Role of strontium-89 as adjuvant to palliative external beam radiotherapy is questionable: results of a double-blind randomized study.

Abstract

To explore the efficacy of adjuvant (89)Sr applied with external beam radiotherapy (EBRT) to treat bone metastases. Ninety-five patients were randomized to (89)Sr (Arm A) or saline (Arm B) on Day 1 of EBRT to demonstrate a reduction in 3-month physician-assessed subjective progression from 70% to 45%. At 3 and 6 months, no difference between treatment arms was observed in the progression rate. At 3 months, the physician-assessed response rate for all patients was 25%, with 46% of the patients progressing. The pretreatment use of opiates was independently associated with short progression-free survival. On the basis of the quality-of-life assessments, pain relief occurred in 50% of patients and 32% experienced improvement in global quality of life, without impact from (89)Sr. Differences were observed between the physician evaluation of radiotherapy efficacy and the patient assessment. In Arm A, serum alkaline phosphatase, but not serum prostate-specific antigen, decreased during the first 3 months after treatment. (89)Sr, adjuvant to ERBT, does not seem to reduce the number of patients with subjective progression at 3 months. Patients should be referred for palliative RT before their bone pain requires high doses of opiates. In radiotherapy trials, the evaluation of pain and pain relief remains problematic because of the confounding use of analgesics.