E2441. A Brave New World: Nuclear Medicine Theranostics for Meningiomas
  1. Justin Peacock; Brooke Army Medical Center; Uniformed Services University of the Health Sciences
  2. Marcus Unterrainer; Ludwig-Maximilians-University of Munich
  3. Igor Yakushev; Klinikum rechts der Isar Technical University of Munich
  4. John Ritter; Brooke Army Medical Center
  5. Kevin Banks; Brooke Army Medical Center; Uniformed Services University of the Health Sciences
Meningiomas are tumors of the central nervous system meninges. They are often incidentally discovered on structural imaging and do not require any intervention. A small subset of meningiomas demonstrate rapid growth and can even metastasize. These anaplastic, aggressive meningiomas can be difficult to treat with conventional therapies. Interestingly, given their neural crest cell origin, meningiomas express somatostatin receptors. These receptors are the targets of new PET radiotracers, including Ga-68 DOTATATE in the United States. Many meningiomas demonstrate DOTATATE avidity. In the United States, a new molecular therapy, Lu-177 Lutathera couples the somatostatin receptor binding DOTA compound with a beta-emitting Lu-177 radionuclide, so that DOTATATE-avid tumors can be treated with Lutathera. In Europe, Nuclear Medicine physicians are treating meningiomas with Lutathera therapy. Additionally, new Nuclear Medicine PET radiotracers targeting amino acid transport may provide additional diagnostic capabilities for meningiomas. The purpose of this educational exhibit is to demonstrate the wide range of imaging modalities that can be used to diagnose and manage meningiomas. We will also present the exciting Nuclear Medicine theranostics capable of diagnosing and treating aggressive meningiomas.

Educational Goals / Teaching Points
We will review common and uncommon locations and presentation of meningiomas on different imaging modalities, including benign and malignant meningiomas. We will discuss and present cases using Nuclear Medicine radiotracers for meningioma diagnosis. The radiotracers that we will present include somatostatin receptor analogs and amino acid analogs. We will present cases of meningiomas treated with targeted Nuclear Medicine molecular therapies.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Meningiomas are often indolent, incidentally-discovered tumors of the meningiomas that extend along the dural meninges, demonstrating intense enhancement and calcifying over time. Some of these meningiomas demonstrate significant enlargement and mass effect on the surrounding structures. These meningiomas may require embolization or resection to relieve the mass effect. Some meningiomas become aggressive and may even metastasize. Many of these aggressive meningiomas still demonstrate somatostatin receptor expression and can be targeted with somatostatin receptor-binding radiopharmaceuticals. A newly developed radiopharmaceutical theranostic pair: Ga-68 DOTATATE and Lu-177 Lutathera, can be used off-label to diagnose and treat aggressive meningiomas. In Europe, Nuclear Medicine physicians have treated many meningiomas with Lutathera therapy with varied success based on somatostatin receptor positivity. Additional PET radiotracers that can be used to diagnose meningiomas include amino acid analogs, such as F-18 Axumin.

Meningiomas are often incidentally discovered on a variety of imaging modalities. While often indolent, some meningiomas can become aggressive and even metastasize. Nuclear Medicine plays an important role in the future diagnosis and treatment of aggressive meningiomas through targeted molecular therapies.