266 the serum PSA concentration. With this evaluation, we tried to determine the clinical proWles of patients for whom bone scanning could be eliminated due to a low probability of bone metastasis. Methods This retrospective study included 579 consecutive patients who were newly diagnosed with adenocarcinoma of the pros- tate and underwent a bone scan study at our single tertiary referral institution between 2002 and July 2010. They all had transrectal ultrasound (TRUS) guided prostate biopsies, serum PSA levels, and bone scans within 3 months of one another. We excluded patients who had a history of 5-alpha- reductase inhibitors treatment for benign prostatic hyper- plasia or that of other malignant diseases with possible development of BM. All prostate biopsies were performed using a standard 18-gauge biopsy gun, and the number of biopsy sites ranged from six to ten with additional targeted biopsies for any hypoechoic or suspicious lesion. For each needle biopsy, certain variables were assessed, including GS, the percentage of tumor as a function of all the biopsy tis- sues, the number of cancer-positive cores, and the total num- ber of cores from all biopsy sites. The serum PSA level was determined by the Hybritech, Tosoh, or Abbot assay with the normal range set between 0 and 4.0 ng/mL. Bone scintigrams were performed with technetium-99m HDP. The dose of Tc-99m HDP used was approximately 20 mCi (740 MBq), and scanning was performed by a sin- gle head—camera high-resolution collimator was used, and whole body anterior and posterior planner images, together with oblique and localized views for areas of interest, were reviewed. The bone scintigrams were reviewed by two experienced radiologists with knowledge of PSA, biopsy GS, and digital rectal examination Wndings. Patients with unclear bone scan Wndings underwent additional computed tomography and/or magnetic resonance imaging to conWrm the bone scan Wndings. To evaluate accuracy of bone metasta- sis with serum PSA · 20 ng/mL or serum PSA · 10 ng/mL, World J Urol (2012) 30:265–269 the receiver operating characteristics (ROC) curve analysis derived area under the curve (AUC) estimates determined the cutoV points of each predictor, and then their sensitiv- ity, speciWcity, and positive predictive value (PPV) were analyzed. The SPSS version 17.0 (SPSS Inc., Chicago, IL, USA) for Windows was used for statistical analysis, and a probability (P) level of <0.05 was considered signiWcant. Results Eighty-three patients (14.3%) had a positive bone scan. Median age of patients with and without bone metastasis was 74 and 68 years old, respectively (P = 0. 027). The median PSA and biopsy GS were 49.6 ng/mL and 7.4, respectively, in patients with bone metastasis and 7.3 ng/mL and 6.4 in those without bone metastasis (Table 1). Of 58 patients with bone pain, 49 (82.8%) had bone metastasis. Positive bone scans were obtained from 27 patients (4.5%) with a serum PSA between 10 and 20 ng/mL, one (0.2%) with serum PSA below 10 ng/mL, and 55 (9.5%) with serum PSA above 20 ng/mL. Of 29 patients with bone metastasis who had GS below 7, 1 (1.2%), 9 (10.8%), 19 (22.9%) patients were found in GS 5, 6, 7, respectively, (Fig 1). Of 83 patients with bone metastasis, 21 (25.3%) with a serum PSA · 20 ng/mL and GS · 7. In the logistic regression analyses, clinical T stage (odds ratio = 3.26; 95% CI, 2.29–4.33; P = 0.021), GS (OR = 3.41; 95% CI, 2.91–4.63; P = 0.019), and serum PSA (OR = 8.37; 95% CI, 3.91–19.21; P < 0.001) were the predictive factor detecting BM (data not shown). With the serum PSA concentration ·20 ng/mL and GS · 7, the mean sensitivity was 74.7%, speciWcity 92.9% (Table 2), and the AUC value of bone scans for the detec- tion of BM 0.640 (P = 0.020; 95% CI, 0.563–0.717) (Fig. 2). With the serum PSA at 10 ng/mL and GS · 7, the mean sensitivity was 98.4%, speciWcity 83.9%, and the AUC values of bone scans 0.828 (P < 0.001; 95% CI, 0.773–0.883) (Fig. 2). Table 1 Patient characteristics and clinical stage at diagnosis * <0.05 by student’s t test ** <0.05 by Pearson chi-square test 123 Clinical variables No. of patients Median age (years) Median PSA (ng/mL)* Biopsy Gleason score (mean)* Clinical stage** T1–2 T3 T4 Bone metastasis (+) 83 74 (53–89) 49.6 (7.9–1221.5) 7.4 § 0.8 5 (6.0%) 41 (49.4%) 37 (44.6%) Bone metastasis (¡) 496 68 (46–87) 7.3 (3.6–54.3) 6.4 § 0.5 393 (79.2%) 84 (16.9%) 19 (3.8%) P value 0.027 <0.001 0.031 <0.001