Platelet function after single [153Sm]EDTMP therapy in prostate cancer.

AIM Aim of the study was to assess whether [153Sm] EDTMP therapy at a low-dose is associated with platelet activation. METHODS In 29 patients suffering from metastatic prostate cancer platelet count and various platelet function parameters have been monitored for 2 months after a single (the first) application of 1.1 GBq mCi [153Sm]EDTMP. RESULTS After 3 days insignificant signs of platelet activation (increase in malondialdehyde, adenosine diphosphate-induced platelet aggregation, decreased platelet sensitivity) occur, normalizing rapidly. At the nadir of platelet count (3-4 weeks) platelet aggregation response in non-count adjusted samples is somewhat lower, while activity per cell (count adjusted samples) is unchanged. Platelet proteins do not change at all. Insignificant activation of platelet function at day 3 is interpreted as an indicator of mild oxidation injury, late aggregation response changes in non-adjusted samples seem only to reflect temporarily decreased number of circulating platelets. Samarium-153-EDTMP therapy at doses (1.1 GBq) used in the Vienna-protocol is not associated with a significantly altered functional behavior of platelets. CONCLUSIONS We conclude that a single dose of 1.1 GBq 153Sm-EDTMP does not significantly affect in vivo and ex vivo platelet function.