Abstract

We studied the correlation between the efficacy of local external beam radiotherapy and the efficacy of strontium-89 in the palliation of osteoblastic metastatic bone pain in 43 patients with cancer. All 43 had been treated with hormonal or chemotherapy according to the primary malignancies and analgetic pharmacotherapy as needed, 36 received local external beam radiotherapy as a palliative before strontium-89 injection, and all 43 were ultimately treated with strontium-89 as salvage therapy. Responses to the first strontium treatment, and to the first radiation treatment if given, were taken from patient files. Pain was evaluated by Karnofsky performance status, analgesic dosage, and duration of response to treatment translated into numeric scores on a pain duration scale and an integrated response scale. The efficacy of limited field external radiation in metastatic bone pain palliation was 80.6% versus 58.1% for strontium-89. Patients treated with both external radiation and strontium had a positive correlation of 0.4 with a probability of P = 0.0158 between the responses to the 2 treatments, indicating that response to external radiotherapy could be viewed as an indicator of strontium-89 efficacy in metastatic osteoblastic bone pain palliation in the same patient. No significant correlation was found between strontium efficacy and gender, location of metastases to weight-bearing bones, duration of hormonal therapy or chemotherapy, or type of primary neoplasm.