Efficacy and safety of adrenalectomy and stereotactic ablative radiotherapy (SABR) for adrenal metastases: A systematic review and meta-analysis.

Abstract

Adrenal metastases presenting as oligometastatic lesions may be treated with adrenalectomy or stereotactic ablative radiotherapy (SABR), yet data comparing their outcomes are lacking. We conducted a systematic review and meta-analysis (PROSPERO, CRD420251071902) to assess the efficacy and safety of these treatments and to explore factors associated with their outcomes. PubMed and EMBASE were searched (01/1999-02/2026) for studies reporting outcomes after adrenalectomy or SABR for adrenal metastases. Eligible studies included ≥ 5 patients and reported oncologic outcomes and/or adverse events. Screening and data extraction followed PRISMA guidelines. Risk of bias was assessed using ROBINS-I. Pooled proportions were estimated using generalized linear mixed models. Meta-regression explored associations between outcomes and clinical or treatment-related variables. Primary endpoints were local control (LC) and treatment-related adverse events (AEs). Secondary endpoints included progression-free survival (PFS) and overall survival (OS). A total of 117 studies (77 adrenalectomy, 39 SABR, 1 both) comprising 5641 patients (3649 adrenalectomy, 1992 SABR) were analyzed; all but one were retrospective and 95% were at moderate-to-serious risk of bias. Both modalities achieved high pooled LC (adrenalectomy 91.7%, SABR 84.8%) with low rates of severe AEs (grade ≥ 3: adrenalectomy 1.6%; SABR 0.4% acute, 0.8% late). LC after SABR was dose-dependent: BED10 ≥ 100 Gy was associated with 95% 1-year LC. OS favored adrenalectomy (1-year 81% and 70%, 2-year 60% and 45%) likely reflecting differences in patient selection. Both adrenalectomy and SABR provide effective local treatment for adrenal metastases with low rates of severe AEs. Treatment selection should be individualized according to patient characteristics, disease presentation, and therapeutic objectives.