22. Current status of systematic radiopharmaceuticals for the treatment of painful metastatic bonr disease

Intractable bone pain secondary to bone metastasis from prostate or breast cancer, or other malignancies is a major problem in the management of the oncological patient. Treatment often includes the use of analgesic drug therapy; however, radiation therapy, hormonal therapy, chemotherapy, and surgery may also be needed. Advances in systemic radionuclide therapy have increased the number of treatment options available for patients with painful osseous metastases. This treatment modality offers three major advantages i.) by addressing all sites of involvement; and ii) by limiting irradiation of normal tissues due to selective absorption into bone which results in an improved therapeutic ratio. Patients with a positive bone scan are eligible for treatment, and indications and contraindications for use are well defined. Large, prospectively randomized clinical trials have established the efficacy of samarium-153 EDTMP and strontium-89 Cl as a first-line therapy. When these agents are used, pain relief often occurs rapidly and lasts several weeks to months with responses seen in 60–80% of patients, depending on the extent and stage of the disease. With the introduction of modern bone-seeking radiopharmaceuticals as Sm-153 EDTMP toxicity is rare and restricted to reversible myelosuppression. In summary, evidenced based literature suggests that these radiopharmaceuticals can significantly reduce pain and analgesic requirements, improve quality of life, reduce lifetime radiotherapy requirements and management costs, and may even slow the progression of painful metastatic lesions. Retreatment is safe and effective