Micro-ultrasound for prostate cancer

Abstract

The diagnostic workflow for prostate cancer detection has evolved substantially with advances in imaging technologies and biopsy techniques. Currently, MRI is the standard modality for prostate imaging in cancer detection. However, the rising incidence of prostate cancer and the limited accessibility and high cost of MRI created a growing need for more cost- and time-effective alternative imaging modalities. Micro-ultrasound (microUS), which enables prostatic ductal anatomy to be imaged with a 70-micron resolution, provides an alternative. Level 1 evidence currently shows the non-inferiority of microUS in detecting Grade Group ≥2 prostate cancer in biopsy-naive men compared with MRI. Clinical trials are ongoing to investigate microUS in various other indications. Inter-reader variability needs to be optimized, possibly through the incorporation of artificial intelligence (AI) assistance. This Review focuses on micro-ultrasound as a new imaging technology in prostate cancer detection, comparing micro-ultrasound performance with that of the current standard MRI. The potential of micro-ultrasound in other applications, including tumour staging and active surveillance, as well as the use of artificial intelligence to support biopsy decision-making, are also discussed, based on completed and ongoing trials.