Hypofractionated stereotactic radiosurgery for dural arteriovenous fistula in the superior sagittal sinus: case report and review of the literature.

Stereotactic radiosurgery (SRS) for dural arteriovenous fistula (dAVF) in the superior sagittal sinus (SSS) is not an established treatment because of relatively poor efficacy and a latency period for treatment effects. Hypofractionated SRS for these lesions has not yet been reported. A 65-year-old man presented with intermittent paraparesis. Brain magnetic resonance imaging (MRI) revealed acute infarction in the premotor and motor cortex of both frontal convexities. Cerebral angiography demonstrated extensive dAVF in the middle and posterior third SSS, associated with an occlusion in the middle third. Transfemoral arterial Onyx embolization was performed through the right middle meningeal arteries, and cerebral venous reflux (CVR) disappeared from the middle third of the SSS. However, the remnant dAVF in the posterior third of the SSS and CVR in the posterior parietal and occipital lobes remained. Novalis SRS was performed on remnant the dAVF with 35 Gy in 5 fractions. Seven months after Novalis SRS, symptoms improved and cortical engorged vessel gradually disappeared on brain MRI. The patient recovered completely at 22 months post-radiosurgery. SRS for dAVF in the SSS could provide an alternative treatment option. Hypofractionated SRS showed a good result in our case.