Dynamic 68 Ga-DOTATATE PET/MRI in the Diagnosis and Management of Intracranial Meningiomas.

Purpose To evaluate dynamic gallium 68 ( ⁶⁸ Ga) tetraazacyclododecane tetraacetic acid octreotate (DOTATATE) brain PET/MRI as an adjunct modality in meningioma, enabling multiparametric standardized uptake value (SUV) and Patlak net binding rate constant ( K _i ) imaging, and to optimize static acquisition period. Materials and Methods In this prospective study (ClinicalTrials.gov no. NCT04081701, DOMINO-START), ⁶⁸ Ga-DOTATATE PET/MRI-derived time-activity curves (TACs) were measured in 84 volumes of interest in 19 participants (mean age, 63 years; range, 36-89 years; 13 women; 2019-2021) with meningiomas. Region- and voxel-specific K _i were determined using Patlak analysis with a validated population-based reference tissue TAC model built from an independent data set of nine participants. Mean and maximum absolute and relative-to-superior-sagittal-sinus SUVs were extracted from the entire 50 minutes (SUV ₅₀ ) and last 10 minutes (SUV ₁₀ ) of acquisition. SUV versus K _i Spearman correlation, SUV and K _i meningioma versus posttreatment-change Mann-Whitney U tests, and SUV ₅₀ versus SUV ₁₀ Wilcoxon matched-pairs signed rank tests were performed. Results Absolute and relative maximum SUV ₅₀ demonstrated a strong positive correlation with Patlak K _i in meningioma ( r = 0.82, P < .001 and r = 0.85, P < .001, respectively) and posttreatment-change lesions ( r = 0.88, P = .007 and r = 0.83, P = .02, respectively). Patlak K _i images yielded higher lesion contrast by mitigating nonspecific background signal. All SUV ₅₀ and SUV ₁₀ metrics differed between meningioma and posttreatment-change regions ( P < .001). Within the meningioma group, SUV ₁₀ attained higher mean scores than SUV ₅₀ ( P < .001). Conclusion Combined SUV and Patlak K _i ⁶⁸ Ga-DOTATATE PET/MRI enabled multiparametric evaluation of meningioma, offering the potential to enhance lesion contrast with K _i imaging and optimize the SUV measurement postinjection window. Keywords: Molecular Imaging-Clinical Translation, Neuro-Oncology, PET/MRI, Dynamic, Patlak ClinicalTrials.gov registration no. NCT04081701 © RSNA, 2022.