Post-radiosurgical edema associated with parasagittal and parafalcine meningiomas: a multicenter study

• Published in: Journal of neuro-oncology 2015-11, Vol.125 (2), p.317-324
• Main Authors: Sheehan, Jason P., Cohen-Inbar, Or, Ruangkanchanasetr, Rawee, Bulent Omay, S., Hess, Judith, Chiang, Veronica, Iorio-Morin, Christian, Alonso-Basanta, Michelle, Mathieu, David, Grills, Inga S., Lee, John Y. K., Lee, Cheng-Chia, Dade Lunsford, L.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Brain Edema - etiology; Clinical Study; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Meningeal Neoplasms - surgery; Meningioma - surgery; Middle Aged; Neurology; Oncology; Radiosurgery - adverse effects; Young Adult
• ISSN: 0167-594X; 1573-7373
• DOI: 10.1007/s11060-015-1911-1

Stereotactic radiosurgery (SRS) offers a high degree of tumor control for benign meningiomas. However, radiosurgery can occasionally incite edema or exacerbate pre-existing peri-tumoral edema. The current study investigates the incidence, timing, and extent of edema around parasagittal or parafalcine meningiomas following SRS. A retrospective multicenter review was undertaken through participating centers in the International Gamma Knife Research Foundation (previously the North American Gamma Knife Consortium or NAGKC). All included patients had a parafalcine or parasagittal meningioma and a minimum of 6 months follow up. The median follow up was 19.6 months (6–158 months). Extent of new or worsening edema was quantitatively analyzed using volumetric analysis; edema indices were longitudinally computed following radiosurgery. Analysis was performed to identify prognostic factors for new or worsening edema. A cohort of 212 patients comprised of 51.9 % (n = 110) females, 40.1 % upfront SRS and 59.9 % underwent adjuvant SRS for post-surgical residual tumor. The median tumor volume at SRS was 5.2 ml. Venous sinus compression or invasion was demonstrated in 25 % (n = 53). The median marginal dose was 14 Gy (8–20 Gy). Tumor volume control was determined in 77.4 % (n = 164 out of 212 patients). Tumor edema progressed and then regressed in 33 % (n = 70), was stable or regressed in 52.8 % (n = 112), and progressively worsened in 5.2 % (n = 11). Tumor location, tumor volume, venous sinus invasion, margin, and maximal dose were found to be significantly related to post-SRS edema in multivariate analysis. SRS affords a high degree of tumor control for patients with parasagittal or parafalcine meningiomas. Nevertheless, SRS can lead to worsening peritumoral edema in a subset of patients such as those with larger tumors (>10 cc) and venous sinus invasion/compression. Long-term follow up is required to detect and appropriately manage post-SRS edema.