Detection of Gleason 6 prostate cancer in patients with clinically significant prostate cancer on multiparametric magnetic resonance imaging

A comprehensive comparison between mpMRI of the prostate, MR-US fusion biopsy and whole mount histopathology

OBJECTIVES

To compare multiparametric magnetic resonance imaging (mpMRI) findings, US-MR fusion prostate biopsy results and whole-mount thin-section histopathology after radical prostatectomy.

PATIENTS AND METHODS

Overall 259 patients, who had undergone mpMRI with lesions reported as PI-RADS 3-5, underwent a MR-US fusion biopsy between 2018 and 2020. Overall 186 biopsies yielded prostate cancer and 104 patients subsequently underwent endoscopic extraperitoneal radical prostatectomy. Histopathology of biopsies was compared to the final histopathology in whole mount thin sections after radical prostatectomy by means of descriptive statistics, and further, the lesions from mpMRT were compared to whole mount histology.

RESULTS

Prostate cancer was diagnosed in 186 (71.8%) of 259 patients (median age 69.2 y, range 42-82 y, median PSA 7.8 ng/ml, range 2.1-31.3 ng/ml). Of those, 95 (51,1%) underwent radical endoscopic prostatectomy, and 80 (43%) chose radiotherapy or active surveillance. In 52/95 (54,7%) with RPE additional lesions were found in the final histological whole mount sections not described at mpMRI. 22/95 (23,2%) of RPE patients had ≥ 1 additional Gleason score ≥ 7 lesions, 23 /259 (8,4%) of biopsies, respectively. The Gleason score after surgery was upgraded in 37/95 (38,9%) and downgraded in 18/95 (18,9%) patients.

CONCLUSION

If we compare all 259 performed biopsies with the final histological whole mount sections which showed additional lesions with Gleason ≥ 7 (23,2%), it can be assumed that up to 10% of clinical significant carcinomas are missed during primary assessment via mpMRI. The majority of additional findings after RP were intermediate/high risk tumors. Upgrades from low-risk to intermediate or high-risk occurred.

The Impact of Visible Tumor (PI-RADS ≥ 3) on Upgrading and Adverse Pathology at Radical Prostatectomy in Low Risk Prostate Cancer Patients: A Biopsy Core Based Analysis

BACKGROUND

The objective of this study was to investigate the impact of the characteristics of a single visible tumor (Prostate Imaging-Reporting and Data System [PI-RADS]≥3) on upgrading and adverse pathology at radical prostatectomy (RP) in biopsy naïve low risk prostate cancer (PCa) patients.

MATERIALS AND METHODS

We retrospectively reviewed 64 biopsy naïve patients from 3 different referral centers between 2018 and 2020 with a PSA<10, cT1c disease, a single PI-RADS≥ 3 index lesion in multiparametric-MRI (mp-MRI), all bearing a GG 1 tumor sampled software fusion biopsy, who underwent RP. Preoperative clinical variables including the localization, number and tumor burden of positive cores for each PI-RADS category were related to upgrading and adverse pathology (GG>2 and/or pT3 and/or lymph node positive disease) at RP.

RESULTS

Overall 37 patients (57.8%) were upgraded with a significant difference of upgrading in PI-RADS3 (30.0%) versus PI-RADS 4 (67.6%) (P = .007) and PI-RADS 4-5 (70.5%) lesions (P = .002). Thirty-three of 37 GG1 tumors were upgraded to GG2, while 6 of these 33 (18.2%) had adverse pathology as well. Overall 9 patients (14.1%) had adverse pathology at RP all harboring PI-RADS4-5 lesions. The number of positive cores differed significantly between the upgraded and nonupgraded patients. Adverse pathology group had significantly higher tumor volume at RP.

CONCLUSION

PI-RADS4-5 lesions are the independent predictors of upgrading and adverse pathology in low risk PCa with visible tumors. Upgrading and adverse pathology were closely related to the number of positive combined cores reflecting the role of tumor volume. This should be kept in mind in shared decision making of an individual patient with low risk disease and a visible tumor.

Use of TDI during MRI/US fusion-guided biopsy for suspected prostate cancer

BACKGROUND

Tissue Doppler imaging (TDI) uses the Doppler principle to quantify the movement of biological tissues.

OBJECTIVE

To investigate the contribution of TDI parameters derived during magnetic resonance imaging and ultrasound (MRI/US) fusion-guided biopsy for prostate cancer (PCa) discrimination.

METHODS

From March 2016 to Dec. 2018, 75 men with suspected PCa prospectively underwent fusion-guided prostate biopsy. TDI overlaid on predefined target lesion were compared to the confirmed contralateral tumor-free area of the prostate gland (using Image J). Diagnostic value of TDI parameters was assessed using histopathology as standard of reference.

RESULTS

Thirty-seven patients were diagnosed with PCa (49.3%), among them 27 with clinically significant PCa (Gleason score >  3 + 3 = 6 (ISUP 1). The LES/REF ratio was lower in confirmed PCa patients compared to patients without PCa (0.42, IQR, 0.22-0.59 vs. 0.52, IQR, 0.40-0.72, p = 0.017). TDI parameters allowed differentiation of low-risk from high-to-intermediate-risk PCa (ISUP 2 versus ISUP 3) based on lower pixel counts within the target ROI (1340, IQR 596-2430 vs. 2687, IQR 2453-3216, p = 0.004), lower pixel percentage (16.4 IQR 11.4-29.5 vs. 27.3, IQR 22.1-39.5; p = 0.005), and lower LES/REF ratios (0.29, IQR 0.19-0.51 vs. 0.52, IQR 0.47-0.74, p = 0.001).

CONCLUSION

TDI of prostate lesions prelocated by MRI discriminates between cancerous and noncancerous lesions and further seems to enable characterization of PCa aggressiveness. This widely available US technique may improve confidence in target lesion localization for tissue sampling.

Contrast enhanced ultrasound (CEUS) with parametric imaging after irreversible electroporation (IRE) of the prostate to assess the success of prostate cancer treatment

AIM

The aim of this study was to assess the success of irreversible electroporation (IRE) in prostate cancer and to differentiate between reactive changes and tumor.

MATERIAL AND METHODS

This is a retrospective pilot study of 50 patients after irreversible electroporation (IRE) in prostate cancer between 50-79 years (mean age 65 years). Each patient received a transabdominal sonography using a 1-6 MHz convex matrix probe. Contrast-enhanced ultrasound (CEUS) was performed after i.v. bolus injection of 2.0 ml sulphur hexafluoride microbubbles. DICOM loops were continuously stored up to one minute. Parametric images were calculated by integrated perfusion analysis software. A comparison was drawn to a follow-up MRI six months after ablation.

RESULTS

While 13 patients showed local recurrence, 37 patients were successfully treated, meaning no local recurrence within six months after ablation. 18 patients showed signs of prostatitis after IRE. Tumorous changes were visually characterized by dynamic early nodular hypervascularization with fast and high wash-in. Correspondingly, nodular red and yellow shades were seen in parametric imaging. All patients with remaining tumor were correctly identified with CEUS and parametric imaging. After IRE there is a relevant decrease in tumor microcirculation in all patients, as seen in more purple shades of the prostate. The sensitivity for detecting residual tumor with CEUS compared to MRI was 76%, the specificity was 81%. The corresponding positive predictive value (PPV) was 73% and the negative predictive value (NPV) was 83%.

CONCLUSION

CEUS and parametric imaging enable a critical analysis of post-ablation defects after IRE for prostate cancer even with a transabdominal approach. Remaining tumor can be detected with the help of pseudo-colors.

Predictive clinical features for negative histopathology of MRI/Ultrasound-fusion-guided prostate biopsy in patients with high likelihood of cancer at prostate MRI: Analysis from a urologic outpatient clinic1

OBJECTIVE

The aim of this study was to evaluate clinical features associated with benign histopathology of Prostate Imaging Reporting and Data System (PI-RADS) category 4 and 5 lesions.

MATERIALS AND METHODS

Between March 2015 and November 2020, 1161 patients underwent mpMRI/Ultrasound-fusion-guided prostate biopsy (FBx) and concurrent 12-core systematic prostate biopsy (SBx) at the Department of Urology of the Ludwig-Maximilians-University of Munich, Germany. 848/ 1161 (73%) patients presented with either PI-RADS 4 or 5 index lesion and were retrospectively evaluated. Multivariate analysis was performed to evaluate clinical parameters associated with a negative outcome of PI-RADS 4 or 5 category lesions after FBx. Area under the receiver operating characteristics (ROC) curve (AUC) was conducted using ROC-analysis.

RESULTS

676/848 (79.7%) patients with either PI-RADS 4 or 5 index lesion were diagnosed with prostate cancer (PCa) by FBx and 172/848 (20.3%) patients had a negative biopsy (including the concurrent systematic prostate biopsy), respectively. Prostate volume (P-Vol) (OR 0.99, 95% CI = 0.98-1.00, p = 0.038), pre-biopsy-status (OR 0.48, 95% CI = 0.29-0.79, p = 0.004) and localization of the lesion in the transitional zone (OR 0.28, 95% CI = 0.13-0.60, p = 0.001) were independent risk factors for a negative outcome of FBx. Age (OR 1.09, 95% CI = 1.05-1.13, p < 0.001) and PSA density (PSAD) (OR 75.92, 95% CI = 1.03-5584.61, p = 0.048) increased the risk for PCa diagnosis after FBx. The multivariate logistic regression model combining all clinical characteristics achieved an AUC of 0.802 (95% CI = 0.765-0.835; p < 0.001) with a sensitivity and specificity of 66% and 85%.

CONCLUSION

Lesions with high or highly likelihood of PCa on multiparametric magnetic resonance imaging (mpMRI) but subsequent negative prostate biopsy occur in a small amount of patients. Localization of the lesion in the transitional zone, prostate volume and prebiopsy were shown to be predictors for benign histopathology of category 4 or 5 lesions on mpMRI. Integration of these features into daily clinical routine could be used for risk-stratification of these patients after negative biopsy of PI-RADS 4 or 5 index lesions.