CT/PET 68Ga-DOTATATE for Gamma Knife Radiosurgery Planning and Target Delineation in Patients with Meningioma

• Published in: Neurosurgery Vol. 67; no. Supplement_1
• Main Authors: Ma, Daniel, Rana, Zaker, Devi, Sirisha, Potters, Louis, Chang, Jenghwa, Schulder, Michael, Goenka, Anuj
• Format: Journal Article
• Language: English
• Published: Philadelphia Wolters Kluwer Health, Inc 01.12.2020
• Subjects: Brain cancer; Brain surgery; Deep brain stimulation; Hemorrhage; Neurosurgery; Patients; Radiation therapy; Radiosurgery; Surgical techniques; Tumors
• ISSN: 0148-396X; 1524-4040
• DOI: 10.1093/neuros/nyaa447_668

INTRODUCTION Planning for stereotactic radiosurgery (SRS) for patients with meningiomas can be confounded by difficulty in identifying the tumor boundary, especially in those who have had prior surgery. Recent data have suggested the benefit of 68-GA-DOTATATE PET scans in delineation of meningioma in comparison to MRI alone. METHODS We reviewed patients who had the diagnosis of grade II meningioma and who had MRI and 68Ga-DOTATATE PET imaging over a 12-month period. Images were imported into Velocity treatment planning software and separated into two different sessions, one in which only the MRI was accessible, and a second which had the PET scan fused to the MRI. Three different users were asked to contour the residual meningioma as gross tumor volume (GTV) first with MRI alone, and then on a separate session with the PET/MRI fusion. The volume of each GTV pre-and post- PET fusion was compared and Dice index was generated to measure overlap. RESULTS A total of 4 patients with 6 GTV targets were identified. PET fusion identified additional lesions in close proximity to the initial GTV targets in 2 patients by all three individuals. One of the lesions was in the skull anterior to the mastoid air cells. The second was a nodular dural based lesion along the left high parietal convexity adjacent to a prior craniectomy and mesh duraplasty site. Across all observers, GTV volumes were significantly increased when PET fusion was used. The average volume (in cc) increase was 111.6% ± 66.2%. The average Dice index was 0.58 ± 0.17. CONCLUSION 68Ga-DOTATATE PET scan when fused with MRI improved the visualization of meningiomas in patients undergoing SRS. A larger experience is needed to confirm this trend, and to report the clinical and imaging outcomes. We have begun to use DOTATATE-PET imaging on a regular basis when imaging patients with meningiomas for SRS.