The impact of the relationship between lesion diameter and total core length on the detection rate of clinically significant prostate cancer for PI-RADS 3 lesions.

BACKGROUND: The aim of our study was to determine the effect of total core length (TCL) for prostate imaging reporting and data system (PI-RADS) 3 lesions to facilitate clinically significant prostate cancer (csPCa) detection based on the lesion diameter. MATERIALS AND METHODS: A total of 149 patients with at least 1 lesion with a PI-RADS 3 were evaluated retrospectively. The lesions with diameters of < 1 cm were categorized as small lesions and lesions of ≥ 1 cm were categorized as large lesions. The lengths of biopsy cores from PI-RADS 3 lesions were summed for each lesion separately, and TCL was calculated. The relationship between TCL and csPCa was analyzed separately for the small and large groups with multiple logistic regression analyses. RESULTS: A total of 208 lesions were detected by multiparametric magnetic resonance imaging (MpMRI) in 149 males included in the study. The mean TCL was 44.68 mm (26-92) and the mean lesion diameter was 10.73 mm (4-27) in PIRADS 3 lesions. For small diameter lesions (< 1 cm), the odds of finding clinically insignificant prostate cancer (ciPCa) increase by 1.67 times if TCL increases by one unit. Hence, increasing TCL for small lesions only increases the odds of ciPCa detection. For large diameter lesions (≥ 1 cm), if TCL increases by one unit, the odds of finding ciPCa increase 1.13 times and the odds of finding csPCa increases1.16 times. Accordingly, large lesions are more likely to have both csPCa and ciPCa as TCL increases. CONCLUSIONS: Our study showed that for PI-RADS 3 lesions, both more csPCa and more ciPCa were detected as TCL increased. However, in lesions with a size of < 1 cm, only ciPCa was detected more frequently as TCL increased. In conclusion, taking more and longer biopsy cores in PI-RADS 3 lesions below 1 cm does not contribute to the detection of csPCa.

In patients with a previous negative prostate biopsy and a suspicious lesion on magnetic resonance imaging, is a 12-core biopsy still necessary in addition to a targeted biopsy?

OBJECTIVES: To evaluate the performance of multiparametric magnetic resonance imaging (mpMRI) in predicting prostate cancer on repeat biopsy; and to compare the cancer detection rates (CDRs) of MRI/transrectal ultrasonography (TRUS) fusion-guided biopsy with standard 12-core biopsy in men with at least one previous negative biopsy. PATIENTS AND METHODS: We prospectively enrolled men with elevated or rising PSA levels and/or abnormal digital rectal examination into our MRI/TRUS fusion-guided prostate biopsy trial. Participants underwent a 3 T mpMRI with an endorectal coil. Three radiologists graded all suspicious lesions on a 5-point Likert scale. MRI/TRUS fusion-guided biopsies of suspicious prostate lesions and standard TRUS-guided 12-core biopsies were performed. Analysis of 140 eligible men with at least one previous negative biopsy was performed. We calculated CDRs and estimated area under the receiver operating characteristic curves (AUCs) of mpMRI in predicting any cancer and clinically significant prostate cancer. RESULTS: The overall CDR was 65.0% (91/140). Higher level of suspicion on mpMRI was significantly associated with prostate cancer detection (P < 0.001) with an AUC of 0.744 compared with 0.653 and 0.680 for PSA level and PSA density, respectively. The CDRs of MRI/TRUS fusion-guided and standard 12-core biopsy were 52.1% (73/140) and 48.6% (68/140), respectively (P = 0.435). However, fusion biopsy was more likely to detect clinically significant prostate cancer when compared with the 12-core biopsy (47.9% vs 30.7%; P < 0.001). Of the cancers missed by 12-core biopsy, 20.9% (19/91) were clinically significant. Most cancers missed by 12-core biopsy (69.6%) were located in the anterior fibromuscular stroma and transition zone. Using a fusion-biopsy-only approach in men with an MRI suspicion score of ≥4 would have missed only 3.5% of clinically significant prostate cancers. CONCLUSIONS: Using mpMRI and subsequent MRI/TRUS fusion-guided biopsy platform may improve detection of clinically significant prostate cancer in men with previous negative biopsies. Addition of a 12-core biopsy may be needed to avoid missing some clinically significant prostate cancers.

Multiparametric magnetic resonance imaging outperforms the Prostate Cancer Prevention Trial risk calculator in predicting clinically significant prostate cancer.

BACKGROUND: The Prostate Cancer Prevention Trial risk calculator for high-grade (PCPTHG) prostate cancer (CaP) was developed to improve the detection of clinically significant CaP. In this study, the authors compared the performance of the PCPTHG against multiparametric magnetic resonance imaging (MP-MRI) in predicting men at risk of CaP. METHODS: Men with an abnormal prostate-specific antigen (PSA) level or digital rectal examination (DRE) and a suspicious lesion on a 3-Tesla MP-MRI were enrolled prospectively. Three radiologists reviewed and graded all lesions on a 5-point Likert scale. Biopsy of suspicious lesion(s) was performed using a proprietary MRI/transrectal ultrasound fusion-guided prostate biopsy system, after which 12-core biopsy was performed. A genitourinary pathologist reviewed all pathology slides. The performance of PCPTHG was compared with that of MP-MRI in predicting clinically significant CaP. RESULTS: Of 175 men who were eligible for analysis, 64.6% (113 of 175 men) were diagnosed with CaP, including 93 of 113 men (82.3%) who had clinically significant disease. Age, abnormal DRE, PSA, PSA density, prostate size, extraprostatic extension on MRI, apparent diffusion coefficient value, and MRI lesion size were identified as significant predictors of high-grade CaP (all P < .05). The area under the receiver operating characteristic curve of PCPTHG for predicting high-grade CaP was 0.676 (95% confidence interval [CI], 0.592-0.751). By using a risk cutoff of ≥15% for biopsy as, proposed previously for high-grade CaP, sensitivity was 96.4%, specificity was 7.6%, and the false-positive rate was 51.1%. In contrast, the area under the receiver operating characteristic curve of MP-MRI for high-grade CaP was 0.769 (95% CI, 0.703-0.834), and it was 0.812 (95% CI, 0.754-0.869) for clinically significant CaP. CONCLUSIONS: MP-MRI outperforms PCPTHG in predicting clinically significant CaP, and its application may help select patients who will benefit from CaP diagnosis and treatment.