Timing of Adjuvant Radiotherapy After Keloid Excision: A Systematic Review and Meta-Analysis.

BACKGROUND: No consensus exists regarding the appropriate timing of adjuvant radiotherapy administration after surgical excision of keloids. OBJECTIVE: This study investigated the appropriate timing of adjuvant radiotherapy. MATERIALS AND METHODS: A systematic review and meta-analysis of randomized controlled trials and observational cohort studies was performed. A pooled estimate of the incidence rate was performed using a random-effects model. Subgroup analyses based on different anatomic region, biologically effective dose, keloid length, and radiotherapy regimen were also conducted. RESULTS: Sixteen observational cohort studies (1,908 keloid lesions) met the inclusion criteria. The incidence rate was significantly lower in the group treated with electron beam therapy more than 24 hours after surgery (3.80%; 95% confidence interval [CI], 1.78%-8.13%) than that in the group treated with the same therapy within 24 hours of surgery (37.16%; 95% CI, 20.80%-66.37%; p < .0001), but no significant difference was observed between the groups regarding brachytherapy and x-ray treatments. CONCLUSION: Immediate adjuvant radiotherapy did not significantly reduce the incidence rate of recurrent keloids.