Reirradiation with stereotactic radiosurgery for vestibular schwannomas – a systematic review and meta-analysis

Abstract Introduction Stereotactic radiosurgery (SRS) is a widely used treatment modality for vestibular schwannomas due to its non-invasive nature and high tumor control rates. However, some patients experience tumor progression after treatment. In this setting, reirradiation with SRS represents a potential treatment option. This systematic review and meta-analysis evaluates the evidence for reirradiation of vestibular schwannomas with SRS. Methods This systematic literature review and meta-analysis investigates the efficacy and safety of reirradiation with SRS for vestibular schwannoma and was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results A total of 806 studies were screened and 35 included, comprising 394 reirradiated patients. The median time from first treatment to reirradiation was 45 months (range: 12 – 65 months). Reirradiation with SRS, applying a median marginal/prescription dose of 12 Gy, achieved an estimated local control of 95 % (95 % confidence interval (CI): 92 – 97 %, I² = 29.62, p = 0.10). Trigeminal and facial nerve deterioration rates after repeat SRS were 7 % (95 % CI: 4 – 10 %, I² = 0.0 %, p = 0.44) and 6 % (95 % CI: 3 – 8 %, I² = 0.0 %, p = 0.53), respectively. Serviceable hearing after reirradiation with SRS was rare (6 %, 95 % CI: 3 – 9 %, I² = 10.74, p = 0.34). Among patients with serviceable hearing before reirradiation, 40 % maintained it after treatment (95 % CI: 28 – 52 %, I² = 62.29 %, p = 0.01). The risk of bias across all studies was high. Conclusion Reirradiation with SRS appears to be a safe and effective salvage treatment for progressive vestibular schwannomas. Prospective studies are warranted to define the optimal dose, timing, and dose constraints for reirradiation.