Introduction: Intracranial arteriovenous malformations (AVMs) are vascular lesions consisting of direct, abnormal connections between arteries and veins. Aggressive multimodal treatment regimen are used for their management. The CyberKnife is a frameless, robotic, stereotactic device which was recently developed for use in the radiosurgical treatment of AVMs. Long-term follow up data on lesions treated via this technique, however, is limited.
Methods: A retrospective analysis of all patients who underwent CyberKnife treatment for intracranial AVMs at a single academic institution in the U.S. between 2002 and 2012, was performed. AVM characteristics, patient demographics, AVM obliteration status post-radiosurgery, and functional outcomes were recorded.
Results: Eleven patients (and 11 AVMs) were included in the analysis (8 male; 3 female), and were followed up for an average of 86.2 months (range: 56.2 – 119.4) post radiosurgery treatment. Two (18.2%) and seven (63.6%) patients underwent microsurgery and embolization prior to CyberKnife treatment, respectively. The lesions had an average size of 3.9 cm and Spetzler-Martin grade of 3.5. Ten (90.9%) AVMs were treated with a single dose of radiation (average Dmax: 24.7 Gy). One (9.1%) lesion was obliterated immediately post CyberKnife treatment, and eight (72.7%) of the 11 AVMs were obliterated at last angiographic follow up. Post radiosurgery adverse radiation effects were cited in 7 (58.3%) cases. One patient (9.1%) presented with an acute hemorrhage from the AVM post-CyberKnife treatment. Four (36.4%) patients underwent repeat embolization and/or radiosurgery following radiosurgery. One (9.1%) patient underwent microsurgery for management of radiation necrosis.
Conclusions: Limited long-term data on AVMs treated with the CyberKnife stereotactic device is available within the neurosurgical literature. Transient post-radiosurgery adverse effects were common in our case series, though delayed hemorrhages following CyberKnife treatment were rarely seen. Almost three fourths of the AVM’s treated with the CyberKnife were completely obliterated at last imaging follow up in our cohort.
Patient Care: Our research is a retrospective study assessing long term clinical outcomes in patients with intracranial AVMs who underwent treatment with the CyberKnife device.
Learning Objectives: By the conclusion of this session, participants should be able to: (1) recognize that the CyberKnife device can be used successfully in the long-term for the management of intracranial AVMs, (2) discern that functional/clinical outcomes following CyberKnife treatment remained the same or improved in most of the cases presented herein, and (3) that obliteration rates at last imaging follow up approaching 75% were observed.