Stratifying Risk of Future Growth Among Sporadic Vestibular Schwannomas

Area of Science:

• Neurosurgery
• Oncology
• Radiology

Background:

• Vestibular schwannomas (VS) are tumors that can grow over time.
• Continued observation (wait-and-scan) is an option for some patients with growing VS.
• Predicting subsequent growth is crucial for management decisions.

Purpose of the Study:

• To determine if initial growth behavior can stratify patients with growing sporadic vestibular schwannomas.
• To assess the likelihood of subsequent growth based on initial volumetric growth rate.

Main Methods:

• Analysis of 3,505 serial MRI studies from 952 patients with sporadic VS.
• Volumetric tumor measurements to calculate growth rates.
• Stratification based on annual volumetric growth rate: <25%, 25-50%, 50-100%, and ≥100%.

Main Results:

• Initial growth rate significantly predicted subsequent growth or need for treatment.
• Patients with ≥100% annual growth rate had a 2.01 hazard ratio for subsequent growth/treatment.
• At 5 years, growth-free survival was 31% for <25% growth vs. 6% for ≥100% growth.

Conclusions:

• Initial volumetric growth rate is a reliable stratification tool for growing sporadic VS.
• Tumor growth rate, not age or initial volume, predicts aggressive behavior.
• Nearly all tumors that double in volume before initial growth detection will grow further or require treatment.