Efficacy and safety analysis: 24‐month outcomes from a prospective cohort of 106 fields treated with widefield radiation therapy for extensive skin field cancerization, with or wit... oleh Lynda Spelman, Andrew E. Potter, Chris Baker, Stephen Shumack, Robert Sinclair, David Christie, Bradley Wong, Peter Foley, Steven Hacker, Cody C. Allison, the National Dermatology Radiation Oncology Registry (NDROR) investigators and sites