Volume staged stereotactic radiosurgery and endovascular embolization in the treatment of cerebral proliferative angiopathy: lessons learned.

Purpose of the Article Cerebral proliferative angiopathy (CPA) is a rare and recently characterized vascular malformation that is often mistaken for a large, diffuse arteriovenous malformation (AVM). However, distinguishing the two entities is critical, as while the diseases may appear similar on imaging, they are completely different entities. The most distinguishing features of CPA compared to AVM are the presence of normal functioning brain within the 'nidus' of the abnormality and the proliferative nature of the nidus. While the management of AVM is considered well understood, the management of CPA is unclear. Typical treatment may include conservative management, targeted embolization, and/or surgical revascularization. Materials and Methods Here, we present a patient who was initially diagnosed with a large, diffuse AVM in the posterior fossa. Initially managed conservatively, the development of progressive, debilitating neurologic symptoms prompted treatment. We pursued staged endovascular intervention and improved her initial outlook. Thereafter, volume-staged stereotactic radiosurgery (VS-SRS) was pursued to attempt to achieve a definitive treatment. Results and Conclusions Ultimately, while the treatment proved successful clinically and radiographically, the post-treatment course was exceptionally challenging. In retrospect, it is clear the working diagnosis was incorrect, and CPA was the true diagnosis. To our knowledge, this is the first known application of this treatment approach for CPA. However, the post-treatment course and final clinical outcome likely reflect the important differences between AVM and CPA. For these reasons, we are cautious to recommend the treatment course as prescribed in this case but hope to highlight important lessons learned in managing this rare condition.