Presenter(s)
V. Elangovan1, K. Bennet2, N. Zia2, C. T. Wilke3, A. H. Zureick3, and S. Choi1,3; 1Department of Radiation Oncology, University of Pittsburgh, Pittsburgh, PA, 2Division of Nuclear Medicine, Department of Radiology, University of Pittsburgh/UPMC, Pittsburgh, PA, 3Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA
Purpose/Objective(s): Meningiomas are the most common primary intracranial tumors. MRI remains the standard imaging modality for postoperative surveillance and treatment planning for meningiomas. However, its specificity may be reduced in the presence of radiation- or surgery-induced changes. 68Ga-DOTATATE PET targeting somatostatin receptor 2A (SSTR2A) has shown value in radiation treatment planning and differentiating tumor from posttreatment change, but its short half-life (68 minutes) can restrict institutional availability. 64Cu-DOTATATE offers a longer half-life (12.7 hours), enabling expanded access through centralized production and broader distribution. However, clinical studies using 64Cu-DOTATATE for meningioma are limited. We hypothesize that 64Cu-DOTATATE PET provides effective tumor-to-background differentiation and report the initial experience at a single institution.
Materials/Methods: We retrospectively reviewed 28 consecutive patients with meningiomas who underwent 64Cu-DOTATATE PET between April 2024 and January 2026. Patient demographics, treatment history, PET parameters, and standardized uptake value (SUV) measurements (using MIM Software version 7.2.8) were collected. Tumor-to-superior sagittal sinus (SSS) SUVmax ratios were calculated; the SSS served as a background reference. The Wilcoxon signed-rank test compared tumor and SSS SUVmax values.
Results: Median age was 65 years (range 24-90); 18 (64%) were female. Twenty (71%) patients had pathology-proven meningioma at initial diagnosis (Grade 1 = 7, Grade 2 = 9, Grade 3 = 4); four (14%) demonstrated histopathologic progression on subsequent surgery. 22 (79%) patients had prior surgery and 17 (61%) received prior RT including stereotactic radiosurgery (n=10), IMRT (n=5), and both (n=2). Of the 19 patients receiving RT after 64Cu-DOTATATE PET, techniques included stereotactic radiosurgery (n=9), IMRT (n=7), and both (n=2). In one patient, 64Cu-DOTATATE PET confirmed gross total resection of a grade 2 meningioma and was on observation. Among 27 patients with detectable meningioma, the median tumor SUVmax was 19.0 (IQR 10.6-30.75), pituitary SUVmax 16.29 (IQR 11.65-28.45), and SSS SUVmax 1.1 (IQR 0.6-1.65). Tumor SUVmax was significantly higher than SSS SUVmax (P<0.0001). The median tumor-to-SSS ratio was 15.0 (IQR 11.9-34.4). Two patients underwent paired pre- and post-RT imaging, demonstrating decreased tumor SUVmax (11.8 to 9.0 after 12 months and 27.9 to 19.0 after 6 months).
Conclusion: 64Cu-DOTATATE PET is a useful alternative imaging tool for meningioma evaluation with significantly higher tumor uptake versus background. Preliminary paired imaging suggests utility for treatment response assessment. The longer half-life of 64Cu-DOTATATE may facilitate wider clinical adoption via centralized radiopharmaceutical production and distribution. Prospective studies comparing 64Cu- and 68Ga-DOTATATE are warranted.