MRI versus non-MRI diagnostic pathways before radical prostatectomy: Impact on nerve-sparing, positive surgical margins, and biochemical recurrence

Multiparametric MRI lesion dimension as a significant predictor of positive surgical margins following laparoscopic radical prostatectomy for transitional zone prostate cancer

BACKGROUND

Positive surgical margins (PSM) after laparoscopic radical prostatectomy are a critical factor influencing treatment outcomes and prognosis in prostate cancer. Optional treatment strategies (neoadjuvant therapy, surgical techniques) and intraoperative margin monitoring highlight the importance of PSM risk assessment. This study aims to evaluate the potential PSM risk in transitional zone (TZ) tumors.

MATERIALS AND METHODS

This retrospective study included 434 patients who underwent laparoscopic radical prostatectomy after multiparametric magnetic resonance imaging at our center between 2019 and 2023.

RESULTS

The PSM rate was significantly higher in patients with TZ lesions compared to those with peripheral zone lesions (47%, n = 175 vs. 28%, n = 226, p < 0.01). Lesion location in TZ (OR: 4.29, 97.5% CI: 2.60-7.23, p < 0.01) was identified as independent risk factors for PSM. Further analysis identified largest dimension of lesions (OR: 1.27, 97.5% CI: 1.09-1.50, p < 0.01) and the number of positive biopsy cores (OR: 1.39, 97.5% CI: 1.16-1.70, p < 0.01) as independent risk factors for PSM in patients with TZ tumors. LASSO regression identified four significant variables (largest dimension of lesions-the most important variable, number of positive biopsy cores, prostate-specific antigen density, and International Society of Urological Pathology grade). These variables were used to construct three PSM risk prediction models, each demonstrating favorable predictive accuracy and clinical benefit.

CONCLUSIONS

Certain TZ prostate cancer patients demonstrate a higher predisposition to PSM occurrence. Lesion dimension as a significant predictor of PSM for TZ patients. Separate PSM risk assessments for subgroups, like TZ prostate cancer patients, may enhance predictive accuracy and clinical utility.

CLINICAL TRIAL REGISTRATION

China Clinical Trial Registry (ChiCTR2300075944, 2023).

Intraoperative technologies to assess margin status during radical prostatectomy - a narrative review

Positive surgical margin (PSM) is a frequent concern for surgeons performing radical prostatectomy for prostate cancer (PCa). PSM are recognized as risk factors for earlier biochemical recurrence and expose patients to adjuvant or salvage treatments such as external radiotherapy and hormonotherapy. Several strategies have been established to reduce PSM rate, while still allowing safe nerve-sparing surgery. Precise preoperative staging by multiparametric magnetic resonance imaging (mpMRI) and fusion biopsy is recommended to identify suspicious areas of extracapsular extension (ECE) that warrant special attention during dissection. However, even with optimal imaging, ECE can be missed, some cancers are not well defined or visible, and capsular incision during surgery remains an issue. Hence, intraoperative frozen section techniques, such as the neurovascular structure-adjacent frozen section examination (NeuroSAFE) have been developed and lately widely disseminated. The NeuroSAFE technique reduces PSM rate while allowing higher rate of nerve-sparing surgery. However, its use is limited to high volume or expert center because of its high barrier-to-entry in terms of logistics, human resources and expertise, as well as cost. Also, NeuroSAFE is a time-consuming process, even in expert hands. To address these issues, several technologies have been developed for an ex vivo and in vivo use. Ex vivo technology such as fluorescent confocal microscopy and intraoperative PET-CT require the extraction of the specimen for preparation, and digital images acquisition. In vivo technology, such as augmented reality based on mpMRI images and PSMA-fluorescent guided surgery have the advantage to provide an intracorporeal analysis of the completeness of the resection. The current manuscript provides a narrative review of established techniques, and details several new and promising techniques for intraoperative PSM assessment.

Predictive model for PSA persistence after radical prostatectomy using machine learning algorithms

Objective

To evaluate the efficacy of a machine learning model for predicting prostate-specific antigen (PSA) persistence after radical prostatectomy (RP).

Methods

Data from 470 patients who underwent RP at the Affiliated Hospital of Qingdao University from January 2018 to June 2021 were retrospectively analyzed. Ten risk factors, including age, body mass index (BMI), preoperative PSA, biopsy Gleason score, total prostate specific antigen density (PSAD), clinical tumor stage, clinical lymph node status, seminal vesicle invasion, capsular invasion and positive surgical margin, were included in the analysis. The data were randomly divided into a training set and a test set at a ratio of 7:3, and seven different machine learning algorithms were compared. The confusion matrix, receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to evaluate the diagnostic performance of the model, and the random forest algorithm found to be the optimal prediction model.

Results

In the entire cohort, 142 (30.21%) patients developed PSA persistence. Based on all included risk factors, the random forest model had the best effect among the seven models, with an AUC of 0.8607 in the training set and 0.8011 in the test set. The feature importance results showed that capsular invasion, positive surgical margin, preoperative PSA and biopsy Gleason score were the four most important risk factors for PSA persistence after RP.

Conclusion

The Random Forest algorithm performed excellently in this study and can be used to construct a predictive model for PSA persistence. By incorporating clinical data from the Asian region and exploring the risk factors for PSA persistence, this study contributes to the existing research and aids clinicians in assessing the risk of PSA persistence occurrence, enabling timely treatment planning and improving patient prognosis.

Oncological outcomes after radical prostatectomy of localized prostate cancer: stratified by magnetic resonance imaging and risk classification

Background

We investigated whether combining T2-weighted magnetic resonance imaging (MRI) findings and clinical risk categories improves upon established prognostic indicators of oncological outcomes in prostate cancer.

Methods

Patients who underwent radical prostatectomy, but not preoperative hormone therapy, radiotherapy, or chemotherapy, for localized prostate cancer at Seoul National University Bundang Hospital from October 2007 to April 2016 were included. MRIs were classified according to the Prostate Imaging-Reporting and Data System (PI-RADS). Patients were divided into the following five groups: 1, no focal suspicious lesion; 2, organ-confined suspicious lesion PI-RADS ≤3; 3, organ-confined suspicious lesion PI-RADS 4 or 5; 4, suspicious lesion with extraprostatic extension (EPE), no seminal vesicle invasion (SVI); 5, suspicious lesion with EPE and SVI. Risk classified according to the National Comprehensive Cancer Network (NCCN) and MRI findings were combined to analyze survival curves for biochemical recurrence (BCR)-free and metastasis-free survival. The area under a time-dependent receiver operating characteristic was analyzed for event prediction after 5 years.

Results

We analyzed 1,290 patients. In multivariate Cox regression models, PI-RADS ≥4 (hazard ratio [HR] 2.33, P < 0.001), EPE (HR 1.46, P = 0.027), SVI (HR 5.03, P < 0.001) and NCCN high-risk (HR 2.33, 95% CI 1.66-3.26, P < 0.001) were associated with BCR. For metastasis, EPE (HR 2.33, P = 0.047), SVI (HR 13.08, P < 0.001) and NCCN high-risk (HR 2.78, P = 0.026) were independent risk factors. Depending on MRI group, BCR-free survival significantly decreased in NCCN intermediate-risk (P = 0.001) and high-risk (P < 0.001) groups, and metastasis-free survival decreased in the intermediate-risk group (P = 0.39) and significantly decreased in the high-risk (P < 0.001) group. Adding MRI group to NCCN risk classification significantly improved the predictive accuracy for BCR in comparison with NCCN risk classification alone (P = 0.042), but not for metastasis (P = 0.012).

Conclusion

Combining prostate MRI with NCCN risk classification improves the prediction value of BCR following radical prostatectomy for localized prostate cancer.

Real-Life Comparative Analysis of Robotic-Assisted Versus Laparoscopic Radical Prostatectomy in a Single Centre Experience

Background: The advantage of a robotic-assisted (RARP) over a laparoscopic (LRP) approach in radical prostatectomy (RP) remains to be demonstrated. Aim: The aim of the study is to use a homogeneous population in real life and single primary surgeon surgery to analyze the oncological and functional results based on the type of surgical approach and pathological features. Methods: This is a prospective trial on non-metastatic prostate cancer (PCa) patients considered after a multidisciplinary decision to conduct a RP, using a RARP or LRP approach. A real-life setting was analyzed at our Urological Departments using homogeneous criteria for the management of PCa cases and a single surgeon experience on 444 cases (284 LRP and 160 RARP). Results: Mean operating time was significantly lower in RARP (153.21 ± 25.1 min) than in LRP (173.33 ± 44.3 min) (p < 0.001). In cases submitted to an extended lymph node dissection (eLND), the mean number of lymph nodes removed was 15.16 ± 7.83 and 19.83 ± 4.78, respectively, in LRP and RARP procedures (p < 0.001), but positive lymph nodes (pN1) were similarly found in 15.8% of LRP patients and 13.6% of RARP patients (p = 0.430). Surgical margins (SM) positivity was not significantly higher in the RARP group (20.0%) when compared to the LRP group (15.9%) (p = 0.145). During the postoperative follow-up, a biochemical recurrence (BCR) was detected in 14.4% and 7.5% of cases in the LRP and RARP group, respectively, (p = 0.014). Better results of PAD tests at 3-month intervals using the RARP approach (mean pad weight 75.57 ± 122 g and 14 ± 42 g, respectively, in LRP and RARP (p < 0.01)) were described. Conclusions: In the comparison between the RARP and LRP approach, a clear advantage of the robotic approach is a significant reduction in operating times, days of hospitalization, and postoperative catheterization compared to laparoscopic surgery. It is not possible to describe any certain oncological advantage both in terms of surgical margins and pathological lymph nodes removed. In RARP cases a reduction to the limit of significance is described in terms of biochemical recurrence. RARP produces a more rapid recovery of urinary continence at 3 months postoperatively without significant advantages in terms of erective potency recovery.

Effect of preoperative PI-RADS assessment on pathological outcomes in patients who underwent radical prostatectomy

OBJECTIVE

To assess the effect of preoperative MRI with standardized Prostate Imaging-Reporting and Data System (PI-RADS) assessment on pathological outcomes in prostate cancer (PCa) patients who underwent radical prostatectomy (RP).

PATIENTS AND METHODS

This retrospective cohort study included patients who had undergone prostate MRI and subsequent RP for PCa between January 2017 and December 2022. The patients were divided into the PI-RADS group and the non-PI-RADS group according to evaluation scheme of presurgery MRI. The preoperative characteristics and postoperative outcomes were retrieved and analyzed. The pathological outcomes included pathological T stage (pT2 vs. pT3-4) and positive surgical margins (PSMs). Patients were further stratified according to statistically significant preoperative variables to assess the difference in pathological outcomes. A propensity score matching based on the above preoperative characteristics was additionally performed.

RESULTS

A total of 380 patients were included in this study, with 201 patients in the PI-RADS group and 179 in the non-PI-RADS group. The two groups had similar preoperative characteristics, except for clinical T stage (cT). As for pathological outcomes, the PI-RADS group showed a significantly lower percentage of pT3-4 (21.4% vs. 48.0%, p < 0.001), a lower percentage of PSMs (31.3% vs. 40.9%, p = 0.055), and a higher concordance between the cT and pT (79.1% vs. 64.8%, p = 0.003). The PI-RADS group also showed a lower proportion of pT3-4 (p < 0.001) in the cT1-2 subgroup and the cohort after propensity score matching. The PSM rate of cT3 patients was reduced by 39.2% in the PI-RADS group but without statistical significance (p = 0.089).

CONCLUSIONS

Preoperative MRI with standardized PI-RADS assessment could benefit the decision-making of patients by reducing the rate of pathologically confirmed non-organ-confined PCa after RP and slightly reducing the PSM rate compared with non-PI-RADS assessment.