Risk factors for local recurrence of keloids and hypertrophic scars after postoperative electron beam radiotherapy

Keloids and hypertrophic scars are benign fibroproliferative lesions that occur as a result of skin injury. Postoperative radiation therapy is used to reduce the recurrence rate because of the high recurrence rate with surgical treatment alone. This study aimed to identify the risk factors for recurrence after postoperative electron beam radiotherapy.

Patients with keloid or hypertrophic scars with at least one lesion and who underwent postoperative electron beam radiotherapy at our institution from June 2013 to March 2022 were included in the study, while patients with a follow-up period of fewer than three months were excluded.

A retrospective analysis was performed on 94 lesions in 81 patients. Exactly two years after the treatment, the actuarial local control rate was 86.4%. The chest wall, shoulder, and suprapubic area were identified as high-risk recurrence sites. Compared to other body sites, these sites had significantly lower local control rates (two-year local control rates: 75.5% vs. 95.2%, P = 0.005). After multivariate analysis, treatment site (P = 0.014), male gender (P = 0.019), and younger age (P = 0.029) were revealed to be statistically significant risk factors for local recurrence. Risk factors for keloid recurrence after postoperative electron beam radiotherapy were therefore identified.

This result could be used for follow-up and as a determinant for the optimal dose/fractionation of postoperative radiotherapy.