Optimizing safety and accuracy of prostate biopsy

Abstract

Purpose of review: The objective of this article is to examine the safety of prostate biopsy and discuss the emerging role of MRI-ultrasound fusion technology in improving diagnostic accuracy.

Recent findings: Men undergoing prostate biopsy frequently experience minor complications, including hematospermia, hematuria, and infection. Quinolone-resistant bacteria are a growing concern; thus, transperineal access or modification of antibiotic prophylaxis based on local antibiograms is now used to avoid infectious complications.Multiparametric MRI allows visualization of many prostate cancers, and by fusing MRI with real-time ultrasound, a biopsy needle can be directed by a urologist into suspicious regions of interest. Using this new method, detection of clinically significant prostate cancer has increased and the incidence of falsely negative biopsies has decreased.

Summary: Prostate biopsy is generally a safe procedure, and with attention to local patterns of antibiotic resistance, infectious complications can be minimized. MRI-ultrasound fusion has significantly improved the accuracy of prostate biopsy, allowing tracking and targeting not previously possible.

Figure 1

Percent likelihood of clinically significant prostate cancer (csCaP) based on region of interest (ROI) grade, (N=825). (10) Region of interest grade is shown at lower left corner of each section. Chance of csCaP is directly related to ROI grade.

Figure 2

This graph shows the number of subjects with a prior negative biopsy and persistently elevated PSA diagnosed with significant and insignificant cancers depending on biopsy method. The combination of systematic and targeted biopsy results in detection of more csCaP than either alone.

Figure 3

Effect of MRI grade on reclassification beyond Epstein criteria using mpMRI-US biopsy. (52) The higher the suspicion grade (UCLA scoring system), the greater the chance of reclassification beyond traditional Epstein criteria.

Figure 4

Example of resampling of prior positive biopsy sites using the MRI - ultrasound fusion (Artemis) device. (A) A 3-dimensional model of the prostate from a second biopsy (brown) is superimposed on the model from a first biopsy (blue), revealing a close match in shape and size. The superimposed model is created in real time at second biopsy. An MRI target (red) is displayed in the model. (B) The location of prior positive sites (1 and 2) is mapped by the Artemis device. Site 1 is a systematic site and site 2 is from the MRI-targeted core. (C) A total of 4 cores (black cylinders) are taken from each site.

Figure 5

68 year old man with PSA 8.3 ng/ml underwent mp-MRI, including T2-weighted (A), diffusion weighted (B) and DCE (C) imaging, followed by fusion biopsy (D). Mapping biopsy revealed Gleason 3+3 but targeted biopsy (E) revealed Gleason 4+5 disease (reduced from ×20). GS on whole mount prostatectomy specimen was Gleason 4+3 with tertiary pattern 5 (F, reduced from ×1). Fusion biopsy, which included MRI targeted ROI, predicted highest Gleason grade at final pathology. (55)