Hypofractionated Radiosurgery for Intracranial Meningioma—A Systematic Review and Meta-analysis of Literature

Introduction: Radiosurgery is a well-established technique used to treat intracranial meningiomas. To mitigate radiation side-effects, fractionation protocols deliver equivalent or higher total radiation in manageable fractions and with favorable side-effect profiles. Hypofractionated stereotactic radiosurgery (HF-SRS) is a fractionation strategy that administers higher doses per fraction, necessitating fewer fractions overall. We performed a systematic review and meta-analysis to evaluate the outcomes of HF-SRS utilization (2–10 fractions) in the treatment of meningiomas.

Materials and Methods: PubMed and Embase were systematically reviewed for literature on “hypofractionated” “radiosurgery” for “meningiomas.” Patient/meningioma characteristics, treatment details, and follow-up outcomes were extracted from eligible studies. Meta-analyses were performed on variables reported by ≥3 studies on R version-4.3.2. Subgroup analyses were conducted for photon-based and proton-based HF-SRS.

Results: We investigated 1,714 cases from 25 studies meeting inclusion criteria, representing 27.4% males [24.1–30.9] (Table 1 and 2). Mean age was 57.2 [54.4–60.2] for photon-based patients and 53.7 [52.3–55.1] for proton-based patients (p = 0.03) (Table 2). Mean HF-SRS dose was 23.6 Gy [22.0–25.4] in 4.1 fractions [3.7–4.6] for a mean dose per fraction of 5.8 Gy [5.3–6.4]. Mean isodose line was 75.6% [69.5–82.2] with a conformity index of 1.4 [1.1–1.8]. Partial obliteration rate was 25.2% [17.3–35.1] at 34.7 months [25.5–47.3] of follow-up with an associated 1.7% [1.0–2.8] meningioma-related mortality. Compared with photon-based protocols, proton-based HF-SRS showed comparable meningioma-related mortality (2.6 vs. 1.6%, p = 0.55) and overall survival at one (97.4 vs. 97.6%, p = 0.93), two (97.4 vs. 97.4%, p = 0.99), three (97.4 vs. 96.7%, p = 0.83), and five years (97.4 vs. 96.4%, p = 0.75).

Conclusion: HF-SRS is promising among radiosurgical strategies for meningioma, with no differences in meningioma-related mortality or overall survival between photon- or proton-based therapies. Significant heterogeneity regarding HF-SRS dosing strategies warrants additional investigation.

Publication History

Article published online:
07 February 2025