Our experience on pain palliation of bone metastasis with Sr-89 or Sm-153 in cancer patients resistant to a conventional analgesic therapy. A retrospective study

These retrospective study is aimed to evaluate the efficacy of therapy with Stronthium-chloride 89 (89SrCl) and Samarium 153 conjugated with ethylenediaminetetramethylene phosphonic acid (153Sm–EDTMP) in the palliation of bone pain due to metastatic malignancy. The study refers to a presentation sample of 27 patients with bone metastases caused by different cancers (16 prostate, 5 breast, 6 lung) who were enrolled and followed-up for 11.5 ± 6.3 months. 89SrCl (150MBq) was administered in 17 pts, 153Sm–EDTMP (37 MBq/Kg) in 10 pts. All patients showed multiple metastatic sites of 99Tc-HDP uptake documented by a standard bone scintigraphy. Effectiveness of treatment was evaluated by questionnaires about pain and quality of life, Karnofsky index, specific cancer markers, a post-treatment bone scintigraphy. Presence of flare reaction and haematological toxicity were evaluated too. Questionnaire scores decreased both in patients treated with 89SrCl and in those given 153Sm–EDTM, without significant difference. Karnofsky index significantly increased only in patients with prostate cancer. After therapy, there were no significant changes of tumor marker levels, neither in bone scintigraphic pattern. Flare reaction occurred in 44% of the cases within 2 weeks from the therapy. Remarkable variations of platelets and leukocytes occurred in 33.3% and 18.5% of patients, respectively, independently of the radiopharmaceutical used, but reversed within 6 weeks after therapy. Conclusions. Radionuclide therapy with bone-seeker agents 89Sr and 153Sm in the palliation of painful bone metastases allows a partial/total relief of pain with an improvement of quality of life. No tumoricid effect was found. Haematological toxicity was limited and reversible. Patients with prostate cancer seem to have a higher response rate.