Surgically excised keloids reportedly recur at a rate of >45%. Post-excision radiation (RT) has been delivered via external beam radiotherapy (EBRT) or interstitial high dose rate (HDR) brachytherapy. Despite historical data showing 10% to 20% keloid recurrences with post-excision RT, there is a paucity of high-quality evidence comparing keloid recurrences between the two RT modalities.

We performed the largest single-institution case-control retrospective study (2004-2014) of keloid recurrence rates and complications between post-excision EBRT and HDR brachytherapy.

One-hundred and twenty-eight patients, with 264 keloid lesions, were treated by excision alone (n = 28), post-excision EBRT (n = 197), or post-excision HDR brachytherapy (n = 39). Patient and keloid recurrence data were analyzed using mixed effect Cox regression modeling with a statistical threshold of P < .05.

Fifty-four percent of keloids recurred after surgical excision alone (9-month median follow up); 19% of keloids recurred with post-excision EBRT (42-month median follow up); 23% of keloids recurred with post-excision brachytherapy (12-month median follow up). Adjuvant EBRT and brachytherapy each showed significant control of keloid recurrence compared to excision alone (P < .01). EBRT significantly delayed the time of keloid recurrence over brachytherapy by a mean difference of 2.5 years (P < .01).

Post-excision RT shows significant reduction in keloid recurrence compared to excision alone. While the recurrence control rates are not statistically different between EBRT and brachytherapy, keloids treated with EBRT recurred significantly later than those treated by HDR brachytherapy by a mean of 2.5 years. Further workup with a randomized control study will help to refine optimal adjuvant RT treatment. LEVEL OF EVIDENCE 3.