Radiosurgery and fractionated radiotherapy for cavernous sinus meningioma: a systematic review and meta-analysis

IntroductionRadiosurgery (RS) and fractionated radiotherapy (FRT) are part of the therapeutic armamentarium for the management of cavernous sinus meningiomas. We propose a systematic review of the local tumor control and clinical outcomes after monofractionated radiosurgical treatment, including gamma knife radiosurgery (GKRS) and linear accelerator (Linac RS), or fractionated radiotherapy.Materials and MethodsThe current review and meta-analysis adhered to the PRISMA guidelines. We performed a search in PubMed, Embase, and Medline based on the following mesh terms, used alone or in diverse combinations, in both title and abstract: cavernous sinus, meningioma, radiosurgery, gamma knife, linac, cyberknife, and radiotherapy. We screened 425 studies. We selected 36 studies, matching all selection criteria: 24 for GK, 5 for Linac, and 7 for FRT.ResultsWere included 2817 patients (GKRS, n=2047, LinacRS, n=350, FRT, n=420). Half of patients benefited from upfront RS or FRT; the other half benefited from adjuvant RS or FRT (combined approach or tumor recurrence). The mean gross target volume (GTV) was smaller for RS as compared to FRT (p=0.07). The median marginal doses were 13.9Gy (range, 11 to 28) for GKRS and 14Gy (range, 12.8 to 17.7) for LinacRS. For FRT, patients received a mean dose of 51.2Gy (25.5 fractions, 1.85Gy each). The mean overall follow-up values were 48months (range, 15 to 89) for GKRS, 69months (range, 46 to 87) for Linac, and 59.5months (range, 33 to 83) for FRT. PFS at 5years for GKRS, LinacRS, and FRT were respectively 93.6%, 95.6%, and 97.4% (p=0.32, the Kruskal-Wallis). Monofractionated treatments (GKRS and LinacRS) induced more tumor volume regression than FRT (p=0.001). Tumor recurrence or progression ranged between 3 and 5.8%, without statistically significant differences between modalities (p>0.05). Trigeminal symptoms improved in approximately 54%, and III-IV-VI cranial nerves (CN) palsies improved in approximately 45%. After GKRS, visual acuity improved in 21% (not enough data available for other modalities). De novo deficits occurred in 5 to 7.5%. Adverse radiation effects appeared in 4.6 to 9.3% (all techniques pooled).ConclusionRS achieved a twice-higher rate of tumor volume regression than FRT. GKRS series reported an improvement in visual acuity in 21% of the cases. GKRS, Linac, and FRT provided similar clinical post therapeutic outcomes for the trigeminal and oculomotor CN.