Radiosurgical Decompression of Cavernous Sinus Tumor Causing Compressive Optic Neuropathy: Case Report

Abstract

Here, we report on a patient suffering a visual deterioration caused by cavernous sinus tumor, who achieved a successful visual recovery after hypofractionated stereotactic radiosurgery (SRS) guided by a detailed image analysis. A 41-year-old woman presented with a 2-month history of progressive visual disturbance. Her best corrected visual acuity (BCVA) was measured 0.5 in the right eye and 1.0 in the left, and she had a right-sided monocular inferior visual field defect (VFD). Fundoscopic examination disclosed papilledema in her right eye. On magnetic resonance images (MRI), a 2.7 × 2.2 × 2.0 cm tumor was noted in the right cavernous sinus, and meningioma was suggested. Tumor was encroaching onto the orbital apex through the superior orbital fissure, thereby compressing the optic nerve (ON) inside the annulus of Zinn. A SRS plan was produced with a minimum dose to tumor 25.5 Gy (mean 30.5 Gy) and a maximum dose to ON 23.8 Gy, and was administered in 5 daily fractions. On follow-up examinations, she reported her vision recovered in 2 months after treatment, and BCVA in her right eye improved to 1.0 with complete resolution of VFD and papilledema, which maintained through the last follow-up of 2.5 years. MRI taken at 2 years demonstrated an evident shrinkage of the tumor and decompression of ON. The term “radiosurgical ON decompression” may be coined for this case. This approach needs to be validated with more cases and a longer follow-up.