DOTATATE-PET in custom spheno-orbital implant design for meningiomas with orbital involvement: a case series

Hyperostosing spheno-orbital meningiomas (SOMs) infiltrate bone and cause bone overgrowth leading to progressive visual and cosmetic deformities. DOTA0-Tyr3-octreotate (DOTATATE) is a somatostatin receptor-targeted PET ligand that enables highly sensitive identification of meningiomas. This ligand is useful in defining the extent of bone infiltration by the meningioma, which can be difficult to detect on standard CT and MRI. In this study, the authors aimed to provide a pragmatic technical framework for integrating molecular imaging, navigation, and patient-specific reconstruction in the management of complex SOMs by reporting their experience designing custom spheno-orbital implants based on DOTATATE-PET for skull and orbital reconstruction, as well as to report patient outcomes.

Four patients with SOMs who underwent cranio-orbital resection and rigid orbital reconstruction with custom polyetheretherketone patient-specific implants (PSIs) at a single center between 2023 and 2025 were retrospectively reviewed. Three patients had DOTATATE-PET/CT data available, and all had undergone CT and MRI to delineate tumor extent and guide implant design. All surgical procedures involved a multidisciplinary neurosurgery-oculoplastics team. The exophthalmos index was measured pre- and postoperatively.

All patients underwent tumor resection with a single PSI for skull and orbital reconstruction. Gross-total resection was achieved in 1 patient. Radiotracer-defined transosseous tumor involvement extended beyond the structural hyperostosis seen on CT and MRI and directly informed both the planned bony resection and PSI design. Visual outcomes stabilized or improved in all patients; 1 pediatric patient with neurofibromatosis type 2 (NF2) had persistent poor vision despite decompression due to significant tumor involvement at the orbital apex. The exophthalmos index improved in all patients, with a return to normal globe position in 3 patients and persistent proptosis due to intraorbital residual tumor in 1 patient. One patient developed transient diplopia and a pseudomeningocele, which resolved with conservative management. There were no enophthalmos or implant-related complications.

Integrating DOTATATE-PET with custom cranio-orbital PSIs allows single implant reconstruction of combined skull and orbital defects after resection of hyperostosing SOMs. DOTATATE-PET is useful for defining transosseous tumor extent and informing implant design. By enlarging the orbital volume with the implant compared with the contralateral normal side, excellent correction of proptosis can be achieved.