2026 Poster Presentations
P499: EFFICACY OF STEREOTACTIC RADIOSURGERY FOR VESTIBULAR SCHWANNOMA ACROSS AGE COHORTS
Pranav Bingi, BS; Anika Walia, BS; Khoa Nguyen, BS; Kalena Liu, BS; Jacob Hunter, MD; Thomas Jefferson University, Department of Otolaryngology
Introductions: Vestibular Schwannomas (VS) are benign tumors often managed with stereotactic radiosurgery (SRS). Treatment choice for VS depends on a range of modulating factors, including age. While prior literature has examined age in SRS patients, there is limited literature analyzing SRS success across finer age stratifications.
Methods: A single-institutional retrospective chart review was conducted for VS patients treated with SRS from 2001 to 2023. Data on demographics, hearing outcomes, radiation modality (single-dose vs fractionated), and serial MRI sizes were collected. Patients with neurofibromatosis 2, follow-up <12 months, and without imaging prior to radiation were excluded.
Patients were stratified into cohorts based on age at time of treatment, separated by decade (<40, 40-49, 50-59, 60-69, 70+). Outcomes analyzed included tumor control (<2 mm growth in greatest linear dimension), tumor size change, post-treatment growth rate, change in pure-tone average (PTA), and incidence of non-serviceable hearing, defined as PTA ≥50 dB and WRS ≤50%. Survival analyses and linear mixed-effects modeling tests were conducted.
Results: A total of 186 patients met inclusion criteria, distributed in cohorts as follows: <40 (n=23), 40-49 (n=21), 50-59 (n=53), 60-69 (n=57), and 70+ (n=32), with tumor control observed in 95.7%, 95.2%, 96.2%, 100.0%, and 100.0% respectively (p=0.26). Average follow-up in months was significantly different (p=0.013) across cohorts (<40: 73.28; 40-49: 54.84; 50-59: 62.4; 60-69: 62.5; 70+: 41.05). Median post-treatment growth rates were low across all groups (-0.0018, -0.0034, -0.0044, -0.0069, -0.0051 mm/month, p=0.27).
At 5-year follow-up, the rate of serviceable hearing for the <40, 40-49, 50-59, 60-69, and 70+ cohorts were 100%, 75%, 95.7%, 80.5%, and 53%, respectively (Figure 1), with log-rank test not reaching significance (p=0.84).
Examining PTA, patients aged <40 demonstrated PTA decline of 7.9 dB/year (n=12, fractionated) versus 13.9 dB/year (n=1, single-dose). The 40-49 year old cohort declined at 3.6 dB/year (n=10, fractionated) versus 4.8 dB/year (n=2, single-dose). The 50-59 year old cohort demonstrated the slowest decline among fractionated patients compared to single-dose (n=28, 2.6 dB/year vs n=8, 4.6 dB/year; interaction p=0.017). The 60-69 year old cohort declined at 2.8 dB/year (n=27, fractionated) versus 5.6 dB/year (n=12, single-dose, p=0.022). Patients aged 70+ declined at 3.5 dB/year (n=4, fractionated) versus 9.5 dB/year (n=6, single-dose), demonstrating that single-dose radiosurgery consistently produced accelerated hearing loss across all age groups.
Overall, tumor control, size change, and post-treatment growth did not differ significantly.
Conclusion: Tumor control and post-treatment growth rate were similar across cohorts, suggesting efficacy of SRS across age groups. While SRS remains popular in older populations over invasive procedures like surgery, results suggest SRS may be equally effective in younger VS patients. Hearing outcomes suggest that older patients may experience greater loss of serviceable hearing in the short term, warranting future research to guide counseling.
Figure 1: Kaplan-Meier analyses of probability of serviceable hearing by age group. Censored observations (serviceable) are indicated by tick marks.