Surgery is the treatment of choice for large vestibular schwannomas (VS). Stereotactic radiosurgery (SRS) has been suggested as an alternative to resection in selected patients. However, the safety and e cacy of SRS in Koos grade IV patients ≤45 years old has not been evaluated. The aim of this study is to describe the clinical and radiological outcomes of Koos grade IV in young patient managed with a single-session SRS.
MethodsThis retrospective, multicenter analysis included SRS-treated patients, ≤45 years old presenting with nonlife threatening or incapacitating symptoms due to a Koos Grade IV VS and with follow-up ≥ 12 months. Tumor control and neurological outcomes were evaluated.
Results176 patients (median age of 36.0 (IQR 9) and median tumor volume of 9.3 cm 3 (IQR 4.7)) were included. The median prescription dose was 12 Gy (IQR 0.5). Median follow-up period was 37.5 (IQR 53.5) months.The 5-and 10-year progression-free survival was 90.9 and 86.7%. Early tumor enlargement occurred in 10.9% of cases and was associated with tumor progression at the last follow-up. The probability of serviceable hearing preservation at 5-and 10-years was 56.8% and 45.2%, respectively. The probability of improvement or preservation of facial nerve function was 95.7% at 5 and 10-years. Adverse radiation effects were noted in 19.9%. New-onset hydrocephalus occurred in 4.0%.
ConclusionSingle-session SRS is a safe and effective alternative to surgical resection in selected patients ≤45 years old particularly those with medical co-morbidities and those who decline resection. Longer term follow up is warranted.