Woo Hee Choi

The clinical value of dual-time point 18F-FDG PET/CT for differentiating extrahepatic cholangiocarcinoma from benign disease.

Purpose The aim of this study was to assess the value of dual–time point PET/CT in the differentiation of extrahepatic cholangiocarcinoma from benign stricture and the added benefits of delayed PET/CT image. Patients and Methods Thirty-nine patients with suspected extrahepatic biliary malignancy based on conventional imaging studies such as ultrasonography, CT, and MRI between July 2008 and December 2010 were included. All patients underwent dual–time point PET/CT scans at 1 and 2 hours after radiotracer injection. From the site of suspected malignancy, the SUVmax for both time points (SUVmax1 and SUVmax2), the percent change in SUVmax between the 2 (&Dgr;%SUVmax) and the ratio of SUVmax1, SUVmax2, &Dgr;%SUVmax in comparison with average SUV of right hepatic lobe (T/L ratio1, T/L ratio2, and &Dgr;%T/L ratio) were generated. Diagnostic performances using visual assessment and various SUVmax cutoff values were analyzed in the differential diagnosis of extrahepatic cholangiocarcinoma from benign disease. PET/CT results were correlated with histological results and radiological follow-up for at least 6 months. Results Of 39 patients, the final diagnosis was cholangiocarcinoma in 34 and benign disease in 5. Between malignant and benign lesions, there were significant differences in SUVmax1 (5.43 ± 4.66 vs 2.26 ± 0.83, P = 0.003) and SUVmax2 (6.02 ± 5.26 vs 2.26 ± 0.76, P = 0.002). There was no significant difference in &Dgr;%SUVmax, T/L ratio1, T/L ratio2, and &Dgr;%T/L ratio. On receiver operator curve analysis, SUVmax1 with cutoff value of 2.5 demonstrated sensitivity of 97.6%, specificity of 60.0%, and accuracy of 92.3% and SUVmax2 with cutoff value of 3.1 demonstrated sensitivity of 88.2%, specificity of 100%, and accuracy of 89.7%. Conclusion SUVmax from both early and delayed PET/CT scans are useful parameters in the differentiation of extrahepatic biliary malignancy from benign disease. However, there was no added benefit of delayed PET/CT in patients suspicious for extrahepatic cholangiocarcinoma.

Clinical Value of Integrated [18F]Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography/Computed Tomography in the Preoperative Assessment of Papillary Thyroid Carcinoma Comparison With Sonography

The purpose of this study was to evaluate the clinical value of preoperative [18F]fluoro‐2‐deoxy‐d‐glucose (FDG) positron emission tomography/computed tomography (PET/CT) by comparing it to neck sonography in papillary thyroid carcinoma.

Prognostic value of early response assessment using 18F-FDG PET/CT in chemotherapy-treated patients with non-small-cell lung cancer.

ObjectiveWe aimed to evaluate the prognostic value of early response assessment using a volumetric fluorine-18-fluorodeoxyglucose (18F-FDG) PET analysis in chemotherapy-treated patients with non-small-cell lung cancer (NSCLC). Materials and methodsWe retrospectively reviewed 33 patients with NSCLC who received first-line chemotherapy and performed 18F-FDG PET/computed tomography before (baseline PET) and after two cycles of chemotherapy (interim PET). The maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of the total malignant lesion were measured in baseline (SUV1 and MTV1) and interim (SUV2 and MTV2) PET images, and percentage changes in SUVmax (&Dgr;SUV) and MTV (&Dgr;MTV) were calculated between the two images. We compared PET parameters and clinicopathologic variables in terms of the 2-year overall survival (OS). ResultsThe median follow-up period was 14.3 months and the 2-year OS was 31%. In PET images, the mean SUV1, MTV1, SUV2, MTV2, &Dgr;SUV, and &Dgr;MTV were 13.1±4.5, 307.9±340.0 cm3, 9.5±5.1, 180.4±29.6 cm3, 27±28%, and 42±65%, respectively. In univariable analysis, M stage, TNM stage, and all six PET parameters associated significantly with OS. Both the MTV1 and the &Dgr;MTV were tested against OS controlling for M stage, one at time, and the effect remained significant in multivariable analyses. ConclusionA smaller baseline MTV and greater decrease in MTV between baseline and interim PET images are associated with a significantly prolonged OS. A volume-based 18F-FDG PET analysis would facilitate prediction of clinical outcome and identification of treatment-resistant patients early during chemotherapy and could thus be used in personalized treatment approaches for patients with NSCLC.

Prognostic value of SUVmax and metabolic tumor volume on 18F-FDG PET/CT in early stage non-small cell lung cancer patients without LN metastasis

This paper aimed to evaluate the prognostic value of maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of the primary tumor on (18)F-FDG PET/CT scan in early stage non-small cell cancer (NSCLC) patients without lymph node (LN) metastasis. In the experiment, eighty NSCLC patients pathologically staged as T1N0 or T2N0 were included (M:F=50:30; mean age, 64.8 years). All patients had preoperative (18)F-FDG PET/CT scan and curative surgery. FDG uptake in the primary tumor was measured by SUVmax and MTV with various SUV threshold values. SUVmax, MTV of the primary tumor, age, tumor size, histology and differentiation grade were analyzed for association with disease-free survival (DFS). The experimental results showed that the histology types included adenocarcinoma (n=58), squamous cell carcinoma (n=20), and others (n=2); Twenty-two (27.5%) of the 80 patients had a recurrence during follow-up at a median time of 29.1 months; The median SUVmax was 5.26, and the median MTV2.5 was 2.2 cm(3). Univariate analysis showed higher SUVmax (>4), greater MTV (MTV2.5 >4 cm(3)), and non-squamous histology were significantly associated with shorter period DFS (p=0.001, p=0.030 and p<0.001). In multivariate analysis, higher SUVmax (p=0.004) and adenocarcinoma histology (p=0.005) were associated with shorter DFS. Therefore, high SUVmax (>4) of the primary tumor on preoperative (18)F-FDG PET/CT scan is an independent prognostic factor of shorter DFS in early stage of NSCLC.

Cerebral Vascular Burden on Hippocampal Subfields in First-onset Drug-naïve Subjects with Late-Onset Depression

BACKGROUND Although there is substantial evidence of associations between frontal-striatal circuits and cerebral vascular burden in late-onset depression (LOD), relationships between vascular burden and hippocampal subfields are not clear. The purpose of this study was to investigate relationships between cerebral vascular burden and hippocampal subfield volume in LOD patients. METHODS Fifty subjects with LOD and 50 group-matched healthy control subjects underwent magnetic resonance imaging scanning. Hippocampal subfields volumes were measured and compared between the groups. In addition, association patterns between white matter hyperintensity (WMH) volumes, clinical measures and hippocampal subfield volumes were investigated in the LOD group. RESULTS Subjects with LOD exhibited significant hippocampal volume reductions in the total hippocampus, cornu ammonis (CA) 1 and 3 and dentate gyrus (DG) areas compared with healthy subjects. Total WMH volume was negatively correlated with left total hippocampal volume and CA1 in the LOD group. In addition, depression severity was negatively associated with left and right CA3 volumes in the LOD group. LIMITATION Our findings of distinctive relationships between WMH and hippocampal subfields demonstrate a simple correlation, but do not prove causation CONCLUSION: This study is the first to elaborate distinctive association patterns between hippocampal subfield volumes and cerebral vascular burden in LOD. These structural changes in the hippocampal CA1, CA3 and DG areas might be at the core of the underlying neurobiological mechanisms of hippocampal dysfunction in LOD. However, longitudinal studies will be needed to identify the mechanisms of these structural changes.

Impact of Amyloid Burden on Regional Functional Synchronization in the Cognitively Normal Older Adults

Previous studies have shown aberrant functional connectivity in preclinical Alzheimer’s disease (AD). However, the effects of beta-amyloid (Aβ) retention on regional functional synchronization in cognitively normal older adults still remain unclear. The aim of this study was to explore the distinctive association pattern between Aβ retention and regional functional synchronization in cognitively normal older adults. Sixty-one older adults with normal cognition underwent functional magnetic resonance imaging and regional functional synchronizations were quantified using regional homogeneity (ReHo). Subjects were dichotomized using 18F-Florbetaben positron emission tomography imaging into subjects with (Aβ+; n = 30) and without (Aβ-; n = 31) Aβ burden. The Aβ+ group exhibited significantly higher ReHo in the fusiform gyrus and lower ReHo in the precuneus compared with the Aβ- group. We found significant negative correlations between global Aβ retention and ReHo in the precuneus and medial prefrontal cortex and positive correlations between global Aβ retention and ReHo in the bilateral lingual gyrus, left fusiform gyrus, and right middle temporal gyrus in the Aβ+ group. Our findings suggest that regional functional synchronization might have distinctive association patterns with Aβ retention in the cognitively normal older adults. These findings can enrich the functional characterization of early stages of disease progression in AD.

Is the Glut expression related to FDG uptake in PET/CT of non-small cell lung cancer patients?

Though 18F-FDG PET/CT scans are widely used in non-small cell lung cancer (NSCLC), the mechanism of FDG uptake by lung cancer cells has not yet been fully elucidated. This study evaluated the relationship between FDG uptake and the expression of glucose transporters in NSCLC. Sixty-four NSCLC patients who underwent both preoperative 18F-FDG PET/CT scanning and thoracotomy were included. The maximum standardized uptake value (SUVmax) of the primary lung cancer was compared to the immunohistochemistry results for Glut expression and tumor size. In all the NSCLC cases, degree of FDG uptake significantly correlated with both Glut-1 and Glut-3 expression. When stratified by the histology, squamous cell carcinomas showed higher mean SUVmax, Glut-1 expression intensity, and percentage of area positive for Glut-1 expression than adenocarcinomas. Glut-1 and Glut-3 expressions correlated with SUVmax in adenocarcinomas, but there was no significant correlation in squamous cell carcinomas. No significant correlation was observed between tumor size and FDG uptake or Glut expression. These results show that Glut expression was significantly correlated with SUVmax in NSCLC, especially in adenocarcinomas, and that neither FDG uptake nor the expression of Glut was associated with tumor size.

A Case Report of a 37-Year-Old Alzheimer's Disease Patient with Prominent Striatum Amyloid Retention

With recent advancement in amyloid imaging, diagnostic application of this new modality has become a great interest among researchers. New ligands, such as 18F- florbetaben, florbetapir and flutemetamol, have been discovered to overcome limitations of preexisting ligand Pittsburgh compound B. We report here a case of a 37-year-old male patient whose initial complaints comprised of gradual cognitive decline, apraxia, disorientation and sleep disturbances. 18F-Florbetaben amyloid imaging of the patient showed diffuse amyloid retention with prominent striatal uptake. This finding supports the clinical utility of amyloid imaging in diagnostic process of early-onset AD. Moreover, striatal dominant uptake pattern demonstrated in this patient include some meaningful clinical implications that warrant special attention among clinicians.

Whole Brain Voxel-Wise Analysis of Cerebral Retention of Beta-Amyloid in Cognitively Normal Older Adults Using 18F-Florbetaben

Objective Recently developed 18F-labelled amyloid beta (Aβ) positron emission tomography (PET) tracers have demonstrated potentials to enable more prevalent application of amyloid imaging in the clinical setting. The aim of this study is to demonstrate cerebral retention of Aβ in cognitively normal older adults, by implementing voxel-based analysis on images acquired from 18F-Florbetaben amyloid PET. Methods Fifty cognitive normal elderly subjects were recruited and included in the study. Demographic data and cognitive measurements were collected. Magnetic resonance imaging (MRI) and 18F-Florbetaben PET data were obtained followed by whole brain voxel-based analysis. Results Compared to the florbetaben (FBB) (−) counterpart, FBB (+) showed significantly higher Aβ deposition in the brain regions comprising anterior cingulate, middle cingulate, posterior cingulate and precuneus (family wise error corrected p<0.05). There was no significant correlation between amyloid retention and cognitive functions. Conclusion Our results confirms previous results regarding Aβ deposition by using 18F-Florbetaben, demonstrating potentials in application of 18F-Florbetaben PET imaging in clinical settings.

CLINICAL SIGNIFICANCE OF STRIATAL UPTAKE IN AMYLOID POSITRON EMISSION TOMOGRAPHY

the use of [F]ICMT-11 PET tracer in an AD population, and we have detected an increased [F]ICMT-11 uptake in the Alzheimer’s disease subjects, compared to the HC group. This is in line with ex vivo demonstration of Caspase 3 activity in Alzheimer’s disease. While larger studies are necessary to validate these finding, these preliminary data suggest that [F]ICMT-11 has the potential to detect Caspase 3 activity in Alzheimer’s disease.