RADT-15. THE ROLE OF STEREOTACTIC RADIOSURGERY IN WHO GRADE II MENINGIOMAS: RESULTS FROM A LARGE EUROPEAN MULTICENTER STUDY

• Published in: Neuro-oncology (Charlottesville, Va.) Va.), 2024-11, Vol.26 (Supplement_8), p.viii75-viii75
• Main Authors: Santacroce, A, Tuleasca, C, Liščák, R, Kollova, A, Motti, E, Lindquist, C, Radatz, M, Frischer, J, Lippitz, B, Álvarez, R Martínez, Skeie, B Sandvei, Nicolato, A, Longhi, M, Unger, F, Sabin, I, Mindermann, T, Bundschuh, O, Horstmann, G A, van Eck, A T C, Nakamura, M, Steiger, H -J, Ewelt, C, Alsofy, S Zafy, Lewitz, M, Régis, J, Muacevic, A, Hofmann, T, Ehret, F, Picozzi, P, Faedo, S, Franzini, A, Masaranov, S, Greve, Tobias
• Format: Article
• Language: English
• ISSN: 1522-8517; 1523-5866
• DOI: 10.1093/neuonc/noae165.0299

Abstract BACKGROUND This study evaluates the outcomes of WHO grade II meningiomas treated with stereotactic radiosurgery (SRS) using a large, multi-institutional European database. We aim to investigate the long-term tumor control rate and morbidity associated with SRS. METHODS Data from 355 consecutive patients treated between 1992 and 2022 at 16 European radiosurgery centers were retrospectively analyzed. After excluding 40 patients due to loss to follow-up, results from 315 patients were included. Clinical and imaging data were independently collected by each center and uniformly entered into a multicenter database. RESULTS The median age of patients was 56 years, with 54% being female. The median follow-up duration was 46.3 ± 36.9 months. Tumors had prior surgical treatment and biopsy in 99% and 1% of cases, respectively. Tumors received previous radiotherapy or SRS in 27.4% of cases. SRS was performed due to local progression in 89.6% of cases, residual tumor in 6.4%, and distant progression in 4.0%. SRS characteristics included a median target volume of 5.1 cm³ and a median margin dose of 16 Gy (53.5% isodose). The 3-year local control rate was 72.0%, with a progression-free survival rate of 66.6% and an overall survival rate of 89.7%. Transient and permanent morbidity rates were 6.4% and 3.5%, respectively. Multivariate analysis identified previous radiotherapy and age as significant factors influencing these outcomes. CONCLUSIONS This study is the largest to date on SRS in WHO grade II meningiomas. Our data shows that SRS is a viable and safe treatment option for residual and recurrent WHO grade II meningiomas