Study designs of evaluations included in the review
Only randomised controlled trials were eligible for inclusion in the review. The duration of follow-up in the included trials ranged from 5 weeks to 3 years. The authors excluded review articles, including one systematic review published in 1995 that did not provide pooled estimates of effects.
Specific interventions included in the review
Studies were eligible for inclusion in the review if they assessed one of the following comparisons:
strontium-89 versus placebo in multiple sites of painful osseous metastases;
strontium-89 versus conventional radiotherapy in multiple sites of painful osseous metastases; or
strontium-89 plus involved field radiotherapy versus involved field radiotherapy alone in isolated painful metastases.
The dose and schedule of strontium-89 varied between the studies included in the review:
150 MBq in week 1, 150 MBq in week 6 if needed (versus placebo);
75 MBq each month for 3 months (versus placebo);
200 MBq (versus involved field or hemibody radiotherapy);
400 MBq injection added to involved field radiotherapy (versus radiotherapy alone).
Participants included in the review
Studies were eligible for inclusion in the review if they included men with hormone resistant stage D adenocarcinoma of the prostate with painful bone metastases. There were two patient populations: men with multiple painful skeletal metastases; and men with isolated painful bone metastases receiving strontium-89 as an adjunct to involved field radiation. The authors did not report the demographic characteristics of the participants.
Outcomes assessed in the review
Studies were eligible for inclusion in the review if they reported data on palliation (e.g. change in analgesic requirements, functional status, quality of life), time to further radiotherapy, survival, or toxicity. The primary outcome in the included studies was pain relief, which was measured using a composite score or binary score.
How were decisions on the relevance of primary studies made?
Apart from the general inclusion criteria described, the authors did not report the methods used to select the studies for the review. The studies were selected by three members of the Cancer Care Ontario Practice Guidelines Initiative Genitourinary Cancer Disease Site Group and methodologists.