Vestibular Schwannoma - Radiosurgery or Expectation

The purpose of this study is to compare the outcome of patients with vestibular schwannomas in two groups of randomised to either radiosurgery or expectation.

The optimal treatment for a small vestibular schwannoma is a matter of controversy and there are no class 1 studies investigating this. Even the natural tumor growth rate remains controversial and is reported to be from near 100% of cases showing growth to 40-60% in various reports. The clinical results of various treatment strategies are documented, but comparative studies are very few. Immediate radiosurgery or wait-and scan with subsequent treatment upon growth are two strategies that have both been used in many different centers. There are only two studies comparing these treatment modalities .These studies indicate significant effect of GKRS in reducing tumor growth, with less differences in hearing and complaint outcomes. None of the studies are blinded or randomised, allowing for bias.

The present study aims at comparing the two modalities above. To achieve this, we intend to randomise patients with newly diagnosed VS to either of Wait-and Scan or immediate radiosurgery.

The primary study endpoint is the relative tumor size measured as the ratio between tumor volume at four years compared with volume at inclusion. Secondary endpoints include symptom and sign development measured by clinical examination and by patient's responses to standardised validated questionnaires. In addition, the health economics involved with both strategies will be evaluated and compared, as well as the patient's working status.

Patients will be asked to participate if their VS is diagnosed within the last six months, their age is between 18 and 70, and pending there are no exclusion criteria (see below). A power analysis indicates that about 50 patients per group is sufficient.

In case of failure to recruit patients, we will change the design to a study based on patient's own choice of treatment.

The study will be announced according to international guidelines. A steering committee will monitor the study and an intermediate analysis will be performed when the study group has been followed for two years. If the effect aim is already observed, the study should nonetheless continue, as it is too early to evaluate the results after such a short time course.

It will also be discussed to do a follow-up of all patients ten years after inclusion.