourable outcomes of patients with idiopathic inflammatory myopathy (IIM). This study aimed to identify the clinical value of PET/CT scans in IIM-ILD patients and to construct a predictive model for RP-ILD.MethodsAdult IIM-ILD patients who were hospitalized at four divisions of the First Affiliated Hospital, Zhejiang University School of Medicine (FAHZJU), from 1 January 2017 to 31 December 2020 were reviewed. PET/CT scans and other characteristics of patients who met the inclusion and exclusion criteria were collected and analysed.ResultsA total of 61 IIM-ILD patients were enrolled in this study. Twenty-one patients (34.4%) developed RP-ILD, and 24 patients (39.3%) died during follow-up. After false discovery rate (FDR) correction, the percent-predicted diffusing capacity of the lung for carbon monoxide (DLCO%, P = 0.014), bilateral lung mean standard uptake value (SUVmean, P = 0.014) and abnormal mediastinal lymph node (P = 0.045) were significantly different between the RP-ILD and non-RP-ILD groups. The subsequent univariate and multivariate logistic regression analyses verified our findings. A “DLM” model was established by including the above three values to predict RP-ILD with a cut-off value of ≥ 2 and an area under the curve (AUC) of 0.905. Higher bilateral lung SUVmean (P = 0.019) and spleen SUVmean (P = 0.011) were observed in IIM-ILD patients who died within 3 months, and a moderate correlation was recognized between the two values.ConclusionsElevated bilateral lung SUVmean, abnormal mediastinal lymph nodes and decreased DLCO% were significantly associated with RP-ILD in IIM-ILD patients. The “DLM” model was valuable in predicting RP-ILD and requires further validation.

Tumor Sink Effect in 68Ga-PSMA-11 PET: Myth or Reality?

We aimed to systematically determine the impact of tumor burden on 68Ga-prostate-specific membrane antigen-11 (68Ga-PSMA) PET biodistribution by the use of quantitative measurements. Methods: This international multicenter, retrospective analysis included 406 men with prostate cancer who underwent 68Ga-PSMA PET/CT. Of these, 356 had positive findings and were stratified by quintiles into a very low (quintile 1, ≤25 cm3), low (quintile 2, 25-189 cm3), moderate (quintile 3, 189-532 cm3), high (quintile 4, 532-1,355 cm3), or very high (quintile 5, ≥1,355 cm3) total PSMA-positive tumor volume (PSMA-VOL). PSMA-VOL was obtained by semiautomatic segmentation of total tumor lesions using qPSMA software. Fifty prostate cancer patients with no PSMA-positive lesions (negative scan) served as a control group. Normal organs, which included salivary glands, liver, spleen, and kidneys, were semiautomatically segmented using 68Ga-PSMA PET images, and SUVmean was obtained. Correlations between the SUVmean of normal organs and PSMA-VOL as continuous and categoric variables by quintiles were evaluated. Results: The median PSMA-VOL was 302 cm3 (interquartile range [IQR], 47-1,076 cm3). The median SUVmean of salivary glands, kidneys, liver, and spleen was 10.0 (IQR, 7.7-11.8), 26.0 (IQR, 20.0-33.4), 3.7 (IQR, 3.0-4.7), and 5.3 (IQR, 4.0-7.2), respectively. PSMA-VOL showed a moderate negative correlation with the SUVmean of the salivary glands (r = -0.44, P < 0.001), kidneys (r = -0.34, P < 0.001), and liver (r = -0.30, P < 0.001) and a weak negative correlation with the spleen SUVmean (r = -0.16, P = 0.002). Patients with a very high PSMA-VOL (quintile 5, ≥1,355 cm3) had a significantly lower PSMA uptake in the salivary glands, kidneys, liver, and spleen than did the control group, with an average difference of -38.1%, -40.0%, -43.2%, and -34.9%, respectively (P < 0.001). Conclusion: Tumor sequestration affects 68Ga-PSMA biodistribution in normal organs. Patients with a very high tumor load showed a significantly lower uptake of 68Ga-PSMA in normal organs, confirming a tumor sink effect. As similar effects might occur with PSMA-targeted radioligand therapy, these patients might benefit from increased therapeutic activity without exceeding the radiation dose limit for organs at risk.

Splenic uptake on FDG PET/CT correlates with Kikuchi-Fujimoto disease severity

Kikuchi-Fujimoto disease (KFD) is usually self-limiting, but prolonged systemic symptoms often result in frequent hospital visits, long admission durations, or missed workdays. We investigated the role of fluorine-18 fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in assessing KFD severity. We reviewed the records of 31 adult patients with pathologically confirmed KFD who underwent 18F-FDG PET/CT between November 2007 and April 2018 at a tertiary-care referral hospital. Disease severity was assessed using criteria based on clinical manifestations of advanced KFD. Systemic activated lymph nodes and severity of splenic activation were determined using semi-quantitative and volumetric PET/CT parameters. The median of the mean splenic standardized uptake value (SUVmean) was higher in patients with severe KFD than those with mild KFD (2.38 ± 1.18 vs. 1.79 ± 0.99, p = 0.058). Patients with severe KFD had more systemically activated volume and glycolytic activity than those with mild KFD (total lesion glycolysis: 473.5 ± 504.4 vs. 201.6 ± 363.5, p = 0.024). Multivariate logistic regression showed that myalgia (odds ratio [OR] 0.035; 95% confidence interval [CI] 0.001–0.792; p = 0.035), total lymph node SUVmax (cutoff 9.27; OR 24.734; 95% CI 1.323–462.407; p = 0.032), and spleen SUVmean (cutoff 1.79; OR 37.770; 95% CI 1.769–806.583; p = 0.020) were significantly associated with severe KFD. 18F-FDG PET/CT could be useful in assessing KFD severity.

18F-FDG PET/CT Associates With Disease Activity and Clinical Recurrence of AOSD Patients.

Objective: The purpose of this study was to explore the value of 18F-FDG PET/CT in monitoring the disease activity and predicting the prognosis of the Adult-onset Still's disease (AOSD).Methods: We retrospectively analyzed the electronic medical records of 45 AOSD patients who underwent 18F-FDG PET/CT in the Second Xiangya Hospital. PET/CT imaging and clinical information were retrospectively reviewed and analyzed. 18F-FDG uptake was assessed by measuring standard uptake value (SUV) in the spleen, liver, bone marrow, and lymph nodes. The spleen-to-liver ratio of the SUVmax (SLRmax) and SUVmean (SLRmean), the bone-to-liver ratio of the SUVmax (BLRmax), and SUVmean (BLRmean), and the lymph nodes-to-liver ratio of the SUVmax (LyLRmax) were calculated. Clinical and laboratory information were collected and evaluated for association with metabolic parameters of 18F-FDG PET/CT. The influencing factors for recurrence within 1 year were analyzed to determine whether 18F-FDG PET/CT can predict the prognosis of AOSD patients.Results: Elevated 18F-FDG uptake could be observed in bone marrow, spleen, and lymph nodes of AOSD patients. Correlation analysis between 18F-FDG uptake of organs and laboratory examinations showed that SLRmean positively correlated with LDH, AST, ferritin, and the systemic score (r = 0.572, 0.353, 0.586, and 0.424, P < 0.05). The SLRmean had the highest correlation with ferritin (r = 0586, P < 0.001). All metabolic parameters in spleen, including SUVmax, SUVmean, SLRmax, and SLRmean, are positively correlated with LDH level (r = 0.405, 0.539, 0.481, and 0.572, P < 0.05). Bone marrow SUVmax, BLRmax, and BLRmean were correlated with C-reactive protein (CRP) level (r = 0.395, 0.437, and 0.469, P < 0.05). Analysis of the influencing factors of recurrence within 1 year showed that the spleen SUVmax, spleen SUVmean, SLRmax, SLRmean, ferritin, and the systemic score of the recurrence group was significantly higher than the non-recurrence group (P < 0.05). The SLRmean cutoff of 1.66 with a sensitivity of 72.7% and specificity of 80.0% had the highest performance in predicting recurrence.Conclusion: The glucose metabolism of the liver, spleen, and bone marrow of AOSD patients were correlated with laboratory inflammatory indicators and system score, suggesting that 18F-FDG PET/CT could be applied to evaluate disease activity. Moreover, spleen 18F-FDG uptake may be a potential biomarker for predicting clinical prognosis of AOSD patients.

Diagnostic performance of a whole-body dynamic 68GA-DOTATOC PET/CT acquisition to differentiate physiological uptake of pancreatic uncinate process from pancreatic neuroendocrine tumor.

To evaluate the diagnostic performance of net influx rate (Ki) values from a whole-body dynamic (WBD) Ga-DOTATOC-PET/CT acquisition to differentiate pancreatic neuroendocrine tumors (pNETs) from physiological uptake of pancreatic uncinate process (UP).Patients who were benefited from a WBD acquisition for the assessment of a known well-differentiated neuroendocrine tumor (NET)/suspicion of disease in the prospective GAPET-NET cohort were screened. Only patients with a confirmed pNET/UP as our gold standard were included. The positron emission tomography (PET) procedure consisted in a single-bed dynamic acquisition centered on the heart, followed by a whole-body dynamic acquisition and then a static acquisition. Dynamic (Ki calculated according to Patlak method), static (SUVmax, SUVmean, SUVpeak) parameters, and tumor-to-liver and tumor-to-spleen ratio (TLRKi and TSRKi (according to hepatic/splenic Ki)), tumor SUVmax to liver SUVmax (TM/LM), tumor SUVmax to liver SUVmean (TM/Lm), tumor SUVmax to spleen SUVmax (TM/SM), and tumor SUVmax to spleen SUVmean (TM/Sm) (according to hepatic/splenic SUVmax and SUVmean respectively) were calculated. A Receiver Operating Characteristic (ROC) analysis was performed to evaluate their diagnostic performance to distinguish UP from pNET.One hundred five patients benefited from a WBD between July 2018 and July 2019. Eighteen (17.1%) had an UP and 26 (24.8%) a pNET. For parameters alone, the Ki and SUVpeak had the best sensitivity (88.5%) while the Ki, SUVmax, and SUVmean had the best specificity (94.4%). The best diagnostic accuracy was obtained with Ki (90.9%). For ratios, the TLRKi and the TSRKi had the best sensitivity (95.7%) while the TM/SM and TM/Sm the best specificity (100%). TLRKi had the best diagnostic accuracy (95.1%) and the best area under the curve (AUC) (0.990).Our study is the first one to evaluate the interest of a WBD acquisition to differentiate UP from pNETs and shows excellent diagnostic performances of the Ki approach.

Standardized uptake values and ratios on 68Ga-DOTATATE PET-computed tomography for normal organs and malignant lesions and their correlation with Krenning score in patients with metastatic neuroendocrine tumors.

The aim was to estimate the physiological standardized uptake values (SUVs) on Ga-DOTATATE PET-computed tomography (CT) in normal organs and metastatic tumor lesions (both standard and delayed), and correlating the uptake values and ratios with Krenning Scores (K-score) in patients with metastatic/advanced neuroendocrine tumors (NETs) undergoing PET-CT studies for their management work-up. A total of 32 patients of metastatic NET with 95 discrete tumor lesions were included in this analysis. These patients underwent standard whole-body PET-CT following injection of 2-3 mCi (74-111 MBq) of Ga-DOTATATE at 1-1.5 h. The normal physiological SUVmean of the liver and spleen and SUVmax and SUVmean of tumor lesions were estimated by an in-built automated procedure. These patients also underwent a delayed scan (2.5-3 h) and the same parameters were obtained for the delayed study. The tumorous lesions were further classified on the basis of K-score, and this was correlated with the mean SUVmax on both early and delayed scans. SUVmean ratios (tumor-to-liver and tumor-to-spleen) were also calculated for both time-points and correlated with individual K-scores. In lesions with K-score 4, the mean SUVmax was 32.5 in early and 30.5 in delayed scan, for lesions with K-score of 3 and 2, the mean SUVmax were 17.3, 20, and 9.3, 9.2, respectively, while in K-score 1 (n = 1), the delayed mean SUVmax was found to be more than early mean SUVmax (3.2 to 2.3). Statistical significance was evaluated by paired t test, and the changes in SUVmax was found to be statistically insignificant (P > 0.05) in all 3 K-scores. The paired t test was also performed between early and delayed tumor/liver and tumor/spleen mean SUVmean ratios, and no significant changes were observed across all K scores. The mean SUVmean values of the liver in the standard 1-h scan and delayed scans were 8.05 (range: 3-15) and 8.17 (range: 3.2-16), while for spleen, the values were 18 (range: 8.4-36.7) and 20 (range: 10-38.6), respectively. Statistically significant changes were observed in delayed spleen SUVmean values compared to the early scan (P < 0.05), while for liver SUVmean, the difference was not significant. Thus, in the present study, the SUVmax and SUVmean (range and mean values) for normal liver and spleen, and malignant NET lesions, and tumor-to-liver and tumor-to-spleen SUVmean ratios of different K-scores were generated. As could be theoretically expected in receptor-based PET-CT, there was no significant change in the delayed scan compared to the standard 1-1.5 h values.

Hepatic steatosis is associated with abnormal hepatic enzymes, visceral adiposity, altered myocardial glucose uptake measured by 18F-FDG PET/CT

BackgroundNonalcoholic fatty liver disease (NAFLD) is a multisystem disease that affects the liver and a variety of extra-hepatic organ systems. This study aimed to investigate the relationship between hepatic steatosis and glucose metabolism in liver and extra-hepatic tissues and organs.MethodsThe whole body 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) images of 191 asymptomatic tumor screening patients were retrospectively analyzed. Patients with the ratio of spleen/liver CT densities > 1.1 were defined to have NAFLD, and their clinical symptoms, laboratory markers, FDG uptake in a variety of tissues and organs including heart, mediastinal blood pool, liver, spleen, pancreas, and skeletal muscle, as well as abdominal adipose tissue volumes including visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume were compared with those of the non-NAFLD patients and used to analyze the independent correlation factors of NAFLD.ResultsAmong the 191 patients, 33 (17.3%) were NAFLD, and 158 (82.7%) were non-NAFLD. There was no significant correlation between the mean standardized uptake value (SUVmean) and CT density of liver as well as the ratio of spleen/liver CT densities. Hepatic steatosis, but not FDG intake, was more significant in NAFLD patients with abnormal liver function than those with normal liver function. Compared with the non-NAFLD patients, NAFLD patients had significantly reduced myocardial glucose metabolism, but significantly increased mediastinal blood pool, spleen SUVmean and abdominal adipose tissue volumes (including VAT and SAT volumes) (P < 0.05). Multivariate regression analysis showed that elevated serum ALT, increased abdominal VAT volume, and decreased myocardial FDG uptake were independent correlation factors for NAFLD. Further studies showed that hepatic steatosis and myocardial FDG uptake were mildly linearly correlated (r = 0.366 with hepatic CT density and − 0.236 with the ratio of spleen/liver CT densities, P < 0.05).ConclusionsNAFLD is a systemic disease that can lead to the change of glucose metabolism in some extra-hepatic tissues and organs, especially the myocardium.

Diffuse splenic FDG uptake is predictive of clinical outcomes in patients with rectal cancer

This study aimed to investigate the correlations between diffuse splenic Fluorine-18-fluorodeoxyglucose (18F-FDG) uptake on positron emission tomography/computed tomography (PET/CT) and inflammatory markers and to evaluate the prognostic significance of splenic FDG uptake in rectal cancer patients who underwent curative surgery. We retrospectively analyzed the data from 161 patients who underwent splenic FDG PET/CT staging and subsequent curative surgical resection of rectal cancer between July 2006 and September 2014. The spleen-to-liver uptake ratio (S/L ratio) was calculated by dividing the spleen SUVmean by liver SUVmean. We found significant positive correlations between the S/L ratio and neutrophil-to-lymphocyte ratio (P = 0.013) and platelet-to-lymphocyte ratio (P = 0.007). In a Kaplan–Meier analysis, patients with S/L ratio ≤0.815 had a significantly higher recurrence-free survival rate than those with S/L ratio >0.815 (P = 0.028). Also, patients with S/L ratio ≤0.731 had a significantly higher overall survival rate than those with S/L ratio >0.731 (P = 0.036). In multivariate analysis, higher S/L ratio, as well as male, poor differentiation, higher TNM stage, perineural invasion, and larger tumor size, was independently predictive of cancer recurrence (>0.815 vs ≤0.815, hazard ratio [HR]: 2.04, P = 0.046). With regard to OS, S/L ratio was also an independent prognostic factor for death during follow-up (>0.731 vs ≤0.731, HR: 3.81, P = 0.017). Our results show significant correlations between S/L ratio on PET/CT and systemic inflammatory markers. Further, S/L ratio was an independent prognostic factor for predicting recurrence and death in patient with rectal cancer after curative surgery.

Biodistribution and radiation dose estimates for 68Ga-DOTA-JR11 in patients with metastatic neuroendocrine tumors

Somatostatin receptor antagonists have shown promise for imaging neuroendocrine tumors (NETs) in preclinical studies, but clinical data is still very limited. In this study, we assess the feasibility of using the novel somatostatin antagonist 68Ga-DOTA-JR11 for PET imaging of NETs. Twenty patients with advanced NETs underwent whole-body PET/CT imaging 60min after injection of 169MBq (median) 68Ga-DOTA-JR11 as part of a prospective study. Volumes of interest were drawn around up to four 68Ga-DOTA-JR11-avid lesions per patient (with uptake greater than liver) and standardized uptake values were estimated. Additionally, target-to-normal tissue ratios were calculated. A subset of six patients had additional imaging (25-min dynamic scan of the upper abdomen including, at least partly, cardiac left ventricle, liver, spleen, and kidney, and a whole-body PET/CT scan at 30min post-injection) to determine the time course of tracer distribution and facilitate radiation dose estimates. Absorbed doses were calculated using OLINDA/EXM 1.0. In contrast to the known biodistribution of somatostatin receptor agonists, little or no uptake above background was seen in the pituitary gland, spleen, adrenals, and uninvolved liver; e.g., median spleen SUVmean 1.4 (range: 0.7-1.8), liver SUVmean 1.1 (0.7-1.9). A total of 42 tumor lesions were analyzed with median SUVmax 13.0 (range: 2.9-94), TNR blood 9.3 (1.8-87), TNR spleen 4.9 (1.9-48), TNR kidney 2.2 (0.52-28), and TNR liver 10.5 (2.3-107). Tumor uptake reached plateau levels by 20-30min post-injection. The highest absorbed dose estimates (mGy/MBq) to normal tissues were: urinary bladder wall (0.30; SD 0.06) and kidneys (0.050; SD 0.013). The effective dose (ICRP 103) was 0.022 (SD 0.003) mSv/MBq. 68Ga-DOTA-JR11 demonstrated rapid tumor uptake, high tumor/background ratios, and rapid clearance from blood. The low liver background is advantageous and may facilitate detection of liver metastases. Dosimetric data compare favorably with published data for 68Ga-DOTATATE and 68Ga-DOTATOC.

The effects of HIV and smoking on aortic and splenic inflammation.

To determine the association of smoking and HIV status with tissue-specific inflammation measured by flurodeoxyglucose positron emission tomography (PET). A cross-sectional study. We prospectively enrolled 55 HIV study participants on stable antiretroviral therapy and 19 age-matched HIV-uninfected controls without known cardiovascular disease. We measured aortic target-to-background ratio (TBR) and spleen standardized uptake values (SUV) 3-h post-FDG, and used regression models to examine the independent association of HIV and smoking status with PET variables. Overall, median (interquartile range) age was 50 (42-55) years; 81% were men and 54% were current smokers (median 0.5 packs/day, 25 pack-years]. Median CD4 of HIV study participants was 690 cells/ml and 88% had HIV-1 RNA less than 20 c/ml; 43% were on a protease inhibitor. In fully adjusted models, HIV was associated with 0.16 (95% confidence interval 0.04-0.27; P = 0.009) higher aortic TBR, whereas current smoking was marginally associated with a lower TBR [-0.11 (95% confidence interval -0.23 to 0.01); P = 0.07]. Spleen SUVmean was not associated with HIV or smoking, and there was no evidence for an HIVsmoking interaction for aortic or spleen models (all P > 0.1). Spleen SUVmean was positively associated with biomarkers of inflammation and coronary artery calcium, but adjustment for traditional cardiovascular disease risk factors attenuated these relationships. The FDG-PET study of HIV study participants suggests that HIV is associated with increased aortic inflammation independent of traditional risk factors, but smoking is not. Future studies should continue to explore the mechanistic roles of smoking and inflammation at various stages of clinical and subclinical atherosclerotic vascular disease in HIV.

HER2-Positive Breast Cancer: Tumor-to-Liver SUV Ratio is the Best Parameter for Detection in F-18 FDG-PET/CT

Background: Fluorine-18 fluorodeoxyglucose (F-18 FDG)-positron emission tomography/computed tomography (PET/CT) is widely used in most malignancy workups, including detection, differential diagnosis, staging and/or restaging, therapeutic decision-making, follow-up, and prognosis. Objectives: The aim of this study was to evaluate the usefulness of F-18 FDG-PET/CT for predicting breast cancer molecular subtypes. Patients and Methods: Sixty-six patients with pathologically proven invasive breast carcinoma (IBC) underwent F-18 FDG-PET/CT imaging for tumor staging. The maximum standardized uptake value (tumor SUVmax) of the IBC and mean SUVs of the liver and spleen (liver and spleen SUVmean) were measured. Molecular subtype was determined according to genomic analysis. The tumor SUVmax, tumor-to-liver SUV ratio, and tumor-to-spleen SUV ratio were correlated with molecular subtype data. Results: Logistic analysis demonstrated that only the tumor-to-liver SUV ratio was a significant parameter for human epidermal growth factor type 2 (HER2)-positive subtype identification (P = 0.0049). The sensitivity, specificity, and area under the receiver-operating-characteristic curve (AUC) of this parameter for HER2-positive subtype detection were 83%, 79%, and 0.87, respectively. Conclusion: The tumor-to-liver SUV ratio appears to be useful for HER2-positive subtype identification, thus indicating the potential use of F-18 FDG-PET/CT as an imaging biomarker that could facilitate the clinical management of patients with breast cancer.

Splenic FDG uptake predicts poor prognosis in patients with unresectable cholangiocarcinoma

Diffuse splenic 18F-Fluorodeoxyglucose (FDG) uptake has shown to be associated with concurrent inflammation. We evaluated the prognostic value of diffuse splenic FDG uptake for predicting prognosis in cholangiocarcinoma patients. Sixty-four patients with unresectable cholangiocarcinoma performed Positron emission tomography/computed tomography (PET/CT) using FDG between July 2009 and April 2012. Patients were divided into two groups according to splenic FDG uptake relative to hepatic FDG uptake. Eleven patients showing splenic FDG uptake exceeding hepatic uptake were included in group A, while 53 patients with hepatic FDG uptake exceeding splenic uptake were included in group B. Prognostic factors for overall survival were evaluated using log-rank test. Variables with a probability of less than or equal to 0.1 on univariate analysis were considered as possible independent factors. Cox-proportional hazards model was used to analyze univariate and multivariate analysis. Mean standardized uptake value of the liver (Liver SUVmean)/Spleen SUVmean (L/S) ratio <1 (p = 0.0034), WBC > 10 000 (p = 0.1155) and CEA >30 (p = 0.0946) were predictors of overall survival on univariate analysis. In a subsequent multivariate analysis, L/S ratio <1 remained a significant independent predictor of poor prognosis (HR 6.0153, 95% CI, 1.7193-21.0460, p = 0.0052). Our study has shown that splenic FDG uptake could be a predictor of overall survival of unresectable cholangiocarcinoma patients.