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Oral Presentation

Tumor

Lunsford & Leksell Radiosurgery Award: Vestibular Schwannoma International Study of Active Surveillance Versus Stereotactic Radiosurgery: the VISAS Study

Saturday, May 4, 2024
4:41 PM – 4:45 PM CT
Location:  N427bc
Disclosure(s):
Othman Bin-Alamer, MBBS: No financial relationships to disclose
Douglas Kondziolka, MD, MSc: No financial relationships to disclose
Ronald E. Warnick, MD: No financial relationships to disclose
Gabriel Zada, MD: Stryker Corp: Consultant (Ongoing)
Introduction: This study compares the outcomes of stereotactic radiosurgery (SRS) with non-interventional observation and monitoring in patients with Koos grade I and II vestibular schwannomas (VS).

Methods: A multicenter investigation was conducted, which included Koos grade I and II VS patients who either underwent SRS or were observed over time. Propensity score matching was employed to ensure comparability between groups in terms of demographics, tumor size, and hearing function. The primary measures of success were tumor control, preservation of functional hearing, and incidence of adverse radiation effects.

Results: Among 125 propensity matched paired individuals per group with a median follow-up of 36 months (p=0.49), SRS led to higher tumor control at both 5 and 10 years (99%, Confidence Interval [CI]: 97.1%-100%, and 91.9%, CI: 79.4%-100%, respectively) as opposed to observation alone (45.8%, CI: 36.8%-57.2%, and 22%, CI: 13.2%-36.7%; p< 0.001). Hearing preservation rates at 5 and 9 years were similar between the two approaches (SRS 60.4%, CI: 49.9%-73%, vs. observation 51.4%, CI: 41.3%-63.9%, and SRS 27%, CI: 14.5%-50.5%, vs. observation 30%, CI: 17.2%-52.2%; p=0.53). Moreover, SRS was associated with reduced risk of tinnitus (Odds Ratio [OR]=0.39, p=0.01), vestibular dysfunction (OR=0.11, p=0.004), and cranial nerve complications (OR=0.36, p=0.003), without significant changes in cranial nerves V or VII (p>0.05). Composite endpoints of tumor progression and/or any of the aforementioned outcomes showed significant lower odds associated with SRS compared to observation alone (p < 0.001).

Conclusion : SRS offers substantial benefits in tumor control and is as effective as observation in hearing conservation, with a significantly decreased risk of neurological symptoms in patients with Koos grade I and II VS. These results affirm the safety and effectiveness of SRS for treating these patients.