18F-FDG Standardized Uptake Value Research Articles

Association of serum lactate dehydrogenase with prognosis and tumor metabolism in patients with hepatocellular carcinoma treated with atezolizumab plus bevacizumab therapy.

Treatment outcomes are predicted by analyzing peripheral blood markers such as serum lactate dehydrogenase (LDH). We conducted this study to investigate whether serum LDH levels can predict the prognosis of patients treated with atezolizumab plus bevacizumab (ATZ/BEV) therapy for hepatocellular carcinoma (HCC) and whether LDH levels correlate with metabolic changes. We enrolled 66 HCC patients treated with ATZ/BEV. Based on the change in serum LDH levels before and after treatment, the patients were divided into two groups, and the prognosis of each group was examined. Moreover, the association of LDH levels with tumor metabolism was analyzed by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). There were 32 patients categorized as the LDH-decrease group. Kaplan-Meier survival analysis indicated worse progression-free survival (PFS) in the LDH-increase group than in the LDH-decrease group (p = 0.0029). Multivariate analysis showed that an increase in the LDH level was an independent risk factor for worse PFS (p = 0.0045). The baseline LDH level correlated significantly with a high maximum standardized uptake value of 18F-FDG, according to the PET/CT findings. Transcriptomic analyses of specimens resected after ATZ/BEV therapy showed downregulated mitochondria-related pathways. Serum LDH levels are a potential prognostic marker and an indicator of tumor metabolism.

Correlation between standardized uptake value of 18F-FDG PET/CT and conductivity with pathologic prognostic factors in breast cancer

We investigated the correlation between standardized uptake value (SUV) of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and conductivity parameters in breast cancer and explored the feasibility of conductivity as an imaging biomarker. Both SUV and conductivity have the potential to reflect the tumors’ heterogeneous characteristics, but their correlations have not been investigated until now. Forty four women diagnosed with breast cancer who underwent breast MRI and 18F-FDG PET/CT at the time of diagnosis were included. Among them, 17 women received neoadjuvant chemotherapy followed by surgery and 27 women underwent upfront surgery. For conductivity parameters, maximum and mean values of the tumor region-of-interests were examined. For SUV parameters, SUVmax, SUVmean, and SUVpeak of the tumor region-of-interests were examined. Correlations between conductivity and SUV were evaluated, and among them, the highest correlation was observed between mean conductivity and SUVpeak (Spearman’s correlation coefficient = 0.381). In a subgroup analysis for 27 women with upfront surgery, tumors with lymphovascular invasion (LVI) showed higher mean conductivity than those without LVI (median: 0.49 S/m vs 0.06 S/m, p < 0.001). In conclusion, our study shows a low positive correlation between SUVpeak and mean conductivity in breast cancer. Furthermore, conductivity showed a potential to noninvasively predict LVI status.

NIMG-49. VALIDATION OF SIMULTANEOUS PH- AND O2-WEIGHTED MOLECULAR MRI USING 18F-FDG PET, IMMUNOHISTOCHEMISTRY, AND BIOENERGETICS

Abstract This study aimed to investigate the potential of a novel MRI metric related to aerobic glycolysis in patients with diffuse gliomas. All subjects (Study I–III; 7, 26, and 11 subjects, respectively) were scanned on 3-T systems and underwent pH-weighted amine chemical exchange saturation transfer spin-and-gradient-echo echoplanar imaging (CEST-SAGE-EPI) or CEST-EPI, and perfusion imaging. Relative oxygen extraction fraction (rOEF) was calculated by dividing hypoxia-sensitive R2’ by normalized relative cerebral blood volume (nrCBV); a novel metric that characterizes glycolytic status (aerobic glycolytic index, AGI) was calculated by dividing amine CEST contrast by rOEF. Patients in Study I were additionally scanned by 18F-fluorodeoxyglucose (FDG)-PET. Stereotactic image-guided biopsies were performed on patients in Study II and III, and samples were analyzed by immunohistochemistry (IHC) and extracellular flux bioenergetic analysis, respectively. Pairwise correlation between MR metrics and standardized uptake value of 18F-FDG, IHC metrics, or indices of cellular metabolism was calculated using Spearman’s correlation analysis. In Study I, AGI showed very strong significant correlation with 18F-FDG uptake in glioma (correlation coefficient ρ = 0.86, P =0.014). In Study II, AGI was significantly correlated with glucose transporter 3 (ρ = 0.71; P = 0.0041) and hexokinase 2 (ρ = 0.73; P = 0.0029) in IDH wild-type glioma, while it was significantly correlated with monocarboxylate transporter 1 (ρ = 0.59; P = 0.0094) in IDH mutant glioma. This result may reflect the different glycolytic statuses of these gliomas; specifically, the rate-limiting steps in glycolysis. In Study III, a strong significant correlation with cellular AGI derived from the bioenergetic analysis was found for AGI derived from MRI (ρ = 0.79, P = .036). In conclusion, AGI derived from MRI was correlated with FDG, IHC measurements, and cellular AGI. Future studies investigating the clinical utility of AGI in prediction and evaluation of treatment effects are warranted.

High standardized uptake values of 18F-FDG PET/CT imaging but not MRI correlates to pathology findings in patients with cervical cancer.

This study was to explore the correlation between the standardized uptake value (SUV) of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging and the apparent diffusion coefficient (ADC) value of magnetic resonance imaging (MRI) to the pathological features of cervical cancer (CC). The maximum and mean SUV of 18F-FDG PET/CT (SUVmax and SUVmean) and the minimum ADC (ADCmin) were collected from 72 patients with CC. The correlation between SUVmax and ADCmin was also assessed. Furthermore, the relationship between SUVmax, SUVmin, ADCmin and the clinical pathological characteristics of CC was analyzed. A significant increase in the SUVmax was observed in the group of CC cases with lymph node metastases and in the group with distant metastases compared to those without metastases (F=6.782, P=0.002; F=4.483, P=0.015). Furthermore, in the low differentiation groups compared to high/middle differentiation groups (F=3.342,P=0.024), in the squamocellular carcinoma groups compared to the adenocarcinoma and adenosquamous carcinoma groups (F=3.295, P=0.026) and finally in the International Federation of Gynecology and Obstetrics (FIGO) stage III-IV groups compared with stage III-IV groups (F=3.123, P=0.020).The SUVmean values of the lymph node metastases and distant metastases groups were significantly higher than those without lymph node metastases (F=5.802, P=0.005; F=3.486, P=0.036). We saw no correlation between the ADCmin and lymph node metastases. The SUVmax value had weak correlation with the ADCmin (r=-0.306, P=0.036). The SUVmax is most closely related to the clinical pathological characteristics of CC. An increased SUVmax suggests lymph node metastases or distant metastases, low differentiation and FIGO stage III-IV. A low negative correlation was observed between the SUVmax and ADCmin, while we observed no correlation between the ADCmin and the clinical pathological characteristics of cervical cancer.

Increased Vesicular Monoamine Transporter 2 (VMAT2) and Dopamine Transporter (DAT) Expression in Adolescent Brain Development: A Longitudinal Micro-PET/CT Study in Rodent.

Background: Brain development and maturation in adolescence is a complex process with active changes of metabolic and neurotransmission pathways. Positron emission tomography (PET) is a useful imaging modality for tracking metabolic and functional changes in adolescent brain. In this study, changes of glucose metabolism, expression of vesicular monoamine transporter 2 and dopamine transporter during adolescent brain development in rats were investigated with PET/CT.Methods: A longitudinal PET/CT study of age-dependent changes of VMAT2, DAT and glucose metabolism in adolescent brain was conducted in a group of Wistar rats (n = 6) post sequential intravenous injection of 18F-PF-(+)-DTBZ, 11C-CFT, and 18F-FDG, respectively. PET acquisition was performed at 2, 4, 9, and 12 months of age. Radiotracer uptake in different brain regions, including the striatum, cerebellum, and hippocampus, were quantified and recorded as Standardized uptake value (SUV) and striatal specific uptake ratio (SUVR: SUV in brain regions/SUV in cerebellum).Results: Variable uptake of 18F-PF-(+)-DTBZ and 11C-CFT were detected, with highest level uptake in the striatum and accumbens. There was significant age-dependent increase of 18F-PF-(+)-DTBZ and 11C-CFT uptake in the striatum from 2 months of age (SUV: 1.36 ± 0.22, 1.37 ± 0.39, respectively), to 4 months (SUV: 2.22 ± 0.29, 2.04 ± 0.33), 9 months (1.98 ± 0.34, 2.09 ± 0.18), 12 months (SUV: 1.93 ± 0.19, 2.00 ± 0.17) of age, SUV of 18F-FDG also increased from 2 months of age to older ages (SUV in the striatum: 3.71 ± 0.78 at 2 month, 5.28 ± 0.81, 5.14 ± 0.73, 4.94 ± 0.50 at 4, 9, 12 month, respectively).Conclusion: Age-dependent increases of striatal of 18F-FDG, 18F-PF-(+)-DTBZ, and 11C-CFT uptake were detected in rats from 2 to 4 month of age, demonstrating striatal development presents over the first 4 months of age. Four months of age can be considered a safe threshold to launch brain disease studies for exclusion of confusion of continuing tissue development. These findings support further investigation of age-dependent changes in expression of DAT, VMAT2, and glucose metabolism for their potential use as a new imaging biomarker for study of brain development and functional maturation.

Prognostic significance of venous invasion and maximum standardized uptake value of 18F-FDG PET/CT in surgically resected T1N0 esophageal squamous cell carcinoma

BackgroundThe purpose of this study was to analyze the risk factors of recurrence in patients with early stage esophageal squamous cell carcinoma (ESCC). MethodsWe retrospectively analyzed the medical records of 190 patients with confirmed T1N0M0 ESCC after curative esophagectomy. The following potential prognostic factors for recurrence were investigated: age, sex, pathologic T category, tumor location, differentiation grade, tumor size, venous invasion, angiolymphatic invasion, perineural invasion and the maximum standardized uptake value (SUVmax) of the primary tumor. ResultsThere were 174 male and 16 female patients with a median age of 66.0 years (range, 42.0–79.0 years). The pathologic status of the surgically resected ESCCs was T1a in 93 patients (48.9%) and T1b in 97 patients (51.1%). The median number of dissected lymph nodes was 35 (range, 10 to 86), and all lymph nodes were negative for tumors. The multivariate analysis showed presence of venous invasion [HR (hazard ratio), 11.433; P < 0.001) and SUVmax ≥ 3.2 (HR, 2.830; P = 0.011) as independent risk factors for recurrence. The 5-year recurrence-free survival (RFS) was 25.0% for patients with venous invasion and 78.9% for those without (P < 0.001). The 5-year RFS was 67.1% for patients with an SUVmax ≥3.2 and 81.5% for those with an SUVmax <3.2 (P = 0.003). ConclusionsVenous invasion and high SUVmax could be important prognostic factors coupled with the TNM staging system, in patients with early stage ESCC.

Prognostic impact of initial maximum standardized uptake value of 18F-FDG PET/CT on treatment response in patients with metastatic lung adenocarcinoma treated with erlotinib

PurposeTo investigate whether the initial maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has a prognostic significance in metastatic lung adenocarcinoma.Patients and methodsSixty patients (24 females, mean age: 57.9±12 years) with metastatic stage lung adenocarcinoma who used erlotinib and underwent 18F-FDG PET/CT at the time of diagnosis between May 2010 and May 2014 were enrolled in this retrospective study. The patients were stratified according to the median SUVmax value, which was found as 11. Progression-free survival (PFS) rates for 3, 6, and 12 months were examined for SUVmax values and epidermal growth factor receptor (EGFR) mutation status.ResultsThe number of EGFR-sensitizing mutation positive/negative/unknown was 26/17/17, respectively, and the number of patients using erlotinib at first-line, second-line, and third-line therapy was 15, 31, and 14 consecutively. The PFS rates of EGFR mutation positive, negative, and unknown patients for 3 months were 73.1%, 35.3%, and 41.2% (P=0.026, odds ratio [OR]=4.39; 95% confidence interval [CI]: 1.45–13.26), respectively. The PFS rates of EGFR positive, negative, and unknown patients for 6 months were 50%, 29.4%, and 29.4% (P=0.267, OR: 2.4; 95% CI: 0.82–6.96), respectively. The PFS rates of EGFR positive, negative, and unknown patients for 12 months were 42.3%, 29.4%, 23.5% (P=0.408, OR: 2.0; 95% CI: 0.42–5.26), respectively. Thirty-one of 60 patients had SUVmax values ≤11. The PFS rates for 3, 6, and 12 months were 70.5%/28% (P=0.001, OR=9.0; 95% CI: 2.79–29.04), 61.7%/8% (P<0.001, OR=28.35; 95% CI: 5.5–143), and 52.9%/8% (P<0.001, OR=18.69; 95% CI: 3.76–92.9) for low SUVmax (≤11) group/high SUVmax (>11) group, respectively.ConclusionInitial SUVmax value on 18F-FDG PET/CT is found to be a prognostic factor anticipating the response to erlotinib for 3, 6, and 12-month rates of PFS in both EGFR-sensitizing mutation and wild-type tumor group.

The maximum standardized uptake value of 18F-FDG PET/CT combined with the image features on high resolution CT for the diagnosis of lung cancer

Objective To investigate the diagnostic value of the SUVmax of 18F-FDG PET/CT combined with the image features on high resolution CT(HRCT) for lung cancer.Methods 18F-FDG PET/CT and HRCT data of 122 patients with pulmonary tumor-like lesions from August 2010 to August 2011 were analyzed retrospectively.Diagnoses of the subjects were confirmed by pathology or follow-up (＞ 8 months).x2 test was performed to compare the differences in the constituent ratio of different HRCT features of the lesions.One-way analysis of variance was used to evaluate the differences of SUVmax in different pathological types of lung cancer.Multivariate logistic stepwise regression analysis was performed to evaluate the significance of SUVmax and HRCT features for diagnosis of lung cancer.Results Out of the 122 patients,there were 40 with benign lesions and 82 with malignant lesions.Spiculation sign (64.6％,53/82),lobulation sign (63.4％,52/82) and pleural indentation sign (39.0％,32/82) were the top three HRCT features of the pulmonary malignant tumors,higher than those of benign lesions (x2 =19.08,30.89,10.88,all P ＜0.01).There was a statistical difference of SUVmax between benign (3.01 ± 3.62) and respective type of malignant lesions (F =20.83,P ＜ 0.01).SUVmax of squamous cell carcinoma,small cell carcinoma and adenocarcinoma was 12.57 ± 4.34,10.66 ± 2.90 and 8.19 ± 6.01 respectively.There was a statistical difference of SUVmax between adenocarcinoma and squamous cell carcinoma (P ＜0.01).The AUC on ROC curves of SUVmax was 0.863.The sensitivity,specificity and Kappa value were 89.0％ (73/82),75.0％(30/40),0.644 with a SUVmax cutoff of 2.99 and 91.5％ (75/82),65.0％ (26/40),0.597 with a SUVmax cutoff of 2.50 for malignant lesion,respectively.Multivariate logistic stepwise regression analysis showed that OR for SUVmax 2.99 was higher than OR for SUVmax 2.5 (5.42 vs 3.93).SUVmax (OR =5.42,P =0.01),tumor maximal diameter (OR =7.27,P =0.02),spiculation sign (OR =7.70,P ＜ 0.01) and lobulation sign (OR =12.38,P ＜ 0.01) were the significant parameters in differential diagnoses of lung cancer.Conclusions SUVmax is valuable in the diagnosis of lung cancer.Combination of SUVmax and HRCT may improve the diagnostic capabilities for lung cancer.SUVmax,tumor maximal diameter,spiculation sign and lobulation sign are the significant parameters or features for image interpretation. Key words: Lung neoplasms; Tomography, emission-computed; Tomography, X-ray computed ; Deoxyglucose

Dynamic 11C-methionine PET analysis has an additional value for differentiating malignant tumors from granulomas: an experimental study using small animal PET

We evaluated whether the dynamic profile of L-(11)C-methionine (11C-MET) may have an additional value in differentiating malignant tumors from granulomas in experimental rat models by small animal positron emission tomography (PET). Rhodococcus aurantiacus and allogenic rat C6 glioma cells were inoculated, respectively, into the right and left calf muscles to generate a rat model bearing both granulomas and tumors (n=6). Ten days after the inoculations, dynamic 11C-MET PET was performed by small animal PET up to 120 min after injection of 11C-MET. The next day, after overnight fasting, the rats were injected with 18F-2-deoxy-2-fluoro-D-glucose (18F-FDG), and dynamic 18F-FDG PET was performed up to 180 min. The time-activity curves, static images, and mean standardized uptake value (SUV) in the lesions were calculated. 11C-MET uptake in the granuloma showed a slow exponential clearance after an initial distribution, while the uptake in the tumor gradually increased with time. The dynamic pattern of 11C-MET uptake in the granuloma was significantly different from that in the tumor (p<0.001). In the static analysis of 11C-MET, visual assessment and SUV analysis could not differentiate the tumor from the granuloma in all cases, although the mean SUV in the granuloma (1.48±0.09) was significantly lower than that in the tumor (1.72±0.18, p<0.01). The dynamic patterns, static images, and mean SUVs of 18F-FDG in the granuloma were similar to those in the tumor (p=NS). Dynamic 11C-MET PET has an additional value for differentiating malignant tumors from granulomatous lesions, which deserves further elucidation in clinical settings.