Meningiomas: A Comparative Study of (68)Ga-DOTATOC, (68)Ga-DOTANOC and (68)Ga-DOTATATE for Molecular Imaging in Mice

PURPOSE: The goal of this study was to compare the tumor uptake kinetics and diagnostic value of three (68)Ga-DOTA-labeled somatostatin analogues ((68)Ga-DOTATOC, (68)Ga-DOTANOC, and (68)Ga-DOTATATE) using PET/CT in a murine model with subcutaneous meningioma xenografts. METHODS: The experiment was performed with 16 male NUDE NU/NU mice bearing xenografts of a human meningioma cell line (CH-157MN). (68)Ga-DOTATOC, (68)Ga-DOTANOC, and (68)Ga-DOTATATE were produced in a FASTLab automated platform. Imaging was performed on an Argus small-animal PET/CT scanner. The SUV(max) of the liver and muscle, and the tumor-to-liver (T/L) and tumor-to-muscle (T/M) SUV ratios were computed. Kinetic analysis was performed using Logan graphical analysis for a two-tissue reversible compartmental model, and the volume of distribution (V(t)) was determined. RESULTS: Hepatic SUV(max) and V(t) were significantly higher with (68)Ga-DOTANOC than with (68)Ga-DOTATOC and (68)Ga-DOTATATE. No significant differences between tracers were found for SUV(max) in tumor or muscle. No differences were found in the T/L SUV ratio between (68)Ga-DOTATATE and (68)Ga-DOTATOC, both of which had a higher fraction than (68)Ga-DOTANOC. The T/M SUV ratio was significantly higher with (68)Ga-DOTATATE than with (68)Ga-DOTATOC and (68)Ga-DOTANOC. The V(t) for tumor was higher with (68)Ga-DOTATATE than with (68)Ga-DOTANOC and relatively similar to that of (68)Ga-DOTATOC. CONCLUSIONS: This study demonstrates, for the first time, the ability of the three radiolabeled somatostatin analogues tested to image a human meningioma cell line. Although V(t) was relatively similar with (68)Ga-DOTATATE and (68)Ga-DOTATOC, uptake was higher with (68)Ga-DOTATATE in the tumor than with (68)Ga-DOTANOC and (68)Ga-DOTATOC, suggesting a higher diagnostic value of (68)Ga-DOTATATE for detecting meningiomas.