Does the addition of targeted prostate biopsies to standard systemic biopsies influence treatment management for radiation oncologists?

Abstract

ObjectivesTo study the management impact that magnetic resonance imaging (MRI)-guided targeted prostate biopsies could provide relative to using only non-targeted systematic biopsies in men with clinically localized prostate cancer (PCa). Patients and MethodsA consecutive series of untreated men undergoing Artemis (MRI-ultrasonography fusion) biopsies between March 2010 and June 2013 was evaluated in this retrospective, institutional review board-approved study. Fusion biopsy included MRItargeted and systematic sampling at the same session. 3-Tesla multiparametric MRI was performed at a median of 2 weeks before biopsy. Patients were included if ≥1 systematic core was found to harbour PCa. The impact of the information obtained from targeted vs systematic biopsies was studied with regard to the following: Gleason score (GS), National Comprehensive Cancer Network (NCCN) risk reclassification, cancer core length, percentage of core positive for tumour involvement, and percentage of positive biopsy cores. ResultsThe study sample included 215 men (mean AE SD age 66 AE 8 years). The median (range) prostate-specific antigen (PSA) was 6.0 (0.7-181) ng/mL. The mean number of total biopsy samples was 18 (12 systematic and six targeted samples). Of 215 men, 34 (16%) had a higher GS on targeted vs systematic biopsy. A total of 21/183 men (12%) were stratified into a higher NCCN risk group when incorporating targeted biopsy GS results and 18/101 men (18%) were upgraded to intermediate-or high-risk from the low-risk group. Among the 34 men whose cancer severity was upgraded, increases in cancer core length, percentage of tumour involvement and percentage of cores involved were all statistically significant (P < 0.01). ConclusionTargeted prostate biopsy provided information about GS, NCCN risk and tumour volume beyond that obtained in systematic biopsies, specifically increasing the proportions of men in the intermediate-and high-risk groups. Such men may be recommended for additional treatments (pelvic nodal irradiation or hormonal therapy). The appropriateness of changing treatment because of targeted biopsy results is still unclear.

Targeted Prostate Biopsy Gleason Score Heterogeneity and Implications for Risk Stratification

“…Our rate of upstaging (38%) when adding targeted biopsy results to systematic biopsy is fairly consistent with the literature and confirms the usefulness of using a combined approach. (11, 15, 16)…”

“…The MRI technique has been described in our previous publication. (11) mpMRI was performed with a 3T Siemens SOMATOM ® Trio™ Tim or 3T Skyra scanner (Siemens, Erlangen, Germany) using a multichannel external phased-array body coil. mpMRI sequence parameters included multiplanar (axial and coronal) T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging.…”

Targeted Prostate Biopsy: Lessons Learned Midst the Evolution of a Disruptive Technology

“…The role of serial MRI to evaluate disease progression in men during active surveillance is currently under study. Information derived from MRI-guided biopsy may also have important utility for management of radiation therapy 35 . Thus, MRI/US fusion biopsy leads to improved whole-organ characterization and better-informed treatment decisions.…”

Determination of Gleason score discrepancy for risk stratification in magnetic resonance-ultrasound fusion prostate biopsy

“…The current standard for tissue sampling is the systematic 12-core transrectal biopsy. However, this approach may not be able to detect clinically significant prostate cancer (csPCa) due to improper targeting, as demonstrated by the GS upgrade in 20%–30% of prostate resection cases (1–5).…”