Radiation Therapy (RT) for preventing the recurrence of keloids

Indications for RT are given for (repeated) recurrences postoperatively or high-risk situations (e.g., marginal resection, wider spread, unfavorable location). Primary RT is promising in cases of functional inoperability and in actively proliferating disorders within about 6 months after the triggering trauma. Proliferating fibroblasts and mesenchymal and inflammatory cells are the target cells.

Fully matured keloids hardly respond to primary RT; prophylactic RT immediately after excision of the recurrence is most effective. In only 20% to 25% of cases, recurrences occur after postoperative RT. RT is initiated 24 hours after surgery. Radiation quality has to be adapted to the local conditions. Conventional x-rays (70 to 150 kV), electrons (<6 MeV), and iridium-192 brachytherapy with implants or strontium-90 dermal plates are useful. The target volume is limited to the scar plus a 1-cm deep safety margin on both sides of the scar. Lead absorbers need to be prepared if required. The recommended total dose is 12 to 20 Gy; for example, 5 × 3 or 4 × 4 Gy within 1 week. Single-dose RT with 7.5 to 10 Gy is also effective. Clinical end points are long-term control, low relapse rate, and good cosmesis.