PD17-03: Comparative analyses of Micro-ultrasound versus MRI-targeted biopsy for the diagnosis of clinically significant prostate cancer. Preliminary results from the prospective US-MIRROR Trial.

Simone Scuderi*, Armando Stabile, Gabriele Sorce, Mario De Angelis, Luigi Nocera, Francesco Pellegrino, Francesco Barletta, Milan, Italy, Andrea Salonia, Milano, Italy, Giuseppe Cirulli, Milan, Italy, Lucia D’Ambrosio, Milano, Italy, Giorgio Gandaglia, Vito Cucchiara, Elio Mazzone, Giuseppe Rosiello, Milan, Italy, Riccardo Leni, Donato Cannoletta, Milano, Italy, Antony Pellegrino, Milan, Italy, Nicola Fossati, Lugano, Switzerland, Shahrokh Shariat, Vienna, Austria, Francesco Montorsi, Alberto Briganti, Milan, Italy

Introduction: There is currently increasing interest on the use of micro-ultrasound (micro-US) as new imaging modality approach in the diagnosis of prostate cancer (PCa). However, current evidence is limited by the fact that most studies testing this novel technique have been performed only men with lesion already visible at multi-parametric (mp-MRI). In this prospective paired-cohort trial, we aimed at performing a head-to-head comparison between micro-US and mpMRI for the diagnosis of clinically significant PCa (csPCa) in a population of men with clinical suspicion of PCa.

Methods: This is a prospective, single center paired-cohort trial (NCT04832997). After Ethical approval, each patient received both mpMRI and micro-US in a randomized sequence followed by systematic prostate biopsy plus mpMRI and/or micro-US targeted biopsy. Each mpMRI was centrally performed by an experienced radiologist that was blinded for micro-US result. We compared the diagnostic accuracy of micro-US versus mpMRI in detecting csPCa (defined as PCa with Gleason score = 7) in terms of sensitivity, specificity, negative (NPV) and positive (PPV) predictive values.

Results: Since October 2020, 85 men were enrolled in the study. Overall, 64 men with clinical suspicion of PCa received both micro-US and mpMRI. The two tests were either both negative or positive in 28/64 patients (43%) of men while discordance between the two tests was reported in the remaining 36/64 patients (57%). Overall, 73% and 48% of men had a positive micro-US and a positive mpMRI, respectively. Among those 32 men who completed the study receiving prostate biopsy, 47% and 28% of men were diagnosed with PCa and csPCa, respectively. Sensitivity, specificity, PPV and negative NPV of micro-US vs mpMRI for csPCa were 67% vs 100%, 57% vs 57%, 38% vs 47% and 81% vs 100%, respectively. Micro-US increased the detection of clinically insignificant PCa by 6% while mpMRI allowed to increase the detection of csPCa by 9%.

Conclusions: Our preliminary results showed that the accuracy of micro-US for the detection of csPCa detection was lower as compared to mpMRI. Further evidence is needed to support these preliminary results.

Source of Funding: None.