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

Abstract

PurposeThe goal of this study was to compare the tumor uptake kinetics and diagnostic value of three 68Ga-DOTA-labeled somatostatin analogues (68Ga-DOTATOC, 68Ga-DOTANOC, and 68Ga-DOTATATE) using PET/CT in a murine model with subcutaneous meningioma xenografts.MethodsThe experiment was performed with 16 male NUDE NU/NU mice bearing xenografts of a human meningioma cell line (CH-157MN). 68Ga-DOTATOC, 68Ga-DOTANOC, and 68Ga-DOTATATE were produced in a FASTLab automated platform. Imaging was performed on an Argus small-animal PET/CT scanner. The SUVmax 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 (Vt) was determined.ResultsHepatic SUVmax and Vt were significantly higher with 68Ga-DOTANOC than with 68Ga-DOTATOC and 68Ga-DOTATATE. No significant differences between tracers were found for SUVmax in tumor or muscle. No differences were found in the T/L SUV ratio between 68Ga-DOTATATE and 68Ga-DOTATOC, both of which had a higher fraction than 68Ga-DOTANOC. The T/M SUV ratio was significantly higher with 68Ga-DOTATATE than with 68Ga-DOTATOC and 68Ga-DOTANOC. The Vt for tumor was higher with 68Ga-DOTATATE than with 68Ga-DOTANOC and relatively similar to that of 68Ga-DOTATOC.ConclusionsThis study demonstrates, for the first time, the ability of the three radiolabeled somatostatin analogues tested to image a human meningioma cell line. Although Vt was relatively similar with 68Ga-DOTATATE and 68Ga-DOTATOC, uptake was higher with 68Ga-DOTATATE in the tumor than with 68Ga-DOTANOC and 68Ga-DOTATOC, suggesting a higher diagnostic value of 68Ga-DOTATATE for detecting meningiomas.

Functional segmentation of dynamic PET studies: Open source implementation and validation of a leader-follower-based algorithm

“…In our tests, the algorithm successfully extracted the TACs for the relevant tissues or regions when the threshold was above a certain critical value, and the results were comparable with those obtained in [37]. Images with lower injected radioactivity, which tend to be more affected by noise, were separated into more clusters for the same threshold value.…”

“…To do so, we aim to replicate the results obtained in [37] by replacing the manual TAC extraction used in that study with the method presented here. We also include a comparison with the classic k means algorithm.…”

Treatment of aggressive recurrent meningiomas: spinning towards peptide receptor radionuclide therapy

“…From a biological standpoint, a recent study confirmed that meningiomas overexpress SST2, with a high expression pattern in 67% of cases, comparable to gastroenteropancreatic NET [5]. These findings agree with imaging studies with 68 Ga-DOTA-SSAs that showed highly elevated tumour uptake [6,7]. 68 Ga-DOTA-SSAs PET/CT is currently recommended in meningioma patients by the international recommendation of the RANO group for differential diagnosis, grading, delineation, radiation planning, follow-up, evaluation of response and progression [1].…”

Improving PET Quantification of Small Animal [68Ga]DOTA-Labeled PET/CT Studies by Using a CT-Based Positron Range Correction

“…The results presented in this paper, together with the validations presented in [31], demonstrate that the quantitative evaluation of small animal PET images obtained with 68 Ga-DOTA-labeled radiotracers is improved when using appropriate PRC. This improved quantification can increase the diagnostic value of 68 Ga radiotracers, already established or under development [5,[38][39][40]. This would also apply to any preclinical study performed using radiotracers based on medium-large positron range radionuclides, such as O-15, I-124, or Rb-82 [41][42][43][44].…”

“…[ 68 Ga]DOTA-labeled somatostatin analogues bind specifically to somatostatin receptors (SSTRs) and are commonly used for imaging and treatment planning of neuroendocrine tumors (NETs) [3][4][5][6][7][8]. Moreover, [ 68 Ga]DOTA-labeled somatostatin analogues have been reported to show higher sensitivity for the detection of NETs and other somatostatin-receptor expressing tumors than the most widely used radiotracer, 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG), which is used to measure glucose metabolism [9][10][11].…”