How to Improve TRUS-Guided Target Biopsy following Prostate MRI

SIMPLE SUMMARY: Radiologists or urologists prefer to use transrectal ultrasound (TRUS) for detecting a prostate cancer. Therefore, it is of great importance to depict and target an index lesion with TRUS after the prostate MRI is scanned. They need to know the new TRUS protocols, imaging features, and biopsy techniques. The new TRUS protocols include using fundamental imaging rather than harmonic imaging and lowering dynamic range to increase tumor-to-normal tissue contrast. The new TRUS features show how to identify an index lesion and how to differentiate insignificant and significant cancers in terms of tumor size, echogenicity, echotexture, margin, and perfusion. The new biopsy techniques include how to understand different tumor locations, sizes, and shapes between magnetic resonance imaging (MRI) and TRUS and how to target an index lesion regarding biopsy strategy and cores. Systematic biopsy is necessary but can be skipped in patients with invasive behaviors such as extra-capsular extension, seminal vesicle invasion, or metastasis. Image fusion biopsy as well as cognitive biopsy can be improved if radiologists or urologists are familiar with the new TRUS protocol, imaging features, and biopsy techniques. ABSTRACT: TRUS is a basic imaging modality when radiologists or urologists perform cognitive fusion or image fusion biopsy. This modality plays the role of the background images to add to an operator’s cognitive function or MRI images. Operators need to know how to make TRUS protocols for lesion detection or targeting. Tumor location, size, and shape on TRUS are different from those on MRI because the scan axis is different. TRUS findings of peripheral or transition tumors are not well known to radiologists and urologists. Moreover, it remains unclear if systematic biopsy is necessary after a tumor is targeted. The purpose of this review is to introduce new TRUS protocols, new imaging features, new biopsy techniques, and to assess the necessity of systematic biopsy for improving biopsy outcomes.