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.     

MRI/US成像融合引导的经会阴前列腺穿刺活检的单中心研究

目的:评估磁共振/超声(MRI/US)成像融合引导的经会阴前列腺穿刺活检对前列腺癌诊断的价值。方法:回顾性分析2014年9月~2016年3月我院行MRI/US成像融合引导的经会阴前列腺穿刺活检的121例患者资料,每例均行12针系统性穿刺活检(SB)+每个目标靶点(ROI)2针靶向穿刺活检(TB)。活检标本行病理学分析,获知Gleason评分和阳性单针癌组织长度。记录所有患者的临床、影像及病理资料,采用t检验、秩和检验、卡方检验等统计学方法对各项数据进行分析对比。结果:TB的前列腺癌单针阳性率(20.0%)以及高危前列腺癌单针阳性率(10.3%)均明显高于SB(12.7%和5.5%),差异均有统计学意义(P=0.001和P=0.002);TB的阳性单针癌组织长度高于SB,差异有统计学意义(P=0.046);TB的阳性针癌组织主要分化程度的Gleason评分、次要分化程度的Gleason评分、Gleason总评分均高于SB,但差异无统计学意义(P>0.05)。结论:MRI/US成像融合引导的前列腺穿刺活检中的TB较SB能够更有效地检出高危前列腺癌。在条件允许的情况下可推广应用MRI/US成像融合引导的前列腺穿刺活检技术。     

Technique for a hybrid system of real‐time transrectal ultrasound with preoperative magnetic resonance imaging in the guidance of targeted prostate biopsy

Diagnostic magnetic resonance imaging (MRI) for prostate has achieved increasingly higher levels of accuracy. Because real‐time MR‐guided targeted biopsy is still a complicated and expensive procedure, there is considerable interest in a technique of MR/transrectal ultrasound (TRUS) hybridized image‐guided biopsy. However, because the 3‐D shapes of the prostate at the time of image‐acquisition at preoperative MRI are likely to be different from the intra‐operative TRUS images, the precise registration of each 3‐D volume data is critical. To reduce the potential errors in registration of TRUS with MRI, we introduce new procedural techniques in a rigid image fusion technique. First, preoperative MR images were obtained with a specifically‐made plastic outer‐frame, with exactly the same shape as the real TRUS probe, placed in the rectum, in order to simulate the deformation of the prostate caused by the absence or presence of a TRUS probe during the acquisition of MR or TRUS images. Second, instead of using a single plane of longitudinal image, we applied biplane TRUS images to be shown in parallel on a multiplanar display with corresponding reconstructed MRI, in order to register both horizontal and longitudinal images of the prostate simultaneously, thereby achieving improved 3‐D anatomical matching.     

The clinical impact of Prostate Imaging–Reporting and Data System classification in patients with haemospermia undergoing multiparametric magnetic resonance imaging of the prostate

In this study, we evaluated the role of the Prostate Imaging–Reporting and Data System (PI-RADS) classification of multiparametric magnetic resonance imaging (mpMRI) to determine the likelihood of prostate cancer (PCa) in patients with haemospermia. Fifty-one patients presenting with haemospermia between 2018 and 2020 were included in this retrospective study. Forty-two of the patients (82.4%) were over 40 years, and the median prostate-specific antigen (PSA) level was 1.4 ng/ml. Fourteen of the patients (27.5%) had recurrent haemospermia. All patients underwent mpMRI, and assessments were classified according to PI-RADS v2. The mpMRI revealed PI-RADS one to four lesions in 10 (19.6%), 30 (58.8%), 6 (11.8%) and 5 (9.8%) patients respectively. One patient with PI-RADS 3 and five with PI-RADS 4 lesions underwent cognitive fusion prostate biopsy depending on MRI findings, and two patients with PI-RADS 4 lesions were diagnosed with PCa. Patients with haemospermia and risk factors, that is aged over 40 years, a high PSA level or familial history of PCa, need a more thorough evaluation with mpMRI.