Re: Prospective Assessment of Prostate Cancer Aggressiveness Using 3-T Diffusion-weighted Magnetic Resonance Imaging–guided Biopsies Versus a Systematic 10-core Transrectal Ultrasound Prostate Biopsy Cohort

731

EUROPEAN UROLOGY 62 (2012) 728–734

Maurizio Seratia,*, Elena Cattonia, Andrea Bragaa,

[3] Laurikainen E, Kiilholma P. The tension-free vaginal tape procedure

Giacomo Novarab

for female urinary incontinence without preoperative urodynamic a

evaluation. J Am Coll Surg 2003;196:579–83. stress incontinence—which test and when? Curr Opin Urol 2008; 18:359–64.

Department of Obstetrics and Gynecology, University of Insubria, Del Ponte Hospital, Varese, Italy

[4] Patel AK, Chapple CR. Urodynamics in the management of female b

Department of Surgical, Oncological, and Gastroenterological Sciences, Urology Clinic, University of Padua, Padua, Italy

[5] Novara G, Artibani W, Barber MD, et al. Updated systematic review and meta-analysis of the comparative data on colposuspensions,

*Corresponding author. Department of Obstetrics and

pubovaginal slings, and midurethral tapes in the surgical treatment

Gynecology, University of Insubria, Del Ponte Hospital,

of female stress urinary incontinence. Eur Urol 2010;58:218–38. [6] Abdel-Fattah M, Ford JA, Lim CP, Madhuvrata P. Single-incision

Piazza Biroldi 1, Varese 21100, Italy. E-mail address: [email protected] (M. Serati).

mini-slings versus standard midurethral slings in surgical management of female stress urinary incontinence: a meta-analysis of effectiveness and complications. Eur Urol 2011;60:468–80.

Re: Prospective Assessment of Prostate Cancer Aggressiveness Using 3-T Diffusion-weighted Magnetic Resonance Imaging–guided Biopsies Versus a Systematic 10-core Transrectal Ultrasound Prostate Biopsy Cohort Hambrock T, Hoeks C, Hulsbergen-van de Kaa C, et al Eur Urol 2012;61:177–84 Experts’ summary: In this article, the diagnostic accuracy of prostate cancer (PCa) using magnetic resonance imaging (MRI)–guided biopsy was investigated in patients with elevated serum prostate-specific antigen (PSA) level and a negative transrectal ultrasound biopsy (TRUSB) compared with patients who completed a 10-core TRUSB. Using T2-weighted, diffusion-weighted (DW), and dynamic contrast-enhanced (DCE) MRI, the apparent diffusion coefficient (ADC) value was calculated and suspicious lesions were identified. Biopsies performed in the suspicious areas were guided by multiparametric MRI (MP-MRI) to obtain the tissue, and the pathology diagnosis and Gleason score were determined. The results showed that specimens from the MRI-guided biopsies were superior to those collected by TRUSB for pretreatment risk stratification with Gleason score and more accurately reflected the Gleason score of the radical prostatectomy specimen (88% vs 55%). The authors concluded that MRI could be a valuable diagnostic tool for PCa. Experts’ comments: This article elucidated the value of MRI-guided biopsy as a diagnostic tool for PCa. MRI-guided prostate biopsy is performed in two sessions: diagnostic MRI examination and MRI-guided biopsy. In this study, the results of DW-MRI and T2-MRI of the prostate showed promising value in PCa localization because of its high-contrast resolution between tumors and normal tissue. For example, ADC produced by DW-MRI is significantly lower in malignant tissue compared to nonmalignant prostate tissue, and this aids in locating cancer tissue. Moreover, ADC is a significant predictor of Gleason score [1]. MRI-guided biopsy based on the results of MP-MRI (T2-weighted combined with DW imaging) is more accurate than digital rectal examination and systematic random biopsy results and is able to target previously determined regions suspicious for cancer. DW-MRI combined with T2-weighted MRI can detect PCa with 89% sensitivity and 91%

http://dx.doi.org/10.1016/j.eururo.2012.07.018

specificity; using TRUSB, cancer was missed in 10–38% of PCa patients [2]. Furthermore, for the patients with elevated serum PSA and a negative TRUSB, Engelhard et al recently reported a 38% detection rate for MRI-guided rebiopsies, compared with a 20–30% detection rate for TRUS saturation rebiopies[3]. There are still some limitations with MRI-guided biopsy. Many factors, such as temperature, blood perfusion, different MP-MRI sequence, and magnetic susceptibility in the tissue, could vary the MP-MRI results, affecting values such as ADC. There is also a lack of standardization regarding the MRI technique and imaging protocols (eg, surface or endorectal coil, field strengths, and sequence) across multiple centers, which makes defining the guidelines problematic. Also, the presence of benign prostatic hyperplasia, prostatitis, hemorrhage, and fibrosis, make cancer in central and transition zones more difficult to discern using both the T2-MRI and DW-MRI. There is limited availability of MRI-guided biopsy due to long examination times, space restriction, material restriction, organ motion, and need to adjust the needle’s direction. Prostate motion during the procedure could also affect the accuracy of the biopsy. To compensate for technical limitations, technological advancements have been developed, such as real-time fusion of ultrasound and magnetic resonance (MR) images of the prostate and MR-compatible robots for transrectal prostate biopsy systems [4,5]. Further research is still needed to determine their diagnostic effectiveness. In future MP-MRI studies, the focus should be to obtain evidence to improve the performance of MRI. Random clinical trials are needed to evaluate the feasibility of replacing the TRUSB with the MRI-guided biopsy. The clinical implications and optimal technique for PCa diagnosis using MRI needs to be evaluated to establish a standardized protocol. The development of new instrumentation for use in the MRI environment is necessary to enhance the suitability for clinical application as well as to overcome any pitfalls. Moreover, the next generation of iconography should be molecular imaging, which could provide unprecedented opportunities for accurate cancer localization, staging, and prognosis evaluation. These, in turn, could lead to the prevention of overtreatment and better cancer control. For example, hypoxia-inducible

732

EUROPEAN UROLOGY 62 (2012) 728–734

factors or iron oxide nanoparticles should be the future of prostate cancer imaging.

[4] Singh AK, Kruecker J, Xu S, et al. Initial clinical experience with real-

Conflicts of interest: The authors have nothing to disclose.

[5] Xu H, Lasso A, Vikal S, et al. MRI-guided robotic prostate biopsy: a

time transrectal ultrasonography-magnetic resonance imaging fusion-guided prostate biopsy. BJU Int 2008;101:841–5. clinical accuracy validation. Med Image Comput Comput Assist Interv 2010;13:383–91.

References [1] Morgan VA, Riches SF, Thomas K, et al. Diffusion-weighted mag-

Jinyi Li*, Siobhan Gruschow, Ashutosh Tewari Institute of Prostate Cancer and LeFrak Center for Robotic Surgery,

netic resonance imaging for monitoring prostate cancer progres-

James Buchanan Brady Foundation Department of Urology,

sion in patients managed by active surveillance. Br J Radiol

Weill Cornell Medical College–New York Presbyterian Hospital, New York, NY, USA

2011;84:31–7. [2] Giannarini G, Petralia G, Thoeny HC. Potential and limitations of diffusion-weighted magnetic resonance imaging in kidney, pros-

*Corresponding author. Institute of Prostate Cancer and LeFrak Center

tate, and bladder cancer including pelvic lymph node staging: a

for Robotic Surgery, James Buchanan Brady Foundation Department of Urology, Weill Cornell Medical College,

critical analysis of the literature. Eur Urol 2012;61:326–40. [3] Engelhard K, Hollenbach HP, Kiefer B, et al. Prostate biopsy in

525 East 68th St., New York, NY 10065, USA.

the supine position in a standard 1.5-T scanner under real time

E-mail address: [email protected] (J. Li).

MR-imaging control using a MR-compatible endorectal biopsy device. Eur Radiol 2006;16:1237–43.

Re: Video Technique for Human Robot-assisted Microsurgical Vasovasostomy Parekattil SJ, Atalah HN, Cohen MS J Endourol 2010;24:511–4 Experts’ summary: The reviewed article is the first prospective control trial of significant size to compare robot-assisted vasovasostomy (RAVV) and robot-assisted vasoepididymostomy (RAVE) with traditional microsurgical vasovasostomy (MVV) and microsurgical vasoepididymostomy (MVE). Below, we will discuss this manuscript and also refer to a follow-up publication published shortly thereafter by Parekattil and Brahmbhatt on this topic [1]. RAVV achieved a 96% patency rate versus 80% for MVV for 123 total cases. Median operative duration (which did not include robot or operating microscope setup) was 90 min for RAVV versus 120 min for MVV. The rate of postoperative sperm count recovery was significantly greater in RAVV versus RAVE (13 million/mo vs 3 million/mo), although mean total motile sperm counts were not significantly increased. The authors, in their practice, also reported a reduced cost for RAVV and RAVE that has recently made it less expensive at their institution than MVV or MVE. Experts’ comments: Previous studies in animals have suggested potential advantages of RAVV over MVV, including increased patency rates and ease of performing the procedure afforded by more ergonomic instrument manipulation [2]. The authors are to be commended for pursuing a relatively large cohort in a prospective trial to further elucidate an increasingly important and timely question: Are robot-assisted techniques superior to traditional microsurgical approaches in vasectomy reversal? The authors note 96% patency in the robotic group, which was superior to the MVV group (80%) and approaches the maximum published patency rate for MVV of 97% [3]. Significantly, data available for the first 90 study subjects

http://dx.doi.org/10.1016/j.eururo.2012.07.019

reveal a RAVV population with median duration from vasectomy at 8 yr (range: 1–19) compared with 6.5 yr (range: 1–19) for MVV. Thus RAVV seems to have outperformed MVV even in a group possessing a stronger independent risk factor (longer obstructive interval) for reversal failure, as described in a recently published nomogram [4]. It is noteworthy that both surgeons and support staff require an initial training investment and experience a learning curve regarding equipment setup and technique (eg, bent needles, suture breakage). While Parekattil et al noted a shorter operative duration for RAVV and RAVE, the robot and operating microscope setup times were not included in the measure of operative duration. These specific time measurements are important data points to consider when comparing the two operative techniques. Surgical robotics is a quickly advancing urologic platform. In their study, Parekattil et al provide early insight into the application of robotic technology in the field of vasectomy reversal. Enhancements in operating technique and rate of sperm return to the ejaculate have been nicely highlighted by the authors. Limitations of this study include a lack of randomization, a relatively short follow-up time, and lack of incorporation of robotic and operating microscope setup in the reported operative times. Long-term follow-up derived from multicenter, randomized trials is needed to further clarify the role of robot-assisted vasectomy reversal procedures. At this time, it is unclear whether the potential incremental technical enhancements outweigh the probable increase in cost and operative time that most surgeons would incur with this approach. Conflicts of interest: The authors have nothing to disclose.

References [1] Parekattil SJ, Brahmbhatt JV. Robotic approaches for male infertility and chronic orchialgia microsurgery. Curr Opin Urol 2011;21: 493–9.