Radionuclide therapy of cancer patients with bone metastases.

Objectives: We report our experience in the use of radionuclides in the treatment of bone metastases in patients with various primary cancers: breast cancer, prostate cancer, lung cancer, etc.

Material And Methods: Eighty-seven patients (53 women, 34 men) with bone metastases were treated for pain relief with either 32-P (71 patients) or 89-Sr (16 patients). Fifty-three of the patients had breast cancer, 27--rostate cancer, 6--lung cancer and 1--kidney cancer. The patients were examined for side effects when 32-P was administered perorally and 89-Sr injected intravenously. We also studied the changes in the levels of hemoglobin, white blood cells (WBCs) count and platelets count.

Results: We found a significant decrease in the WBC and platelet count in the patients treated with 32-P (U = 2.20, P < 0.05 and U = 4.57, P < 0.001) one month after the therapy. These parameters showed no significant decrease in the group treated with 89-Sr. The pain, which was the rationale to use the radioactive isotopes, was relieved and the patients restored their previous mobility.

Discussion: The fact that 32-P alleviated the grave symptom of pain at the relatively weak radiation dose used (2 mCi) is a strong indication that this radiopharmaceutical can be used successfully for such a purpose, although some authors argue against its use in view of the myelosuppresion it causes. This myelosuppression, however, is mild and transient even without treatment and patients could benefit from this adjuvant treatment to manage the pain syndrome. 89-Sr administered intravenously in a dose of 4mCi also relieves pain efficiently but its use is limited by the cost of the quantity needed for 1 patient and for a single dose. The National Health Insurance Fund currently reimburses for a very limited quantity of this substance which makes the cost of the procedure 15 times as expensive as that using radioactive phosphorus.

Conclusions: Using the radiopharmaceuticals 32-P and 89-Sr provides an additional, easy and efficacious means for palliation of cancer patients with bone metastases, especially those who are refractory to percutaneous irradiation.