Feasibility and Safety of Diffusing Alpha-Emitter Radiation Therapy for Recurrent or Unresectable Skin Cancers

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Recurrent or unresectable skin cancers present limited therapeutic options.
• Novel treatment strategies are needed to improve patient outcomes.
• Diffusing alpha-emitter radiation therapy (DaRT) offers a potential new modality using alpha-particle interstitial brachytherapy.

Purpose of the Study:

• To assess the feasibility and safety of DaRT for managing skin cancers that have recurred or cannot be surgically removed.
• To evaluate the efficacy of DaRT in achieving tumor response.

Main Methods:

• A prospective cohort study involving 10 patients with recurrent or unresectable skin or soft tissue tumors.
• DaRT was administered over 2–3 weeks, delivering a physical dose of 10 Gy (200 CGE).
• Feasibility was assessed by successful radiation delivery; safety by adverse events (AEs) over 24 weeks; and tumor response via physical examination and imaging at 12 weeks post-treatment.

Main Results:

• The study included 10 participants (median age 72 years) with recurrent (60%) or unresectable (40%) skin cancers.
• DaRT achieved high tumor coverage (mean 91%) with no grade 3 AEs; common AEs were mild erythema, edema, and pruritus.
• A 100% complete response rate was observed at 12 weeks, with 90% confirmed by CT imaging.

Conclusions:

• DaRT is a feasible and preliminarily safe treatment for recurrent or unresectable skin cancers.
• The therapy shows a favorable safety profile and high efficacy, with promising response rates.
• Further investigation in a US trial for marketing approval is underway based on these findings.