Strontium-89 in palliative treatement of painfull bone metastases.

Background. Bone metastases are observed in 30-70% of patients with cancer. Pain is most frequent symptom that requires regular control and treatment. Systemic palliative radionuclide therapy using beta-emitters is alternative method for analgetic drugs and external beam radiotherapy. The aim of the study was to establish efficacy and risk of side effects of radionuclide treatment in patients with painful osseous metastases.
Material and methods. Sr-89 therapy was performed in 33 patients 13 women and 13 men aged 42 to 79 years (mean 61) with cancer and bone metastases confirmed in MDP-Tc99m whole body scan. Prostate cancer was primary tumour in 18 patients, breast cancer in 12, urinary bladder cancer in 2 and renal cancer in 1 patient.
After intravenous administration of 150 MBq of strontium-89 chloride patients were observed during
3 months and more. Changes in blood counts, intensity of pain, drugs intake, life activity and duration of pain relief was evaluated from 0 to 3 points. Overall Response Index was very good if total points amounted 10-12, good - 7-9, satisfying - 4-6, poor - 2-3 and no response 0-1 points. Myelosuppression was evaluated according to Common Toxicity Criteria by WHO.
Results. Very good response in 6 patients (18%), good in 15 (46%), satisfying in 6 (18%), poor in 2 (6%) and no response in 4 (12%) patients. Transient haemotoxicity post Sr-89 therapy was observed in 16 patients (48%), in 11 patients it was grade I CTC, in 1 grade II CTC, in 3 grade 3 CTC and in one man grade IV which required treatment. Duration of life after therapy was between 21 to 138 weeks (mean 58 weeks). Therapy was repeated in 16 (48%) patients after more than 3 months. Third dose was injected in 2 patients (6%).
Conclusions. Palliative strontium-89 treatment of painful osseous metastases is effective therapy with very mild haemotoxicity.