Results of Targeted Biopsy in Men with Magnetic Resonance Imaging Lesions Classified Equivocal, Likely or Highly Likely to Be Clinically Significant Prostate Cancer.

BACKGROUND

The Prostate Imaging Reporting and Data System (PI-RADS) is the most commonly used scoring system in prostate magnetic resonance imaging (MRI). One of the available techniques to target suspicious lesions is direct in-bore MRI-guided biopsy (MRGB).

OBJECTIVE

To report on the experience and results of MRGB in a large cohort of patients with lesions classified as equivocal (PI-RADS 3), likely (PI-RADS 4), or highly likely (PI-RADS 5) to be clinically significant (cs) prostate cancer (PCa).

DESIGN, SETTING, AND PARTICIPANTS: We retrospectively included 1057 patients having MRGB, between January 2012 and September 2016, of lesions classified as PI-RADS≥3 on multiparametric MRI. Biopsy-naïve patients, patients with prior negative systematic transrectal ultrasound-guided biopsy, and patients in active surveillance were included.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome measurement is the detection rate of csPCa. Descriptive statistics and chi-square tests were used to calculate the differences in proportions. We considered a Gleason score of ≥3+4 as csPCa.

RESULTS AND LIMITATIONS

PCa was diagnosed in 35% (55/156), 60% (223/373), and 91% (479/528), and csPCa in 17% (26/156), 34% (128/373), and 67% (352/528) of patients with PI-RADS 3, 4, and 5 lesions, respectively. Follow-up of patients with negative biopsy findings resulted in csPCa in 1.7% (5/300) after a median period of 41 (interquartile range 25-50) mo. The evaluation of prostate-specific antigen density (PSAD) to predict csPCa resulted in 42% of patients with a PI-RADS 3 lesion who could avoid biopsy in case a PSAD of ≥ 0.15ng/ml/ml would be used. In 6% (95% confidence interval, 2-15), csPCa would then be missed. The study is limited because of its retrospective character.

CONCLUSIONS

MRGB in lesions scored PI-RADS≥3 yields high detection rates of csPCa in daily clinical practice in cases with previous negative biopsy.

PATIENT SUMMARY

In daily clinical practice, direct in-bore magnetic resonance imaging-guided biopsy of suspicious lesions reported according to the Prostate Imaging Reporting and Data System yields high detection rates of clinically significant prostate cancer.