Role of magnetic resonance imaging in defining a biopsy strategy for detection of prostate cancer

Prostate cancer is the second most common male cancer worldwide. It has a broad spectrum, from low‐risk, clinically indolent disease, to high‐risk aggressive cancer. This variety conveys certain diagnostic and management challenges. The use of prostate‐specific antigen as a screening test for prostate cancer is increasing the diagnosis of low‐grade, low‐volume disease. By targeting biopsies towards suspicious areas on multiparametric magnetic resonance imaging, we can accurately diagnose clinically significant prostate cancer, reducing identification of low‐risk, clinically indolent disease. This could avoid the radical treatment of histopathological cancer that might never have become clinically apparent. In the present review, we consider the use of multiparametric magnetic resonance imaging to inform the biopsy strategy. By identification of suspicious lesions on multiparametric magnetic resonance imaging, biopsy targets can be identified, and the sampling bias associated with blind standard transrectal prostate biopsy can be reduced. We consider the reliability of these radiological lesions for detection of clinically significant prostate cancer, and the methods of targeting them to ensure the radiological lesion is accurately sampled. Evidence suggests that targeted biopsy is efficient and accurate for diagnosis of clinically significant prostate cancer. By rationalizing diagnosis, and subsequently preventing overtreatment of clinically insignificant disease, magnetic resonance imaging‐informed prostate biopsy can provide a method for streamlining the diagnostic pathway in prostate cancer.     

Targeted prostate biopsy： value of multiparametric magnetic resonance imaging in detection of localized cancer

Prostate cancer is the second most common cancer in men, with 1.1 million new cases worldwide reported by the World Health Organization in one recent year. Transrectal ultrasound （TRUS）-guided biopsy has been used for the diagnosis of prostate cancer for over 2 decades, but the technique is usually blind to cancer location. Moreover, the false negative rate of TRUS biopsy has been reported to be as high as 47%. Multiparametric magnetic resonance imaging （mp-MRI） includes T1- and T2-weighted imaging as well as dynamic contrast-enhanced （DCE） and diffusion-weighted imaging （DWI）. mp-MRI is a major advance in the imaging of prostate cancer, enabling targeted biopsy of suspicious lesions. Evolving targeted biopsy techniquesmincluding direct in-bore biopsy, cognitive fusion and software-based MRI-ultrasound （MRI-US） fusion--have led to a several-fold improvement in cancer detection compared to the earlier method. Importantly, the detection of clinically significant cancers has been greatly facilitated by targeting, compared to systematic biopsy alone. Targeted biopsy via MRI-US fusion may dramatically alter the way prostate cancer is diagnosed and managed.     

经直肠实时弹性成像引导靶向穿刺在前列腺病变的应用价值研究

［摘要］ 目的 本研究主要探讨经直肠实时弹性成像（TRTE）引导靶向穿刺在前列腺病变中的应用价值。方法 对符合纳入标准的112例可疑前列腺癌患者进行经直肠前列腺超声检查,在TRTE引导下对可疑病灶进行2针靶向穿刺活检及超声引导下传统12针系统穿刺活检。分析TRTE对前列腺良恶性病变诊断效能及比较TRTE引导下靶向穿刺与系统穿刺诊断的准确性。结果 本研究112例患者中,TRTE共诊断前列腺癌54例,良性病变58例,最终病理确诊前列腺癌42例,良性病变70例,诊断的灵敏度、特异度、准确度、阳性预测值、阴性预测值分别为88.1%、75.7%、80.3%、0.68、0.91。TRTE引导靶向穿刺诊断前列腺癌针数84针,阳性率37.5%（84/224）,系统穿刺诊断前列腺癌针数313针,阳性率23.3%（313/1344）,二者具有统计学差异,χ2=4.08,P<0.05。同时行靶向加系统穿刺诊断前列腺癌针数397针,阳性率25.3%（397/1568）。结论 TRTE在前列腺病变诊断中具有较高的灵敏度、特异度、准确度。利用TRTE引导靶向穿刺诊断Pca拥有比系统穿刺更高的准确性,但就目前来讲TRTE引导靶向穿刺尚无法完全取代系统穿刺法,而两者相结合是减少前列腺癌穿刺假阴性率的主要方案。     

超声引导下12+x针前列腺穿刺活检单中心407例临床分析

目的:分析单中心超声引导下12+x针前列腺穿刺活检结果,比较不同穿刺途径的临床效果。方法:回顾分析2016年6月~2019年12月我院完成的407例前列腺穿刺活检的临床资料,经直肠前列腺穿刺290例(经直肠组),经会阴前列腺穿刺117例(经会阴组),均采用超声引导下12+x针法,前列腺影像学正常者行系统穿刺,影像学异常者行系统+靶向穿刺。比较两组前列腺癌(PCa)的检出率及并发症差异,分析两组按PSA、影像学分层PCa检出率的差异,比较靶向穿刺与系统穿刺癌检出率的差异,分析临床有意义前列腺癌(csPCa)的检出情况。结果:(1)PCa总检出率为44.0%(179/407),经直肠组与经会阴组PCa检出率比较差异无统计学意义[44.8%(130/290)vs.41.9%(49/117),P>0.05]。其中,PSA≤4 ng/mL、4 ng/mL20 ng/mL各水平分层中,两组PCa检出率比较差异无统计学意义(P>0.05)。两组中前列腺影像学异常者的PCa检出率均高于影像学正常者(P<0.05)。影像学异常者中,经直肠组与经会阴组PCa检出率比较差异无统计学意义(P>0.05)。(2)前列腺影像学异常者总的PCa检出率为57.5%(111/193),靶向穿刺PCa检出率为42.0%(81/193),系统穿刺为47.7%(92/193),两者比较差异无统计学意义(P>0.05),但靶向穿刺单针阳性率比系统穿刺更高(P<0.01)。同一途径下的靶向穿刺与系统穿刺PCa检出率比较差异无统计学意义(P>0.05)。两组中分别比较靶向穿刺、系统穿刺的PCa检出率,差异均无统计学意义(P>0.05)。(3)在所有患者中,经直肠途径csPCa检出率为36.9%(107/290),经会阴途径csPCa检出率为40.2%(47/117),两者比较差异无统计学意义(P>0.05)。靶向穿刺与系统穿刺在csPCa的检出率上比较差异无统计学意义。csPCa在诊断出的PCa患者中的占比,经会阴途径占比高于经直肠途径[95.9%(47/49)vs.82.3%(107/130),P<0.05]。(4)经直肠组总并发症发生率显著高于经会阴组[39.3%(114/290)vs.20.5%(24/117),P<0.01]。经直肠组发热、血便发生率比经会阴组更高,分别为[10.3%(30/290)vs.3.4%(4/117),P<0.05]、[14.1%(41/290)vs.1.7%(2/117),P<0.01],两组在血尿、下尿路症状、尿潴留、迷走反射发生率上比较差异均无统计学意义(P>0.05)。结论:超声引导下12+x针前列腺穿刺活检PCa检出率较好,影像学异常者靶向穿刺与系统穿刺PCa、csPCa检出率差异均无统计学意义,靶向穿刺单针阳性率较高。经直肠途径与经会阴途径在PCa、csPCa检出率比较差异无统计学意义,经会阴途径并发症更少。在诊断出的PCa中,经会阴途径可检出更多的csPCa。     

The rapid assessment for prostate imaging and diagnosis (RAPID) prostate cancer diagnostic pathway

Objective

To report outcomes within the Rapid Assessment for Prostate Imaging and Diagnosis (RAPID) diagnostic pathway, introduced to reduce patient and healthcare burdens and standardize delivery of pre-biopsy multiparametric magnetic resonance imaging (MRI) and transperineal biopsy.

Patients and Methods

A total of 2130 patients from three centres who completed the RAPID pathway (3 April 2017 to 31 March 2020) were consecutively entered as a prospective registry. These patients were also compared to a pre-RAPID cohort of 2435 patients. Patients on the RAPID pathway with an MRI score 4 or 5 and those with PSA density ≥0.12 and an MRI score 3 were advised to undergo a biopsy. Primary outcomes were rates of biopsy and cancer detection. Secondary outcomes included comparison of transperineal biopsy techniques, patient acceptability and changes in time to diagnosis before and after the introduction of RAPID.

Results

The median patient age and PSA level were 66 years and 6.6 ng/mL, respectively. Biopsy could be omitted in 43% of patients (920/2130). A further 7.9% of patients (168/2130) declined a recommendation for biopsy. The percentage of biopsies avoided among sites varied (45% vs 36% vs 51%; P < 0.001). In all, 30% (221/742) had a local anaesthetic (grid and stepper) transperineal biopsy. Clinically significant cancer detection (any Gleason score ≥3 + 4) was 26% (560/2130) and detection of Gleason score 3 + 3 alone constituted 5.8% (124/2130); detection of Gleason score 3 + 3 did not significantly vary among sites (P = 0.7). Among participants who received a transperineal targeted biopsy, there was no difference in cancer detection rates among local anaesthetic, sedation and general anaesthetic groups. In the 2435 patients from the pre-RAPID cohor, time to diagnosis was 32.1 days (95% confidence interval [CI] 29.3–34.9) compared to 15.9 days (95% CI 12.9–34.9) in the RAPID group. A total of 141 consecutive patient satisfaction surveys indicated a high satisfaction rate with the pathway; 50% indicated a preference for having all tests on a single day.

Conclusions

The RAPID prostate cancer diagnostic pathway allows 43% of men to avoid a biopsy while preserving good detection of clinically significant cancers and low detection of insignificant cancers, although there were some centre-level variations.     

Other biomarkers for detecting prostate cancer

Prostate‐specific antigen (PSA) has been used for detecting prostate cancer since 1994. Although it is the best cancer biomarker available, PSA is not perfect. It lacks both the sensitivity and specificity to accurately detect the presence of prostate cancer. None of the PSA thresholds currently in use consistently identify patients with prostate cancer and exclude patients without cancer. Novel approaches to improve our ability to detect prostate cancer and predict the course of the disease are needed. Additional methods for detecting prostate cancer have been evaluated. Despite the discovery of many new biomarkers, only a few have shown some clinical value. These markers include human kallikrein 2, urokinase‐type plasminogen activator receptor, prostate‐specific membrane antigen, early prostate cancer antigen, PCA3, α‐methylacyl‐CoA racemase and glutathione S‐transferase π hypermethylation. We review the reports on biomarkers for prostate cancer detection, and their possible role in the clinical practice.     

Current status of magnetic resonance imaging (MRI) and ultrasonography fusion software platforms for guidance of prostate biopsies

Prostate MRI is currently the best diagnostic imaging method for detecting PCa. Magnetic resonance imaging (MRI)/ultrasonography (US) fusion allows the sensitivity and specificity of MRI to be combined with the real‐time capabilities of transrectal ultrasonography (TRUS). Multiple approaches and techniques exist for MRI/US fusion and include direct ‘in bore’ MRI biopsies, cognitive fusion, and MRI/US fusion via software‐based image coregistration platforms.     

A risk index for prostate cancer

BACKGROUND: The aim of the present study was to create a simple numerical index predicting the presence of prostate cancer in a group of high risk patients, for the purpose of selecting those most likely to need prostate biopsy. METHODS: 100 consecutive patients at high risk of having prostate cancer seen at Ramathibodi Hospital, Thailand between November 2000 and February 2002 were prospectively studied. All patients underwent transrectal prostate biopsies. The following predictor variables were obtained: age, digital rectal examination (DRE) findings, prostate specific antigen level, transrectal ultrasonography (TRUS) findings, and prostate volume determined by TRUS. The outcome was the presence of prostate cancer on histological examination of the biopsy specimens. A risk index for prostate cancer based on the linear predictor of a multiple logistic regression model was created. RESULTS: Almost all predictor variables were significantly related to the presence of prostate cancer. The final multiple logistic regression model with four categorized predictors (excluding DRE) was shown to have good discrimination, calibration, and cross-validity. For a cutoff risk index of 10, corresponding to a 10% probability of having prostate cancer, the sensitivity for detecting prostate cancer was 96.2%, with a specificity of 73.0%. Based on this cutoff, 55% of patients in this series might not require prostate biopsy. CONCLUSION: A risk index for prostate cancer was developed. If this index can be externally validated, the potential savings from avoiding unnecessary prostate biopsies, on the basis of selection using the index, could be significant.