Topical 188Re Ionizing Radiation Therapy Exerts High Efficacy in Curing Nonmelanoma Skin Cancer

Purpose of the report Nonmelanoma skin cancer (NMSC) is the most frequent malignancy. Surgical intervention is the common treatment but may lead to disappointing results; alternative treatment options are needed. Methods In this monocentric pilot study, topical 188 Re resin was investigated as a treatment for invasive NMSC up to 3-mm thickness. Twenty-two patients with 40 histologically confirmed NMSCs with a median size of 1.25 cm 2 (range, 0.04–16.8 cm 2 ) and a median tumor thickness of 0.35 mm (range, 0.1–2.1 mm) were included. Patients were treated once with 188 Re resin with a targeted dose of 50 Gy. The median applied activity was 111.4 MBq (range, 21.0–168.0 MBq), and the median treatment time was 89 minutes (range, 38–175 minutes). The response rate, adverse events, and cosmetic outcome were assessed at 14 days, 4 months, and 12 months. Results Response rate at 12 months was 97.5%, with 95% complete responses (clinically or histologically proven in case of clinical doubt). Most adverse events were reported at 14 days, with 20% itching and 12.5% mostly minor pain. Forty-nine percent of the lesions showed hypopigmentation only at 12 months. Forty-one percent of the lesions were graded as cosmetically superior to the expected result after surgery and 51.3% as comparable to successful surgery. The cosmetic outcome on the head and face was superior compared with the trunk and leg ( P = 0.003). Conclusion 188 Re resin is a highly effective treatment for NMSC up to 3-mm thickness and a valid alternative to surgery, specifically for tumors located on sensitive areas such as nose or ear.