Excision followed by adjuvant irradiation is considered safe and most efficacious for treatment of keloid scars. Recently, different authors published successful treatment protocols and recommended the following: (1) the use of high-dose-rate brachytherapy instead of low-dose-rate brachytherapy or external radiation; (2) a short-time interval between operation and irradiation; (3) single fraction instead of multifraction irradiation; and (4) a minimum of 12- to 24-month follow-up post treatment.

This study evaluates the above recommendations with a systematic review of the English-language literature, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. Both PubMed and EMBASE were searched. Studies were graded according to the American Society of Plastic Surgeons Rating Levels of Evidence.

Thirty-three studies were selected. Six studies were graded as level of evidence type II studies and 27 as type III. High-dose-rate brachytherapy showed lower recurrence rates compared with low-dose-rate brachytherapy and external radiation. A short-time (<7 hours) interval between scar excision and irradiation results in a lower recurrence rate compared with long-time intervals (>24 hours). Single-fraction irradiation showed promising results in terms of recurrence rate and patient convenience. Finally, scar recurrences were seen between 2 and 36 months, with a mean of 15 months.

Based on this systematic review of the literature, the evidence confirms the recommendations stated by authors in the recent years. However, due to the lack of high-quality randomized studies, the quality of this evidence is limited. More randomized studies will generate stronger recommendations.