When to perform bone scintigraphy in patients with newly diagnosed prostate cancer? a retrospective study.

Background: To determine when a bone scintigraphy investigation is appropriate in patients with newly diagnosed prostate cancer (PCa).

Methods: We retrospectively reviewed 703 newly diagnosed PCa patients who were referred for bone scintigraphy. The association between age, prostate specific antigen (PSA), Gleason score (GS) and bone scintigraphy result were investigated by series of crude or stratified analysis.

Results: Overall, 15.08% (106/703) patients had bone metastases. PSA and GS between positive bone scan group and negative bone scan group were significantly different, while age was not. The incidence of bone metastasis in patient with PSA < 20 ng/ml or GS < 8 was less than 10%, but increased dramatically with rising PSA and upgrading GS. In multivariate analysis, PSA ≥ 20 ng/ml (OR = 5.10, 95%CI (2.12-12.27)) and GS ≥ 8 (OR = 3.61, 95%CI (1.55-8.41)) were independently predictive of positive bone scan.

Conclusions: Patients with PSA ≥ 20 ng/ml or GS ≥ 8 were in higher risk of bone metastasis, bone scintigraphy was recommended. But a bone scintigraphy is of limited value in PCa patients with PSA ≤ 20 ng/ml and GS ≤ 7.