To evaluate the safety and efficacy of 89 SrCl 2 in the treatment of painful skeletal metastases of cancer patients. 25 metastatic bony pain patients received 1.48—2.22MBq/kg 89 SrCl 2 intraveneously. After therapy the white blood cell

platelet count

liver and renal function was measured every two weeks during 8—12 weeks. The pain relier and adverse effect were also observed and dose was carried out after 3 months or re-occurrence of pain. Results shown that

pain relief was observed in 18 of 25 patients

among them

complete relief in 4

improved in 14 and no relief in 7. The bony pain responded well in prostate cancer and breast cancer (4/4 and 6/8 respectively)

and also effective in repeat treatment (6/6). Pain relief begin from 2—14 days and the duration of pain relief was 12—36 weeks. The toxicity was mild

only transient and restricted to hematological toxicity (<grade II). No adverse reaction

such as bleeding

gastrointestinal symptom and anaphylaxis had been found 5 of 25 patients had pain flar. Conclusions 89 SrCl 2 was an pain-relief agent for skeletal metastases. It can improve the quality of life in the patients and was sate and valuable for clinical use.