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.