Optimal imaging follow-up strategies for conservatively managed cerebral cavernous malformations: a cost-effectiveness analysis.

Objective: Cavernous malformations are low-flow vascular anomalies within the central nervous system, notable for their potential to cause seizures or intraparenchymal hemorrhage. Currently, no consensus exists to recommend a specific interval for following radiographic imaging of cerebral cavernous malformations (CCMs) that are not treated with either resection or radiation. Herein, the authors aimed to determine the most cost-effective strategy for MRI follow-up of CCM in both brainstem and nonbrainstem locations in order to enable earlier diagnosis and potentially circumvent fatal events due to CCM-related hemorrhages.

Methods: A decision analysis was performed using a Markov model with Monte Carlo simulations for patients with CCMs undergoing MRI follow-up at different time intervals (0.5-, 1-, 2-, and 3-year intervals). Input data for the model were extracted from the current literature, primarily meta-analyses, and the willingness-to-pay threshold was defined as $50,000 per quality-adjusted life year (QALY), as standard in the United States. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model.

Results: Given the current literature and the authors' model, MRI follow-up every 1 year for brainstem CCM is the most cost-effective strategy (cost $395,580, effectiveness 20.42 QALYs), showing the highest net monetary benefit. For nonbrainstem CCM, follow-up every 3 years with MRI was the most cost-effective strategy (cost $125,438, effectiveness 23.23 QALYs). This conclusion remains robust in probabilistic and deterministic sensitivity analyses.

Conclusions: For patients followed conservatively, the most cost-effective follow-up strategy for brainstem CCM using MRI is every 1 year, while for nonbrainstem CCM, follow-up every 3 years tends to be the most cost-effective. More frequent follow-up strategies for nonbrainstem CCM or prompt preventive treatment would be more appropriate in symptomatic patients or patients with higher risk factors for hemorrhagic events.