Excision of the neurovascular bundle at radical prostatectomy in cases with perineural invasion on needle biopsy

OBJECTIVES: To assess, in a group of patients who had undergone radical prostatectomy and who were likely to have extraprostatic extension of their tumors based on the previous finding of perineural invasion on needle biopsy, how effective excision of the neurovascular bundle was in reducing the number of positive margins and increasing the potential cure rate. METHODS: Eighty radical prostatectomy cases from our institution that had perineural invasion on prostate needle biopsy were retrospectively studied to determine the presence and location of extraprostatic extension, positive margins, and seminal vesicle or lymph node involvement, whether the neurovascular bundle had been excised, and whether tumor was present in the bundle region. RESULTS: In 14 (17.5%) of 80 cases, excising the neurovascular bundle led to a situation in which there was tumor in the neurovascular bundle, all the surgical margins of resection were negative for tumor, and there was no seminal vesicle or lymph node involvement. The remaining cases were equally divided between (a) less aggressive tumors that were organ-confined or had only focal extraprostatic extension with no tumor in the neurovascular bundle and (b) more aggressive tumors that had positive margins or involvement of the seminal vesicles or lymph nodes. Within the latter group, however, there were 9 patients (11.3% of all 80 cases) with negative seminal vesicles and lymph nodes in whom excision of the neurovascular bundle at least reduced the extent of positive margins. Most of the positive margins in patients with tumor in the neurovascular bundle occurred outside the bundle region, and in this study, none of the cases with positive surgical margins were the sole result of failure to excise the neurovascular bundle. CONCLUSIONS: When perineural invasion is seen on needle biopsy, the morbidity of resecting one or both neurovascular bundles, which in some cases could turn out to be unnecessary, must be weighed against the benefit of reducing the incidence of positive margins (17.5% of our cases) or decreasing the extent of positive margins (11.3% of our cases).     

Prostate cancer management choices in patients undergoing multiparametric magnetic resonance imaging/ultrasound fusion biopsy compared to systematic biopsy

Objectives

To assess management choices in patients who undergo magnetic resonance imaging (MRI)/ultrasound (MRI/US) fusion-guided prostate biopsy compared to patients who undergo systematic biopsy.

A novel nomogram predicting lymph node invasion among patients with prostate cancer: The importance of extracapsular extension at multiparametric magnetic resonance imaging

PurposeTo develop a novel risk tool that allows the prediction of lymph node invasion (LNI) among patients with prostate cancer (PCa) treated with robot-assisted radical prostatectomy (RARP) and extended pelvic lymph node dissection (ePLND).MethodsWe retrospectively identified 742 patients treated with RARP + ePLND at a single center between 2012 and 2018. All patients underwent multiparametric magnetic resonance imaging (mpMRI) and were diagnosed with targeted biopsies. First, the nomogram published by Briganti et al. was validated in our cohort. Second, three novel multivariable logistic regression models predicting LNI were developed: (1) a complete model fitted with PSA, ISUP grade groups, percentage of positive cores (PCP), extracapsular extension (ECE), and Prostate Imaging Reporting and Data System (PI-RADS) score; (2) a simplified model where ECE score was not included (model 1); and (3) a simplified model where PI-RADS score was not included (model 2). The predictive accuracy of the models was assessed with the receiver operating characteristic-derived area under the curve (AUC). Calibration plots and decision curve analyses were used.ResultsOverall, 149 patients (20%) had LNI. In multivariable logistic regression models, PSA (OR: 1.03; P= 0.001), ISUP grade groups (OR: 1.33; P= 0.001), PCP (OR: 1.01; P= 0.01), and ECE score (ECE 4 vs. 3 OR: 2.99; ECE 5 vs. 3 OR: 6.97; P< 0.001) were associated with higher rates of LNI. The AUC of the Briganti et al. model was 74%. Conversely, the AUC of model 1 vs. model 2 vs. complete model was, respectively, 78% vs. 81% vs. 81%. Simplified model 1 (ECE score only) was then chosen as the best performing model. A nomogram to calculate the individual probability of LNI, based on model 1 was created. Setting our cut-off at 5% we missed only 2.6% of LNI patients.ConclusionsWe developed a novel nomogram that combines PSA, ISUP grade groups, PCP, and mpMRI-derived ECE score to predict the probability of LNI at final pathology in RARP candidates. The application of a nomogram derived cut-off of 5% allows to avoid a consistent number of ePLND procedures, missing only 2.6% of LNI patients. External validation of our model is needed.     

Accuracy of preoperative multiparametric magnetic resonance imaging for prediction of unfavorable pathology in patients with localized prostate cancer undergoing radical prostatectomy

Introduction

We investigated the accuracy of multiparametric MRI (mpMRI) for preoperative staging and its influence on the determination of neurovascular bundle sparing and disease prognosis in patients with localized prostate cancer.

Methods

We reviewed 1045 patients who underwent radical prostatectomy with preoperative mpMRI at a single institution. Clinical local stages determined from mpMRI were correlated with preoperative and postoperative pathological outcomes.

Results

The sensitivity and specificity to diagnose seminal vesicle invasion (SVI) on mpMRI were 43.8 and 95.4 %, respectively. The negative predictive value was 78.9 %. The sensitivity and specificity to diagnose extracapsular extension (ECE) were 54.5 and 80.5 %, respectively. The overall sensitivity and specificity of diagnosing pathological T3 or higher were 52.6 and 82.1 %, respectively. Non-organ-confined disease determined by mpMRI was significantly associated with positive surgical margin and pathological T3 disease on multivariate analysis. Preoperative adverse findings on mpMRI were significantly associated with performance of the non-nerve-sparing technique.

Conclusion

mpMRI did not show outstanding diagnostic accuracy relative to our expectations in predicting SVI or ECE preoperatively. However, adverse findings on preoperative mpMRI were significantly related to worse postoperative pathological outcomes as well as postoperative biochemical recurrence.

     

Transrectal ultrasound versus magnetic resonance imaging in the estimation of prostate volume as compared with radical prostatectomy specimens

INTRODUCTION: There are relatively few studies that compare the use of transrectal ultrasound (TRUS) to magnetic resonance imaging (MRI) to estimate the prostate volume. In this study, we compared the prostate volumes measured with MRI and TRUS with a surgical specimen volume. PATIENTS AND METHODS: Seventy-three patients underwent TRUS examination of the prostate prior to radical prostatectomy. All specimens were weighed and measured when freshly excised. The corresponding volume measurements calculated using TRUS and MRI were compared retrospectively with the measured volumes of freshly excised prostate. RESULTS: The volume measured with TRUS and MRI was linearly related to the radical prostatectomy volume. The estimated increase in the prostate volumes measured with TRUS and MRI per specimen volume was 0.9508 and 0.9331 by regression analysis, respectively. If the prostate volumes were <35 cm(3), the prostate volumes measured with MRI overestimated the specimen volumes. If the prostate volumes were >35 cm(3), the prostate volumes measured with MRI underestimated the specimen volumes. The classic ellipsoid formula was adequate for determining the prostate volume. CONCLUSIONS: In this study, MRI and TRUS gave different volumes. MRI is more accurate than TRUS for determining the prostate volume. However, because TRUS is inexpensive, noninvasive, and almost as accurate as MRI, it should be the preferred method for measuring the prostate volume.     

Blood loss during radical retropubic prostatectomy: relationship to morphologic features on preoperative endorectal magnetic resonance imaging

Objectives. To determine whether morphologic features at preoperative magnetic resonance imaging (MRI) are related to intraoperative blood loss during radical retropubic prostatectomy.Methods. Endorectal MRI was performed in 143 patients with newly diagnosed prostate cancer before radical retropubic prostatectomy. Two independent readers rated the prominence of the periprostatic veins (on the basis of number and size) at four anatomic sites on a 3-point scale. Other features analyzed were prostate volume and interspinous diameter.Results. A prominence of the anterior and posterior apical periprostatic veins was positively associated with blood loss (correlation coefficient = 0.22 and 0.17 and P <0.01 and <0.05, respectively). Blood loss was not related to prostate volume (correlation coefficient = 0.02, P = 0.8) or interspinous diameter (correlation coefficient = 0.01, P = 0.9). The site-specific scores of both readers demonstrated positive agreement, with Pearson’s correlation coefficients of 0.51 to 0.65 (P <0.01).Conclusions. A marked prominence of the apical periprostatic veins on preoperative MRI is associated with greater intraoperative blood loss during radical retropubic prostatectomy. Other morphologic factors appear unrelated to the amount of intraoperative blood loss.     

Endorectal magnetic resonance imaging has limited clinical ability to preoperatively predict pT3 prostate cancer

Study Type – Diagnostic (non‐consecutive case series)
Level of Evidence 3b What’s known on the subject? and What does the study add? A wide range of performance characteristics has been reported for the preoperative prediction of extraprostatic extension by erMRI, with sensitivities as high as 90%. Our study differs in design from previous investigations in three ways: we examined the performance characteristics of the erMRI on patients with clinical parameters of prostate cancer worrisome for advanced disease; we dichotomized erMRI reports as “positive” or “negative”; and erMRIs were conducted at both academic and community radiology centers, which we believe is more reflective of current practice patterns in the USA. We found the overall accuracy of erMRI to be 62%, with a positive predictive value of 50%, suggesting that pretreatment erMRI offers minimal clinical information.

OBJECTIVE

• ? To assess the clinical value of preoperative knowledge of the presence of extracapsular extension (ECE) or seminal vesicle invasion (SVI) in the planning for prostatectomy.

MATERIALS AND METHODS

• ? An institutional database of 1161 robotic‐assisted laparoscopic prostatectomies (RALP) performed by a single surgeon (D.B.S.) was queried for those who underwent endorectal coil magnetic resonance imaging (erMRI) before robotic‐assisted laparoscopic prostatectomy.
• ? erMRI reports were dichotomized into positive or negative and compared with the final histopathology. The erMRIs performed at academic centres were compared with those performed in non‐academic settings.
• ? A sub‐group of high‐risk patients was also analyzed for erMRI accuracy.

RESULTS

• ? The 179 patients who underwent erMRI had significantly worse disease compared to the 982 patients without imaging. Of the 110 patients with histopathologically organ‐confined disease, 81 (74%) were correctly diagnosed as such on erMRI, whereas 29 (26%) were felt to have cT3 disease and constituted false‐positives. Among the 69 patients with pT3 disease, erMRI correctly predicted 30 (43%), whereas 39 (57%) were incorrectly considered organ‐confined.
• ? The overall sensitivity and specificity for diagnosing pT3 disease was 43% and 73%.
• ? When stratified by pT3a and pT3b, the sensitivity and specificity of erMRI to accurately diagnose ECE is 33% and 81%, respectively. In evaluating SVI, erMRI has a sensitivity and specificity of 33% and 89%, respectively. The positive predictive value of erMRI to assess for ECE and SVI is 50% in both, with a negative predictive value of 61% and 63%, respectively.
• ? erMRIs performed at academic centres compared to non‐academic locations demonstrated similar rates of sensitivity at 67% vs 77% and specificity at 39% vs 54%, respectively (P= 0.33).

CONCLUSIONS

• ? In the setting of the present study, which was designed to be more reflective of current practice patterns in the USA, erMRI has limited clinical value in preoperatively detecting ECE and SVI.
• ? The accuracy of detecting T3 disease did not improve in academic centres or in high‐risk patients.

     

Phased-array magnetic resonance imaging of the prostate with correlation to radical prostatectomy specimens: local experience

PURPOSE: To evaluate local experience of phased-array magnetic resonance imaging (MRI) in the staging of locally advanced prostate carcinoma with comparison to clinical staging. METHODS: The study population was 21 patients who underwent preoperative MRI with pelvic phased-array coils followed by radical prostatectomy. The MRI findings were correlated with completely embedded serially sliced and whole-mounted sections of the prostate gland and clinical staging. RESULTS: Overall accuracy of 57.1% was obtained, with specificity of 90.0% and sensitivity of 27.3%. All but one case of locally advanced disease missed by MRI was microscopic. Clinical staging in these cases also achieved accuracy of 57.1%, specificity of 90.0% and sensitivity of 27.3%. CONCLUSIONS: MRI with a phased-array coil has high specificity but low sensitivity for detection of extraprostatic disease. Phased-array MRI does not image microscopic tumour extension. It did not perform better than clinical staging and is not recommended for routine staging.     

Prediction of focal extracapsular extension at radical prostatectomy: Relative merit of transrectal ultrasound, endorectal magnetic resonance imaging, prostate specific antigen, prostate specific antigen density, and systematic biopsy

We conducted a study to compare the relative merits of prostate specific antigen (PSA), PSA density (PSAD), transrectal ultrasound (TRUS), endorectal magnetic resonance imaging (MRI), and systematic biopsy in the prediction of focal extracapsular extension (ECE) at radical prostatectomy. A retrospective review of patients who underwent TRUS, endorectal MRI, and radical prostatectomy at our institution was performed. Patients with a diagnosis of prostate cancer who were thought to be surgical candidates by digital rectal examination and TRUS underwent endorectal MRI prior to radical prostatectomy. Imaging, PSA, PSAD, and systematic biopsy results (tumor grade and fraction of positive systematic biopsies) were correlated with step-sectioned, radical prostatectomy pathologic data. Data was analyzed for the entire prostate and on each individual side. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios were calculated for each modality, and receiver operating characteristic (ROC) curves were generated. Stepwise logistic regression analysis was used to weigh the relative contributions of preoperative parameters in predicting ECE.

Data was collected from 54 patients who had sextant systematic biopsy, imaging, and radical prostatectomy. A total of 24 sides demonstrated ECE (19 patients, 5 with bilateral ECE). When assessed for the dominant prostate side and on a side-for-side basis, MRI had the highest sensitivity and NPV for detecting focal ECE. MRI also had the highest PPV, and TRUS had the highest specificity for side-for-side analysis. For the dominant prostate side, PSA had the highest specificity and PPV for detecting focal ECE. Of note, significant overlap was demonstrated in the 95% confidence intervals of all modalities with each other for all analyses. ROC analyses found MRI and Gleason sum to be superior for the dominant prostate side assessment and MRI and the fraction of positive systematic biopsies to be superior for a side-for-side analysis. Optimal likelihood ratios for positive test results were seen for PSA (dominant prostate side) and MRI (side-for-side), and for negative test results for MRI. Logistic regression demonstrated MRI and Gleason sum to be powerful predictors of ECE. Thus, we would conclude that endorectal MRI and tumor grade provide unique information in the prediction of focal ECE in select patients.