Several
radiopharmaceuticals were investigated to determine their efficacy and toxicity in the palliation of painful bone
metastases. Data on the influence of
rhenium-188 hydroxyethylidene diphosphonate (188Re-HEDP),
rhenium-186 hydroxyethylidene diphosphonate (186Re-HEDP), and
strontium-89 (89Sr) on
pain symptoms, quality of life, and bone-marrow function were obtained in 64 patients with breast and
prostate cancer. Thirty-one patients were treated with 188Re-HEDP (3194 +/- 387 MBq), 15 patients with 186Re-HEDP (1358 +/- 158 MBq), and 18 patients with 89Sr (152 +/- 19 MBq). The 188Re-HEDP group included six
breast cancer patients and 25
prostate cancer patients; the 186Re-HEDP group included three
breast cancer patients and 12
prostate cancer patients; and the 89Sr group included three
breast cancer patients and 15
prostate cancer patients. All subjects participated in an interview using a standardized sets of questions before and after the 12-week term of
therapy. Blood counts were taken weekly for six weeks and after 12 weeks. Results showed that 77 percent of patients reported
pain relief
after treatment with 188Re-HEDP, 67 percent
after treatment with 186Re-HEDP, and 72 percent
after treatment with 89Sr. Sixteen percent of patients treated with 188Re-HEDP, 13 percent treated with 186Re-HEDP, and 17 percent treated with 89Sr were able to discontinue their
analgesics and were
pain-free. Patients described an improvement on Karnofsky performance status (KPS) from 73 +/- 7 percent to 85 +/- 8 percent 12 weeks after 188Re-HEDP (p < 0. 05), from 72 +/- 13 percent to 79 +/- 12 percent after 186Re-HEDP (p = 0.251), and from 62 +/- 14 percent to 69 +/- 16 percent after 89Sr (p = 0.415). Only three patients undergoing 188Re-HEDP
therapy, one undergoing 186Re-HEDP
therapy, and three undergoing 89Sr
therapy had
thrombocytopenia (platelet count below 100 x 10(3)/microl) following treatment. The maximum nadir of platelet and leukocyte counts was observed between the second and fifth week
after treatment for all
radionuclides and was reversible within 12 weeks. The nadir was earlier for 188Re-HEDP with a shorter physical half-life compared with 89Sr. There were no significant differences in bone marrow toxicity (p = 0.123-0.421). Results of this study indicate that all evaluated
radiopharmaceuticals were effective in
pain palliation without induction of severe side effects. The increase in KPS after 188Re-HEDP was the only statistically significant finding (p = 0.001).