High-contrast somatostatin receptor imaging of meningiomas with [¹⁸F]SiTATE PET/CT.

Abstract

Somatostatin receptor (SSTR)-targeted PET imaging is increasingly used in the management of meningiomas. While gallium-68-labeled tracers are widely used, fluorine-18-labeled compounds may offer logistical and imaging advantages. We evaluated the feasibility and imaging characteristics of the novel SSTR ligand [¹⁸F]SiTATE PET/CT in patients with suspected or known meningioma. Thirty-seven consecutive patients undergoing [¹⁸F]SiTATE PET/CT for suspected or known meningioma were retrospectively analyzed. Lesion detectability, tracer uptake, and tumor-to-background contrast were assessed. Semiquantitative parameters including SUVmax, SUVpeak, somatostatin receptor-expressing tumor volume (SRETV), and total lesion somatostatin receptor expression (TLSRE) were calculated. PET findings were verified by histopathology when available and otherwise by MRI follow-up as part of a composite reference standard. Focal tracer uptake consistent with meningioma was observed in 32/37 examinations (86.5%), identifying 69 lesions in total. Meningiomas demonstrated intense uptake (SUVmax 20.44 ± 14.54; SUVpeak 12.10 ± 8.04), significantly higher than non-meningioma lesions and reference tissues (all p < 0.01 except pituitary gland). Physiological uptake in normal brain parenchyma was minimal (SUVmax 0.11 ± 0.06), resulting in excellent tumor-to-background contrast. Mean SRETV and TLSRE were 9.81 ± 13.64 mL and 102.86 ± 193.69, respectively. No tracer-related adverse events occurred. In this retrospective cohort, [¹⁸F]SiTATE PET/CT enabled high-contrast visualization of meningiomas with intense tumor uptake and minimal background activity. These findings support the feasibility of [¹⁸F]SiTATE as an ¹⁸F-labeled SSTR tracer for meningioma imaging and justify prospective comparative evaluation.