Prof Robert Coleman from Weston Park Hospital, University of Sheffield, UK, spoke with ecancer about the treatment benefits of radium-223 dichloride. Radium-223 is an isotope preferentially taken up in bone, where it inhibits bone cell function and irradiates tumour cells within the bone microenvironment. The results of a phase III clinical trial, which were recently published in the New England Journal of Medicine, showed that radium-223 significantly improved overall survival and delayed time to the first skeletal-related event in patients with metastatic prostate cancer, as Prof Coleman discusses. Earlier trials have also shown that it has a favourable safety profile. Prof Coleman gives his interpretation of these results and predicts their impact on current treatment practices, particularly in the elderly patient.