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Purpose: The objective of this study was to assess the prognostic value of metabolic tumor burden on 2-deoxy-2-[F]fluoro- D-glucose (F-FDG) positron emission tomography (PET)/CT measured with metabolic tumor volume (MTV) and total lesion glycolysis (TLG), independent of Union Internationale Contra la Cancrum (UICC)/American Joint Committee on Cancer (AJCC) tumor, node, and metastasis (TNM) stage, in comparison with that of standardized uptake value (SUV) in nonsurgical patients with non-small cell lung cancer (NSCLC). Methods: This study retrospectively reviewed 169 consecutive nonsurgical patients (78 men, 91 women, median age of 68 years) with newly diagnosed NSCLC who had pretreatment F-FDG PET/CT scans. The F-FDG PET/CT scans were performed in accordance with National Cancer Institute guidelines. The MTV of whole-body tumor (MTV), of primary tumor (MTV), of nodal metastases (MTV), and of distant metastases (MTV); the TLG of whole-body tumor (TLG), of primary tumor (TLG), of nodal metastases (TLG), and of distant metastases (TLG); the SUV of whole-body tumor (SUV), of primary tumor (SUV), of nodal metastases (SUV), and of distant metastases (SUV) as well as the SUV of whole-body tumor (SUV), of primary tumor (SUV), of nodal metastases (SUV), and of distant metastases (SUV) were measured with the PETedge tool on a MIMvista workstation with manual adjustment. The median follow-up among survivors was 35 months from the PET/CT (range 2-82 months). Statistical methods included Kaplan-Meier curves, Cox regression, and C-statistics. Results: There were a total of 139 deaths during follow-up. Median overall survival (OS) was 10.9 months [95% confidence interval (CI) 9.0-13.2 months]. The MTV was statistically associated with OS. The hazard ratios (HR) for 1 unit increase of ln(MTV), √(MTV), √(MTV), and √(MTV) before/after adjusting for stage were: 1.47/1.43 ( p < 0.001/<0.001), 1.06/1.05 ( p < 0.001/<0.001), 1.11/1.10 ( p < 0.001/<0.001), and 1.04/1.03 ( p = 0.007/0.043), respectively. TLG had statistically significant associations with OS with the HRs for 1 unit increase in ln(TLG), √(TLG), √(TLG), and √(TLG) before/after adjusting for stage being 1.36/1.33 ( p < 0.001/<0.001), 1.02/1.02 ( p = 0.001/0.002), 1.05/1.04 ( p < 0.001/<0.001), and 1.02/1.02 ( p = 0.003/0.024), respectively. The ln(SUV) and √(SUV) were statistically associated with OS with the corresponding HRs for a 1 unit increase before/after adjusting for stage being 1.46/1.43 ( p = 0.013/0.024) and 1.22/1.16 ( p = 0.002/0.040). The √(SUV) was statistically associated with OS before and after adjusting for stage with HRs for a 1 unit increase of 1.32 ( p < 0.001) and 1.24 ( p = 0.015), respectively. The √(SUV) and √(SUV) were statistically associated with OS before adjusting for stage with HRs for a 1 unit increase of 1.26 ( p = 0.017) and 1.18 ( p = 0.007), respectively, but not after adjusting for stage ( p = 0.127 and 0.056). There was no statistically significant association between OS and √(SUV), ln(SUV), or √(SUV). There was low interobserver variability among three radiologists with intraclass correlation coefficients (ICC) greater than 0.94 for SUV, ln(MTV), and ln(TLG). Interobserver variability was higher for SUV with an ICC of 0.806. Conclusion: Baseline metabolic tumor burdens at the level of whole-body tumor, primary tumor, nodal metastasis, and distant metastasis as measured with MTV and TLG on FDG PET are prognostic measures independent of clinical stage with low inter-observer variability and may be used to further stratify nonsurgical patients with NSCLC. This study also suggests MTV and TLG are better prognostic measures than SUV and SUV. These results will need to be validated in larger cohorts in a prospective study. [ABSTRACT FROM AUTHOR]

Purpose: Attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUDs) are highly comorbid and may share a genetic vulnerability. Methylphenidate (MPH), a dopamine transporter (DAT) blocker, is an effective drug for most ADHD patients. Although dopamine D4 receptor ( DRD4) and dopamine transporter ( DAT1) genes have a role in both disorders, little is known about how these genes influence brain response to MPH in individuals with ADHD/SUDs. The goal of this study was to evaluate whether ADHD risk alleles at DRD4 and DAT1 genes could predict the change in striatal DAT occupancy after treatment with MPH in adolescents with ADHD/SUDs. Methods: Seventeen adolescents with ADHD/SUDs underwent a SPECT scan with [Tc99m]TRODAT-1 at baseline and after three weeks on MPH. Caudate and putamen DAT binding potential was calculated. Comparisons on DAT changes were made according to the subjects' genotype. Results: The combination of both DRD4 7-repeat allele (7R) and homozygosity for the DAT1 10-repeat allele (10/10) was significantly associated with a reduced DAT change after MPH treatment in right and left caudate and putamen, even adjusting the results for potential confounders ( P ≤ 0.02; R2 from 0.50 to 0.56). Conclusions: In patients with ADHD/SUDs, combined DRD4 7R and DAT1 10/10 could index MPH reduced DAT occupancy. This might be important for clinical trials, in terms of better understanding individual variability in treatment response. Synapse 2011. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Background: Although the decrease in striatal dopamine transporter (DAT) density has been described in North American, European, and Asian Parkinson's disease (PD) patients, studies on this issue are required in the rest of the world. This study examined the diagnostic utility of DAT imaging in Brazilian PD patients., Material/methods: Twenty PD patients (13 males, 7 females, median age: 62 years, median age at disease onset: 56 years, median disease duration: 5 years, and median UPDRS-III score: 29) and 9 age- and sex-matched healthy subjects underwent single-photon emission computerized tomography (SPECT) using 99mTc-TRODAT-1., Results: PD patients showed a significant decrease in the striatum, caudate nucleus, and putamen DAT densities compared with data from healthy subjects. Striatal 99mTc-TRODAT-1 bindings had the highest diagnostic accuracy compared to those estimates from caudate nucleus and putamen. For the diagnosis of PD, a striatal 99mTc-TRODAT-1 binding cut-off value of 0.90 was associated with a sensitivity of 100% and a specificity of 89%. There was no significant difference between striatal 99mTc-TRODAT-1 binding values provided by different readers, contrary to 99mTc-TRODAT-1 binding estimates in the caudate nucleus., Conclusions: Striatal DAT imaging using 99mTc-TRODAT-1 can be considered a marker for differentiating PD patients from healthy individuals, with a good interobserver reproducibility.

Background: Dopamine transporter (DAT) neuroimaging radiotracers were developed to estimate dopamine neuronal loss in vivo in Parkinsons disease (PD)., Objective: To evaluate DAT density in vivo using [99mTc]-TRODAT-1 and single photon computerized tomography (SPECT) in a population of Brazilian PD., Method: Fifteen PD patients and 15 matched healthy controls scanned with [99mTc]-TRODAT-1 (INER-Taiwan) and SPECT. Estimates of striatum DAT density were calculated using binding potential (BP). Patients were assessed with PD scales., Results: PD patients had significantly lower striatal DAT-BP (mean+/-SD) (0.38+/-0.12) compared to controls (BP=0.84+/-0.16; p<0.01). A 100% sensitivity and 100% specificity was obtained to discriminate PD cases from controls. Negative correlations between striatal DAT-BP and PD severity (rho=-0.7, p<0.001) and motor scales (rho=-0.80, p<0.001) were found., Conclusion: [99mTc]TRODAT-1 SPECTs scanning was able to discriminate PD patients from controls. The technique is a powerful instrument to measure DAT density that can be used in clinical and research settings in Brazil.