Relationship Between [18F]FDOPA PET Uptake, Apparent Diffusion Coefficient (ADC), and Proliferation Rate in Recurrent Malignant Gliomas

Purpose: Diffusion magnetic resonance imaging (MRI) and 6-[18F]fluoro-l-dopa ([18F]FDOPA) positron emission tomography (PET) are used to interrogate malignant tumor microenvironment. It remains unclear whether there is a relationship between [18F]FDOPA uptake, diffusion MRI estimates of apparent diffusion coefficient (ADC), and mitotic activity in the context of recurrent malignant gliomas, where the tumor may be confounded by the effects of therapy. The purpose of the current study is to determine whether there is a correlation between these imaging techniques and mitotic activity in malignant gliomas.Procedures: We retrospectively examined 29 patients with recurrent malignant gliomas who underwent structural MRI, diffusion MRI, and [18F]FDOPA PET prior to surgical resection. Qualitative associations were noted, and quantitative voxel-wise and median measurement correlations between [18F]FDOPA PET, ADC, and mitotic index were performed.Results: Areas of high [18F]FDOPA uptake exhibited low ADC and areas of hyperintensity T2/fluid-attenuated inversion recovery (FLAIR) with low [18F]FDOPA uptake exhibited high ADC. There was a significant inverse voxel-wise correlation between [18F]FDOPA and ADC for all patients. Median [18F]FDOPA uptake and median ADC also showed a significant inverse correlation. Median [18F]FDOPA uptake was positively correlated, and median ADC was inversely correlated with mitotic index from resected tumor tissue.Conclusions: A significant association may exist between [18F]FDOPA uptake, diffusion MRI, and mitotic activity in recurrent malignant gliomas

Teaching: Natural or Cultural?

In this chapter I argue that teaching, as we now understand the term, is historically and cross-culturally very rare. It appears to be unnecessary to transmit culture or to socialize children. Children are, on the other hand, primed by evolution to be avid observers, imitators, players and helpers—roles that reveal the profoundly autonomous and self-directed nature of culture acquisition (Lancy in press a). And yet, teaching is ubiquitous throughout the modern world—at least among the middle to upper class segment of the population. This ubiquity has led numerous scholars to argue for the universality and uniqueness of teaching as a characteristically human behavior. The theme of this chapter is that this proposition is unsustainable. Teaching is largely a result of recent cultural changes and the emergence of modern economies, not evolution

Short-interval estimation of proliferation rate using serial diffusion MRI predicts progression-free survival in newly diagnosed glioblastoma treated with radiochemotherapy

Cell invasion, motility, and proliferation level estimate (CIMPLE) mapping is a new imaging technique that provides parametric maps of microscopic invasion and proliferation rate estimates using serial diffusion MRI data. However, a few practical constraints have limited the use of CIMPLE maps as a tool for estimating these dynamic parameters, particularly during short-interval follow-up times. The purpose of the current study was to develop an approximation for the CIMPLE map solution for short-interval scanning involving the assumption that net intervoxel tumor invasion does not occur within sufficiently short time frames. Proliferation rate maps created using the “no invasion” approximation were found to be increasingly similar to maps created from full solution during increasingly longer follow-up intervals (3D cross correlation, R(2)=0.5298, P=0.0001). Results also indicate proliferation rate maps from the “no invasion” approximation had significantly higher sensitivity (82% vs. 64%) and specificity (90% vs. 80%) for predicting six month progression free survival and was a better predictor of time to progression during standard radiochemotherapy compared to the full CIMPLE solution (Log-rank; No Invasion estimation, P=0.0134; Full Solution, P=0.0555). Together, results suggest the “no invasion” approximation allows for quick estimation of proliferation rate using diffusion MRI data obtained from multiple scans obtained daily or biweekly for use in quantifying early treatment response

A screening platform for glioma growth and invasion using bioluminescence imaging: Laboratory investigation

10.3171/2008.8.JNS08644Journal of Neurosurgery1112238-246JONS