Is Noninvasive Stereotactic Radiosurgery for Skull Base Meningiomas With Carotid Artery Involvement Supported by Long-Term Clinical Outcomes?

Abstract

Gamma knife radiosurgery (GKRS) is utilized (at our institution) for residual or recurrent skull base meningiomas (SKBM), and as primary treatment when the patients' advanced age, medical illness or preference exclude surgery. Published studies of GKRS use for SKBM with intracavernous sinus carotid artery involvement (CAI) are scarce. The current retrospective study was undertaken to determine the effects of GKRS in a cohort comprising cases of SKBM-CAI.Forty-six patients who underwent single-session GKRS for SKBM-CAI between January 2000 and August 2017 were identified from our prospectively maintained radiosurgery and radiation oncology databases. After excluding individuals with missing clinical or radiological follow-up information, 30 patients (with a mean age of 62 years; 23 women and 7 men) composed the study participants. The median maximal tumor volume was 5.7 cm3 (range, 1.4-14.1) and applied marginal dose was 13 Gy (range,8-18). The chosen investigation endpoints included subjective and objective responses to treatment (i.e., the exhibited symptoms, neurological deficits, and the tumor) and after-therapy observed toxicity.Regarding response to treatment of symptoms and cranial nerve impairments, improvement (43%; 13/30), non-improvement (40%; 12/30), or progression (10%; 3/30) were noted during a median follow-up of 50.5 months (range 6-194); two patients (7%) remained asymptomatic and neurologic deficit-free until last follow-up. At a median radio imaging follow-up of 48 months (range 3-194), 21 (70%) treated tumors were stable, 7 (23%) showed continued growth, and 2 (7%) were smaller or had completely resolved following GKRS. No patients experienced treatment-related side-effects, cerebrovascular complications, and developed radiation oncogenesis. All participants, save for one subject, were alive during a period extending from 5 to 212 months (median 67.5 months).In this analysis, GKRS appeared to be an effective and safe treatment strategy in patients with SKBM-CAI as it offered an overall 77% chance of tumor control and preserved neurological function in over half of the patients with no acute or late ill-effects. Gamma knife radiosurgery, a less invasive management option for skull base meningiomas with carotid artery involvement, can be considered useful because it obviates the need to resect the intracavernous sinus carotid artery or perform bypass grafting.F.L. Ampil: None. A. Sin: None. D. Smith: None. T.A. Richards: None.