The value of Gleason score and prostate-specific antigen level in predicting the need for a baseline nuclear bone scan in patients with newly diagnosed 84 prostate cancer cases

Purpose: The objective of the present study was to correlate the prostate-specific antigen (PSA) level and Gleason score with the baseline bone scan results in patients with newly diagnosed prostate cancer and try to determine a group of patients whose risk of bone metastases is low enough to omit safely this staging modality. Methods: This retrospective study included 84 consecutive patients with newly diagnosed prostate cancer (Pca) who underwent a staging bone scan in Nuclear Medicine department between August 2013 and August 2014. Data were collected on age, bony pain, prostate-specific antigen (PSA) level and Gleason score, then, bone scan results were analyzed with respect to these parameters. Bone scan was recorded as positive, negative or equivocal. In case of equivocal lesions, a single-photon emission computed tomography combined with computed tomography (SPECT-CT) was performed allowing a better morphological precision. Results: The median age of the patients was 71, 38 years. Bone metastases were detected in 41 patients (49% of cases), bony pain was a reliable presenting sign of skeletal involvement. Both prostate-specific antigen (PSA) level and Gleason score were independent predictors of positive bone scan. However, the combination of these two parameters enhanced predictability of bone scan results. According to this study, the risk to develop a bone metastasis was very low in asymptomatic patients with PSA level < 20 ng/ml irrespective of the Gleason score or with PSA level < 30 ng/ml associated to a Gleason score < 7. Conclusion: The present study discourages the routine use of bone scan as a pre-treatment staging modality in asymptomatic patients with PSA level < 20 ng/ml irrespective of the Gleason score or with PSA level < 30 ng/ml associated to a Gleason score < 7, allowing considerable cost savings and decreasing time from diagnosis to treatment.