We retrospectively analysed 38 patients treated with Radium-223 between 2015 and 2018. All patients underwent a baseline visit and a bone scintigraphy. Bone scan, ALP and PSA levels were repeated after third and after the end of therapy. All patients were re-evaluated after 2 months from the end of therapy. Survival curves were plotted according to the Kaplan-Meier method and differences between groups were analysed by using a two-tailed log-rank test.
The response to the treatment in term of change in pain was reduction in 16 patients; no change in 14 and increased in eight. We arbitrarily established a cut-off 10 bone lesions to evaluate the response: patients with less than 10 metastasis had significant differences in PFS (P < 0.001) compared to patients with more than 10, no statistical significance was found considering the OS (P = 0.23) between the two groups. The same results were founded in patients with baseline ALP <220 U/L with a PFS (P < 0.001) and OS (P = 0.027).
The most important finding was the correlation between the number of bone metastasis and ALP with outcome survival and efficacy of Radium-223 treatment.