Long-term growth patterns of vestibular schwannomas after stereotactic radiotherapy: delayed re-growth

Conlan, O. and Kontorinis, G. (2022) Long-term growth patterns of vestibular schwannomas after stereotactic radiotherapy: delayed re-growth. European Archives of Oto-Rhino-Laryngology, 279(10), pp. 4825-4830. (doi: 10.1007/s00405-022-07281-2) (PMID:35129632) (PMCID:PMC9474560)

Abstract

Purpose: To determine the long-term outcomes of patients with vestibular schwannomas (VS) after stereotactic radiosurgery (SRS) who experience delayed tumour regrowth. Methods: We carried out a retrospective case series in tertiary university settings. We included patients with VS with initial response to SRS and delayed regrowth, assessing a database of 735 patients with VS and 159 patients who had SRS as sole treatment. Following SRS, all patients had clinical follow-up and serial magnetic resonance imaging (MRI). We documented the post-SRS clinical assessment, pre- and post-SRS VS size as per MRI in predetermined time periods, response to treatment and rate of (re-) growth and the final outcome in each case. Results: We identified six patients with good initial response but delayed VS regrowth at a faster rate than pre-SRS. The mean growth rate for these VS was 0.347 mm/month (range 0.04–0.78 mm/month) prior to treatment; the mean growth rate at the time of delayed re-growth was 0.48 mm/month (range 0.17–0.75 mm/month); this did not reach the level of statistical significance (p = 0.08). This regrowth occurred at a mean time of 42 months (range 36–66 months) post-SRS and stopped 22 months (mean, range 12–36 months) post regrowth detection in all cases. Conclusions: Given that delayed post-SRS VS regrowth can occur in approximately 4% of the treated cases, it is important to continue close clinical and radiological follow-up. Despite this abnormal behaviour, VS do stop growing again; still, patients should be made aware of the possibility of this uncommon VS behaviour following SRS.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kontorinis, Mr Georgios
• Authors: Conlan, O., and Kontorinis, G.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: European Archives of Oto-Rhino-Laryngology
• Publisher: Springer
• ISSN: 0937-4477
• ISSN (Online): 1434-4726
• Published Online: 07 February 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in European Archives of Oto-Rhino-Laryngology 279(10): 4825-4830
• Publisher Policy: Reproduced under a Creative Commons License