Role of transrectal ultrasonography (TRUS) in focal therapy of prostate cancer: report from a Consensus Panel

Abstract

What's known on the subject? and What does the study add? Focal therapy techniques are emerging in prostate cancer treatment. However, several key questions about patient selection, treatment and monitoring still have to be addressed. The concept of focal therapy is barely discussed in current urological guidelines. In the present manuscript, we report the results of a consensus meeting focused on ultrasonography, the most common used urological imaging method, in relation to focal therapy of prostate cancer. To establish a consensus on the utility of ultrasonography (US) to select patients for focal therapy. Topics were the current status of US to determine focality of prostate cancer, to monitor and assess outcome of focal therapy and the diagnostic advantages of new US methods. In addition, the biopsy techniques required to identify focal lesions were discussed. Urological surgeons, radiation oncologists, radiologists, and basic researchers from Europe and North America participated in a consensus meeting on the use of transrectal US (TRUS) in focal therapy of prostate cancer. The consensus process was face‐to‐face and specific clinical issues were raised and discussed with agreement sought when possible. TRUS is commonly used and essential for diagnosing men with prostate cancer. It is particularly useful for targeting specific anatomical regions or visible lesions. However, it has several limitations and there is a need for improvement. Newer visualisation techniques, e.g. colour Doppler US, contrast‐enhanced US and elastography, are being developed but currently there is no US technique that can accurately characterise a cancer suitable for focal therapy. Systematic biopsy is the only known procedure that allows the identification of prostate cancers suitable for focal therapy. Scarce data exist about the role of US for monitoring patients during or after ablative therapy. Consensus was reached on all key aspects of the meeting. US cannot reliably identify focal prostate cancer. New US methods show promising results in identifying prostate cancer focality. Currently selecting appropriate candidates for focal therapy should be performed using dedicated protocols and biopsy schemes.

Comparison of Real-Time Elastography and Multiparametric MRI for Prostate Cancer Detection: A Whole-Mount Step-Section Analysis

“…These patients then may undergo multiparametric MRI to achieve the high sensitivity of the combined approach as found in this study. If lesions suspicious for being prostate cancer are found at multiparametric MRI, they can be biopsied with multiparametric MRI targeting or with cognitive or technical fusion by means of ultrasound [26][27][28].…”

Trans-rectal ultrasound visibility of prostate lesions identified by magnetic resonance imaging increases accuracy of image-fusion targeted biopsies

“…sPCa was defined as biopsy Gleason score ≥7 and/or maximum cancer core length ≥5 mm. appear hypo-echoic, which therefore is not a specific sign of cancer [1,3,4].…”

“…Emerging data indicate that, depending on the clarity of MR findings, MR-TRUS image-fusion targeted biopsies may better diagnose higher grade and/or higher volume cancer compared to systematic random biopsies, while utilizing fewer cores [5,6,10]. As mentioned above, TRUS examination can often identify multiple hypo-echoic areas within the prostate which, in fact, ultimately turn out to be non-cancerous on needle biopsy [1,3,4]. However, if mp-MR identifies a highly suspicious prostate lesion, fusion of that stored MR image with the real-time TRUS image may indicate which specific hypo-echoic TRUS lesion best corresponds with the suspected lesion on mp-MR, and should therefore be targeted for TRUS-biopsy.…”

MRI-TRUS fusion for electrode positioning during irreversible electroporation for treatment of prostate cancer

“…However, prostate cancer often cannot be sufficiently visualized by TRUS alone. Thus, for planning of the target volume ultrasound imaging alone may be insufficient, even if the location of prostate cancer is known from previous multiparametric MRI (14).…”