Sphenoorbital Meningiomas: Tumor Control, Visual Function, and Cranial Nerve Outcomes in a Large, Longitudinally followed Single-Surgeon Cohort

Background: Sphenoorbital meningiomas (SOM) are an uncommon subset of benign intracranial tumors, characterized phenotypically by expansive involvement of the sphenoid bone, with frequent involvement of the orbital compartment, and other surrounding structures. SOM present a host of unique management challenges attributable to the intimate involvement of the orbital apex and nearby cranial nerves (CN), which may result in proptosis, visual loss, or multiple CN neuropathies including II, III, IV, V, and VI. Surgical and postoperative management are similarly fraught, and the demands of tumor control are inevitably balanced against significant risk of ophthalmologic morbidity. We describe our experience with the largest and most extensively followed cohort of surgically SOM reported to date.

Methods: Retrospective review of a prospectively maintained institutional database identified all candidate patients by keyword and surgical code searches. Blinded imaging review by two study team members was completed to confirm SOM, after which supplemental chart review was performed for all included patients to capture endpoints including demographics, clinical presentation, work-up, surgical management, adjuvant treatments, tumor control, complications, morbidity, mortality, and follow-up. All statistical testing was completed using IBM SPSS Statistics 22.0, with significance defined as p < 0.05.

Results: Ninety-five patients who were surgically managed for SOM by the same neurosurgery/neuro-ophthalmology team during the study period 2002–2017 met criteria and were included. Median age at surgery was 51 years (range: 15–76), 77% were female, and mean follow-up was 59 months (range: 0–185). Proptosis was noted in 55% on presentation, measuring a median 4.4 mm. Preoperatively, 55 patients had decreased visual acuity (58%), and 42 patients had a visual field deficit (44%). All operations were approached using a fronto-temporal craniotomy, orbital-optic osteotomy, and anterior clinoidectomy, with maximal safe extensive resection of all involved bone and soft tissue. Gross-total resection was achieved in 43 patients (45%). Twenty-two patients underwent up-front adjuvant therapies, including stereotactic radiosurgery (SRS) in 8, and fractionated radiotherapy (FR) in 14. Fourteen patients had a recurrence/progression in follow-up, which were treated with SRS in 3 and fractionated radiotherapy in 10, and repeat resection followed by FR in 1. Postoperative CN neuropathy was most common in CN III (25 patients; 26%), followed by VI (8; 8%), V (6; 6%), and IV (5; 5%). Visual outcomes were excellent, with improvement in 45%, stable deficits in 32%, and new deficits noted in 3%. Proptosis resolved in 81% of patients; where persistent, the mean displacement was reduced by >1 mm overall (3.3 mm; range: 2–7). Postoperative infarcts were noted in 4%, and new seizures in 9%; there were no mortalities.

Conclusion: SOM are complex and challenging skull base tumors that are best managed via multidisciplinary, multimodality approaches to treatment. Surgery is very good first-line treatment option for most SOM, with excellent visual and tumor control outcomes, as well as an acceptable side effect profile with complications predominantly limited to cranial nerve dysfunction. However, given the potential for treatment morbidity and the propensity for recurrence, consideration should be aggressive to subtotal resection followed by multiple radiation treatment modalities.