Preoperative PET/MRI and radio-guided surgery using [Cu64]DOTATATE in meningioma: a feasibility study. Illustrative case.

Background: Meningiomas are the most common primary intracranial neoplasms. Gross-total resection, the primary treatment goal, is not achieved in up to 50% of patients, affecting progression-free and overall survival. The traditionally used intraoperative assessment of resection extent using the Simpson grade has recently been shown to be less accurate than postoperative MRI. Improving intraoperative resection extent delineation thus represents a paramount goal. Somatostatin receptor (SSTR)-targeted PET has improved meningioma management. [Cu64]DOTATATE is a clinically approved PET radiotracer that avidly binds to SSTR2 with properties similar to [Ga68]DOTATATE but with a significantly longer half-life of approximately 13 hours.

Observations: The authors assessed the feasibility of immediate preoperative [Cu64]DOTATATE PET/MRI and subsequent intraoperative tumor detection using a handheld gamma probe device typically used in sentinel node biopsy. They describe [Cu64]DOTATATE PET-guided surgical debulking of a meningioma and demonstrate the feasibility of intraoperative tumor detection using the gamma probe device, with activity 10 times higher than the background after exposing the tumor, decreasing by 50% after debulking. The authors further demonstrate 3-month clinical and PET/MRI outcomes, with accurate delineation of minimal residual viable tumor.

Lessons: This pilot study for the first time demonstrates the feasibility of preoperative PET with in vivo radio-guided surgery in meningiomas, laying the foundation for larger-scale prospective trials. https://thejns.org/doi/10.3171/CASE24867.