Metastatic bone pain palliation with 89-Sr and 186-Re-HEDP in breast cancer patients

Aim. The study evaluates the therapeutic efficacy of Strontium-89-chloride (89Sr) and 186Re-1,1-hydroxy-ethylidene diphosphonate (186Re-HEDP) in the p alliation of painful bone metastases from breast cancer. Patients and methods. Fifty patients with painful multifocal bone metastase s from breast cancer entered the study and were randomized into two groups according to the radiopharmaceutical used: 148 MBq 89Sr i.v. (Group A: 25 p atients) and 1406 MBq 186Re-HEDP i.v. (Group B: 25 patients). Pain palliati on was evaluated on the basis of the Wisconsin pain test improvement at two months and response was graded as complete, partial, minimal or absent. He matological toxicity and side effects were reported according to WHO guidel ines. Results. The global response rate was 84% (21/25) for 89Sr and 92% (23/25) for 186Re-HEDP, respectively. The onset of pain palliation appeared signifi cantly earlier in Group B (p < 0.0001). The duration of pain relief ranged from two months to 14 months (mean of 125 days with a median value of 120 d ays) in Group A and from one month to 12 months (mean of 107 days with a me dian value of 60 days) in Group B (p = 0.39). A moderate hematological toxi city was apparent in both groups. Platelet and white blood cell counts retu rned to baseline levels within 12 weeks after 89Sr administration and 6 wee ks after 186Re-HEDP administration (p < 0.01). Conclusions. Both 89Sr and 186Re-HEDP are effective and safe in bone pain p alliation in breast cancer with the latter showing a significantly faster o nset of pain relief.