New Biopsy Techniques and Imaging Features of Transrectal Ultrasound for Targeting PI-RADS 4 and 5 Lesions

Abstract

Purpose: To introduce new biopsy techniques and imaging features of transrectal ultrasound (TRUS) for targeting Prostate Imaging Reporting and Data System (PI-RADS) 4 and 5 lesions Methods: TRUS-guided targeted and/or systematic biopsies were performed in 432 men with PI-RADS 4 and 5 lesions following magnetic resonance imaging examination. A TRUS operator who was familiar with the new techniques and imaging features performed lesion detection. Overall and significant cancer detection rates (CDRs) were compared among the men with PI-RADS 4 and 5 lesions. The CDRs in the peripheral and transition zones were compared. Additionally, we assessed whether targeted or systematic biopsies contributed to cancer detection. The standard reference was a biopsy examination.

Results: The overall CDRs in the men with PI-RADS 4 and 5 lesions were 49.5% (139/281) and 74.8% (113/151) (p < 0.0001); significant CDRs were 33.1% (93/281) and 58.3% (88/151) (p < 0.0001); and CDRs in the peripheral and transition zones were 53.6% (187/349) and 78.3% (65/83) (p < 0.0001), respectively. Of the 139 men with clinically significant cancer PI-RADS 4 lesions, 107 (77.0%) were diagnosed by targeted biopsy, 5 (3.6%) by systematic biopsy, and 27 (19.4%) by both. Of the 113 men with clinically significant cancer PI-RADS 5 lesions, 97 (85.8%) were diagnosed by targeted biopsy, 3 (2.7%) by systematic biopsy, and 13 (11.5%) by both.

Conclusions: Most PI-RADS 4 and 5 lesions can be targeted with TRUS if the new techniques and imaging features are applied.

Keywords: Prostate Imaging Reporting and Data System; biopsy; magnetic resonance imaging; prostate adenocarcinoma; transrectal ultrasound.

Figure 1

Flow diagram of the study population.

Figure 2

A PI-RADS 4 peripheral cancer in a 70-year-old man. (A) Diffusion-weighted axial MR image shows a hyperintense peripheral lesion (white arrows) in the left mid-gland measuring 1.3 cm, suggesting that the PI-RADS lesion category is 4. The patient’s PSA level was 3.56 ng/mL prior to biopsy. (B) TRUS axial image clearly shows a hypoechoic peripheral lesion (white arrows) in the left base. The TRUS lesion is located more superiorly to the MRI lesion. Moreover, white arrowheads indicate that the prostate is not compressed by a TRUS probe. TRUS-guided targeted biopsy alone was performed with four cores. All confirmed a Gleason score of 7 (4 + 3) adenocarcinomas.

Figure 3

A PI-RADS 5 transition cancer in a 61-year-old man. (A) T2-weighted axial MR image shows a moderately hypointense transition lesion (white arrows) in the anterior midline base measuring 2.7 cm, suggesting that the PI-RADS lesion category is 5. The patient’s PSA level was 12.27 ng/mL prior to biopsy. (B) TRUS axial image clearly shows a hyperechoic transition lesion (white arrows) in the anterior midline mid-gland. The TRUS lesion is located more inferiorly to the MRI lesion. White arrowheads indicate that the prostate is compressed by a TRUS probe to reduce the tumor-to-probe distance. A TRUS-guided targeted biopsy alone was performed with five cores, in which three and one confirmed Gleason scores of 7 (4 + 3) and 6 (3 + 3) adenocarcinomas, respectively.