Hypofractionated electron-beam radiation therapy for keloids: Retrospective study of 568 cases with 834 lesions

We aimed to analyze the outcomes of hypofractionated high-energy electron beam radiotherapy for the treatment of keloids. from february 1998 to january 2012,568 patients with a total of 834 keloids underwent radiotherapy: 826 lesions with postoperative radiotherapy,and 36 with skin-grafting. lesion size was >5 cm in 335 keloids. an electron-beam of 6 or 7 mev was used,with a total dose of 18 gy (two fractions with a 1-week interval) covering the lesion with a 1-cm margin. the time between surgery and radiotherapy was 24-48 h. skin-grafted patients underwent radiotherapy 10-15 days after the operation. the median follow-up was 40 months (range: 12-160 months). the local control rate was 88.25% (736/834). the relapse rate was 9.59% (80/834),and the time to relapse was 6-28 months (median: 12 months). univariate analyses showed that gender,age,keloid size,keloid site,skin grafting,and operation-to-irradiation interval influenced the local control rate. multivariate analysis showed that the relapse rate was correlated with gender (p = 0.048),age (p < 0.01),operation-to-irradiation interval (p < 0.01),keloid site (p < 0.01),surgical method (p = 0.04) and keloid size (p < 0.02). adverse effects were observed in 9.83% (82/834). no radiation-induced cancers were observed. hypofractionated high-energy electron beam radiotherapy for keloids yielded excellent outcomes,especially in cases without skin grafting. early postoperative radiotherapy with limited hypofractionation could be a good choice for keloid treatment. © 2015 the author 2015. published by oxford university press on behalf of the japan radiation research society and japanese society for radiation oncology.