Strontium and samarium therapy for bone metastases from prostate carcinoma

A review was performed of all patients who received strontium-89 chloride or samarium-153 ethylenediamine-tetramethylenephosphonate for prostate cancer metastatic to bone at the Royal Brisbane Hospital between 1992 and 1997. There were 57 patients, 38 treated with strontium-89 and 19 with samarium-153. Forty patients had radionuclide therapy alone, and 28/40 (or 70%) responded in terms of experiencing a beneficial effect on pain. In the other 17 patients, the effect of the radionuclide on pain could not be assessed because they received external beam radiotherapy concomitant with a therapeutic radionuclide. There was no difference in response rates between the samarium and strontium groups as measured by the effect on pain or in the time to progression. The median time to progression for all patients was 2-3 months. The present study confirms that following administration of a therapeutic radionuclide, a high proportion of patients experienced improvement of pain, but the time to progression is not long, so that the overall degree of benefit is modest.