Microultrasound in the detection of the index lesion in prostate cancer

INTRODUCTION AND OBJECTIVE

The natural progression of prostate cancer is primarily driven by an index lesion (IL). Studies have shown that different metastases within the same patient arise from a single precursor cell. Therefore, our aim is to assess the effectiveness of transrectal microultrasound (MUS) in comparison to multiparametric magnetic resonance imaging (mpMRI) for detecting the IL in prostate cancer. We used quarter-mount pathological results as the reference standard for this evaluation.

MATERIALS AND METHODS

Three hundred and sixty-three patients who underwent Robot-Assisted Radical Prostatectomy (RARP) from June 2021 to August 2022 were included. All received mpMRI and MUS before RARP. MUS was performed by experienced operators blinded to mpMRI and biopsy results. The IL in the radical prostatectomy specimen was defined as the lesion with extraprostatic extension, the highest Grade Group (GG), or the largest tumor volume if the GG was the same. The correlation between imaging and final pathology findings was performed. A descriptive statistical analysis is presented.

RESULTS

The patients' prostates were analyzed in 12 regions (anterior/posterior, right/left, apex/mid/base). A total of 4308 regions were identified. Of these, 935 were involved by the ILs. Compared with final pathology, MUS demonstrated a sensitivity, specificity, PPV, and NPV of 68.7%, 96.3%, 80.8%, and 93.1%, respectively, while mpMRI showed a sensitivity, specificity, PPV, and NPV of 68.6%, 97.2%, 86.1%, and 92.5%, respectively, for the detection of the IL. Most of the lesions missed by MUS were located in the anterior zone (62%).

CONCLUSION

MUS exhibits a diagnostic performance similar to mpMRI when it comes to detecting the IL in prostate cancer. MUS is a cost-effective option, offers real-time evaluation, and has no delay in the acquisition process.

The prognostic value of zonal origin in clinically localized prostate cancer: a systematic review and meta-analysis

Introduction

Correlation between zonal origin of clinically localized prostate cancer (PC) and biochemical recurrence (BCR) after treatment is still controversial.

Methods

We performed a meta-analysis of published articles to investigate the prognostic value of zonal origin in clinically localized PC. Literature was searched from Medline, Embase, Scopus, and Web of Science, from inception to Nov 1st, 2022. The risk of BCR was compared between PC originating from transition zone with peripheral zone. Relative risk (RR) was pooled in a random-effects model. Subgroup analysis and meta-regression were conducted to assess the source of heterogeneity.

Results

16 cohorts and 19,365 patients were included. PC originating from transition zone was associated with a lower risk of BCR (RR, 0.79, 95%CI; 0.69-0.92, I2, 76.8%). The association was consistent in studies with median follow-up time ≥60 months (RR, 0.65; 95%CI, 0.48 to 0.88, I2 56.8%), studies with NOS score ≥8 (RR, 0.70; 95%CI, 0.62 to 0.80, I2 32.4%), and studies using multivariate regression model (RR, 0.57; 95%CI, 0.48 to 0.69, I2 23%).

Discussion

This meta-analysis supported that transition zone origin was an independent prognostic factor of a better biochemical result in clinically localized prostate cancer after treatment.

Systematic review registration

10.37766/inplasy2023.11.0100, identifier INPLASY2023110100.

Quantitative Evaluation of Apparent Diffusion Coefficient Values, ISUP Grades and Prostate-Specific Antigen Density Values of Potentially Malignant PI-RADS Lesions

The aim of this study was to demonstrate the correlation between ADC values and the ADC/PSAD ratio for potentially malignant prostate lesions classified into ISUP grades and to determine threshold values to differentiate benign lesions (noPCa), clinically insignificant (nsPCa) and clinically significant prostate cancer (csPCa). We enrolled a total of 403 patients with 468 prostate lesions, of which 46 patients with 50 lesions were excluded for different reasons. Therefore, 357 patients with a total of 418 prostate lesions remained for the final evaluation. For all lesions, ADC values were measured; they demonstrated a negative correlation with ISUP grades (p < 0.001), with a significant difference between csPCa and a combined group of nsPCa and noPCa (ns-noPCa, p < 0.001). The same was true for the ADC/PSAD ratio, but only the ADC/PSAD ratio proved to be a significant discriminator between nsPCa and noPCa (p = 0.0051). Using the calculated threshold values, up to 31.6% of biopsies could have been avoided. Furthermore, the ADC/PSAD ratio, with the ability to distinguish between nsPCa and noPCa, offers possible active surveillance without prior biopsy.

Pathological features of Prostate Imaging Reporting and Data System (PI-RADS) 3 MRI lesions in biopsy and radical prostatectomy specimens

OBJECTIVE

To assess the whole pathology spectrum of Prostate Imaging Reporting and Data System (PI-RADS) 3 lesions, identified on magnetic resonance imaging, using systematic (SB), targeted biopsy (TB) and radical prostatectomy (RP) specimen analysis.

METHODS

From a prospective database of patients undergoing RP after a combination of SB (median 12 cores) and fusion TB (median 3 cores), we included 150 PI-RADS 3 cases. Clinically significant prostate cancer (csPCa) was defined by a Grade Group 2 or more. The primary endpoints were unfavourable features in RP specimens.

RESULTS

Targeted biopsy was negative in 20.7% of patients. Final Grade Group 3 or more and a pT3 stage was reported in 36.7% and 38.7% of RP specimens. The upgrading rate was 38.2% between biopsy and RP specimens. The concordance rate between Grade Group on TB and RP was only 38.0%. The two independent predictive factors for unfavourable disease (pT3-4 and/or final Grade Group 3-5) were prostate-specific antigen density (PSAD; P = 0.001) and presence of csPCa on TB (odds ratio 3.7; P = 0.001). The risk of unfavourable disease was increased 2.3-fold and 5.8-fold, respectively, for patients with a PSAD between 0.15 and 0.20, and a PSAD >0.20 ng/mL/g. The 5-year biochemical recurrence-free survival rate was 93.2%.

CONCLUSIONS

PI-RADS 3 lesions exhibited aggressive features in almost 40% of cases. PSAD and presence of csPCa on TB are independent predictive factors for high-grade and/or extraprostatic disease. A combination of SB and TB improve grade prediction compared to use of TB alone.

Comparison of preoperative locoregional Ga-68 PSMA-11 PET-CT and mp-MRI results with postoperative histopathology of prostate cancer

BACKGROUND

Conventional imaging modalities are inadequate to evaluate locoregional extension of prostate cancer (PCa). The aim of the current retrospective study was to investigate the diagnostic efficacy of Gallium-68 prostate-specific membrane antigen-11 (Ga-68 PSMA-11) positron emission tomography/computed tomography (PET/CT) and multiparametric magnetic resonance imaging (mp-MRI) for staging preoperative PCa patients with correlating histopathology.

MATERIALS AND METHODS

Twenty-four patients with histologically proven PCa underwent both Ga-68 PSMA-11 PET/CT and mp-MRI before robot-assisted laparoscopic radical prostatectomy. For each tumor area, correlations with histopathological results were defined for tumor localization, extraprostatic extension (EPE) of the tumor, invasion of seminal vesicle (SVI) and bladder neck invasion (BNI). In patients with regional lymph node (LN) dissection, histopathological results were also correlated with imaging modalities.

RESULTS

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for detection of EPE and SVI were higher for mp-MRI than Ga-68 PSMA-11 PET/CT. On the other hand Ga-68 PSMA-11 PET/CT had significant successful results for detection of LN metastases when compared with mp-MRI. But for BNI detection both modalities had same insufficient results. Ga-68 PSMA-11 PET/CT had strong results for appropriate tumor localization in the gland.

CONCLUSION

Ga-68 PSMA PET/CT has superior results for assessing local LN metastases and for intraprostatic tumor localization. Whereas, mp-MRI must be the preferred modality for determining SVI and EPE. But both imaging modalities failed for determining BNI accurately. Both modalities should be used in conjunction with each other for better treatment planning.