s S489 (3.7%), pneumonia (3.7%) and peripheral edema (3.7%). Median number of cycles administered was 5 (1−6). Four patients required delay on treatment administration due to toxicity. No dose reductions were reported. Median overall survival (OS) was 8.1 months (95%CI, 5.8–10.4 months) after 15 events at the time of analysis. Median PSA progression free survival (PFS) was 4.4 months (95%CI, 1.8−7.0 months). Median PFS according to the investigator was 6.0 months (95%CI, 4.0−7.9 months). There was a significant correlation between basal alkaline phosphatase levels less than 200 U/L (p = 0.014) and no concomitant use of biphosphonate (p = 0.001) with a longer OS. Conclusions: Compared to data from registration trial, radium-223 showed less activity with a poor safety profile in CRPC pts treated in office-based practice with comorbidities and prior systemic treatments. There is a need to improve how to select the best clinical profile for candidates to radium223. No conflict of interest.