Microultrasound in the detection of the index lesion in prostate cancer

Abstract

Introduction and ObjectiveThe natural progression of prostate cancer is primarily driven by an index lesion (IL). Studies have shown that different metastases within the same patient arise from a single precursor cell. Therefore, our aim is to assess the effectiveness of transrectal microultrasound (MUS) in comparison to multiparametric magnetic resonance imaging (mpMRI) for detecting the IL in prostate cancer. We used quarter‐mount pathological results as the reference standard for this evaluation.Materials and MethodsThree hundred and sixty‐three patients who underwent Robot‐Assisted Radical Prostatectomy (RARP) from June 2021 to August 2022 were included. All received mpMRI and MUS before RARP. MUS was performed by experienced operators blinded to mpMRI and biopsy results. The IL in the radical prostatectomy specimen was defined as the lesion with extraprostatic extension, the highest Grade Group (GG), or the largest tumor volume if the GG was the same. The correlation between imaging and final pathology findings was performed. A descriptive statistical analysis is presented.ResultsThe patients' prostates were analyzed in 12 regions (anterior/posterior, right/left, apex/mid/base). A total of 4308 regions were identified. Of these, 935 were involved by the ILs. Compared with final pathology, MUS demonstrated a sensitivity, specificity, PPV, and NPV of 68.7%, 96.3%, 80.8%, and 93.1%, respectively, while mpMRI showed a sensitivity, specificity, PPV, and NPV of 68.6%, 97.2%, 86.1%, and 92.5%, respectively, for the detection of the IL. Most of the lesions missed by MUS were located in the anterior zone (62%).ConclusionMUS exhibits a diagnostic performance similar to mpMRI when it comes to detecting the IL in prostate cancer. MUS is a cost‐effective option, offers real‐time evaluation, and has no delay in the acquisition process.

Inter-reader Agreement for Prostate Cancer Detection Using Micro-ultrasound: A Multi-institutional Study

“…only included two anterior cases (6%), which were the only two lesions missed. This is consistent with findings that up to 62% of lesions missed on MUS are in the anterior zone, probably owing to the heterogeneous appearance of the transition zone, sources of artifacts such as periurethral calcifications and corpora amylaceae, and overall signal attenuation at greater tissue depths [9] . The PRI-MUS protocol was only recently updated to include criteria for localizing anterior lesions, and the update has yet to undergo prospective external validation [27] .…”

“…First, we did not prospectively biopsy reader-outlined targets owing to the multireader study design. Additional biopsy of these targets may have increased detection because of the multifocality of PCa [9] . However, all patients in our study underwent thorough 14-core systematic transperineal biopsy that included additional targeted cores from MRI-visible lesions, and thus it is likely that the presence of undetected GG ≥2 lesions was low.…”

“…MUS may differentiate PCa from normal tissue, which could allow live targeted biopsy. Preliminary evidence has shown that MUS has comparable sensitivity to mpMRI at high-volume centers, but consistency between users has yet to be described [9] , [10] , [11] . Variability in image interpretation is a known limitation of mpMRI [12] , [13] , [14] .…”

A Comparative Evaluation of Multiparametric Magnetic Resonance Imaging and Micro-Ultrasound for the Detection of Clinically Significant Prostate Cancer in Patients with Prior Negative Biopsies

“…This highlights the necessity of a balanced application of these imaging techniques and the careful interpretation of results within the broader clinical context. However, the diagnostic accuracy observed in our analysis concurs with the performance of mUS reported in other patient cohorts, including those who are biopsy-naïve, thereby reinforcing the consistency and reliability of mUS across diverse clinical settings [40,41]. In addition to this, the accuracy reported for mpMRI, although slightly lower, aligns with prior studies conducted on biopsy-naïve patients [42] This might highlight the very challenging management of patients with a history of a prior negative biopsy, where consolidated imaging methodologies might present limitations, therefore reinforcing the importance of a specific focus on this cohort to maximize their diagnostic pathway.…”