Using CT Data to Improve the Quantitative Analysis of 18F-FBB PET Neuroimages

18F-FBB PET is a neuroimaging modality that is been increasingly used to assess brain amyloid deposits in potential patients with Alzheimer’s disease (AD). In this work, we analyze the usefulness of these data to distinguish between AD and non-AD patients. A dataset with 18F-FBB PET brain images from 94 subjects diagnosed with AD and other disorders was evaluated by means of multiple analyses based on t-test, ANOVA, Fisher Discriminant Analysis and Support Vector Machine (SVM) classification. In addition, we propose to calculate amyloid standardized uptake values (SUVs) using only gray-matter voxels, which can be estimated using Computed Tomography (CT) images. This approach allows assessing potential brain amyloid deposits along with the gray matter loss and takes advantage of the structural information provided by most of the scanners used for PET examination, which allow simultaneous PET and CT data acquisition. The results obtained in this work suggest that SUVs calculated according to the proposed method allow AD and non-AD subjects to be more accurately differentiated than using SUVs calculated with standard approaches.This work was supported by the MINECO/FEDER under the TEC2012-34306 and TEC2015-64718-R projects and the Ministry of Economy, Innovation, Science and Employment of the Junta de Andalucía under the Excellence Project P11-TIC- 7103. The work was also supported by the Vicerectorate of Research and Knowledge Transfer of the University of Granada

Tomografía por Emisión de Positrones (PET) con fluorocolina en gliomas cerebrales

1. En el seguimiento de pacientes tratados de un glioma cerebral de bajo grado, el empleo de la PET-FCH para la detección de actividad tumoral en progresión ha mostrado una validez diagnóstica global del 83.8%; una sensibilidad del 83.8% y una especificidad del 85.7%. II. La evaluación de la utilidad clínica de la PET-FCH en términos de impacto clínico (negativo, neutro y positivo) mostró que la incorporación de la PET-FCH en el control evolutivo de pacientes tratados de glioma cerebral de bajo grado: . No indujo la realización de ningún procedimiento invasivo innecesario o que supusiera un riesgo adicional para el paciente en ningún paciente; es decir no tuvo en ningún caso un impacto negativo. . En el 40.54% de los pacientes la exploración PET-FCH tuvo un impacto neutro, apoyando los resultados ofrecidos por otros procedimientos diagnósticos previos. . En el 59.46% de los pacientes la PET-FCH aportó información de utilidad que permitió cambios en el manejo asistencial ulterior de estos pacientes. III. Al valorar la modificación de la actitud clínica que hubiera sido adoptada exclusivamente en base a los resultados de la RM: . En el subgrupo de pacientes con una exploración de RM con un resultado positivo para progresión tumoral, la realización de la PET-FCH modificó la actitud clínica pretest en el 63.2% de los pacientes. . En el subgrupo de pacientes con una exploración previa de RM con un resultado inconcluyente o negativo para progresión tumoral, el empleo de la PET-FCH supuso un cambio en la actitud clínica en el 77.8% de los pacientes.Tesis Univ. Granada

Comparison of integrin α v β 3 expression with 68Ga-NODAGA-RGD PET/CT and glucose metabolism with 18F-FDG PET/CT in esophageal or gastroesophageal junction cancers

Abstract Background The primary aims of this study were to compare in patients with esophageal or esophagogastric junction cancers the potential of 68Ga-NODAGA-RGD PET/CT with that of 18F-FDG PET/CT regarding tumoral uptake and distribution, as well as histopathologic examination. Methods Ten 68Ga-NODAGA-RGD and ten 18F-FDG PET/CT were performed in nine prospectively included participants (1 woman; aged 58 ± 8.4 y, range 40–69 y). Maximum SUV (SUVmax) and metabolic tumor volumes (MTV) were calculated. The Mann–Whitney U test and Spearman correlation analysis (ρ) were used. Results 68Ga-NODAGA-RGD PET/CT detected positive uptake in 10 primary sites (8 for primary tumors and 2 for local relapse suspicion), 6 lymph nodes and 3 skeletal sites. 18F-FDG PET/CT detected positive uptake in the same sites but also in 16 additional lymph nodes and 1 adrenal gland. On a lesion-based analysis, SUVmax of 18F-FDG was significantly higher than those of 68Ga-NODAGA-RGD (4.9 [3.7–11.3] vs. 3.2 [2.6–4.2] g/mL, p = 0.014). Only one participant showed a higher SUVmax in an osseous metastasis with 68Ga-NODAGA-RGD as compared to 18F-FDG (6.6 vs. 3.9 g/mL). Correlation analysis showed positive correlation between 18F-FDG and 68Ga-NODAGA-RGD PET parameters (ρ = 0.56, p = 0.012 for SUVmax, ρ = 0.78, p < 0.001 for lesion-to-background ratios and ρ = 0.58, p = 0.024 for MTV). We observed that 18F-FDG uptake was homogenous inside all the confirmed primary sites (n = 9). In contrast, 68Ga-NODAGA-RGD PET showed more heterogenous uptake in 6 out of the 9 confirmed primary sites (67%), seen mostly in the periphery of the tumor in 5 out of the 9 confirmed primary sites (56%), and showed slight extensions into perilesional structures in 5 out of the 9 confirmed primary sites (56%). Conclusions In conclusion, 68Ga-NODAGA-RGD has lower potential in the detection of esophageal or esophagogastric junction malignancies compared to 18F-FDG. However, the results suggest that PET imaging of integrin α v β 3 expression may provide complementary information and could aid in tumor diversity and delineation. Trial registration: Trial registration: NCT02666547. Registered January 28, 2016—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02666547