Comparative analysis of different modalities of radiotherapy in vestibular schwannoma: tumor control, symptom evolution, and toxicity profiles

Background Stereotactic radiotherapy (SRT) is a standard treatment for vestibular schwannoma (VS). Long-term comparative data on single-fraction radiosurgery (SRS) versus normofractionated SRT (NFSRT) are limited. Methods We retrospectively analyzed 175 VS patients treated between 1998 and 2023 (SRS n = 69; NFSRT n = 106; median age 61 years; median follow-up 46 months). Tumor control was evaluated with Kaplan–Meier and Cox regression. Group differences were tested with Mann–Whitney U and chi-square/Fisher’s exact tests. Symptom changes were assessed with McNemar tests, and binary logistic regression identified predictors of acute and late toxicity. Results Overall, in-field PFS was 94.3% and out-field was PFS was 99.4%. All 10 recurrences (median 58.5 months) occurred in NFSRT patients treated with 55.8–56 Gy. Higher total dose predicted recurrence (HR = 2.97; p = 0.003). At baseline, 97.1% reported symptoms (hearing loss 86.9%, vertigo 48.0%, tinnitus 42.3%). After therapy, symptoms remained stable, except the incidence of headache, which increased from 14.3% to 22.3% ( p = 0.02). Early toxicities were more common after NFSRT, including headache (OR = 4.05; p = 0.01), fatigue (OR = 5.12; p = 0.01), and alopecia (OR = 19.9; p = 0.04), but had resolved by late follow-up. Age and prior surgery predicted vertigo patterns over time. Radionecrosis was rare (0.6%). Conclusion Both SRS and NFSRT achieve excellent long-term tumor control with low severe toxicity. For NFSRT, normofractionated doses above 55 Gy did not improve efficacy and may increase the recurrence risk, supporting moderate-dose regimens (50–54 Gy). Symptom stabilization confirms the safety of SRT, though headache and vertigo remain relevant long-term issues. Careful dose selection, patient counseling, and rehabilitation are essential to optimize outcomes.