Progression of bone metastases is uncommon during radium-223 treatment for castration-resistant prostate cancer, researchers concluded in a report published online ahead of print in Prostate Cancer and Prostatic Diseases. Bone flares (pain and/or radiologic) may be observed during the first 3 months and should not be confused with progression, they noted.


Daniel Keizman, MD, of the Sackler School of Medicine in Tel Aviv, Israel, and colleagues studied a retrospective cohort of 130 patients, of whom 84 (65%) received radium-223 after docetaxel treatment. Seventy patients (54%) completed the planned 6 injections of radium-223. The investigators observed a transient increase in bone metastases-related pain in 27% of patients with available data. At 3 and 6 months of treatment, bone imaging showed stable disease in 74% and 94% of patients with available data, respectively. An increase in the number of bone lesions was documented in 26% of patients at 3 months compared with baseline and in 6% of patients at 6 months compared with 3 months. Radiologic extraskeletal disease progression occurred in 46% of patients with available computed tomography (CT) data at 3 and/or 6 months, Dr Keizman's team reported.


CT imaging should be considered after 3 and 6 doses of radium-223 to rule out extraskeletal disease progression, according to the investigators.