Comparison of Single-Fraction Versus Fractionated Adjuvant Electron Beam Radiotherapy Following Excision of Auricular Keloids: A Retrospective Cohort Study

Postoperative radiotherapy is effective for reducing recurrence of auricular keloids, yet the optimal dose fractionation remains debated. This retrospective cohort study compared single-fraction 10 Gy versus fractionated 10 Gy (2×5 Gy) electron beam radiotherapy following keloid excision. Seventy-seven patients were enrolled, with 37 receiving a single 10 Gy fraction (group A) and 40 receiving 5 Gy×2 fractions (group B). All patients underwent complete surgical excision and initiated radiotherapy within 24 hours postoperatively. The primary endpoint was local recurrence; secondary endpoints included scar aesthetic quality assessed using the Patient and Observer Scar Assessment Scale (POSAS 2.0) and radiotherapy-related complications. With a median follow-up of 19.0 months in both groups, the recurrence rate was 2.7% in group A and 7.5% in group B (P=0.616). The total observer POSAS score was significantly lower in group A (14.3±3.7 versus 16.5±4.3, P=0.019), indicating superior objective scar quality, while patient-reported scores showed no significant difference. Both regimens were well-tolerated, with no severe adverse events and comparable rates of acute dermatitis, pigmentary changes, and telangiectasia. In conclusion, single-fraction 10 Gy electron beam radiotherapy achieves comparable local control to fractionated 10 Gy and yields superior objective aesthetic outcomes. Combined with its convenience and health economic advantages, single-fraction 10 Gy represents a safe and preferred clinical option for auricular keloids.