P2 Microultrasound in diagnostics of prostate cancer

Introduction & Objectives: In 2020 there were over 300 000 new cases of prostate cancer (PCa), while it accounts for nearly 27% of all male neoplastic disorders in Lithuania. Standart systematic prostate biopsy (SPB) method has been proven to have its limitations, which result in diminished diagnostic rate of tumors. Micro-ultrasound (microUS) is an emerging high-resolution imaging technology used for prostate cancer diagnosis, particularly for guiding targeted biopsies. Compared to conventional ultrasound, microUS provides improved visualization of prostate tissue, allowing for better differentiation of suspicious lesions. This study aims to prospectively evaluate the effectiveness and diagnostic accuracy of microUS in guiding prostate biopsies for detecting clinically significant prostate cancer (csPCa). Materials & Methods: We conducted a prospective study on 152 patients who underwent systematic and lesion targeted (S+T) biopsy using ExactVu microUS system (29Hz frequency). Clinical indications for the biopsy were abnormal DRE, PSA and lesions in mpMRI. Tissue samples were sent for pathologic examination to determine the Gleason score of the tumor. All data were accumulated, analysed, and compared using the IBM SPSS Statistics package version 30.0. Results: Among the sample of 152 men (aged 47-86; median PSA: 7,76 ng/ml) 139 (91,4% ) of them were confirmed positive for PCa, while 70,5 % of them were csPCa. For PCa alone systemic and targeted biopsies alone diagnostic rate was 84,9% and 84,2%, while combining them together yielded a rate of 91,4%. Meanwhile for csPCa systemic, targeted and combined biopsy methods shown diagnostic rates of 55,3%, 67,7% and 70,5% respectably. Lesion targeted PB alone had the sensitivity and specificity of 89,9% and 47,8% for cancer, while PPV and NPV was 90,6% and 45,8%. Compared to combined diagnostics of S+T biopsy, we observed a sensitivity and specificity of 99,2% and 52,2%, with PPV and NPV being 92,1% and 92,3%. When taking into consideration the csPCa lesion targeted PB performed with 69,8% sensitivity and 54,5% specificity (PPV=94,2%; NPV=14,6%). Comparing with S+T biopsy we observed a sensitivity of 81% and specificity of 54,5% for csPCa (PPV=94,9%; NPV=21,4%). Finally, comparing microUS guided diagnostic modalities by ROC curve, we discover, that targeted PB alone (AUC=0,689) had a lower accuracy than S+T biopsy (AUC=0,757). This type of trend continues around csPCa diagnostics, since additional S+T biopsy (AUC=0,656) performs better than targeted biopsy alone (AUC=0,622). Conclusions: S+T PB guided by microUS has shown the best overall accuracy and performance in PCa diagnostics. The addition of systematic biopsy proves to enhance the specificity and sensitivity of diagnosis in PCa and csPCa groups, while lesion targeted prostate biopsy alone still has a likelihood to miss csPCa.