Intra-Subject Heterogeneity of Lesion SUV on [68GA]Dotatate PET/MRI in Patients with Multiple Meningiomas: Implications for Tumor Biology and Clinical Management

Purpose: Meningiomas are the most common primary intracranial neoplasms. While MRI remains the gold standard for the evaluation of meningiomas, it has significant limitations, including limited sensitivity and specificity for infiltrative or “en plaque” lesions, presence of osseous or parenchymal invasion, and in the context of postsurgical and postradiation change.¹ Meningiomas overexpress SSTR2. [68Ga]DOTATATE is a PET radiotracer that binds to somatostatin receptor 2 (SSTR2) with high affinity.^2,3 [68Ga]DOTATATE PET/CT and PET/MR have previously demonstrated substantial clinical benefit compared with MRI-alone.^4–7 Previous [68Ga]DOTATATE PET/CT and PET/MR studies in patients with meningiomas have demonstrated no significant between WHO grade and standardized uptake value (SUV) or SUV ratio of lesion relative to superior sagittal sinus SUV, respectively.^3,5 Furthermore, prior [68Ga]DOTATATE PET/CT and PET/MR studies in patients with meningiomas focused primarily on inter-subject variability and range of SUV,⁸ with the assumption that all lesions within the same subject exhibit similar behavior. It is common for patients to present with multiple meningiomas; patients also develop new lesions posttreatment, both in the resection/radiation bed as well as at discontiguous disease sites. The degree of intra-subject heterogeneity with respect to [68Ga]DOTATATE PET SUV is unknown. The purpose of our study was to assess the intra-subject heterogeneity of lesion SUV in patients with >5 meningiomas and evaluate the effect of WHO Grade on meningioma SUV and SUVR.

Materials and Methods: Patients were enrolled prospectively on our observational clinical trial (NCT04081701). Inclusion criteria were (1) at least one pathology-proven meningioma and (2) >5 lesions that were radiographically compatible with meningioma (MRI findings of dural-based avidly enhancing extra-axial mass; PET findings of SUVR > 3). Clinical and demographic characteristics were collected via chart review. Maximum absolute SUV and SUVR were obtained for each lesion using syngo.via PET analysis software (Siemens Healthineers, Erlangen, Germany). Intra-subject heterogeneity of lesion SUV was descriptively visualized via box-and-whiskers plot for each subject.

Results: The cohort was comprised 118 patients. Thirteen patients met inclusion criteria. Five patients were WHO Grade 1, five patients were WHO Grade 2, and three patients were WHO Grade 3. Intra-subject heterogeneity is visualized using descriptive statistics and box-and-whiskers plots in [Figs. 1] [2] [3]. Maximum absolute SUV and SUVR were obtained for each lesion.

Conclusions: A wide range of both SUV and SUVR of intra-subject lesions were visualized across all WHO grades in our cohort. This suggests that each new lesion in a given patient should be evaluated individually based on published data on diagnostic SUV and SUVR threshold, and the range of preexisting lesions does not allow for conclusions regarding newly apparent lesions. Future work will focus on evaluating the effects of other clinical and demographic characteristics—such as treatment history, histopathology, age, and sex—on intra-subject range of SUV and SUVR of meningioma. This work has the potential to advance the clinical translation of DOTATATE PET/MR in patients in meningioma, thereby improving clinical outcomes.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
01 February 2023