Outcomes of Primary Radiation Therapy for Patients With Widespread or Unresectable Keloids

Keloids are scars that grow beyond their original margins, typically presenting as pigmented, thickened lesions accompanied by pain and pruritus that affects patients' quality of life. Keloids can be resectable or unresectable, and currently, no gold standard treatment exists for widespread or unresectable keloids. Radiation therapy is effective for keloids, but the efficacy and safety of primary radiation therapy for unresectable keloids have rarely been reported. Our study aims to evaluate the clinical outcomes of primary radiation therapy as a definitive treatment for widespread or unresectable keloids. The primary endpoint is radiation therapy response, including symptomatic and cosmetic improvement. The secondary endpoint is the recurrence rate after radiation therapy.

We retrospectively reviewed 35 patients with 64 keloid lesions treated with primary radiation therapy between January 2010 and July 2023. All received 30 Gy in 6 fractions. Treatment modalities, including 6 MeV or 9 MeV electrons and photon-based intensity modulated radiation therapy, were individualized according to lesion thickness and anatomic complexity. Clinical improvements were evaluated using the Visual Analog Scale, Vancouver Scar Scale, and Japan Scar Workshop Scar Scale. Longitudinal outcomes were analyzed using generalized estimating equations.

Prominent symptomatic relief and cosmetic improvement were achieved with primary radiation therapy, with significant and sustained reductions in the Visual Analog Scale, Vancouver Scar Scale, and Japan Scar Workshop scores during follow-up. Disease control was excellent, with no cases of recurrence or serious adverse events.

Primary radiation therapy is safe and effective for unresectable or extensive keloids. Both electron and photon beams provided reliable symptomatic relief, local control, and favorable cosmetic outcomes. Modern radiation therapy techniques, such as intensity modulated radiation therapy, provide similar efficacy with greater adaptability and may offer an innovative therapeutic option for challenging keloid cases. These findings highlight the expanding role of radiation therapy for benign but symptomatic dermatologic conditions.