Radiosurgery for dural carotid-cavernous sinus fistulas: Gamma Knife compared with XKnife radiosurgery

Abstract

Object In the modern era, stereotactic radiosurgery is an important part of the multidisciplinary and multimodality approach used to treat dural carotid-cavernous fistulas (DCCFs). Based on the ease of performance of techniques to fuse cerebral angiography studies with MR images or CT scans during the radiosurgical procedure, the Gamma Knife and XKnife are 2 of the most popular radiosurgical instruments for patients with DCCF. In this study, the authors compared the efficacy, neurological results, and complications associated with these 2 radiosurgical devices when used for DCCF. Methods Records for 41 patients with DCCF (15 treated using the XKnife and 26 with Gamma Knife surgery [GKS]) were retrieved from a radiosurgical database encompassing the period of September 2000 to August 2008. Among these patients, at least 2 consecutive MR imaging or MR angiography studies obtained after radiosurgery were available for determining radiological outcome of the fistula. All patients received regular follow-up to evaluate the neurological and ophthalmological function at an interval of 1–3 months. The symptomatology, obliteration rate, radiation dose, instrument accuracy, and adverse effects were determined for each group and compared between 2 groups. The data were analyzed using the Student t-test. Results The mean age of the patients was 63 ± 2.6 years, and the mean follow-up period was 63.1 ± 4.4 months (mean ± SD). Thirty-seven patients (90%) achieved an obliteration of the DCCF (93% in the XKnife cohort and 88% for the GKS cohort). In 34 of 40 patients (85%) with chemosis and proptosis of the eyes, these symptoms were resolved after treatment (4 had residual fistula and 2 had arterializations of sclera). All 5 patients with high intraocular pressure demonstrated clinical improvement. Ten (71%) of 14 patients with cranial nerve palsy demonstrated improvement following radiosurgery. Significant discrepancies of treatment modalities existed between the XKnife and GKS groups, such as radiation volume, conformity index, number of isocenters, instrument accuracy, peripheral isodose line, and maximum dosage. The XKnife delivered significantly higher radiation dosage to the lens, optic nerve, optic chiasm, bilateral temporal lobe, and brainstem. Few adverse events occurred, but included 1 patient with optic neuritis (GKS group), 1 intracranial hemorrhage (XKnife group), 1 brainstem edema (XKnife), and 3 temporal lobe radiation edemas (XKnife). Conclusions Radiosurgery affords a substantial chance of radiological and clinical improvement in patients with DCCFs. The Gamma Knife and XKnife demonstrated similar efficacy in the obliteration of DCCFs. However, a slightly higher incidence of complications occurred in the XKnife group.

Surgical access on the superior ophthalmic vein to the cavernous sinus dural fistula for embolization

“…There are several exciting recent reports of successful use of stereotactic radiosurgery for the treatment of CSDF. Pan et al 24 reported their series of 41 patients treated by stereotactic radiosurgery for CSDF with a 90% obliteration rate. Yang and colleagues25 showed similar results in their cohort of 40 patients treated by stereotactic radiosurgery.…”

Stereotactic radiosurgery for dural arteriovenous fistula

“…The latency period between SRS and complete occlusion is one of the main drawbacks of SRS. Compared with AVMs, DAVFs seem to more promptly react to SRS because the shunt size in DAVFs is smaller than that in AVMs [15,16]. Moreover, slow occlusion of DAVFs may reduce the likelihood of venous hypertension [17].…”

Intracranial Dural Arteriovenous Fistulas: A Review

“…In case of failure of both endovascular and surgical treatments, stereotactic radio surgery (SRS) represents an alternative. However, this treatment has low success rate as the only treatment 28 , especially in case of complex lesions for which targeting of the shunt is difficult 29 . Moreover, SRS is generally inappropriate for lesions presenting with bleeding because during the latency period of IDAVF obliteration, which lasts several months to a year, the rehemorrhage risk remains elevated 10 .…”