Preoperative steroid use in brain tumor surgery: a systematic review of neurological and surgical site infectious outcomes

• This is the first systematic review evaluating both neurological benefit and infection risk of preoperative steroids in brain tumor surgery. • Across 65,861 patients from eight cohort studies, preoperative steroids were inconsistently associated with surgical site infection risk. • Neurological benefit, the primary justification for steroid use, was systematically under-investigated, with only two studies reporting relevant outcomes • The current evidence base is limited by retrospective designs, heterogeneous outcome definitions, and lack of randomized trials, underscoring the need for prospective studies to guide steroid stewardship. Preoperative dexamethasone is routinely administered to brain tumor patients to reduce vasogenic edema and preserve neurological function. However, its immunosuppressive effects raise concerns regarding surgical site infection risk. Despite its widespread use, the balance between neurological benefit and infection risk remains poorly defined. To systematically review the evidence evaluating preoperative steroid use in adult brain tumor surgery, with specific focus on neurological improvement and surgical site infection risk. A systematic search of PubMed, Embase, Scopus, Web of Science, and Cochrane Library was performed in accordance with PRISMA guidelines. Eligible studies included adult patients undergoing craniotomy for tumor resection, comparing those receiving preoperative steroids to those not receiving steroids. Primary outcomes were neurological improvement and SSI. Risk of bias was assessed with ROBINS-I. Eight retrospective cohort studies (n = 65,861) met inclusion criteria. Although ∼ 80% of patients are reported to receive dexamethasone, only 25.7% in our pooled cohort had documented exposure (mean 11.2 days), likely reflecting underreporting and practice variability. SSI outcomes were inconsistent: two large NSQIP-based studies reported reduced risk (RR 0.74, 95% CI 0.62–0.89) or no significant association (RR 1.14, 95% CI 0.93–1.39). Smaller cohorts showed significant results but often lacked valid comparators or consistent SSI definitions. Neurological outcomes were sparsely reported, only two studies provided data, with Bowden et al. showing improvement in 38.5% of patients, and Medikonda et al. reporting postoperative decline. Evidence on preoperative steroids in brain tumor surgery is limited, heterogeneous, and largely retrospective. Neurological benefits are suggested but sparsely assessed, and surgical site infection risk findings are inconsistent. Prospective studies with standardized outcome reporting are urgently needed to guide optimal steroid use.