Purpose

We sought to determine the rate of upgrading to Gleason score 4 + 3 or greater using targeted biopsy for diagnosis and monitoring in men undergoing active surveillance of prostate cancer.

Materials and methods

Study subjects comprised all 259 men, including 196 with Gleason score 3 + 3 and 63 with Gleason score 3 + 4, who were diagnosed by magnetic resonance imaging/ultrasound fusion guided biopsy from 2009 to 2015 and underwent subsequent fusion biopsy for as long as 4 years of active surveillance. The primary end point was the discovery of Gleason score 4 + 3 or greater prostate cancer. Followup biopsies included targeting of positive sites, which were tracked in an Artemis™ device. Kaplan-Meier curves were generated to determine upgrading rates, stratified by initial Gleason score and prostate specific antigen density.

Results

Based on a Cox proportional hazard model, men with Gleason score 3 + 4 were 4.65 times more likely to have upgrading than men with an initial Gleason score of 3 + 3 at 3 years (p <0.01). By the third surveillance year 63% of men with Gleason score 3 + 4 had been upgraded compared with 18.0% who started with Gleason score 3 + 3 (p <0.01). Of all 33 upgrades 32 (97%) occurred at a magnetic resonance imaging visible or a tracked site of tumor, rather than at a previously negative systematic site. Independent predictors of upgrading were Gleason score 3 + 4, prostate specific antigen density 0.15 ng/ml/cm³ or greater and a grade 5 lesion on magnetic resonance imaging. The incidence rate ratio of upgrading (Gleason score 3 + 4 vs 3 + 3) was 4.25 per year of patient followup (p <0.01).

Conclusions

During active surveillance of prostate cancer, targeting of tracked tumor foci by magnetic resonance imaging/ultrasound fusion biopsy allows for heightened detection of Gleason score 4 + 3 or greater cancers. Baseline variables directly related to important upgrading that warrant increased vigilance include Gleason score 3 + 4, prostate specific antigen density 0.15 ng/ml/cm³ or greater and grade 5 lesions on magnetic resonance imaging.

Purpose

We compared the upgrading rate obtained by resampling precise spots of prostate cancer (tracking biopsy) vs conventional systematic resampling during followup of men on active surveillance.

Materials and methods

From 2009 to 2017 in 352 men prostate cancer was Gleason 3 + 3 in 268 and Gleason 3 + 4 in 84 at initial magnetic resonance imaging-ultrasound fusion biopsy. These men subsequently underwent a second fusion biopsy. At the first biopsy session all men underwent 12-core systematic biopsies and, when magnetic resonance imaging visible lesions were present, targeted biopsies. All cancerous sites were recorded electronically. During active surveillance at a second fusion biopsy session 6 to 18 months later tracking and systematic nontracking samples were obtained. The primary outcome measure was an increase in Gleason score (upgrading) at followup sampling, which was stratified by biopsy method.

Results

Overall 91 of the 352 men (25.9%) experienced upgrading at the second biopsy during a median 11-month interval. The upgrade rate in the Gleason 3 + 3 and 3 + 4 groups was 26.9% and 22.6%, respectively. The mean number of cores taken at second biopsy was 12.2 ± 3.3 in men with upgrading and 12.4 ± 4.1 in those who remained stable (p not significant). Men with grade 0 to 4 magnetic resonance imaging targets were all upgraded at approximately the same rate of 20% to 30% (p not significant). However, 58.8% of the men with grade 5 magnetic resonance imaging targets were upgraded. Of the 91 upgrades 48 (53%) were detected only by tracking.

Conclusions

The tracking function of magnetic resonance imaging-ultrasound fusion biopsy warrants further study. When specific sites are resampled in men undergoing active surveillance of prostate cancer, upgrading is detected more often than by nontracking biopsy.

Objective

The objective of our study was to determine the clinical and MRI characteristics of clinically significant prostate cancer (PCA) (Gleason score ≥ 3 + 4) in men with Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) category 3 transition zone (TZ) lesions.

Materials and methods

From 2014 to 2016, 865 men underwent prostate MRI and MRI/ultrasound (US) fusion biopsy (FB). A subset of 90 FB-naïve men with 96 PI-RADSv2 category 3 TZ lesions was identified. Patients were imaged at 3 T using a body coil. Images were assigned a PI-RADSv2 category by an experienced radiologist. Using clinical data and imaging features, we performed univariate and multivariate analyses to identify predictors of clinically significant PCA.

Results

The mean patient age was 66 years, and the mean prostate-specific antigen density (PSAD) was 0.13 ng/mL². PCA was detected in 34 of 96 (35%) lesions, 14 of which (15%) harbored clinically significant PCA. In univariate analysis, DWI score, prostate volume, and PSAD were significant predictors (p < 0.05) of clinically significant PCA with a suggested significance for apparent diffusion coefficient (ADC) and prostate-specific antigen value (p < 0.10). On multivariate analysis, PSAD and lesion ADC were the most important covariates. The combination of both PSAD of 0.15 ng/mL² or greater and an ADC value of less than 1000 mm²/s yielded an AUC of 0.91 for clinically significant PCA (p < 0.001). If FB had been restricted to these criteria, only 10 of 90 men would have undergone biopsy, resulting in diagnosis of clinically significant PCA in 60% with eight men (9%) misdiagnosed (false-negative).

Conclusion

The yield of FB in men with PI-RADSv2 category 3 TZ lesions for clinically significant PCA is 15% but significantly improves to 60% (AUC > 0.9) among men with PSAD of 0.15 ng/mL² or greater and lesion ADC value of less than 1000 mm²/s.