A Retrospective Registry Study Evaluating the Long-Term Efficacy and Safety of Superficial Radiation Therapy Following Excision of Keloid Scars

BACKGROUND: Surgical treatment of keloid scars is associated with an approximately 70% recurrence rate at the excision site. OBJECTIVE: We sought to assess keloid recurrence rates when superficial radiation therapy (SRT) was applied following surgical excision. METHODS: Medical records were reviewed of subjects treated for keloid scars followed by SRT (SRT-100™; Sensus Healthcare, Boca Raton, Florida) using a biologically effective dose (BED) of 30Gy and for whom the required retrospective data was available. Eligible subjects (N=61) were treated for 96 keloid scars with SRT. Subjects were male (48%) and female (52%) with a mean age of 38.87 years. Subjects were treated for ≥1 keloid scars following removal by sutured excision (93%) or tangential excision with secondary intention technique (7%). Almost all subjects (98%) received BED 30Gy with irradiation scheme of three 6Gy SRT treatments on Days 1, 2 and 3 following surgery. Mean energy of 100KV (73%) or 70KV (27%) were applied. RESULTS: Ten treated keloidectomy sites (10.4%) had recurrences (i.e., presence of any new tissue growth on the surgical scar) within 12 months increasing to 11 (12.7%) at 18 months. Kaplan-Meier survival probability cure rate was 85.6% from 24 months post-SRT treatment onwards. Transient hyperpigmentation was the most frequent adverse event and there were no malignancies in the treatment area during follow-up evaluations. CONCLUSIONS: SRT with a BED value of 30 Gy delivered to keloidectomy excision sites immediately following excision was well-tolerated and resulted in markedly fewer long-term recurrences than reported following keloidectomy alone. Most keloid scar recurrences occurred within one year. There were no malignancies during follow-up evaluations.