Faculty Bibliography

OBJECTIVE: To compare renal functional outcomes in robotic partial nephrectomy (RPN) with selective arterial clamping guided by near-infrared fluorescence (NIRF) imaging to a matched cohort of patients who underwent RPN without selective arterial clamping and NIRF imaging. METHODS: From April 2011 to December 2012, NIRF imaging-enhanced RPN with selective clamping was used in 42 cases. Functional outcomes of successful cases were compared with a cohort of patients, matched by tumor size, preoperative estimated glomerular filtration rate (eGFR), functional kidney status, age, sex, body mass index, and American Society of Anesthesiologists score, who underwent RPN without selective clamping and NIRF imaging. RESULTS: In matched-pair analysis, selective clamping with NIRF was associated with superior kidney function at discharge, as demonstrated by postoperative eGFR (78.2 vs 68.5 mL/min/1.73 m2; P = .04), absolute reduction of eGFR (-2.5 vs -14.0 mL/min/1.73 m2; P <.01), and percent change in eGFR (-1.9% vs -16.8%; P <.01). Similar trends were noted at 3 month follow-up, but these differences became nonsignificant (P[eGFR] = .07; P[absolute reduction of eGFR] = .10; and P[percent change in eGFR] = .07). In the selective clamping group, a total of 4 perioperative complications occurred in 3 patients, all of which were Clavien grade I-III. CONCLUSION: Use of NIRF imaging was associated with improved short-term renal functional outcomes when compared with RPN without selective arterial clamping and NIRF imaging. With this effect attenuated at later follow-up, randomized prospective studies and long-term assessment of kidney-specific functional outcomes are needed to further assess the benefits of this technology.

PURPOSE: Optimization of prostate biopsy requires addressing the shortcomings of standard systematic transrectal ultrasound guided biopsy including false negative rates, incorrect risk stratification, detection of clinically insignificant disease, and the need for repetitive biopsy. MRI is an evolving noninvasive imaging modality that increases the accurate localization of prostate cancer (PCa) at the time of biopsy, thereby enhancing clinical risk assessment, and improving the ability to appropriately counsel patients regarding therapy. The purpose of this review is to 1) summarize the various sequences that comprise a prostate multiparametric MRI exam along with its performance characteristics in cancer detection, localization and reporting standards, 2) evaluate potential applications of MRI targeting in prostate biopsy among men with no previous biopsy, a negative previous biopsy, and those with low stage cancer and 3) describe the techniques of MRI-targeted biopsy and their comparative study outcomes MATERIALS AND METHODS: A bibliographic search covering the period up to October, 2013 was conducted using MEDLINE(R)/PubMed(R). Articles were reviewed and categorized based on which of the three objectives of this review was addressed. Data was extracted, analyzed, and summarized. RESULTS: Mp-MRI consists of anatomic T2-weighted imaging coupled with at least 2 functional imaging techniques and has demonstrated improved PCa detection sensitivity up to 80% in the peripheral zone and 81% in the transition zone. A PCa MRI suspicion score has been developed and is depicted using the Likert or PI-RADS scale for better standardization of MRI interpretation and reporting. Among men with no previous biopsy, MRI increases the frequency of significant cancer detection to 50% in low risk and 71% in high risk patients. In low risk men, the negative predictive valve of a combination of negative MRI with prostate volume parameters is nearly 98%, suggesting a potential role in avoiding a biopsy and reducing overdetection/overtreatment. Among men with previous negative biopsy, 72-87% of cancers detected by MRI guidance are clinically significant. Among men with known low risk cancer, repeat biopsy by MR-targeting demonstrates a high likelihood of confirming low risk disease in low suspicion score lesions and for upgrading in high suspicion score lesions. Techniques of MRI-targeted biopsy include visual estimation TRUS-guided biopsy, software co-registered MRI-US TRUS-guided biopsy, and in-bore MRI-guided biopsy. Although the improvement in accuracy and efficiency of visual estimation biopsy compared to systematic appears limited, both co-registered MRI-US biopsy and in-bore MRI-guided biopsy appears to increase cancer detection rates in conjunction with increasing suspicion score. CONCLUSIONS: Use of MRI for targeting prostate biopsies has potential to reduce the sampling error associate with conventional biopsy by providing better disease localization and sampling. More accurate risk stratification through improved cancer sampling may impact upon therapeutic decision-making. Optimal clinical application of MRI-targeted biopsy remains under investigation.

A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection and avoidance of a repeat biopsy while minimizing the detection of insignificant prostate cancers. Magnetic resonance imaging-guided prostate biopsy has an evolving role in both initial and repeat prostate biopsy strategies, potentially improving sampling efficiency, increasing the detection of clinically significant cancers, and reducing the detection of insignificant cancers. Hematuria, hematospermia, and rectal bleeding are common complications of prostate needle biopsy, but are generally self-limiting and well tolerated. All men should receive antimicrobial prophylaxis before biopsy.