BACKGROUNDPostembolization syndrome (PES), characterized by pain, fever, nausea, and vomiting, is a common but nonserious adverse event following arterial embolization, negatively impacting patient satisfaction with the procedure. This study aimed to evaluate the efficacy of dexamethasone-based prophylactic therapy in preventing PES, as well as to assess the effects of its dosage and timing of administration.METHODSA systematic search was conducted across 3 databases, 2 trial registries, and citation searches to identify relevant studies. Data related to postoperative pain, fever, nausea, and vomiting were extracted and meta-analyzed using a random-effects model and the Mantel-Haenszel method. Meta-regression was performed to examine the role of dexamethasone dose and timing of administration as mediators.RESULTSDexamethasone-based prophylactic therapy significantly reduced the risk of postoperative pain (risk ratio (RR) = 0.58, 95% confidence interval (CI): 0.48-0.69; P < 0.00001), fever (RR = 0.36, 95% CI: 0.22-0.61; P < 0.00001), nausea (RR = 0.52, 95% CI: 0.41-0.67; P < 0.00001), and vomiting (RR = 0.54, 95% CI: 0.36-0.82; P = 0.004) compared to placebo or no treatment. A higher dose of dexamethasone was associated with a significantly lower incidence of postoperative pain (P = 0.038). Regarding timing, postoperative and continuous (extending throughout the perioperative period) administration, was more effective than preoperative administration (P = 0.024; P = 0.007). A dosage of 6-12 mg was particularly effective in reducing the risk for all 4 symptoms.CONCLUSIONDexamethasone effectively prevents PES in patients undergoing arterial embolization. An optimal protocol may involve a divided dose regimen within the range of 6-12 mg, extending throughout the recovery period for maximum benefit.