Upfront radiosurgery bests coservative approach for treating Vestibular Schwannomas: JAMA

Vestibular schwannomas represent 8% of all intracranial tumors and are the most common neoplasm of the cerebellopontine angle. The symptoms are usually presented with ipsilateral hearing loss, tinnitus, dizziness, and imbalance, but large tumors with mass effect and hydrocephalus may present with more severe symptoms. Microsurgery is the known treatment of choice in large vestibular schwannomas.

A new randomized clinical trial determined whether upfront radiosurgery provides superior tumor volume reduction to a wait-and-scan approach for small- to medium-sized vestibular schwannoma. The trial included 100 patients and reveals that among patients with small or medium vestibular schwannoma, a treatment strategy consisting of upfront radiosurgery was (0.87) more effective at reducing tumor volume at 4 years than was the initial wait-and-scan approach (1.51). The findings are published in JAMA Network.

Researchers conducted randomized clinical trial of 100 patients with a newly diagnosed (<6 months) unilateral vestibular schwannoma and a maximal tumor diameter of less than 2 cm in the cerebellopontine angle as measured on magnetic resonance imaging. 50 participants were randomized to receive either upfront radiosurgery or to undergo a wait-and-scan protocol, for which treatment was given and 50 participants upon radiographically documented tumor growth. Participants underwent 5 annual study visits consisting of clinical assessment, radiological examination, audiovestibular tests, and questionnaires. The primary outcome was the ratio between tumor volume at the trial end at 4 years and baseline (V4:V0). There were 26 prespecified secondary outcomes, including patient-reported symptoms, clinical examinations, audiovestibular tests, and quality-of-life outcomes.

The key findings of the study are

• In the upfront radiosurgery group, 1 participant (2%) received repeated radiosurgery upon tumor growth, 2 (4%) needed salvage microsurgery, and 45 (94%) had no additional treatment.

• In the wait-and-scan group, 21 patients (42%) received radiosurgery upon tumor growth, 1 (2%) underwent salvage microsurgery, and 28 (56%) remained untreated.

• For the primary outcome of the ratio of tumor volume at the trial end to baseline, the geometric mean V4:V0 was 0.87 (95% CI, 0.66-1.15) in the upfront radiosurgery group and 1.51 (95% CI, 1.23-1.84) in the wait-and-scan group, showing a significantly greater tumor volume reduction in patients treated with upfront radiosurgery (wait-and-scan to upfront radiosurgery ratio, 1.73; 95% CI, 1.23-2.44; P = .002).

• Of 26 secondary outcomes, 25 showed no significant difference. No radiation-associated complications were observed.

Researchers concluded that “Among patients with newly diagnosed small- and medium-sized vestibular schwannoma, upfront radiosurgery demonstrated a significantly greater tumor volume reduction at 4 years than a wait-and-scan approach with treatment upon tumor growth. These findings may help inform treatment decisions for patients with vestibular schwannoma, and further investigation of long-term clinical outcomes is needed.”

Reference: Dhayalan D, Tveiten ØV, Finnkirk M, et al. Upfront Radiosurgery vs a Wait-and-Scan Approach for Small- or Medium-Sized Vestibular Schwannoma: The V-REX Randomized Clinical Trial. JAMA. 2023;330(5):421–431. doi:10.1001/jama.2023.12222.