Cryptic splice mutation in the fumarate hydratase gene in patients with clinical manifestations of Hereditary Leiomyomatosis and Renal Cell Cancer.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal dominant condition characterized by the development of cutaneous and uterine leiomyomas and risk for development of an aggressive form of papillary renal cell cancer. HLRCC is caused by germline inactivating pathogenic variants in the fumarate hydratase (FH) gene, which encodes the enzyme that catalyzes the interconversion of fumarate and L-malate. We utilized enzyme and protein mobility assays to evaluate the FH enzyme in a cohort of patients who showed clinical manifestations of HLRCC but were negative for known pathogenic FH gene variants. FH enzyme activity and protein levels were decreased by 50% or greater in three family members, despite normal FH mRNA expression levels as measured by quantitative PCR. Direct Nanopore RNA sequencing demonstrated 57 base pairs of retained intron sequence between exons 9 and 10 of polyadenylated FH mRNA in these patients, resulting in a truncated FH protein. Genomic sequencing revealed a heterozygous intronic alteration of the FH gene (chr1: 241498239 T/C) resulting in formation of a splice acceptor site near a polypyrimidine tract, and a uterine fibroid obtained from a patient showed loss of heterozygosity at this site. The same intronic FH variant was identified in an unrelated patient who also showed a clinical phenotype of HLRCC. These data demonstrate that careful clinical assessment as well as biochemical characterization of FH enzyme activity, protein expression, direct RNA sequencing, and genomic DNA sequencing of patient-derived cells can identify pathogenic variants outside of the protein coding regions of the FH gene.

Cumulative Impact of Serial Partial Nephrectomy for the Treatment of Recurrent Renal Masses.

PURPOSE: Reoperative partial nephrectomy (RePN) offers several advantages for the treatment of recurrent, multifocal renal masses. RePN has been previously demonstrated to be technically feasible and delay the need for renal replacement therapy. However, there is still inherent complexity and known risks to reoperative nephrectomy. We studied the largest population of RePNs to characterize renal functional outcomes and the likelihood of intra- and postoperative complications. MATERIALS AND METHODS: Query of an institutional surgical registry was conducted. Demographic data, serum creatinine for estimated glomerular filtration rate (eGFR), and protein dipstick results were assessed within 1 week prior to surgery, and postoperative function assessments were studied within a year of surgery. RePN was defined as serial surgical resection of the ipsilateral renal unit. RESULTS: A total of 1131 partial nephrectomies performed on 663 patients at a single center were retrospectively evaluated. In reoperative cases, median number of operations per renal unit was 2 (range: 2-6). There was a stepwise decline in eGFR with an average decline of 6.1 with each RePN. With each subsequent nephrectomy, surgical duration, estimated blood loss, and incidence of preoperative anemia increased. Postoperative eGFR showed a significant positive association with preoperative eGFR, while negative associations were found with age, number of previous ipsilateral partial nephrectomies, number of tumors, and largest tumor size. High-grade complications were associated with the number of ipsilateral partial nephrectomies, tumor count, and tumor size. Robotic or laparoscopic procedures exhibited a likelihood of grade 3 or greater complications compared to open surgery. CONCLUSION: RePN contributes to renal dysfunction and an increased risk of surgical complications. Intraoperative blood loss and surgical duration increase with subsequent nephrectomy. Such risks are dependent on the number of prior operative interventions on the kidney, suggesting a stepwise progression of surgical morbidity.

Non-Invasive Tumor Grade Evaluation in Von Hippel-Lindau-Associated Clear Cell Renal Cell Carcinoma: A Magnetic Resonance Imaging-Based Study.

BACKGROUND: Pathology grading is an essential step for the treatment and evaluation of the prognosis in patients with clear cell renal cell carcinoma (ccRCC). PURPOSE: To investigate the utility of texture analysis in evaluating Fuhrman grades of renal tumors in patients with Von Hippel-Lindau (VHL)-associated ccRCC, aiming to improve non-invasive diagnosis and personalized treatment. STUDY TYPE: Retrospective analysis of a prospectively maintained cohort. POPULATION: One hundred and thirty-six patients, 84 (61%) males and 52 (39%) females with pathology-proven ccRCC with a mean age of 52.8 ± 12.7 from 2010 to 2023. FIELD STRENGTH AND SEQUENCES: 1.5 and 3 T MRIs. Segmentations were performed on the T1-weighted 3-minute delayed sequence and then registered on pre-contrast, T1-weighted arterial and venous sequences. ASSESSMENT: A total of 404 lesions, 345 low-grade tumors, and 59 high-grade tumors were segmented using ITK-SNAP on a T1-weighted 3-minute delayed sequence of MRI. Radiomics features were extracted from pre-contrast, T1-weighted arterial, venous, and delayed post-contrast sequences. Preprocessing techniques were employed to address class imbalances. Features were then rescaled to normalize the numeric values. We developed a stacked model combining random forest and XGBoost to assess tumor grades using radiomics signatures. STATISTICAL TESTS: The model's performance was evaluated using positive predictive value (PPV), sensitivity, F1 score, area under the curve of receiver operating characteristic curve, and Matthews correlation coefficient. Using Monte Carlo technique, the average performance of 100 benchmarks of 85% train and 15% test was reported. RESULTS: The best model displayed an accuracy of 0.79. For low-grade tumor detection, a sensitivity of 0.79, a PPV of 0.95, and an F1 score of 0.86 were obtained. For high-grade tumor detection, a sensitivity of 0.78, PPV of 0.39, and F1 score of 0.52 were reported. DATA CONCLUSION: Radiomics analysis shows promise in classifying pathology grades non-invasively for patients with VHL-associated ccRCC, potentially leading to better diagnosis and personalized treatment. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2.

Complications after Nephron-sparing Interventions for Renal Tumors: Imaging Findings and Management.

The two primary nephron-sparing interventions for treating renal masses such as renal cell carcinoma are surgical partial nephrectomy (PN) and image-guided percutaneous thermal ablation. Nephron-sparing surgery, such as PN, has been the standard of care for treating many localized renal masses. Although uncommon, complications resulting from PN can range from asymptomatic and mild to symptomatic and life-threatening. These complications include vascular injuries such as hematoma, pseudoaneurysm, arteriovenous fistula, and/or renal ischemia; injury to the collecting system causing urinary leak; infection; and tumor recurrence. The incidence of complications after any nephron-sparing surgery depends on many factors, such as the proximity of the tumor to blood vessels or the collecting system, the skill or experience of the surgeon, and patient-specific factors. More recently, image-guided percutaneous renal ablation has emerged as a safe and effective treatment option for small renal tumors, with comparable oncologic outcomes to those of PN and a low incidence of major complications. Radiologists must be familiar with the imaging findings encountered after these surgical and image-guided procedures, especially those indicative of complications. The authors review cross-sectional imaging characteristics of complications after PN and image-guided thermal ablation of kidney tumors and highlight the respective management strategies, ranging from clinical observation to interventions such as angioembolization or repeat surgery. Work of the U.S. Government published under an exclusive license with the RSNA. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available in the Online Learning Center. See the invited commentary by Chung and Raman in this issue.

A germline 1;3 translocation disrupting the VHL gene: a novel genetic cause for von Hippel-Lindau.

Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary tumour susceptibility disease caused by germline pathogenic variation of the VHL tumour suppressor gene. Affected individuals are at risk of developing multiple malignant and benign tumours in a number of organs.In this report, a male patient in his 20s who presented to the Urologic Oncology Branch at the National Cancer Institute with a clinical diagnosis of VHL was found to have multiple cerebellar haemangioblastomas, bilateral epididymal cysts, multiple pancreatic cysts, and multiple, bilateral renal tumours and cysts. The patient had no family history of VHL and was negative for germline VHL mutation by standard genetic testing. Further genetic analysis demonstrated a germline balanced translocation between chromosomes 1 and 3, t(1;3)(p36.3;p25) with a breakpoint on chromosome 3 within the second intron of the VHL gene. This created a pathogenic germline alteration in VHL by a novel mechanism that was not detectable by standard genetic testing.Karyotype analysis is not commonly performed in existing genetic screening protocols for patients with VHL. Based on this case, protocols should be updated to include karyotype analysis in patients who are clinically diagnosed with VHL but demonstrate no detectable mutation by existing genetic testing.

Renal surgery in patients with a duplicated inferior vena cava: a case series and review of the literature.

Abnormal inferior vena cava (IVC) anatomy may present unique challenges for urologists when performing retroperitoneal surgery. Duplication of the IVC is one such anomalous variation and can be found in up to 3% of the population. Misunderstanding of the implications of this aberrant anatomy may lead to intraoperative or postoperative complications. Here, we present two cases of patients undergoing renal surgeries with duplicate IVC. We then review the embryologic origin and anatomic findings in those with abnormal IVC anatomy as well as discuss the surgical implications and considerations for urologists.

Characterization of genetically defined sporadic and hereditary type 1 papillary renal cell carcinoma cell lines.

Renal cell carcinoma (RCC) is not a single disease but is made up of several different histologically defined subtypes that are associated with distinct genetic alterations which require subtype specific management and treatment. Papillary renal cell carcinoma (pRCC) is the second most common subtype after conventional/clear cell RCC (ccRCC), representing ~20% of cases, and is subcategorized into type 1 and type 2 pRCC. It is important for preclinical studies to have cell lines that accurately represent each specific RCC subtype. This study characterizes seven cell lines derived from both primary and metastatic sites of type 1 pRCC, including the first cell line derived from a hereditary papillary renal carcinoma (HPRC)-associated tumor. Complete or partial gain of chromosome 7 was observed in all cell lines and other common gains of chromosomes 16, 17, or 20 were seen in several cell lines. Activating mutations of MET were present in three cell lines that all demonstrated increased MET phosphorylation in response to HGF and abrogation of MET phosphorylation in response to MET inhibitors. CDKN2A loss due to mutation or gene deletion, associated with poor outcomes in type 1 pRCC patients, was observed in all cell line models. Six cell lines formed tumor xenografts in athymic nude mice and thus provide in vivo models of type 1 pRCC. These type 1 pRCC cell lines provide a comprehensive representation of the genetic alterations associated with pRCC that will give insight into the biology of this disease and be ideal preclinical models for therapeutic studies.

Comprehensive characterization of Alu-mediated breakpoints in germline VHL gene deletions and rearrangements in patients from 71 VHL families.

Von Hippel-Lindau (VHL) is a hereditary multisystem disorder caused by germline alterations in the VHL gene. VHL patients are at risk for benign as well as malignant lesions in multiple organs including kidney, adrenal, pancreas, the central nervous system, retina, endolymphatic sac of the ear, epididymis, and broad ligament. An estimated 30%-35% of all families with VHL inherit a germline deletion of one, two, or all three exons. In this study, we have extensively characterized germline deletions identified in patients from 71 VHL families managed at the National Cancer Institute, including 59 partial (PD) and 12 complete VHL deletions (CD). Deletions that ranged in size from 1.09 to 355 kb. Fifty-eight deletions (55 PD and 3 CD) have been mapped to the exact breakpoints. Ninety-five percent (55 of 58) of mapped deletions involve Alu repeats at both breakpoints. Several novel classes of deletions were identified in this cohort, including two cases that have complex rearrangements involving both deletion and inversion, two cases with inserted extra Alu-like sequences, six cases that involve breakpoints in Alu repeats situated in opposite orientations, and a "hotspot" PD of Exon 3 observed in 12 families that involves the same pair of Alu repeats.

Genetic risk assessment for hereditary renal cell carcinoma: Clinical consensus statement.

BACKGROUND: Although renal cell carcinoma (RCC) is believed to have a strong hereditary component, there is a paucity of published guidelines for genetic risk assessment. A panel of experts was convened to gauge current opinions. METHODS: A North American multidisciplinary panel with expertise in hereditary RCC, including urologists, medical oncologists, clinical geneticists, genetic counselors, and patient advocates, was convened. Before the summit, a modified Delphi methodology was used to generate, review, and curate a set of consensus questions regarding RCC genetic risk assessment. Uniform consensus was defined as ≥85% agreement on particular questions. RESULTS: Thirty-three panelists, including urologists (n = 13), medical oncologists (n = 12), genetic counselors and clinical geneticists (n = 6), and patient advocates (n = 2), reviewed 53 curated consensus questions. Uniform consensus was achieved on 30 statements in specific areas that addressed for whom, what, when, and how genetic testing should be performed. Topics of consensus included the family history criteria, which should trigger further assessment, the need for risk assessment in those with bilateral or multifocal disease and/or specific histology, the utility of multigene panel testing, and acceptance of clinician-based counseling and testing by those who have experience with hereditary RCC. CONCLUSIONS: In the first ever consensus panel on RCC genetic risk assessment, 30 consensus statements were reached. Areas that require further research and discussion were also identified, with a second future meeting planned. This consensus statement may provide further guidance for clinicians when considering RCC genetic risk assessment. LAY SUMMARY: The contribution of germline genetics to the development of renal cell carcinoma (RCC) has long been recognized. However, there is a paucity of guidelines to define how and when genetic risk assessment should be performed for patients with known or suspected hereditary RCC. Without guidelines, clinicians struggle to define who requires further evaluation, when risk assessment or testing should be done, which genes should be considered, and how counseling and/or testing should be performed. To this end, a multidisciplinary panel of national experts was convened to gauge current opinion on genetic risk assessment in RCC and to enumerate a set of recommendations to guide clinicians when evaluating individuals with suspected hereditary kidney cancer.

Reoperative Partial Nephrectomy-Does Previous Surgical Footprint Impact Outcomes?

PURPOSE: Historically, open techniques have been favored over minimally invasive approaches for complex surgeries. We aimed to identify differences in perioperative outcomes, surgical footprints, and complication rates in patients undergoing either open or robotic reoperative partial nephrectomy. MATERIALS AND METHODS: A retrospective review of patients undergoing reoperative partial nephrectomy was performed. Patients were assigned to cohorts based on current and prior surgical approaches: open after open, open after minimally invasive surgery, robotic after open, and robotic after minimally invasive surgery cohorts. Perioperative outcomes were compared among cohorts. Factors contributing to complications were assessed. RESULTS: A total of 192 patients underwent reoperative partial nephrectomy, including 103 in the open after open, 10 in the open after minimally invasive surgery, 47 in the robotic after open, and 32 in the robotic after minimally invasive surgery cohorts. The overall and major complication (grade ≥3) rates were 65% and 19%, respectively. The number of blood transfusions, overall complications, and major complications were significantly lower in robotic compared to open surgical cohorts. On multivariate analysis, the robotic approach was protective against major complications (OR 0.3, p=0.02) and estimated blood loss was predictive (OR 1.03, p=0.004). Prior surgical approach was not predictive for major complications. CONCLUSIONS: Reoperative partial nephrectomy is feasible using both open and robotic approaches. While the robotic approach was independently associated with fewer major complications, prior approach was not, implying that prior surgical approaches are less important to perioperative outcomes and in contributing to the overall surgical footprint.

Novel renal medullary carcinoma cell lines, UOK353 and UOK360, provide preclinical tools to identify new therapeutic treatments.

Renal medullary carcinoma (RMC) is a rare, aggressive disease that predominantly afflicts individuals of African or Mediterranean descent with sickle cell trait. RMC comprises 1% of all renal cell carcinoma diagnoses with a median overall survival of 13 months. Patients are typically young (median age-22) and male (male:female ratio of 2:1) and tumors are characterized by complete loss of expression of the SMARCB1 tumor suppressor protein. Due to the low incidence of RMC and the disease's aggressiveness, treatment decisions are often based on case reports. Thus, it is critical to develop preclinical models of RMC to better understand the pathogenesis of this disease and to identify effective forms of therapy. Two novel cell line models, UOK353 and UOK360, were derived from primary RMCs that both demonstrated the characteristic SMARCB1 loss. Both cell lines overexpressed EZH2 and other members of the polycomb repressive complex and EZH2 inhibition in RMC tumor spheroids resulted in decreased viability. High throughput drug screening of both cell lines revealed several additional candidate compounds, including bortezomib that had both in vitro and in vivo antitumor activity. The activity of bortezomib was shown to be partially dependent on increased oxidative stress as addition of the N-acetyl cysteine antioxidant reduced the effect on cell proliferation. Combining bortezomib and cisplatin further decreased cell viability both in vitro and in vivo that single agent bortezomib treatment. The UOK353 and UOK360 cell lines represent novel preclinical models for the development of effective forms of therapy for RMC patients.

Clear Cell Renal Cell Carcinoma Growth Correlates with Baseline Diffusion-weighted MRI in Von Hippel-Lindau Disease.

Background Identification of markers to aid in understanding the growth kinetics of Von Hippel-Lindau (VHL)-associated clear cell renal cell carcinoma (ccRCC) has the potential to allow individualization of patient care, thereby helping prevent unnecessary screening and optimizing intervention. Purpose To determine whether the degree of restricted diffusion at baseline MRI holds predictive potential for the growth rate of VHL-associated ccRCC. Materials and Methods Patients with VHL disease who underwent surgical resection of tumors between November 2014 and October 2017 were analyzed retrospectively in this HIPAA-compliant study. The change in ccRCC volume between two time points and apparent diffusion coefficient (ADC) at baseline was calculated by using segmentations by two readers at nephrographic-phase CT and diffusion-weighted MRI, respectively. Intraclass correlation coefficient was used to assess agreement between readers. Repeated-measures correlation was used to investigate relationships between ADC (histogram parameters) and tumor size at baseline with growth rate and volume doubling time (VDT). Predictive performance of the ADC parameter with highest correlation and tumor size at baseline was reviewed to differentiate tumors based on their VDT (≤1 year or >1 year). Results Forty-six patients (mean age, 46 years ± 7 [standard deviation]; 25 women) with 100 ccRCCs were evaluated. Interreader agreement resulted in mean κ scores of 0.89, 0.82, and 0.93 for mean ADC, baseline tumor volume, and follow-up tumor volume, respectively. ADC percentiles correlated negatively with tumor growth rate but correlated positively with VDT. Lower ADC values demonstrated stronger correlations. The 25th percentile ADC had the strongest correlation with growth rate (ρ = -0.52, P < .001) and VDT (ρ = 0.60, P < .001) and enabled prediction of VDT (≤1 year or >1 year) with an area under the receiver operating characteristic curve of 0.86 (sensitivity, 67%; specificity, 89%) (P < .001). Conclusion Apparent diffusion coefficient at baseline was negatively correlated with tumor growth rate. Diffusion-weighted MRI may be useful to identify clear cell renal cell carcinomas with higher growth rates. © RSNA, 2020See also the editorial by Goh and Prezzi in this issue.

Inherited kidney cancer syndromes.

PURPOSE OF REVIEW: To describe current paradigms for genetic testing, screening, and treatment of patients with inherited kidney cancer syndromes. RECENT FINDINGS: We describe various new aspects of hereditary kidney cancer. Recent data now support that hereditary kidney cancer may account for 5-8% of kidney cancers diagnosed. Methods of testing have evolved including the introduction of multigene next-generation sequencing panels. We continue to learn more about the natural history and management of classic hereditary cancer syndromes. New emerging conditions with lower kidney cancer penetrance have been recognized adding the growing list of syndromes associated with kidney cancer development. The surgical management strategies of enucleation remain however systemic therapy options are being explored both for localized and advanced settings. SUMMARY: Genetic predisposition to kidney cancer is likely more common than once thought. Knowledge of clinical manifestation and genetic testing strategies are needed to properly identify and treat patient and their families.

Renal cell carcinoma: molecular characterization and evolving treatment paradigms.

PURPOSE OF REVIEW: The treatment landscape of advanced renal cell carcinoma (RCC) continues to shift as both new targeted therapies and immunotherapies show efficacy in treating the disease. Contemporary insights into the molecular characterization of RCC are likely to fuel the development of additional therapies. This review summarizes recent advancements in the biologic characterization of RCC and discusses newly approved therapies and ongoing studies in the treatment of advanced RCC. RECENT FINDINGS: The Cancer Genome Atlas has now completed comprehensive molecular characterization of clear cell, papillary, and chromophobe RCC, providing insights into the biology of these entities. Two new 'targeted' therapies, cabozantinib and lenvatinib, as well as a novel immune checkpoint inhibitor, the programed death 1 inhibitor nivolumab, have recently been approved for the treatment of metastatic RCC. Although some of these newer therapies are associated with prolongation of survival, there are few long-term responders and the quest for more durable treatment strategies continues. SUMMARY: The addition of several new agents effective in metastatic RCC has resulted in improvements in overall survival; however, there are few avenues to durable responses or cure. Ongoing studies as well advances in our understanding of the molecular alterations underlying distinct forms of RCC promise further therapeutic advances and have the potential to alter the current treatment paradigm.

International Consultation on Urological Diseases and European Association of Urology International Consultation on Minimally Invasive Surgery in Urology: laparoscopic and robotic adrenalectomy.

The aim of this study was to provide an evidence-based systematic review of the use of laparoscopic and robotic adrenalectomy in the treatment of adrenal disease as part of the International Consultation on Urological Diseases and European Association of Urology consultation on Minimally Invasive Surgery in Urology. A systematic literature search (January 2004 to January 2014) was conducted to identify comparative studies assessing the safety and efficacy of minimally invasive adrenal surgery. Subtopics including the role of minimally invasive surgery for pheochromocytoma, adrenocortical carcinoma (ACC) and large adrenal tumours were examined. Additionally, the role of transperitoneal and retroperitoneal approaches, as well as laparoendoscopic single-site (LESS) and robotic adrenalectomy were reviewed. The major findings are presented in an evidence-based fashion. Large retrospective and prospective data were analysed and a set of recommendations provided by the committee was produced. Laparoscopic surgery should be considered the first-line therapy for benign adrenal masses requiring surgical resection and for patients with pheochromocytoma. While a laparoscopic approach may be feasible for selected cases of ACC without adjacent organ involvement, an open surgical approach remains the 'gold standard'. Large adrenal tumours without preoperative or intra-operative suspicion of ACC may be safely resected via a laparoscopic approach. Both transperitoneal and retroperitoneal approaches to laparoscopic adrenalectomy are safe. The approach should be chosen based on surgeon training and experience. LESS and robotic adrenalectomy should be considered as alternatives to laparoscopic adrenalectomy but require further study.

Pathological analysis of the prostatic anterior fat pad at radical prostatectomy: insights from a prospective series.

OBJECTIVE: To assess factors associated with lymphatic drainage and lymph node (LN) metastasis to the prostatic anterior fat pad (PAFP) in men with prostate cancer and the utility of routine PAFP analysis at the time of radical prostatectomy (RP). PATIENTS AND METHODS: Our institution began to prospectively collect PAFP tissue in 2010. The PAFP was removed at the time of RP and sent as a pathological specimen separate from the pelvic LNs and prostate. Consecutive RPs performed at our institution in which the PAFP was removed were reviewed to determine the rate of LNs in the PAFP, the rate of metastatic LNs in the PAFP, and the association of metastatic PAFP LN with clinical and pathological features. The impact on biochemical recurrence (BCR) was assessed with a Cox's proportional hazard model. RESULTS: In all, 2 413 PAFP specimens were available for analysis. LNs were found in the PAFP in 255 (10.6%) cases and metastatic LNs in the PAFPs were found in 14 (0.6%) cases. Metastatic PAFP LNs were associated with anterior tumours in 11 of the 14 cases (P = 0.01), and were present only in preoperative D'Amico intermediate- (six of 14) and high- (eight of 14) risk patients (P < 0.001). Metastatic PAFP LNs were associated with extraprostatic disease in 13 of the 14 cases, although concomitant pelvic LN involvement was present in only four of the 14 cases. With a mean follow-up of 1.5 years, three of the 14 patients with metastatic PAFP LN developed BCR. Positive LN involvement in either the pelvic LN or PAFP had worse BCR than LN-negative patients (P < 0.001); however, there was no difference in BCR between patients with positive pelvic LN and positive PAFP LN (P = 0.5). CONCLUSION: Metastatic PAFP LNs are rare and always occur in the presence of other adverse pathological features. The routine pathological analysis of PAFP as a separate specimen, especially in low-risk disease, may not be warranted.

MR Safe Robot, FDA Clearance, Safety and Feasibility Prostate Biopsy Clinical Trial.

Compatibility of mechatronic devices with the MR environment has been a very challenging engineering task. After over a decade of developments, we report the successful translation to clinical trials of our MR Safe robot technology. MrBot is a 6-degree-of-freedom, pneumatically actuated robot for transperineal prostate percutaneous access, built exclusively of electrically nonconductive and nonmagnetic materials. Its extensive pre-clinical tests have been previously reported. Here, we present the latest technology developments, an overview of the regulatory protocols, and technically related results of the clinical trial. The FDA has approved the MrBot for the biopsy trial, which was successfully performed in 5 patients. With no trajectory corrections, and no unsuccessful attempts to target a site, the robot achieved an MRI based needle targeting accuracy of 2.55 mm. To the best of our knowledge, this is the first robot approved by the FDA for the MR environment. The results confirm that it is possible to perform safe and accurate robotic manipulation in the MRI scanner, and the development of MR Safe robots is no longer a daunting technical challenge.

Extent of renal vein invasion influences prognosis in patients with renal cell carcinoma.

OBJECTIVE: To compare oncological outcomes for segmental vs main renal vein invasion (RVI) in patients with renal cell carcinoma (RCC). PATIENTS METHODS: Patients undergoing extirpative surgery for RCC at our institution between 2003 and 2013 were stratified into five groups according to clinical stage: T2 (n = 135), T3a with fat invasion (n = 185), T3a with segmental RVI (n = 87), T3a with main RVI (n = 64) and T3b (n = 40). Kaplan-Meier survival analysis and multivariable Cox regression were performed to determine the impact of segmental RVI on recurrence-free survival (RFS) and cancer-specific survival (CSS). Harrell's c index was used to compare the prognostic accuracy of current and proposed staging models. RESULTS: At a median follow-up of 37 months, both RFS and CSS were significantly worse for patients with main RVI as compared with segmental RVI (P = 0.03 and P = 0.009, respectively). On multivariable analysis, main RVI had inferior RFS (hazard ratio [HR] 2.3, 95% confidence interval [CI] 1.1-4.4; P = 0.03] and CSS (HR 3.5, 95% CI 1.3-9.9; P = 0.02) compared with segmental RVI. Sub-stratifying T3a disease by separating segmental and main RVI improved prognostic accuracy compared with the current staging system for CSS (c indices 0.66 vs 0.59) and RFS (0.70 vs 0.60). CONCLUSIONS: Main RVI is independently associated with worse RFS and CSS than segmental RVI. These findings may have significance for patient counselling and future staging guidelines.

Robotic versus laparoscopic radical nephrectomy: comparative analysis and cost considerations.

INTRODUCTION: Robotic-assisted laparoscopic radical nephrectomy (RRN) is an increasing utilized alternative to laparoscopic radical nephrectomy (LRN); however, there is a little data on comparative effectiveness and cost of these procedures. We analyzed perioperative outcomes and hospital charge difference among patients undergoing laparoscopic radical nephrectomy (LRN) and robotic radical nephrectomy (RRN). MATERIALS AND METHODS: Our institutional renal mass registry was queried for patients who underwent either LRN or RRN from 2010 to 2014. Demographic, perioperative outcomes and hospital charge data were compared between surgical approaches. RESULTS: Overall, 319 minimally invasive radical nephrectomies were performed during the study period. Of these, 243 were LRN and 76 were RRN. Patient demographic and tumor characteristics were similar between groups. Among operative characteristics, operative time (136 min versus 139 min, p = 0.531), intraoperative complications (2.8% versus 2.0%, p = 0.650), and length of stay (2 days versus 2 days, p = 0.745) were similar for LRN and RRN, respectively. Estimated blood loss (50 mL versus 100 mL, p = 0.041) and rate of conversion to an alternative surgical approach (1.0% versus 11.1%, p < 0.001) were higher in RRN. RRN cases were also more likely to include lymph node dissection (12.6% versus 24.2%, p = 0.031). Total charges trended higher for RRN but did not meet traditional levels of significance ($14,913 versus $16,265, p = 0.171). CONCLUSIONS: RRN appears to be a clinically equivalent alternative to LRN with similar perioperative outcomes, albeit at greater hospital charges.