多模态经直肠超声与MRI诊断前列腺癌的对比分析

目的:对比多模态经直肠超声与磁共振诊断前列腺癌的一致性及诊断效能。方法:将疑患前列腺癌的208例患者术前分别采用多模态经直肠超声(transrectal ultrasound,TRUS)和MRI判断前列腺病灶的性质,以穿刺活检的病理结果为诊断标准,评价两种检查方法诊断前列腺癌的一致性和诊断效能。结果:208例患者经TRUS引导目标穿刺,病理确诊前列腺癌144例,前列腺增生64例。TRUS诊断前列腺癌167例,前列腺增生41例;MRI诊断前列腺癌165例,前列腺增生43例。TRUS与MRI对本组病例诊断结果的一致性检验结果Kappa值为0.46;两种方法检出前列腺癌的敏感性、特异性、准确度、阳性预测值、阴性预测值分别为:0.99、0.63、0.88、0.86、0.95和0.95、0.59、0.84、0.84、0.83。结论:TRUS与MRI诊断前列腺病变的一致性中等,两种检查方法诊断前列腺结节没有统计学差异;两种检查方法诊断前列腺癌的敏感性、准确度、阳性预测值、阴性预测值均较高,但特异性中等,TRUS略优于MRI。     

超声弹性成像技术与常规超声在前列腺癌和前列腺增生诊断中的应用对比研究

目的探寻早期诊断前列腺癌的方法。方法应用超声弹性成像(UE)技术,对56例前列腺增生伴PSA增高或正常患者,同时行经直肠前列腺二维超声及UE检查,比较普通经直肠超声检查联合PSA与UE联合PSA对前列腺癌诊断的敏感性和特异性。结果以穿刺活检为判断前列腺癌的标准,UE联合PSA无论是敏感性(75.0%)、特异性(85.0%)和符合率(82.1%)均高于普通经直肠超声检查联合PSA敏感性(62.5%)、特异性(15.0%)和符合率(28.6%),差异具统计学意义(P0.05)。结论 UE无痛无创,简便易行,其与PSA相结合对前列腺癌的诊断,比经直肠超声检查联合PSA更具有临床价值,值得推广。     

ROC曲线分析比较tPSA、fPSA／tPSA和PSAD在PSA灰区前列腺癌诊断中的价值

目的 ROC曲线分析探讨前列腺特异性抗原密度(PSAD)、总PSA(tPSA)和游离PSA/总PSA(fPSA/tPSA)3者在PSA灰区前列腺癌(PCa)中的临床诊断价值.方法 同顾性分析tPSA在4～10ng/ml之间的前列腺增生(BPH)患者75例和前列腺癌患者31例.化学发光法测定血清tPSA和fPSA,经直肠超声(TRUS)测定前列腺体积,计算fPSA/tPSA和PSAD.比较BPH组和PCa组间tPSA、PSAD和fPSA/tPSA各指标的差异,分析各指标在ROC曲线卜的面积、各指标的诊断特异性及敏感性.结果 PCa组与BPH组tPSA差异无统计学意义(P＞0.05),PCa组fPSA/tPSA比值较BPH组降低(P＜0.01),PSAD值较BPH组升高(P＜0.05).ROC曲线下的面积从大到小为fPSA/tPSA＞PSAD＞tPSA.在诊断敏感性相同的情况下,fPSA/tPSA比值诊断特异性高于PSAD的诊断特异性.当fPSA/tPSA临界值取0.16时,诊断前列腺癌的灵敏度和特异性为67.7%和79.7%,PSAD临界值取0.12时,其灵敏度和特异性为61.3%和62.7%.结论 当tPSA在诊断灰区时,PSAD和fPSA/tPSA可以提高前列腺癌的诊断特异性和敏感性,fPSA/tPSA较PSAD有更高的诊断价值.     

多参数MRI对PSA为4~10μg/L前列腺癌的诊断价值分析

目的:探讨联合应用磁共振成像(MRI)-T2WI、DWI和DCE-MRI检查对前列腺特异性抗原(PSA)为4~10μg/L的可疑前列腺癌人群的诊断价值。方法:回顾性分析2014年7月~2016年3月间于我院收治的PSA为4~10μg/L的242例前列腺穿刺患者的临床资料。单因素和多因素Logistic回归分析患者的年龄、体质指数(body mass index,BMI)、tPSA、游离与总PSA比值(f/tPSA)、前列腺体积(prostate volume,PV)、PSA密度(PSAD)、经直肠指检(DRE)、经直肠前列腺超声(TRUS)和MRI等指标与前列腺穿刺活检阳性的相关性,建立联合常规临床检查的Logistic回归预测模型,绘制各项指标及预测模型的受试者工作特征(receiver-operating characteristic,ROC)曲线,计算与比较MRI与其他检查的曲线下面积。结果:本组242例患者中,102(41.2%)例患者MRI判定为阳性,其中64.7%(66/102)最终经组织病理学检查诊断为前列腺癌。多因素Logistic回归分析结果显示MRI(OR:14.563;95%CI:6.363~33.329)是前列腺穿刺结果的独立预测因素(P0.05)。ROC曲线下面积MRIPSAD年龄f/tPSADREPSATRUS,依次为0.813、0.726、0.723、0.657、0.642、0.598、0.569、0.568。MRI的ROC曲线下面积显著高于其他临床指标(P0.05)。联合MRI、PSAD、f/tPSA、DRE和TRUS的Logistic回归预测模型1,其ROC曲线下面积为0.892,与不包括MRI检查的预测模型2的ROC曲线下面积0.757相比,差异具有统计学意义(P0.05)。结论:联合MR-T2WI、DWI和DCE-MRI检查有利于对PSA水平在4~10μg/L前列腺癌的早期诊断,可以明显提高预测穿刺阳性的准确性。     

MR弥散加权成像在前列腺癌诊断中的应用价值

目的 探讨MR弥散加权成像(MRDWI)在前列腺癌(PCa)诊断中的应用价值. 方法 临床怀疑PCa患者57例行MRDWI与T_2 WI检查,通过表观弥散系数(ADC)图对可疑病灶进行良恶性评判.并与穿刺或手术病理结果 进行比较,利用曲线下面积(ROC)分析比较MRDWI与T_2 WI在PCa病灶检出中的价值.同时对30例直肠指检无结节,前列腺穿刺活检阴性患者行MRDWI检查,通过ADC值将可疑病灶按照Ⅰ(良性)～Ⅴ(恶性)级标准划分,在经直肠超声横断面上对异常区域进行定位穿刺.评价以MRDWI定位再次穿刺的价值. 结果 57例患者MRDWI与T_2WI的ROC分别为0.830和0.742,MRDWI诊断敏感性为85%、特异性为82%、阳性预测值80%、阴性预测值86%、准确率为83%;T_2 WI的敏感性为77%、特异性为71%、阳性预测值69%、阴性预测值79%、准确率为74%.MRDWI诊断准确性优于TzWl(P<0.05).30例穿刺定位患者中ADC图诊断为PCa 24例(≥Ⅳ级),BPH 6例(Ⅰ～Ⅲ级).穿刺病理证实为PCa 17例(85%),以Ⅳ级为界划分良恶性,诊断敏感性100%、特异性46%、阳性预测值71%、阴性预测值100%、准确率77%.如果以至少有1个区域为V级划为恶性,则17例PCa患者中DWI诊断恶性13例,敏感性77%、特异性85%、阳性预测值87%、阴性预测值73%、准确率80%. 结论 MR弥散加权成像诊断PCa准确性优于T2加权成像,能有效提高PSA持续升高患者前列腺再次穿刺活检的检出率.     

经直肠超声造影和磁共振成像诊断前列腺癌的临床价值比较

目的:探讨经直肠超声造影(CEUS)和磁共振成像(MRI)诊断前列腺癌(PCa)有关问题,评价二者的诊断价值。方法:选取有完整相关临床资料的患者48例,对患者行前列腺超声造影及MRI检查,并与病理检查结果进行比较。结果:48例患者经病理检查证实为PCa 30例。经直肠CEUS诊断符合率为77.08%,敏感性为80.00%,与MRI的符合率(79.16%)、敏感性(76.67%)比较,差异无统计学意义(P>0.05),但其特异性(72.22%)低于MRI的特异性(83.33%),差异有统计学意义(P<0.05)。二者联合诊断的符合率为89.58%,敏感性为90.00%,特异性为88.89%,与单独一种诊断比较,差异均有统计学意义(P<0.05)。结论:经直肠CEUS及MRI对PCa的诊断各有优势,经直肠CEUS联合MRI可提高PCa的检出率。     

前列腺癌超声引导活组织检查临床价值分析

目的探讨前列腺癌采用超声引导下经直肠前列腺穿刺活组织检查诊断临床价值。方法 271例患者均行超声引导下经直肠前列腺穿刺活组织检查,220例经磁共振检查时存在疑似病灶而进行靶向穿刺,以穿刺病理活检结果为金标准,比较两组检查结果的准确性和敏感性、特异性、阳性预测值及阴性预测值。结果经穿刺病理活检检出前列腺癌检出率为50.92%(138/271)。超声引导下经直肠前列腺穿刺活组织检查检出率34.68%与磁共振疑似病灶靶向穿刺检出率45.02%比较,χ2=6.03,P=0.01。磁共振疑似病灶靶向穿刺敏感性、特异性和阳性预测值及阴性预测值均明显高于超声引导下经直肠前列腺穿刺活组织检查,P0.05。结论应用磁共振疑似病灶靶向穿刺较超声引导下经直肠前列腺穿刺活组织检查更易检出前列腺癌,但磁共振疑似病灶靶向穿刺并不能完全替代超声引导下经直肠前列腺穿刺活组织检查,可根据患者实际情况来合理选择。     

TAN贝叶斯网络模型在前列腺癌中的预测研究

目的:评价年龄、前列腺特异性抗原(PSA)以及经直肠前列腺超声影像特征构建的TAN贝叶斯网络(tree-augmented Nave Bayesian network)模型对前列腺癌的预测效果。方法:收集2008年1月至2011年9月行前列腺穿刺活检941例患者的临床数据,包括年龄、PSA、超声影像以及病理诊断,构建TAN贝叶斯网络,对前列腺癌进行预测,并与病理诊断"金标准"比较。结果:941例患者中,358例经活检证实为前列腺癌,583例为非前列腺癌性病变。TAN贝叶斯网络对前列腺癌预测的准确率为85.11%、灵敏度88.37%、特异性83.67%、阳性预测值70.37%、阴性预测值94.25%。结论:基于年龄、PSA以及经直肠前列腺超声影像构建的TAN贝叶斯网络模型对前列腺癌预测效果较好,可作为临床筛查或诊断前列腺癌的一种方法。     

经直肠超声联合弹性成像与超声造影在早期前列腺癌诊断的应用价值

目的 探讨经直肠实时组织超声弹性成像及经直肠前列腺超声造影检查技术在前列腺癌早期诊断的应用价值。方法 对119例可疑前列腺癌患者行经直肠超声成像、经直肠实时组织超声弹性成像及经直肠前列腺超声造影检查,按照经直肠超声引导下穿刺活检的病理Gleason 评分结果分为低危组（≤6分,n=21）、中危组（7分,n=24）、高危组（≥8分,n=28）、良性前列腺增生组（n=46）。分析对比各项超声技术在不同Gleason评分前列腺癌的诊断价值。结果 经直肠超声成像联合经直肠实时组织超声弹性成像及经直肠超声成像联合经直肠前列腺超声造影的诊断符合率在前列腺癌低危组与前列腺增生组之间差异无统计学意义,在前列腺癌中危组、高危组与前列腺增生组组间差异有统计学意义（P<0.05）,经直肠实时组织超声弹性成像联合经直肠前列腺超声造影诊断符合率在低危组、中危组、高危组与前列腺增生组组间均差异有统计学意义（P<0.05）,经直肠超声成像诊断前列腺癌的敏感性、特异性、阴性预测值及阳性预测值分别为46.77%、58.18%、49.23%及55.77%,经直肠实时组织超声弹性成像的敏感性、特异性、阴性预测值及阳性预测值分别为66.13%、70.91%、65.00%及71.93%,经直肠前列腺超声造影的敏感性、特异性、阴性预测值及阳性预测值分别为80.64%、81.82%、78.95%及83.33%,经直肠前列腺超声造影联合经直肠实时组织超声弹性成像的敏感性、特异性、阴性预测值及阳性预测值分别为90.32%、85.45%、88.68%及87.50%,各检查方法比较差异均有统计学意义（P<0.05）。结论 经直肠实时组织超声弹性成像和经直肠前列腺超声造影技术均在前列腺癌早期诊断中有临床价值,二者联合在Gleason评分≤6分的前列腺癌早期诊断中亦有临床应用价值。     

经直肠超声造影与经直肠常规超声诊断前列腺癌的比较研究

目的:比较经直肠超声造影与经直肠常规超声诊断前列腺癌的各自优势。方法:选择前列腺癌患者213例,年龄54~83岁,平均71岁。检测PSA为4.12~150.00μg/L,平均22.53μg/L。先行经直肠常规超声检查,再行经直肠前列腺超声造影检查,绘制时间强度曲线(TIC曲线),分别判读常规超声和超声造影结果。随后行12针前列腺系统穿刺活检。结果:213例患者中,常规超声诊断前列腺癌123例,超声造影诊断前列腺癌113例,穿刺活检病理确诊前列腺癌99例。常规超声与病理检查的诊断符合率为53.52%,超声造影与病理检查的诊断符合率为80.28%。两种诊断方法敏感度、特异度、假阳性率、假阴性率、漏诊率、病理检查符合率差异均有统计学意义(P0.05)。结论:经直肠超声造影可灵敏显示前列腺血流分布情况,对前列腺癌的诊断有较高的准确性,值得推广使用。     

An algorithm for prostate cancer detection in a patient population using prostate-specific antigen and prostate-specific antigen density

Summary Prostate-specific antigen (PSA) is the most accurate serum marker for cancer of the prostate (CaP). However, its sensitivity and specificity are suboptimal, especially at values ranging between 4.1 and 10.0 ng/ml (monoclonal), because benign prostatic hypertrophy and hyperplasia (BPH) and CaP frequently coexist in this range. This study was undertaken to determine the value of incorporating prostate volume measurements with serum PSA levels in a quotient (PSA/volume) entitled PSA density (PSAD). A total of 3140 patients were analyzed and stratified by serum PSA, digital rectal examination (DRE), transrectal prostate ultrasound (TRUS), TRUS volume determination and PSAD. All patients were referred for evaluation and therefore do not represent a screened population. Patients underwent prostate biopsies when abnormalities in TRUS or DRE were detected. Although both PSA and PSAD have statistical significance when the serum PSA value is 4.0 ng/ml, neither has clinical significance in differentiating BPH from CaP. At serum levels ranging between 4.1 and 10.0 ng/ml, PSA has no ability to differentiate BPH from CaP, whereas PSAD does so with statistical and clinical significance. When the PSA value is between 10.1 and 20.0 ng/ml, only PSAD is statistically significant. When PSA exceeds 20 ng/ml, PSAD is redundant. We conclude that all patients with an abnormality on DRE or TRUS should undergo prostate biopsy. If the PSA value is 4.0 ng/ml, TRUS and PSAD are not warranted and routine biopsy is not recommended. For intermediate PSA levels, 4.1–10.0 ng/ml, TRUS, TRUS prostate volume, and PSAD are important. The use of PSAD provides unique information regarding the need for biopsy and the likelihood of CaP. At PSA levels ranging between 10.1 and 20.0 ng/ml, PSAD will identify those patients who are less likely to have CaP, but all should undergo biopsy. If the PSA value is >20 ng/ml, all patients should undergo a biopsy.     

Usefulness of MRI prior to prostate needle biopsy in PSA gray zone

To evaluate the diagnostic accuracy of prostate magnetic resonance imaging (MRI), we compared MRI findings with the results of biopsy as well as findings from specimens following total prostatectomy. The subjects consisted of 260 males who showed a prostate specific antigen (PSA) level in the gray zone (4 ng/ml ≤PSA <10 ng/ml) and also underwent digital rectal examination (DRE), transrectal ultrasound (TRUS), and MRI prior to prostate biopsy between April 2005 and December 2009. In Evaluation 1, the results of DRE/TRUS/MRI were compared with those of prostate biopsy. The biopsy-positive rate was higher in males positive in each examination. However, 24.8% of males negative in all examinations were biopsypositive. Thus, these examinations were considered to be inappropriate for secondary screening. In evaluation 2, the prostate was divided into 4 regions, and the findings from specimens following total prostatectomy were compared with MRI findings in each region. For the region containing prostate cancer, MRI showed a sensitivity of 26.0%, specificity of 98.3%, positive predictive value of 96.2%, and negative predictive value of 44. 4%. In patients with a Gleason score ≥7, cancer foci were more frequently detectable using MRI. MRI prior to prostate biopsy in patients in the PSA gray zone is inappropriate for secondary screening due to its low sensitivity. However, by virtue of its high positive predictive value, MRI is useful for determining patients indicated for biopsy, as well as DRE and TRUS. Accurate evaluation of the localization of all cancer lesions is difficult using MRI. However, when MRI findings are present, they frequently indicate the cancer lesion, which may be useful information for treatment.     

Use of serial multiparametric magnetic resonance imaging in the management of patients with prostate cancer on active surveillance

IntroductionWe evaluated the performance of multiparametric prostate magnetic resonance imaging (mp-MRI) and MRI/transrectal ultrasound (TRUS) fusion–guided biopsy (FB) for monitoring patients with prostate cancer on active surveillance (AS).Materials and methodsPatients undergoing mp-MRI and FB of target lesions identified on mp-MRI between August 2007 and August 2014 were reviewed. Patients meeting AS criteria (Clinical stage T1c, Gleason grade≤6, prostate-specific antigen density≤0.15, tumor involving≤2 cores, and≤50% involvement of any single core) based on extended sextant 12-core TRUS biopsy (systematic biopsy [SB]) were included. They were followed with subsequent 12-core biopsy as well as mp-MRI and MRI/TRUS fusion biopsy at follow-up visits until Gleason score progression (Gleason≥7 in either 12-core or MRI/TRUS fusion biopsy). We evaluated whether progression seen on mp-MRI (defined as an increase in suspicion level, largest lesion diameter, or number of lesions) was predictive of Gleason score progression.ResultsOf 152 patients meeting AS criteria on initial SB (mean age of 61.4 years and mean prostate-specific antigen level of 5.26 ng/ml), 34 (22.4%) had Gleason score≥7 on confirmatory SB/FB. Of the 118 remaining patients, 58 chose AS and had at least 1 subsequent mp-MRI with SB/FB (median follow-up = 16.1 months). Gleason progression was subsequently documented in 17 (29%) of these men, in all cases to Gleason 3+4. The positive predictive value and negative predictive value of mp-MRI for Gleason progression was 53% (95% CI: 28%–77%) and 80% (95% CI: 65%–91%), respectively. The sensitivity and specificity of mp-MRI for increase in Gleason were also 53% and 80%, respectively. The number needed to biopsy to detect 1 Gleason progression was 8.74 for SB vs. 2.9 for FB.ConclusionsStable findings on mp-MRI are associated with Gleason score stability. mp-MRI appears promising as a useful aid for reducing the number of biopsies in the management of patients on AS. A prospective evaluation of mp-MRI as a screen to reduce biopsies in the follow-up of men on AS appears warranted.     

经直肠超声引导下“10+X”点法前列腺穿刺活检术在PSA值介于4～20ng/ml之间患者前列腺癌诊断中的价值

目的 探讨经直肠超声引导下“10 +X”前列腺穿刺活检术在PSA值介于4 ～20ng/ml之间患者前列腺癌诊断中的价值。方法 回顾性分析226例血清PSA值介于4～20ng/ml之间疑似前列腺癌患者临床资料,所有患者均行经直肠超声引导下前列腺穿刺术活检。结果 前列腺癌47例,前列腺增生158例,前列腺炎11例,前列腺上...     

The progress in diagnostic imaging for staging of bladder and prostate cancer: endorectal magnetic resonance imaging and magnetization transfer contrast]

We retrospectively studied the staging accuracy of endorectal magnetic resonance imaging (MRI) in comparison with transrectal ultrasound examination (TRUS) for 71 localized bladder cancers and 19 localized prostate cancers (PC) radically resected. The accuracy of clinical staging for bladder cancer in endorectal MRI and TRUS was 85.9% and 69.2%, respectively. The presence or absence of the continuity of submucosal enhancement on T2-weighted MRI images could be useful for the staging of bladder cancer. The accuracy of the seminal vesicular invasion for prostate cancer in endorectal MRI and TRUS was 95% and 63%, respectively. To determine whether magnetization transfer contrast (MTC) provides additional information in the diagnosis of prostate cancer, the magnetization transfer ratios (MTRs) were calculated in 22 patients with PC, 5 with benign prostatic hyperplasia (BPH) and 4 controls. The mean MTR in the peripheral zone of the normal prostate (8.0% +/- 3.4 [standard deviation]) showed a statistically significant decrease relative to that in the inner zone of the normal prostate (27.4% +/- 3.4, p < 0.01), BPH (25.5% +/- 3.7, p < 0.01), pre-treatment PC (30.6% +/- 5.9, p < 0.01), and PC after hormonal therapy (20.3% +/- 6.3, p < 0.01). The mean MTR in pre-treatment PC was significantly higher than that in BPH, or in PC after hormonal therapy (p < 0.01). MTC was considered to be useful for conspicuity of prostate cancer lesion.     

Patient selection determines the prostate cancer yield of dynamic contrast-enhanced magnetic resonance imaging-guided transrectal biopsies in a closed 3-Tesla scanner

OBJECTIVE

To evaluate the cancer yield of transrectal prostate biopsies in a 3‐T magnetic resonance imaging (MRI) scanner in patients with elevated prostate specific antigen (PSA) levels and recent negative transrectal ultrasonography (TRUS)‐guided prostate biopsies.

PATIENTS AND METHODS

Between July 2004 and November 2005, patients with at least one previous negative prostate biopsy within the previous 12 months had MRI‐guided biopsy of the prostate in a 3‐T MRI scanner. Patients with previous positive biopsies for cancer were excluded. Target selection was based on T2‐weighted imaging and dynamic contrast‐enhanced (DCE) imaging studies.

RESULTS

Thirteen patients were eligible; their median (range) age was 61 (47–74) years and PSA value 4.90 (1.3–12.3) ng/mL. Most patients had one previous negative biopsy (range 1–4). Four patients had a family history of prostate cancer. There were 37 distinct targets based on T2‐weighted imaging. Fifteen of 16 distinct DCE abnormalities were co‐localized with a target based on T2‐weighted imaging. Despite this correlation, only one of 13 patients had a directed biopsy positive for cancer. Including systematic biopsies, two of 13 patients had a biopsy positive for prostate cancer. One patient had prostate intraepithelial neoplasia and one had atypical glands in the specimen.

CONCLUSION

The prostate‐cancer yield of transrectal biopsies in a 3‐T MRI scanner, among patients with recent negative TRUS‐guided prostate biopsies, is similar to repeat systematic TRUS‐guided biopsy. DCE correlates with T2‐imaging but does not appear to improve prostate cancer yield in this population.     

PCA3联合mMRI在前列腺癌诊断中的意义

目的探讨前列腺癌基因3（prostate cancer gene 3,PCA3）和多参数磁共振成像（multiparametric magnetic resonance imaging,mMRI）对前列腺癌的诊断意义。方法对56例首次穿刺结果为阴性但PSA持续升高的患者在第二次穿刺活检之前行PCA3和mMRI检查。评估PCA3评分和mMRI对前列腺癌诊断的准确性和可靠度及其对前列腺穿刺结果的预测性。结果 mMRI结果显示20例（35.7%）患者具有前列腺癌特征;PCA3评分（截断值为35时）显示15例（26.8%）患者疑为前列腺癌;前列腺穿刺活检结果显示23例（41.1%）患者确诊为前列腺癌。PCA3和mMRI对前列腺癌诊断的敏感性和特异性分别为67%、49%及74%、89%。结论 mMRI增加了PCA3对前列腺癌诊断的准确性和敏感性,可以减少不必要的前列腺穿刺。     

Prediction of prostate volume based on total and free serum prostate-specific antigen: is it reliable?

OBJECTIVE: To analyze the utility of total/free prostate-specific antigen (PSA) and age as predictors of the prostate volume in men with symptomatic benign prostatic hyperplasia (BPH) and no evidence of prostate cancer. PATIENTS AND METHODS: Total and free serum PSA were determined in 681 patients with normal digital rectal examination and symptomatic BPH using the Hybritech method. Prostate volume was measured by transrectal ultrasound (TRUS). TRUS-guided biopsy was performed in 459 (67.4%) of the patients with a serum PSA >4.0 ng/ml. RESULTS: The relationship with prostate volume was best described in a log linear fashion by free PSA (R(2) = 0.367), total PSA (R(2) = 0.264) and age (R(2) = 0.017). Multiple linear regression demonstrates no significant influence of age. Free PSA was able to predict the individual TRUS prostate volume +/-10% in 67% of the patients and +/-20% in 91.2% and total PSA in 63 and 90. 9%, respectively. CONCLUSION: Prostate volume is strongly related with free and total PSA. Both determinations would be able to predict the TRUS prostate volume +/-20% in more than 90% of the patients.