Faculty Bibliography

BACKGROUND:Diffusion-weighted imaging (DWI) provides insight into the pathophysiology underlying renal dysfunction. Variants of DWI include intravoxel incoherent motion (IVIM), which differentiates between microstructural diffusion and vascular or tubular flow, and diffusion tensor imaging (DTI), which quantifies diffusion directionality. PURPOSE/OBJECTIVE:To investigate the reproducibility of joint IVIM-DTI and compare controls to presurgical renal mass patients. STUDY TYPE/METHODS:Prospective cross-sectional. SUBJECTS/METHODS:Thirteen healthy controls and ten presurgical renal mass patients were scanned. Ten controls were scanned twice to investigate reproducibility. FIELD STRENGTH/SEQUENCE/UNASSIGNED:Subjects were scanned on a 3T system using 10 b-values and 20 diffusion directions for IVIM-DTI in a study approved by the local Institutional Review Board. ASSESSMENT/RESULTS:Retrospective coregistration and measurement of joint IVIM-DTI parameters were performed. STATISTICAL ANALYSIS/METHODS:Parameter reproducibility was defined as intraclass correlation coefficient (ICC) >0.7 and coefficient of variation (CV) <30%. Patient data were stratified by lesion side (contralateral/ipsilateral) for comparison with controls. Corticomedullary differentiation was evaluated. RESULTS:In controls, the reproducible subset of REnal Flow and Microstructure AnisotroPy (REFMAP) parameters had average ICC = 0.82 and CV = 7.5%. In renal mass patients, medullary fractional anisotropy (FA) was significantly lower than in controls (0.227 ± 0.072 vs. 0.291 ± 0.044, P = 0.016 for the kidney contralateral to the mass and 0.228 ± 0.070 vs. 0.291 ± 0.044, P = 0.018 for the kidney ipsilateral). In the kidney ipsilateral to the mass, cortical Dp,radial was significantly higher than in controls (P = 0.012). Conversely, medullary Dp,axial was significantly lower in contralateral than ipsilateral kidneys (P = 0.027) and normal controls (P = 0.044). DATA CONCLUSION/UNASSIGNED:REFMAP-MRI parameters provide unique information regarding renal dysfunction. In presurgical renal mass patients, directional flow changes were noted that were not identified with IVIM analysis alone. Both contralateral and ipsilateral kidneys in patients show reductions in structural diffusivities and anisotropy, while flow metrics showed opposing changes in contralateral vs. ipsilateral kidneys. LEVEL OF EVIDENCE/METHODS:2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

OBJECTIVE:To describe novel 3-dimensional (3D) printing and augmented reality (AR) methods of image data visualization to facilitate anatomic understanding and to assist with surgical planning and decision-making during robotic partial nephrectomy. MATERIALS AND METHODS/METHODS:We created a video of the workflow for creating 3D printed and AR kidney models along with their application to robotic partial nephrectomy. Key steps in their development are (1) radiology examination (magnetic resonance imaging and computed tomography), (2) image segmentation, (3) preparing for 3D printing or AR, and (4) printing the model or deploying the model to the AR device. RESULTS:We demonstrate the workflow and utility of 3D printing and AR kidney models applied to a case of a 70-year-old woman with a 3.4 cm renal mass on her left pelvic kidney. A 3D printed kidney model was created using multicolor PolyJet technology (Stratasys J750), allowing a transparent kidney with coloring of the renal tumor, artery, vein, and ureter. An AR kidney model was created using Unity 3D software and deployed to a Microsoft HoloLens. The 3D printed and AR models were used preoperatively and intraoperatively to assist in robotic partial nephrectomy. To date, we have created 15 3D printed and AR kidney models to use for robotic partial nephrectomy planning and intraoperative guidance. The application of 3D printed and AR models is safe and feasible and can influence surgical decisions. CONCLUSION/CONCLUSIONS:Our video highlights the workflow and novel application of 3D printed and AR kidney models to provide preoperative guidance for robotic partial nephrectomy. The insights gained from advanced visualization can influence surgical planning decisions.

INTRODUCTION/BACKGROUND:We sought to evaluate the discordance between ureteroscopic biopsy and surgical pathology for grading and staging of upper tract urothelial carcinoma (UTUC) and to establish preoperative predictors of aggressive tumors. METHODS:We performed a retrospective review of 314 patients who underwent ureteroscopic biopsy followed by surgical management for UTUC from 2000-2016 at three institutions. Our primary outcomes were muscle-invasive (≥pT2) disease at surgical pathology and upgrading of clinical low-grade (cLG) tumors to pathologic high-grade (pHG). RESULTS:At biopsy, 61% of patients had high-grade (cHG) tumors, and 21% had subepithelial connective tissue invasion (cT1+). On final pathology, 79% had pHG tumors, and 45% had stage ≥pT2. On multivariate analysis, advanced age, cHG, and cT1+ were independently associated with ≥pT2. The combined presence of cHG and cT1+ had a PPV of 86% for muscle invasion, and the combined absence of cHG and cT1+ had a NPV of 80%. The likelihood of missing invasion on biopsy in patients with muscle-invasive disease was increased when biopsy fragments were limited to ≤1mm. Among patients with cLG disease on biopsy, 51% were upgraded at surgery. The presence of positive urine cytology was associated with an increased risk of upgrading; however, this was not statistically significant. CONCLUSIONS:cHG, cT1+ on biopsy, and advanced patient age are independent risk factors for muscle-invasive UTUC. There is a significant risk of upgrading among patients with cLG tumors on biopsy, especially when urine cytology is positive. The predictive value of biopsy can likely be improved by more extensive ureteroscopic sampling.

PURPOSE/OBJECTIVE:We compared blue light flexible cystoscopy with white light flexible cystoscopy for the detection of bladder cancer during surveillance. MATERIALS AND METHODS/METHODS:Patients at high risk for recurrence received hexaminolevulinate intravesically before white light flexible cystoscopy and randomization to blue light flexible cystoscopy. All suspicious lesions were documented. Patients with suspicious lesions were referred to the operating room for repeat white and blue light cystoscopy. All suspected lesions were biopsied or resected and specimens were examined by an independent pathology consensus panel. The primary study end point was the proportion of patients with histologically confirmed malignancy detected only with blue light flexible cystoscopy. Additional end points were the false-positive rate, carcinoma in situ detection and additional tumors detected only with blue light cystoscopy. RESULTS:Following surveillance 103 of the 304 patients were referred, including 63 with confirmed malignancy, of whom 26 had carcinoma in situ. In 13 of the 63 patients (20.6%, 95% CI 11.5-32.7) recurrence was seen only with blue light flexible cystoscopy (p <0.0001). Five of these cases were confirmed as carcinoma in situ. Operating room examination confirmed carcinoma in situ in 26 of 63 patients (41%), which was detected only with blue light cystoscopy in 9 of the 26 (34.6%, 95% CI 17.2-55.7, p <0.0001). Blue light cystoscopy identified additional malignant lesions in 29 of the 63 patients (46%). The false-positive rate was 9.1% for white and blue light cystoscopy. None of the 12 adverse events during surveillance were serious. CONCLUSIONS:Office based blue light flexible cystoscopy significantly improves the detection of patients with recurrent bladder cancer and it is safe when used for surveillance. Blue light cystoscopy in the operating room significantly improves the detection of carcinoma in situ and detects lesions that are missed with white light cystoscopy.

Introduction & Objectives: Radical nephrectomy (RN) +/- thrombectomy is the standard treatment for kidney cancer (KC) with venous thrombus (VT). Whilst in case of localised KC without VT minimally invasive (MI) techniques are largely used, little evidence exists on the laparoscopic approach for the treatment of KC with VT. Materials & Methods: In a multicentre series including 2552 patients from the International Renal Cell Carcinoma-Venous Thrombus Consortium database receiving surgery for KC + VT (T stage >=3a), 120 had a MI approach. Primary outcomes were post-operative renal function, evaluated through serum creatinine levels (sCr) and eGFR, cancer specific survival (CSS) and overall survival (OS). Complications and comorbidities were graded using the Clavien-dindo and ASA classification respectively. Thrombus level was recorded according to the Mayo Clinic Classification. Results: One hundred and ten procedures were laparoscopic whilst 10 were robotic. Mean age and BMI were 66.48 +/-11.24 years and 27.9 +/-5.27 respectively. Approximately half had an ASA score <=2 (50.98%). Mean Pre-operative eGFR was 77.93 +/-30.6mL/min. Mean tumour size was 6.8 +/-2.57cm; 7.89% and 13.33% were N+ or M+ respectively. Thrombus level was confined to the renal vein or to its segmental branches (level<=I) in 94.53%. Mean operating time was 197.05 +/-88.35min with a mean blood loss of 682.37 +/-2156.61mL. Overall 14.42%, 1.11% and 6.73% underwent lymphadenectomy, cardiopulmonary bypass and cavotomy respectively. Major complications (Clavien >=3) occurred in almost 1 on 4 patients (24.8%) with no intraoperative deaths. Mean hospital stay was 7.97 +/-8.50days. After a mean follow up of 935.33 +/-862.14days, mean eGFR variation was -2.04 +/-47.26 mL/min; CSS and OS were 75.85% and 72.65% respectively with 80.26% of the patients being free of recurrence, 7.89% having disease progression and 11.84% stable disease. Conclusions: In KC + VT MI surgery may be feasible yielding acceptable oncological and functional outcomes. However, blood loss, hospital stay and high grade complications remain relatively high. Further large prospective studies are needed to evaluate the role of MI surgery for KC + VT

E-cigarette smoke delivers stimulant nicotine as aerosol without tobacco or the burning process. It contains neither carcinogenic incomplete combustion byproducts nor tobacco nitrosamines, the nicotine nitrosation products. E-cigarettes are promoted as safe and have gained significant popularity. In this study, instead of detecting nitrosamines, we directly measured DNA damage induced by nitrosamines in different organs of E-cigarette smoke-exposed mice. We found mutagenic O6-methyldeoxyguanosines and γ-hydroxy-1,N2 -propano-deoxyguanosines in the lung, bladder, and heart. DNA-repair activity and repair proteins XPC and OGG1/2 are significantly reduced in the lung. We found that nicotine and its metabolite, nicotine-derived nitrosamine ketone, can induce the same effects and enhance mutational susceptibility and tumorigenic transformation of cultured human bronchial epithelial and urothelial cells. These results indicate that nicotine nitrosation occurs in vivo in mice and that E-cigarette smoke is carcinogenic to the murine lung and bladder and harmful to the murine heart. It is therefore possible that E-cigarette smoke may contribute to lung and bladder cancer, as well as heart disease, in humans.

OBJECTIVES: To study the effect of lymph node dissection (LND) at the time of nephrectomy and tumor thrombectomy on oncological outcomes in patients with renal cell carcinoma (RCC) and tumor thrombus. PATIENTS AND METHODS: The records of 1,978 patients with RCC and tumor thrombus who underwent radical nephrectomy and tumor thrombectomy from 1985 to 2014 at 24 centers were analyzed. None of the patients had distant metastases. Extent and pathologic results of LND were compared with respect to cancer-specific survival (CSS). Multivariable Cox regression models were used to quantify the effect of multiple covariates. RESULTS: LND was performed in 1,026 patients. In multivariable analysis, the presence of LN metastasis, the number of positive LNs, and LN density were independently associated with cancer-specific mortality (CSM). Clinical node-negative (cN-) disease was documented in 573 patients, 447 of them underwent LND with 43 cN- patients (9.6%) revealing positive LNs at pathology. LN positive cN- patients showed significantly better CSS when compared to LN positive cN+ patients. In multivariable analysis, positive cN status in LN positive patients was a significant predictor of CSM (HR, 2.923; P = 0.015). CONCLUSIONS: The number of positive nodes harvested during LND and LN density was strong prognostic indicators of CSS, while number of removed LNs did not have a significant effect on CSS. The rate of pN1 patients among clinically node-negative patients was relatively high, and LND in these patients suggested a survival benefit. However, only a randomized trial can determine the absolute benefit of LND in this setting.

OBJECTIVE: To develop nomograms that predict the probability of overall PCa and clinically significant PCa (Gleason >/=7) on MRI targeted, and combined MRI-targeted and systematic, prostate biopsy. MATERIALS AND METHODS: From June 2012 to August 2014, MR-US fusion targeted prostate biopsy was performed on 464 men with suspicious regions identified on pre-biopsy 3T MRI along with systematic 12 core biopsy. Logistic regression modeling was used to evaluate predictors of overall and clinically significant PCa, and corresponding nomograms were generated for men who were not previously biopsied or had one or more prior negative biopsies. Models were created with 70% of a randomly selected training sample and bias-corrected using bootstrap resampling. The models were then validated with the remaining 30% testing sample pool. RESULTS: A total of 459 patients were included for analysis (median age 66 years, PSA 5.2 ng/ml, prostate volume 49 cc). Independent predictors of PCa on targeted and systematic prostate biopsy were PSA density, age, and MRI suspicion score. PCa probability nomograms were generated for each cohort using the predictors. Bias-corrected areas under the receiver-operating characteristic curves for overall and clinically significant PCa detection were 0.82 (0.78) and 0.91 (0.84) for men without prior biopsy and 0.76 (0.65) and 0.86 (0.87) for men with a prior negative biopsy in the training (testing) samples. CONCLUSION: PSA density, age, and MRI suspicion score predict prostate cancer on combined MRI-targeted and systematic biopsy. Our generated nomograms demonstrate high diagnostic accuracy and may further aid in the decision to perform biopsy in men with clinical suspicion of PCa.

BACKGROUND AND OBJECTIVE: Small kidney cancers are a heterogeneous group with varying malignant potential. Pathologic information obtained from a renal biopsy may guide decision-making for small kidney cancers. We sought to assess the effect of pathologic information from renal biopsy on the nonsurgical management of small kidney cancers in a population-based cohort of patients over 65 years of age. METHODS: In the Surveillance, Epidemiology and End Results-Medicare dataset, we identified patients >/=66 years diagnosed with a kidney cancer<4cm between 2002 and 2011. Diagnostic biopsy was defined by a Medicare claim within 1 month prior through 6 months following cancer diagnosis or before surgery. Nonsurgical management was defined by the absence of a claim for partial or radical nephrectomy or tumor ablation in the first 6 months following diagnosis. The relationship between patient and tumor characteristics and the likelihood of nonsurgical management by receipt of diagnostic biopsy was assessed by multivariable logistic regression models. RESULTS: From 8,933 patients, 2,782 (31%) had a diagnostic renal biopsy of whom 616 (22%) were managed nonsurgically. Controlling for patient, disease, and provider specialty, biopsy was associated with nonsurgical management (adjusted odds ratio = 1.61, 95% Cl: 1.43-1.82) in patients with low-grade tumors but also with more aggressive histology (clear cell renal cell carcinoma). Older age (85+) and geographic region were significantly associated with greater odds of diagnostic biopsy. Patients whose initial renal tumor diagnosis was made by a urologist (vs. other type of provider) were less likely to receive a biopsy (adjust odds ratio = 0.73, 95% Cl: 0.60-0.89). CONCLUSIONS: Although the use of renal biopsy has increased over time and is associated with the use of nonsurgical management of small kidney cancers, the use of the pathologic findings remains limited. Further advances, particularly with prognostic markers, are necessary before renal biopsy can be routinely implemented for treatment decision-making for small kidney cancers.

OBJECTIVE: To describe a novel technique of robotic inguinal lymphadenectomy with near infrared fluorescence imaging (NIRF) using indocyanine green (ICG) to facilitate lymph node identification during robotic groin dissection for penile cancer. MATERIALS AND METHODS: The patient is placed in lithotomy position with access to the groin. Three robotic ports and 1 assist port are placed in a V configuration below the tip of femoral triangle. Intradermal ICG is injected at the base of the penis (0.5 mL of 2 mg/kg concentration in normal saline), and the lymphatic channels and nodes are visualized using NIRF in the robotic console approximately 15 minutes after injection. The surgical template established in the open approach is then replicated using NIRF to ensure complete resection of the affected nodes. RESULTS: A total of 10 groin dissections in 5 patients have been completed using this technique, with an average lymph node yield of 7 per groin (range 5-13 lymph nodes). Mean operative time per groin was 207 minutes (range 164-258 minutes) and estimated blood loss was 38 mL (range 25-50 mL). Mean length of hospital stay was 1.8 days (range 0-4 days). Identification of the lymphatic drainage pattern from the superficial to deep groin nodes to pelvic nodes underneath the inguinal ligament was identified in all patients. With a mean follow-up of 10 months (range 3-16 months), there have been no postoperative infections, lymphatic leaks, wound breakdown, or necrosis. Pathologically involved lymph nodes were identified using NIRF. CONCLUSION: Our novel technique of robotic inguinal lymphadenectomy with fluorescence lymphangiography allows for identification and excision of both superficial and deep groin nodes with a significant reduction in morbidity compared with the open approach. Prospective studies are required to ensure long-term efficacy and results of this procedure.