Adjuvant Radiotherapy Following Surgical Excision of Keloids: A Systematic Review of Dose, Fractionation, and Recurrence

Keloids are pathological scars originating from connective tissue characterized by excessive growth that extends beyond the original edges of the wound. They occur significantly more often in skin areas exposed to increased mechanical tension during the wound-healing process and up to fifteen times more frequently in individuals with darker skin pigmentation. The underlying mechanism of keloid formation is driven by an inflammatory response triggered by skin injury extending into the reticular dermis, leading to fibroblast accumulation and neovascularization. The management of keloids remains challenging, as the recurrence rate is high when surgical excision is performed as a standalone treatment. Evidence indicates that combining surgical resection with adjunctive modalities results in superior clinical outcomes and may significantly lower recurrence rates compared with monotherapy. Adjuvant radiotherapy plays a key role in this approach, as it has been shown to reduce recurrence rates to below 10%, primarily through suppression of inflammation and inhibition of fibroblast activity. This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A systematic search of the PubMed and Web of Science databases identified 22 studies comprising more than 2219 patients treated with surgical excision followed by postoperative radiotherapy. Reported recurrence rates ranged from 1.6% to 55.2% and were influenced by total radiation dose, fractionation schedule, radiotherapy technique, and duration of follow-up. Despite its proven effectiveness when combined with surgery, radiotherapy has certain limitations, including the lack of standardized guidelines regarding dose, fractionation, and timing of administration. Most reported adverse effects were mild to moderate and localized to the treated area, while a direct causal relationship between postoperative radiotherapy and secondary malignancy development could not be established. The variability in treatment protocols highlights the need for further studies to support more effective, evidence-based decision-making in the treatment of keloids.