Updated Results of 3,050 Non-melanoma Skin Cancer (NMSC) Lesions in 1725 Patients Treated with High Resolution Dermal Ultrasound-Guided Superficial Radiotherapy, A Multi-institutional Study

Abstract

ABSTRACTBackgroundImage-guided superficial radiation therapy (IGSRT) using a high resolution dermal ultrasound, is becoming an attractive non-surgical curative treatment option for nonmelanoma skin cancer (NMSC). We previously reported IGSRT treatment results from a multi-institutional study of 1616 patients with 2917 NMSC lesions (Yuet al. Oncol Ther 2021,https://doi.org/10.1007/s40487-021-00138-4) showing excellent local control (LC) of 99.3% with mean follow-up of 69.8 weeks (16.06 months).MethodsThis abstract analyzes an additional 93 patients with 133 lesions, updates previous findings with longer follow-up, using Kaplan-Meier statistics, and performs subgroup analysis. A total of 1709 patients with 3,050 Stage 0, I, and II NMSC lesions treated from 2017 to 2020 were retrospectively analyzed.ResultsLesions received a median of 20 fractions of 50, 70, or 100 kilovoltage(kV) IGSRT using image guidance. Average follow-up was 25.06 months (108.9 weeks) with a maximum follow up of 65.6 months (285.0 weeks) for the entire cohort. 68 patients expired from unrelated causes with no-evidence of disease (NED) at last follow-up prior to death, thus Disease-Free-Survival (DFS) was 100%. Overall, 3,027 of 3,050 lesions achieved an absolute LC of 99.2%. Overall absolute LC for BCC, SCC, and SCCis was 99.0%, 99.2%, and 99.8%, respectively. No additional late complications were found to date as of January 2022.DiscussionThese updated results demonstrate that IGSRT continues to achieve a high level of LC with low complication rates. IGSRT should be considered an attractive first-line option for the non-surgical treatment of NMSC.