18F-Fluorocholine PET/CT, Brain MRI, and 5-Aminolevulinic Acid for the Assessment of Tumor Resection in High-Grade Glioma.

High-grade glioma is a very aggressive and infiltrative tumor in which complete resection is a chance for a better outcome. We present the case of a 57-year-old man with a brain lesion suggestive of high-grade glioma. Brain MRI and F-fluorocholine PET/CT were performed previously to plan the surgery. Surgery was microscope assisted after the administration of 5-aminolevulinic acid. Postsurgery brain MRI and PET were blind evaluated to the surgery results and reported as probably gross total resection.

(18)F-FDG-PET/CT in the assessment of pulmonary solitary nodules: comparison of different analysis methods and risk variables in the prediction of malignancy.

OBJECTIVE: To compare the diagnostic performance of different metabolical, morphological and clinical criteria for correct presurgical classification of the solitary pulmonary nodule (SPN). METHODS: Fifty-five patients, with SPN were retrospectively analyzed. All patients underwent preoperative (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT). Maximum diameter in CT, maximum standard uptake value (SUVmax), histopathologic result, age, smoking history and gender were obtained. Different criteria were established to classify a SPN as malignant: (I) visually detectable metabolism, (II) SUVmax >2.5 regardless of SPN diameter, (III) SUVmax threshold depending of SPN diameter, and (IV) ratio SUVmax/diameter greater than 1. For each criterion, statistical diagnostic parameters were obtained. Receiver operating characteristic (ROC) analysis was performed to select the best diagnostic SUVmax and SUVmax/diameter cutoff. Additionally, a predictive model of malignancy of the SPN was derived by multivariate logistic regression. RESULTS: Fifteen SPN (27.3%) were benign and 40 (72.7%) malignant. The mean values ± standard deviation (SD) of SPN diameter and SUVmax were 1.93±0.57 cm and 3.93±2.67 respectively. Sensitivity (Se) and specificity (Sp) of the different diagnostic criteria were (I): 97.5% and 13.1%; (II) 67.5% and 53.3%; (III) 70% and 53.3%; and (IV) 85% and 33.3%, respectively. The SUVmax cut-off value with the best diagnostic performance was 1.95 (Se: 80%; Sp: 53.3%). The predictive model had a Se of 87.5% and Sp of 46.7%. The SUVmax was independent variables to predict malignancy. CONCLUSIONS: The assessment by semiquantitative methods did not improve the Se of visual analysis. The limited Sp was independent on the method used. However, the predictive model combining SUVmax and age was the best diagnostic approach.

Semi-quantitative lymph node assessment of (18)F-FDG PET/CT in locally advanced breast cancer: correlation with biological prognostic factors.

PURPOSE: The aim of this study was to analyse the correlation between dual-time-point (18)F-2-deoxy-2-fluoro-D-glucose (FDG) uptakes in lymph nodes assessed by positron emission tomography (PET)/CT and histopathological and immunohistochemical prognostic factors. METHODS: Seventy-five women with locally advanced breast cancer were prospectively evaluated. PET/CT was requested in the initial staging previous to adjuvant chemotherapy (multicentre study). All of the patients underwent (18)F-FDG PET/CT with a dual-time-point acquisition. Both examinations were evaluated qualitatively and semi-quantitatively with calculation of maximum standardized uptake values (SUV(max)) in PET-1 (SUV-1) and in PET-2 (SUV-2) and the percentage variation of the SUV or retention index (RI) between PET-1 and PET-2 in lymph nodes with the greater (18)F-FDG uptake. The biological prognostic parameters such as the steroid receptor status, p53 and HER2 expression, proliferation rate (Ki-67) and grading were determined from tissue of the primary tumour. Metabolic and biological parameters were correlated using Spearman's rank-order correlation coefficient and Mann-Whitney U and Kruskal-Wallis tests. RESULTS: Negative receptor status was correlated with higher SUV-1, SUV-2 and RI in lymph nodes. The results were significant for progesterone receptor status. p53 over-expression and triple-negative status were associated with greater semi-quantitative parameters in lymph nodes. Higher tumoural grades were related with greater semi-quantitative parameters (p > 0.05). CONCLUSION: Biological factors of bad prognosis were correlated with higher semi-quantitative metabolic values in lymph nodes. Therefore these results appear to reveal biological significance of lymph node (18)F-FDG accumulation.