Skip to main content
AAO-HNSF 2024 Annual Meeting & OTO EXPO Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Back

Scientific Oral Presentations

Otology/Neurotology

Session: Scientific Oral Presentations 2 - Otology/Neurotology

Optimal Tumor Size Threshold for Primary Radiosurgery of Vestibular Schwannoma: Insights From Salvage Microsurgery Outcomes

Sunday, September 29, 2024
8:24 AM – 8:30 AM EDT
Location: MBCC, 231
Disclosure(s):
John P. Marinelli, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Emily Kay-Rivest, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Neil S. Patel, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Peter L. Santa Maria, MD, PhD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Jacob B. Hunter, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: There is limited evidence to guide optimal timing of treatment after detection of tumor growth during observation of sporadic vestibular schwannoma. The aim of the current work is to inform timing of primary radiosurgical intervention based on analysis of patient outcomes among those who ultimately failed stereotactic radiosurgery (SRS) and underwent salvage microsurgery.

Methods: In this retrospective cohort study of seven tertiary referral centers across the United States and Norway, adults (≥ 18 years old) with sporadic vestibular schwannoma who underwent salvage microsurgery following failed primary SRS were included. The primary outcome of interest was the association between tumor size at the time of primary SRS with ability to achieve gross total resection (GTR) and maintain postoperative House-Brackmann (HB) facial nerve grade I at last follow-up after salvage microsurgery.

Results: A total of 82 patients [median cerebellopontine angle (CPA) tumor size 14.6 mm (IQR, 10-19)] failed primary SRS and underwent salvage microsurgery. A sum of 16 (20%) underwent GTR and maintained HB grade I, while 66 (80%) underwent near-total or subtotal resection (NTR/STR) or developed HB grade >I. Median (IQR) CPA tumor size at primary SRS for the 16 patients was 9.7 mm (7.9-16.5) compared with 15.4 mm (11.9-20) for the 66 patients. Each 1 mm increase in CPA tumor size was associated with a 17% increased likelihood of NTR/STR or postoperative HB grade >I (OR 1.17; 95% CI 1.04-1.32; p = 0.01). The optimal tumor size threshold to distinguish GTR and most recent postoperative HB I vs NTR/STR or HB grade >I was 12 mm of CPA extension with a c-index of 0.72.

Conclusions: Analogous to previously published size threshold data informing timing of primary microsurgery during observation, the current study suggests that patient outcomes are optimized when primary radiosurgical intervention is undertaken when tumors harbor less than 10-15 mm of cerebellopontine angle extension, and continued observation past this size threshold range may lead to worse outcomes should radiosurgery fail and salvage microsurgery be pursued.

    Presenting Author(s)

  • John P. Marinelli, MD

    Fellow, Neurotology
    Mayo Clinic
    San Antonio, TX, United States

    Disclosure(s):

    faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

    • Co-Author(s)

  • Emily Kay-Rivest, MD

    Assistant professor
    McGill University
    Montreal, QC, Canada

    Disclosure(s):

    faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

  • Neil S. Patel, MD

    Assistant Professor
    Department of Otolaryngology-Head and Neck Surgery, University of Utah, Utah
    Salt Lake City, UT, United States

    Disclosure(s):

    faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

  • Peter L. Santa Maria, MD, PhD

    Professor
    University of Pittsburgh Medical Center
    Palo Alto, CA, United States

    Disclosure(s):

    faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

  • Jacob B. Hunter, MD

    Associate Professor
    Thomas Jefferson University Hospitals
    Philadelphia, PA, United States

    Disclosure(s):

    faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

  • ML

    Morten Lund-Johansen, MD, PhD

    Professor of Neurosurgery
    Haukland University
    Bergen, Norway

    Disclosure information not submitted.

    • Senior Author(s)

  • Matthew L. Carlson, MD

    Professor
    Mayo Clinic, Rochester
    Rochester, MN, United States

    Disclosure information not submitted.