HoLEP: the new gold standard for surgical treatment of benign prostatic hyperplasia

INTRODUCTION Transurethral resection of the prostate (TURP) was considered the "gold standard" surgical treatment for medication-refractory benign prostatic hyperplasia (BPH) for decades. With the desire to reduce hospital stay, complications, and cost, less invasive procedures gained usage in the 1990's. With the advent of a soft tissue morcellator, holmium laser enucleation of the prostate (HoLEP) was introduced as an efficacious alternative to TURP and due to its advantageous side effect profile compared to TURP, has grown in popularity ever since. HoLEP has become a size-independent guideline endorsed procedure of choice for the surgical treatment of BPH.

MATERIALS AND METHODS

We provide a review on the evolution of HoLEP as a gold standard compared to the historical reference procedures for BPH, and provide a review of emerging laser technologies.

RESULTS

A growing body of literature has shown HoLEP to be a safe and efficient procedure for the treatment of BPH for all prostate sizes. Long term studies have proven the durability of HoLEP, as a first line surgical therapy for BPH.

CONCLUSIONS

HoLEP is a proven modality for the surgical treatment of BPH. It can be performed on patients with high risk for postoperative bleeding, or after previous prostate reducing procedures. HoLEP is the only procedure that is AUA guideline-endorsed for all prostate sizes for the surgical treatment of BPH. Given these considerations, HoLEP has become the new gold-standard for the surgical treatment of BPH.

Ergonomics in Endourology: Measurement of Force for Deflection in Contemporary Ureteroscopes

Introduction: Few studies have examined the ergonomic hazards to endourologists during endoscopic procedures. We have evaluated the forces required to deflect different flexible ureteroscopes across a range of measurements with several different standard instruments within the working channel. Methods: Five ureteroscopes were studied: the Uscope, Neoflex, LithoVue^™, URF-P6, and the Flex-X2^™. A pull-force meter (Nextech DFS 500) was attached to the thumb lever to deflect the tip from 30° to 210° at 30° intervals. Measurements were made with upward and downward deflection separately. The forces were reported in Newtons (N) to the nearest 10th, as positive values regardless of the direction of the force. Measurements were made with the channel empty or containing an instrument: a 365 μm laser fiber, a 2.4F Nitinol basket, 3F biopsy forceps, or a 0.038" guidewire using the flexible or the stiff tip. Results: The maximum downward deflection force, measured at 210° of deflection, with an empty channel range from a minimum of 5.7 N in one scope to a maximum of 33.4 N in another. The force necessary for deflection ranges from 2.0 to 7.0 N (0.45-1.57 foot-pounds) at 30° to 8.5 to 25.3 N (1.8-5.69) at 180°. Maximum upward deflection shows similar results with a minimum of 7.9 N in one scope and a maximum of 43.1 N of force in another. Working instruments in the channel increased the force needed for deflection. Conclusions: Forces required for steep deflection of the tip of a flexible ureteroscope reach extremely high levels or limit the deflection capability of the scope. The force is higher with increased deflection and with instruments within the channel.

Hypogonadism and prostate cancer detection on multiparametric MRI and mpMRI-TRUS fusion biopsy

PURPOSE

Currently, there is a dearth of data concerning the impact of hypogonadism on prostate cancer detection by imaging. In this study, we evaluated the performance of multiparametric MRI (mpMRI) and mpMRI-TRUS fusion biopsy in hypogonadal patients.

MATERIALS AND METHODS

Clinical and pathologic data from a prospectively maintained, single-institution database of patients who underwent 3T mpMRI and fusion biopsy between 2007 and 2016 were analyzed. Hypogonadism was defined by an institutional cutoff of serum testosterone ≤ 180 ng/dL; T2, DWI, and DCE scores were calculated from mpMRI. Cancer detection rates were compared by Chi-square tests. Multivariate logistic regression was undertaken to evaluate the impact of hypogonadism on clinically significant cancer detection by systematic and fusion biopsy.

RESULTS

We included 522 patients in our study who had total testosterone levels measured within 90 days of mpMRI. Of these, 49 (9.4%) were hypogonadal. Median total testosterone was 148 ng/dL (IQR 41) in the hypogonadal group, and 304 ng/dL (IQR 132) in the normogonadal group (p < 0.001). Imaging results were comparable between the hypo and normogonadal groups. In the hypogonadal group, systematic biopsy detected clinically significant cancer in 28.6% of patients compared to 40.8% with fusion biopsy. In the normogonadal cohort, systematic and fusion biopsy detected 37.3% and 43.2% CS cancer, respectively. In the hypogonadal cohort, fusion biopsy detected 12.2% more CS cancers compared to systematic biopsy, while it detected only 5.9% more in the normogonadal cohort. On multivariate analysis, hypogonadism was found to be an independent predictor of decreased CS cancer detection on systematic (p = 0.048), but not on fusion biopsy (p = 0.170).

CONCLUSIONS

Hypogonadism is an independent predictor of lower CS cancer detection on systematic biopsy. However, it fails to significantly impact CS detection on fusion biopsy with comparable cancer detection rates in both groups. Patients with hypogonadism may benefit more from fusion biopsy than normogonadal patients.

Overlapping surgeries: defining the 'critical portions' of the procedure

INTRODUCTION

An important aspect of overlapping surgery is to determine the 'critical portion' of an operation. Currently, there are no guidelines that standardize the critical portions of common urologic procedures. We sought to determine the relationship between the critical portions of common urologic operations as defined by the primary surgeon compared to the trainee at a single academic medical center.

MATERIALS AND METHODS

In an open-ended survey of the Urology Department at Thomas Jefferson University, attending surgeons and urology residents, were asked to list five of their most commonly performed surgeries and subsequently identify what they defined as the critical portion for each. Responses were examined for surgeon-trainee congruence. Response agreement was defined as identifying key words that provided reasonable evidence that the responders were referring to identical portions of the case.

RESULTS

Nine residents and eight attending physicians provided 67 and 63 responses, respectively, encompassing 28 different procedures. Six procedures were chosen for further analysis based on high volume of responses. Overall, of the 67 resident-reported critical portions, 32 (47.8%) were in agreement with attending-reported critical portions. Year of training in residency was not a predictor of surgeon-trainee agreement.

CONCLUSION

External pressures from the public and lawmakers alike may demand that providers be present during all 'critical portions' of a procedure. Our study shows that the understanding of critical portions of an operation is often incongruent between surgeons and trainees. Critical portions of all procedures should be established by the surgical team in order to accurately schedule overlapping surgeries.

Analyzing the current practice patterns and views among urologists regarding focal therapy for prostate cancer

INTRODUCTION AND OBJECTIVE

Focal therapy (FT) for localized prostate cancer (CaP) has been shown to have encouraging short-term oncological outcomes, excellent preservation of functional outcomes and is increasing in popularity in urologic community. We aim to evaluate the preferences and practice trends among urologists regarding this treatment strategy.

METHODS

A 20 item online questionnaire was designed to collect information on urologists' views and use of FT. The survey was sent to the members of the Endourological Society and the American Urological Association. Multivariate logistic regression analysis was done to determine predictors for utilization of FT.

RESULTS

A total of 425 responses were received [American Urological Association: 319, Endourological Society: 106]. Mean age of respondents was 53(SD: 11.3) years. Although half of the respondents (50.8%) believed FT to be moderate to extremely beneficial in the treatment of CaP, only 24.2% (103) of the respondents currently utilize FT in their practice. Respondents who were fellowship trained in urologic oncology were more likely to consider FT to be at least moderately beneficial (P < 0.001). Surgeon's experience (greater than 15 years in urology practice) (P = 0.025) and seeing more than 10 patients with new CaP diagnosis per month (P = 0.002) were independent predictors of FT utilization for localized CaP. While the most common setting for utilization of FT was in patients with unilateral intermediate-risk (72.8%) CaP, a small percentage of respondents also used FT for patients with unilateral high-risk CaP and bilateral intermediate risk (21.4% and 10.7%, respectively). Most common reasons for not using FT were the lack of belief in 'index lesion theory' (63.2%), lack of experience (41.3%), lack of belief in FT's efficacy (41.1%), lack of infrastructure (35.8%), difficult salvage treatment in cases of recurrence (22.7%) and high cost (21.8%). About 57.6% would use FT more often in an office or outpatient setting if they had access to reliable and cost-effective options.

CONCLUSIONS

Only a quarter of our respondents utilize FT in their practice with surgeon's experience being the important independent predictor for using FT. Majority of respondents though consider FT to be beneficial in CaP management, would use it more often if provided more reliable and cost-effective options. Over time, experience and accessibility to reliable methods to perform FT may lead to further utilization of this novel treatment strategy.

Changes in prostate cancer detection rate of MRI-TRUS fusion vs systematic biopsy over time: evidence of a learning curve

BACKGROUND

To determine the effect of urologist and radiologist learning curves and changes in MRI-TRUS fusion platform during 9 years of NCI's experience with multiparametric magnetic resonance imaging (mpMRI)/TRUS fusion biopsy.

METHODS

A prospectively maintained database of patients undergoing mpMRI followed by fusion biopsy (Fbx) and systematic biopsy (Sbx) from 2007 to 2016 was reviewed. The patients were stratified based on the timing of first biopsy. Cohort 1 (7/2007-12/2010) accounted for learning curve. Cohort 2 (1/2011-5/2013) and cohort 3 (5/2013-4/2016) included patients biopsied prior to and after debut of a new software platform, respectively. Clinically significant (CS) disease was defined as Gleason 7 (3+4) or higher. McNemar's test compared cancer detection rates (CDRs) of Sbx and Fbx between time periods.

RESULTS

1528 patients were included in the study with 230, 537 and 761 patients included in three respective cohorts. Median age (interquartile range) was 61.0 (±9.0), 62.0 (±7.3), and 64.0 (±11.0) years in three cohorts, respectively (P<0.001). Fbx and Sbx had comparable CS CDR in cohort 1 (24.8 vs 22.2%, P=0.377). Fbx detected significantly more CS disease compared to Sbx in the following two periods (cohort 2: 31.5 vs 25.0%, P=0.001; cohort 3: 36.4 vs 30.3%, P<0.001) and detected significantly less low risk disease in the same period (cohort 2: 14.5 vs 19.6%, P<0.001; cohort 3: 12.6 vs 16.7%, P<0.001). Even after multivariate adjustment with age, PSA, race, clinical stage and MRI suspicion score, Fbx CS cancer detection increased in successive cohorts (cohort 2: OR 2.23, P=0.043; cohort 3: OR 2.92, P=0.007).

CONCLUSIONS

In the past 9 years, there has been significant improvement in the accuracy of Fbx. Our results show that after an early learning period, Fbx detected higher rates of CS cancer and lower rates of clinically insignificant cancer than Sbx. Software advances allowed for even greater detection of CS disease.

MRI-targeted biopsy: is systematic biopsy obsolete?

INTRODUCTION

Although prostate cancer is the most common non-cutaneous cancer in men, it is traditionally diagnosed with a non-targeted, systematic transrectal ultrasound prostate biopsy (TRUS-Bx). This technique has been demonstrated to both under-detect clinically significant (CS) cancer and over-detect clinically insignificant cancer, and performs poorly in patients with a prior negative biopsy. With recent advances in MRI technology, most prominently the advent of multiparametric MRI, MRI-targeted prostate biopsy (MRI-TB) has been gaining favor as a more accurate alternative to TRUS-Bx. In this review, we attempt to summarize the current literature on MRI-TB and to determine if there is evidence supporting the use of MRI-TB alone.

MATERIALS AND METHODS

The literature was reviewed for articles pertaining to MRI-TB and its performance compared to systematic biopsy.

RESULTS

Most studies support the increased sensitivity of MRI-TB (0.90, 95% CI 0.85-0.94) compared to TRUS-Bx (0.79, 95% CI 0.68-0.87) for the detection of CS prostate cancer, as MRI-TB can detect up to 30% more high risk and 17% fewer low risk cancers. MRI-TB also tends to perform better than TRUS-Bx in patients with prior negative biopsy, as TRUS-Bx may miss up to half of CS cancers detected by MRI-TB, and in those with lesions at atypical locations. However, as the technology for imaging and image-guided biopsies continues to develop, there is still a role for TRUS-Bx in the management of patients with prostate cancer.

CONCLUSIONS

Our analysis of the literature suggests that although MRI-TB is superior to TRUS-Bx, there is still a role for traditional systematic biopsy.

Abstract 2488: Reovirus (Reolysin) as a potential therapy for malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNST) are a rare form of soft tissue sarcoma which may occur sporadically in the general population or in association with neurofibromatosis type 1 (NF1), and are highly aggressive and often fatal. NF1 patients are at a greater risk for the development of malignant peripheral nerve sheath tumors than the general population. Current therapy relies upon surgical resection with adjuvant chemotherapy and/or radiotherapy. Clinical trials using Reolysin (Respiratory Enteric Orphan Virus) which is developed from the naturally-occurring human reovirus have demonstrated the efficacy of this reovirus as an oncolytic virotherapy. Reolysin selectively replicates in cancer cells with activated Ras (Ras-GTP), resulting in virus-mediated apoptotic cell death. Hence Reolysin demonstrates promising anticancer activity and has minimal toxicity in patients. Since MPNST is associated with neurofibromin (NF1) deficiency and active Ras we tested these tumors as therapeutic targets for Reolysin treatment using two NF1 deficient human MPNST-derived cell lines (CRL-2884, ST8814) with activated Ras and one sporadic MPNST cell line (STS26T) which expresses NF1 but not active Ras. These were compared with normal human Schwann cells (NHSC) which do not show active Ras and mammary gland cells derived from an NF1 patient (CRL-7329). Reolysin inhibited the proliferation and viability of the three MPNST cell lines at a dose of 0.1 to 10 virus particles/cell, including sporadic MPNST cells which do not have active Ras. In contrast, the NHSC and CRL-7329 cells were more resistant to viral treatment, with apoptosis induced at higher viral concentrations (10,000 and 100,000 virus particles/cell respectively). Furthermore, we examined the effects of Reolysin on the Ras-signaling pathway in a bladder cancer cell line (HTB-4) expressing NF1 and Ras and found that virus induced cytotoxicity was similar to the control cell lines (100,000 virus particles/cell). This study shows that MPNST-derived cell lines including sporadic MPNST without active Ras were efficiently transduced, promoted virus replication and were killed by the oncolytic reovirus. In contrast to the highly sensitive MPNST cell lines, NHSC, CRL-7329 and HTB-4 cells were resistant at similar viral concentrations. Our data suggests the use of oncolytic Reolysin may represent a novel treatment approach for patients with MPNST and provides the basis for preclinical testing of the antitumor effects. Therapeutic efficacy of Reolysin in a mouse model for MPNST is underway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2488. doi:1538-7445.AM2012-2488