Human prostate MRI at ultrahigh-performance gradient: A feasibility study.

PURPOSE: To demonstrate the technical feasibility and the value of ultrahigh-performance gradient in imaging the prostate in a 3T MRI system. METHODS: In this local institutional review board-approved study, prostate MRI was performed on 4 healthy men. Each subject was scanned in a prototype 3T MRI system with a 42-cm inner-diameter gradient coil that achieves a maximum gradient amplitude of 200 mT/m and slew rate of 500 T/m/s. PI-RADS V2.1-compliant axial T2 -weighted anatomical imaging and single-shot echo planar DWI at standard gradient of 70 mT/m and 150 T/m/s were obtained, followed by DWI at maximum performance (i.e., 200 mT/m and 500 T/m/s). In comparison to state-of-the-art clinical whole-body MRI systems, the high slew rate improved echo spacing from 1020 to 596 µs and, together with a high gradient amplitude for diffusion encoding, TE was reduced from 55 to 36 ms. RESULTS: In all 4 subjects (waist circumference = 81-91 cm, age = 45-65 years), no peripheral nerve stimulation sensation was reported during DWI. Reduced image distortion in the posterior peripheral zone prostate gland and higher signal intensity, such as in the surrounding muscle of high-gradient DWI, were noted. CONCLUSION: Human prostate MRI at simultaneously high gradient amplitude of 200 mT/m and slew rate of 500 T/m/s is feasible, demonstrating that improved gradient performance can address image distortion and T2 decay-induced SNR issues for in vivo prostate imaging.

MRI-guided focused ultrasound focal therapy for patients with intermediate-risk prostate cancer: a phase 2b, multicentre study.

BACKGROUND: Men with grade group 2 or 3 prostate cancer are often considered ineligible for active surveillance; some patients with grade group 2 prostate cancer who are managed with active surveillance will have early disease progression requiring radical therapy. This study aimed to investigate whether MRI-guided focused ultrasound focal therapy can safely reduce treatment burden for patients with localised grade group 2 or 3 intermediate-risk prostate cancer. METHODS: In this single-arm, multicentre, phase 2b study conducted at eight health-care centres in the USA, we recruited men aged 50 years and older with unilateral, MRI-visible, primary, intermediate-risk, previously untreated prostate adenocarcinoma (prostate-specific antigen ≤20 ng/mL, grade group 2 or 3; tumour classification ≤T2) confirmed on combined biopsy (combining MRI-targeted and systematic biopsies). MRI-guided focused ultrasound energy, sequentially titrated to temperatures sufficient for tissue ablation (about 60-70°C), was delivered to the index lesion and a planned margin of 5 mm or more of normal tissue, using real-time magnetic resonance thermometry for intraoperative monitoring. Co-primary outcomes were oncological outcomes (absence of grade group 2 and higher cancer in the treated area at 6-month and 24-month combined biopsy; when 24-month biopsy data were not available and grade group 2 or higher cancer had occurred in the treated area at 6 months, the 6-month biopsy results were included in the final analysis) and safety (adverse events up to 24 months) in all patients enrolled in the study. This study is registered with ClinicalTrials.gov, NCT01657942, and is no longer recruiting. FINDINGS: Between May 4, 2017, and Dec 21, 2018, we assessed 194 patients for eligibility and treated 101 patients with MRI-guided focused ultrasound. Median age was 63 years (IQR 58-67) and median concentration of prostate-specific antigen was 5·7 ng/mL (IQR 4·2-7·5). Most cancers were grade group 2 (79 [78%] of 101). At 24 months, 78 (88% [95% CI 79-94]) of 89 men had no evidence of grade group 2 or higher prostate cancer in the treated area. No grade 4 or grade 5 treatment-related adverse events were reported, and only one grade 3 adverse event (urinary tract infection) was reported. There were no treatment-related deaths. INTERPRETATION: 24-month biopsy outcomes show that MRI-guided focused ultrasound focal therapy is safe and effectively treats grade group 2 or 3 prostate cancer. These results support focal therapy for select patients and its use in comparative trials to determine if a tissue-preserving approach is effective in delaying or eliminating the need for radical whole-gland treatment in the long term. FUNDING: Insightec and the National Cancer Institute.

The Anatomical Relationships in the Space of Retzius for Penile Implants: An MRI Analysis.

BACKGROUND: The 3-piece inflatable penile prosthesis includes an easy-to-use pump and fluid filled reservoir which is placed in either the space of Retzius (SOR) or in an alternative ectopic location. Reservoir placement in the SOR is a blind procedure despite the SOR being surrounded by many critical structures. To date only a handful of cadaveric studies have described the relevant anatomy. AIM: To use magnetic resonance imaging (MRI) as an in-vivo model to study relevant retropubic anatomy critical for SOR reservoir placement. METHODS: The study population included men with elevated prostate specific antigen or biopsy proven prostate cancer who (i) underwent pelvic MRI, (ii) without prior pelvic or inguinal surgery, and (iii) without pelvic radiation therapy. All MRIs were completed with a 3-Tesla scanner and endorectal coil. Both T1 and T2 weighted images were captured in both axial and sagittal planes. All images were reviewed by 2 independent reviewers under the supervision of a dedicated body MRI radiologist. Bladder volume was calculated using an ellipsoid formula. OUTCOMES: Relevant measurements included (i) the distance between the external inguinal ring (EIR) at the level of the pubic tubercle to the external iliac vein (EIV), (ii) the distance from the EIR at the pubic tubercle to the bladder (accounting for bladder volume) and (iii) the distance from the midline pubic symphysis to the bladder (accounting for bladder volume). Pearson correlation was used to determine correlated measurements. RESULTS: A total of 24 patients were included. Median participant age was 63 years (interquartile range, 59-66). The mean EIR-EIV distance was 3.0 ± 0.4 cm, the mean EIR-bladder distance was 1.8 ± 1.0 cm and the mean distance from the superior pubic symphysis to bladder was 0.9 ± 0.3 cm. There was a weak correlation between bladder volume and distance between the EIR and bladder (r = -0.30, P = .16). CLINICAL IMPLICATIONS: The use of MRI as an in-vivo model is a high-fidelity tool to study real time unaltered anatomy and allows for surgical preparation, diagnosis of anatomic variants and acts as a valuable teaching tool. STRENGTHS & LIMITATIONS: This is the first in-vivo model to report relevant retropubic anatomy in penile implant surgery. Our study is limited by sample size and inclusion of participants with no history of prior pelvic intervention. CONCLUSION: We demonstrate the utility of MRI as an in-vivo model, as opposed to cadaveric models, for the understanding of relevant retropubic anatomy for implant surgeons. Punjani N, Monteiro L, Sullivan J F et al. The Anatomical Relationships in the Space of Retzius for Penile Implants: An MRI Analysis. J Sex Med 2021;18:1830-1834.

A child case of Kawasaki with giant coronary aneurysm: percutaneous coronary intervention due to anterior myocardial infarction.

Kawasaki disease is usually self-limited, but it can lead to aneurysm, stenosis, thrombosis, and myocardial infarction in the coronary arteries. The most important complication of Kawasaki disease is coronary artery aneurysm. Coronary artery aneurysm or ectasia may be seen in 15-25% of patients who do not receive treatment. It develops in 5% of children who receive intravenous immunoglobulin at the appropriate time. Acute myocardial infarction is the most important cause of morbidity and mortality in Kawasaki patients with giant aneurysms. We present a 10-year-old girl who had a history of giant aneurysm in the coronary arteries and underwent percutaneous coronary intervention due to anterior myocardial infarction.

Climacturia After Radical Prostatectomy: MRI-Based Predictors.

BACKGROUND: After radical prostatectomy (RP), climacturia is a prevalent and distressing problem. To date, no specific predictors have been identified. AIM: In this analysis, we sought to find associated pelvic magnetic resonance imaging (MRI) parameters. METHODS: We identified all men in our departmental database who (i) had climacturia post-RP, ≥3 episodes; (ii) underwent a pre-RP endorectal MRI; (iii) had no radiation or androgen deprivation therapy (ADT). Soft tissue and bony dimensions were measured by 2 raters blinded to clinical and pathological data. OUTCOMES: MRI parameters included the following: maximum height, width, and depth of prostate, prostate volume, urethral width and length, lower conjugate of pelvis, bony femoral width, outer and inner levator distances and thickness. Point-biserial correlations were run on univariate associations. Logistic regression was used for the multivariable model. RESULTS: 194 consecutive pre-RP MRI studies were reviewed (56 men with and 138 without climacturia). Mean age was 60 ± 7 years, average time post-RP at assessment, 7 ± 7 months. Of MRI parameters, urethral width (r = 0.13, P = .03) and lower conjugate (r = 0.12, P = .05) were associated with presence of persistent climacturia. 2 others met criteria for multivariable analysis, prostate depth and outer levator distance. Of the non-MRI parameters, none were significantly related to climacturia and only body mass index (BMI) met criteria for multivariable analysis. On multivariable analysis, only urethral width was associated with climacturia (OR = 1.23, 95% CI: 1.01-1.49, P = .04); the wider the urethra, greater the chance of climacturia. CLINICAL IMPLICATIONS: Improved ability to predict the occurrence of orgasm-associated incontinence in the preoperative setting. STRENGTHS AND LIMITATIONS: Limitations include the fact that the MRI endorectal probe may have distorted pelvic tissues during imaging and that our study population size was small. However, prospective data collection, blinded measurements by 2 trained readers, and rigorous statistical analysis should be considered strengths. CONCLUSION: By identifying preoperative risk factors, such as urethral width on MRI, we may be able to better understand the pathophysiology of this condition and furthermore may permit us to better counsel men regarding this postoperative outcome. Sullivan JF, Ortega Y, Matsushita K, et al. Climacturia After Radical Prostatectomy: MRI-Based Predictors. J Sex Med 2020;17:1723-1728.

Systemic therapy for advanced clear cell renal cell carcinoma after discontinuation of immune-oncology and VEGF targeted therapy combinations.

BACKGROUND: Several phase 3 studies reported positive results for combinations of Immune-Oncology (IO) and Vascular Endothelial Growth Factor (VEGF) targeted therapies in patients with metastatic clear cell Renal Cell Carcinoma (ccRCC). However, there are limited data on outcomes to systemic therapy after IO-VEGF combinations. METHODS: A retrospective analysis was performed on patients with metastatic ccRCC treated at the Memorial Sloan Kettering Cancer Center and Cleveland Clinic who initiated systemic therapy post IO-VEGF including combinations with VEGF receptor (VEGFR) tyrosine kinase inhibitors (IO-TKI) and combinations with the anti-VEGF monoclonal antibody bevacizumab (IO-Bev). The study objectives were to evaluate the objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) on systemic therapy post IO-VEGF. RECIST v1.1 criteria were used to determine radiological responses and progression. Survival estimates were evaluated with the Kaplan-Meier methods and the log-rank test from the start of systemic therapy post IO-VEGF to the event of interest. RESULTS: A total of fifty-nine patients were treated post discontinuation of IO-VEGF regimens which included IO-Bev (n = 35; 59%) and IO-TKI (n = 24; 41%). Fifty-eight patients (98%) received IO-VEGF regimens as part of a clinical trial. Subsequent therapies included cabozantinib (n = 22; 37%), axitinib (n = 18; 31%), pazopanib (n = 4; 7%), lenvatinib and everolimus (n = 4; 7%), mTOR inhibitor monotherapy (n = 3; 5%), axitinib and dalantercept (n = 2; 3%), sunitinib (n = 1; 2%), sorafenib (n = 1; 2%), and treatment with agents on unreported clinical trials (n = 4; 7%). Patients treated on unreported clinical trials were excluded from the efficacy analysis. Post IO-VEGF, the ORR was 25% and median PFS was 12.0 months (95% CI, 8.2-24.5). Median OS was 24.5 months (95% CI, 12-NE) and 12 months OS rate was 63.3% (95% CI, 48.6-74.9). We observed no differences post IO-VEGF OS when comparing IO- TKI vs IO-Bev (Log-rank p = 0.73). CONCLUSIONS: Post IO-VEGF, most patients received VEGFR-TKIs. In this setting, VEGFR-TKIs demonstrated clinical activity and remain a viable option for salvage therapy after progression on IO-VEGF.

Advances in oncologic imaging: update on 5 common cancers.

Imaging has become a pivotal component throughout a patient's encounter with cancer, from initial disease detection and characterization through treatment response assessment and posttreatment follow-up. Recent progress in imaging technology has presented new opportunities for improving clinical care. This article provides updates on the latest approaches to imaging of 5 common cancers: breast, lung, prostate, and colorectal cancers, and lymphoma.

The Influence of Background Signal Intensity Changes on Cancer Detection in Prostate MRI.

OBJECTIVE: The objective of this study was to develop a scoring system for background signal intensity changes or prostate homogeneity on prostate MRI and to assess these changes' influence on cancer detection. MATERIALS AND METHODS: This institutional review board-approved, HIPAA-compliant, retrospective study included 418 prostate MRI examinations in 385 men who subsequently underwent MRI-guided biopsy. The Likert score for suspicion of cancer assigned by the primary radiologist was extracted from the original report, and histopathologic work-up of the biopsy cores served as the reference standard. Two readers assessed the amount of changes on T2-weighted sequences and assigned a predefined prostate signal-intensity homogeneity score of 1-5 (1 = poor, extensive changes; 5 = excellent, no changes). The sensitivity and specificity of Likert scores for detection of prostate cancer and clinically significant cancer (Gleason score ≥ 3+4) were estimated in and compared between subgroups of patients with different signal-intensity homogeneity scores (≤ 2, 3, and ≥ 4). RESULTS: Interreader agreement on signal-intensity homogeneity scores was substantial (κ = 0.783). Sensitivity for prostate cancer detection increased when scores were better (i.e., higher) (reader 1, from 0.41 to 0.71; reader 2, from 0.53 to 0.73; p ≤ 0.007, both readers). In the detection of significant cancer (Gleason score ≥ 3+4), sensitivity also increased with higher signal-intensity scores (reader 1, from 0.50 to 0.82; reader 2, from 0.63 to 0.86; p ≤ 0.028), though specificity decreased significantly for one reader (from 0.67 to 0.38; p = 0.009). CONCLUSION: Background signal-intensity changes on T2-weighted images significantly limit prostate cancer detection. The proposed scoring system could improve the standardization of prostate MRI reporting and provide guidance for applying prostate MRI results appropriately in clinical decision-making.

Nonenhancing Component of Clear Cell Renal Cell Carcinoma on Computed Tomography Correlates With Tumor Necrosis and Stage and Serves as a Size-Independent Prognostic Biomarker.

OBJECTIVES: This study aimed to quantify nonenhancing tumor (NT) component in clear cell renal cell carcinoma (ccRCC) and assess its association with histologically defined tumor necrosis, stage, and survival outcomes. METHODS: Among 183 patients with ccRCC, multi-institutional changes in computed tomography attenuation of tumor voxels were used to quantify percent of NT. Associations of NT with histologic tumor necrosis and tumor stage/grade were tested using Wilcoxon signed rank test and with survival outcomes using Kaplan-Meier curves/Cox regression analysis. RESULTS: Nonenhancing tumor was higher in ccRCC with tumor necrosis (11% vs 7%; P = 0.040) and higher pathological stage (P = 0.042 and P < 0.001, respectively). Patients with greater NT had higher incidence of cancer recurrence after resection (P < 0.001) and cancer-specific mortality (P < 0.001). CONCLUSION: Nonenhancing tumor on preoperative computed tomographic scans in patients with ccRCC correlates with tumor necrosis and stage and may serve as an independent imaging prognostic biomarker for cancer recurrence and cancer-specific survival.

Three novel methods to measure the postoperative displacement of lower urinary tract structures following radical prostatectomy in a sample of Korean patients.

BACKGROUND: There is a change in the position of the remaining anatomical structures of the lower urinary tract system following radical prostatectomy. The aims of this investigation were to describe three novel methods used to measure the displacement of i) the vesico-urethral junction (VUJ), proximal membranous urethra (PMU) and anorectal junction (ARJ) and ii) the VUJ angle of displacement in men following radical prostatectomy and determine their intra- and interrater reliability. METHODS: Retrospective comparative measurement of twenty pre- and postoperative MRI scans was undertaken by one observer on two separate occasions and on one occasion by another observer. Three standardized midsagittal pelvimetry reference lines were used to describe three X, Y axis measurement systems. The displacement (mm) of the VUJ, PMU and ARJ, and the angle of displacement (degrees) of the VUJ was measured for each of the three methods. Interrater reliability of VUJ, PMU and ARJ displacement and the VUJ angle of displacement measurements was assessed using a two-way mixed-effects agreement intra-class correlation coefficient (ICC) with 95% confidence intervals (CI). Test-retest (intrarater) reliability was calculated using a two-way random effects consistency ICC with 95% CI for all displacement measures of the VUJ, PMU and ARJ for one observer between two days. RESULTS: The pubococcygeal line (PCL) axis measurement system demonstrated good to excellent intrarater and interrater reliability (ICC 95% interval lower bound > 0.75) for the VUJ and PMU displacement and the VUJ angle of displacement measurements. Other measurement systems were less reliable and more variable. CONCLUSIONS: In this sample of 20 Korean patients with median prostate volume 27.5 mL and maximum volume 70 mL, the measurement methodology using the PCL consistently demonstrated good to excellent reliability and the lowest variability for the measurement of the displacement of the VUJ and PMU and the VUJ angle of displacement. The PCL methodology is recommended as the method of choice. Further studies should validate these results in patients with large prostate volumes.

Cystic Renal Cell Carcinoma: A Report on Outcomes of Surgery and Active Surveillance in Patients Retrospectively Identified on Pretreatment Imaging.

PURPOSE: We evaluated the outcomes of surgical intervention and active surveillance in patients diagnosed with cystic renal cell carcinoma at our hypothesized radiological cutoff of greater than 50% cystic. MATERIALS AND METHODS: We identified all 430 patients with a pathologically confirmed cystic renal mass that fit our criteria from 2000 to 2015. The 292 patients with a lack of computerized tomography, tumors less than 50% cystic on imaging, multifocal tumors and prior renal cell carcinoma were excluded from study. Patients were stratified into benign or malignant subgroups, and radiological, clinicopathological and oncologic features were determined. Univariate and multivariate associations between clinicoradiological parameters in each group were analyzed. We similarly reviewed the records of a separate cohort of patients treated with active surveillance for cystic renal cell carcinoma. RESULTS: Of the 138 identified cases of cystic renal cell carcinoma 102 (73.9%) were renal cell carcinoma and 36 (26.1%) were benign masses. Of the tumors 77.5% were Fuhrman grade 1-2, 83.4% were stage pT2 or less and 65.9% showed clear cell histology. On univariate analysis male gender, a solid component and increasing Bosniak classification were significant for malignancy. In a separate cohort we identified 38 patients on active surveillance. The growth rate was 1.0 mm per year overall and 2.3 mm per year for the solid component. At a median followup of more than 4 years in all cohorts there was no evidence of recurrence or metastasis of cystic renal cell carcinoma. CONCLUSIONS: Patients with unifocal cystic renal cell carcinoma evaluated using a standardized radiological threshold of greater than 50% cystic had an excellent prognosis on active surveillance and after surgical resection.

Preoperative Prostate MRI: A Road Map for Surgery.

OBJECTIVE: MRI of the prostate is widely used in prostate cancer for local staging. The purpose of this article is to show how preoperative prostate MRI findings may be used as a road map for surgery to preserve the neurovascular bundle, identify risk factors associated with positive surgical margins, and evaluate findings associated with intraoperative complications and functional recovery after surgery. CONCLUSION: Knowledge of surgically relevant imaging findings can increase radiologists' confidence in reporting them to our colleagues.

Differentiation of Clear Cell Renal Cell Carcinoma From Other Renal Cortical Tumors by Use of a Quantitative Multiparametric MRI Approach.

OBJECTIVE: The purpose of this study was to develop a quantitative multiparametric MRI approach to differentiating clear cell renal cell carcinoma (RCC) from other renal cortical tumors. MATERIALS AND METHODS: This retrospective study included 119 patients with 124 histopathologically confirmed renal cortical tumors who underwent preoperative MRI including DWI, contrast-enhanced, and chemical-shift sequences before nephrectomy. Two radiologists independently assessed each tumor volumetrically, and apparent diffusion coefficient values, parameters from multiphasic contrast-enhanced MRI (peak enhancement, upslope, downslope, AUC), and chemical-shift indexes were calculated. Univariate and multivariable logistic regression analyses were performed to identify parameters associated with clear cell RCC. RESULTS: Interreader agreement was excellent (intraclass correlation coefficient, 0.815-0.994). The parameters apparent diffusion coefficient (reader 1 AUC, 0.804; reader 2, 0.807), peak enhancement (reader 1 AUC, 0.629; reader 2, 0.606), and downslope (reader 1 AUC, 0.575; reader 2, 0.561) were significantly associated with discriminating clear cell RCC from other renal cortical tumors. The combination of all three parameters further increased diagnostic accuracy (reader 1 AUC, 0.889; reader 2, 0.907; both p ≤ 0.001), yielding sensitivities of 0.897 for reader 1 and 0.897 for reader 2, and specificities of 0.762 for reader 1 and 0.738 for reader 2 in the identification of clear cell RCC. With maximized sensitivity, specificities of 0.429 and 0.262 were reached for readers 1 and 2, respectively. CONCLUSION: A quantitative multiparametric approach statistically significantly improves diagnostic performance in differentiating clear cell RCC from other renal cortical tumors.

Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival.

OBJECTIVE: The objective of this study was to investigate associations between CT features and survival in patients with clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS: The study included 763 patients with histopathologically confirmed ccRCC who underwent preoperative contrast-enhanced CT between 1999 and 2011. Imaging features, both qualitative (cystic tumor, necrosis, tumor contact with renal sinus, renal vein invasion, peritumoral stranding, and peritumoral neovascularity) and quantitative (maximal tumor diameter and distance from the tumor to the renal sinus), were evaluated. Univariate and multivariable Cox regressions were used to assess associations of imaging features with disease-specific survival (DSS) and disease-specific progression-free survival (PFS). RESULTS: Greater tumor size and the presence of renal vein invasion on CT were associated with decreased DSS and disease-specific PFS (p < 0.05), and the presence of extensive necrosis (more than two-thirds of the tumor volume) was associated with decreased disease-specific PFS (p < 0.05); this association remained statistically significant when we controlled for pathologic tumor stage. In contrast, no disease-specific death or progression was seen in patients with purely cystic tumors. Greater distance between the tumor and the renal sinus was not statistically significantly associated with longer survival. CONCLUSION: In patients with ccRCC, observation of extensive necrosis on CT was statistically significantly associated with decreased disease-specific PFS, whereas greater tumor size and the presence of renal vein invasion on CT were statistically significantly associated with decreased DSS and disease-specific PFS. No disease progression was observed in tumors with a cystic appearance. Therefore, selected CT features could potentially aid in risk assessment for and counseling of patients with ccRCC and could provide prognostic information beyond the established tumor staging system.

Assessment of Prostate Cancer Aggressiveness by Use of the Combination of Quantitative DWI and Dynamic Contrast-Enhanced MRI.

OBJECTIVE: The objective of this study was to investigate whether the apparent diffusion coefficient (ADC) value from DWI and the forward volume transfer constant (K(trans)) value from dynamic contrast-enhanced MRI independently predict prostate cancer aggressiveness, and to determine whether the combination of both parameters performs better than either parameter alone in assessing tumor aggressiveness before treatment. MATERIALS AND METHODS: This retrospective study included 158 men with histopathologically confirmed prostate cancer who underwent 3-T MRI before undergoing prostatectomy in 2011. Whole-mount step-section pathologic maps identified 195 prostate cancer foci that were 0.5 mL or larger; these foci were then volumetrically assessed to calculate the per-tumor ADC and K(trans) values. Associations between MRI and histopathologic parameters were assessed using Spearman correlation coefficients, univariate and multivariable logistic regression, and AUCs. RESULTS: The median ADC and K(trans) values showed moderate correlation only for tumors for which the Gleason score (GS) was 4 + 4 or higher (ρ = 0.547; p = 0.042). The tumor ADC value was statistically significantly associated with all dichotomized GSs (p < 0.005), including a GS of 3 + 3 versus a GS of 3 + 4 or higher (AUC, 0.693; p = 0.001). The tumor K(trans) value differed statistically significantly only between tumors with a GS of 3 + 3 and those with a primary Gleason grade of 4 (p ≤ 0.015), and it made a statistically significant contribution only in differentiating tumors with a GS of 4 + 3 or higher (AUC, 0.711; p < 0.001) and those with a GS of 4 + 4 or higher (AUC, 0.788; p < 0.001) from lower-grade tumors. Combining ADC and K(trans) values improved diagnostic performance in characterizing tumors with a GS of 4 + 3 or higher and those with a GS of 4 + 4 or higher (AUC, 0.739 and 0.856, respectively; p < 0.01). CONCLUSION: Although the ADC value helped to differentiate between all GSs, the K(trans) value was only a benefit in characterizing more aggressive tumors. Combining these parameters improves their performance in identifying patients with aggressive tumors who may require radical treatment.

Use of DWI in the Differentiation of Renal Cortical Tumors.

OBJECTIVE: The purpose of this study was to differentiate clear cell renal cell carcinoma (RCC) from other common renal cortical tumors by use of DWI. MATERIALS AND METHODS: The study included 117 patients (mean age, 60 years) with 122 histopathologically confirmed renal cortical tumors who underwent 1.5-T MRI that included DWI before they underwent nephrectomy between 2006 and 2013. For each tumor, two radiologists independently evaluated apparent diffusion coefficient (ADC) values on the basis of a single ROI in a nonnecrotic area of the tumor and also by assessment of the whole tumor. The concordance correlation coefficient (CCC) was calculated to assess interreader agreement. The mean ADC values of clear cell RCC and every other tumor subtype were compared using an exact Wilcoxon rank sum test. RESULTS: Interreader agreement was excellent and higher in whole-tumor assessment (CCC, 0.982) than in single-ROI analysis (CCC, 0.756). For both readers, ADC values for clear cell RCC found on single-ROI assessment (2.19 and 2.08 × 10(-3) mm(2)/s) and whole-tumor assessment (2.30 and 2.32 × 10(-3) mm(2)/s) were statistically significantly higher than those for chromophobe, papillary, or unclassified RCC (p < 0.05) but were similar to those for oncocytoma found on single-ROI assessment (2.14 and 2.32 × 10(-3) mm(2)/s) and whole-tumor assessment (2.38 and 2.24 × 10(-3) mm(2)/s). ADC values were also higher for clear cell RCC than for angiomyolipoma, but the difference was statistically significant only in whole-tumor assessment (p < 0.03). CONCLUSION: ADC values were statistically significantly higher for clear cell RCC than for chromophobe, papillary, or unclassified RCC subtypes; however, differentiating clear cell RCC from oncocytoma by use of DWI remains especially challenging, because similar ADC values have been shown for these two tumor types.

Subcentimeter pulmonary nodules are not associated with disease progression in patients with renal cell carcinoma.

PURPOSE: Renal cell carcinoma most commonly metastasizes to the lung. Indeterminate pulmonary nodules develop preoperatively in half of the patients with localized renal cell carcinoma but clinical significance remains poorly defined. We determined whether the presence of indeterminate pulmonary nodules, or nodule size or number is associated with renal cell carcinoma outcomes. MATERIALS AND METHODS: We reviewed data on 1,102 patients with renal cell carcinoma in whom chest computerized tomography was done within 6 months before nephrectomy from 2002 to 2012. Patients with metastatic disease at presentation, benign tumors, pulmonary nodules greater than 2 cm or concurrent pulmonary disease were excluded, leaving 748 available for analysis. Study outcomes included lung metastasis, any distant metastasis or death from renal cell carcinoma. Cox proportional hazards models were used to assess whether the presence of indeterminate pulmonary nodules, or nodule size or number was associated with outcomes. Models were evaluated by comparing discrimination using the Harrell c-index. RESULTS: Indeterminate pulmonary nodules were present in 382 of 748 patients (51%). Median followup was 4.1 years (IQR 2.2-6.1). The presence of indeterminate pulmonary nodules was not associated with distant metastasis or death from kidney cancer. However, compared to subcm indeterminate pulmonary nodules the nodules greater than 1 cm were associated with metastatic disease after adjusting for tumor histology, stage and size (HR 2.48, 95% CI 1.08-5.68, p = 0.031). The outcome c-index increased slightly after adding nodule size to a predictive model adjusted for tumor characteristics. CONCLUSIONS: No evidence in the current study suggested that indeterminate pulmonary nodules less than 1 cm are associated with renal cell carcinoma progression, although large nodules significantly predicted metastatic disease. Patients with subcm indeterminate pulmonary nodules would be unlikely to benefit from extensive postoperative chest imaging surveillance, which should be reserved for patients with nodules greater than 1 cm.

Preoperative predictive model of recovery of urinary continence after radical prostatectomy.

OBJECTIVE: To build a predictive model of urinary continence recovery after radical prostatectomy (RP) that incorporates magnetic resonance imaging (MRI) parameters and clinical data. PATIENTS AND METHODS: We conducted a retrospective review of data from 2,849 patients who underwent pelvic staging MRI before RP from November 2001 to June 2010. We used logistic regression to evaluate the association between each MRI variable and continence at 6 or 12 months, adjusting for age, body mass index (BMI) and American Society of Anesthesiologists (ASA) score, and then used multivariable logistic regression to create our model. A nomogram was constructed using the multivariable logistic regression models. RESULTS: In all, 68% (1,742/2,559) and 82% (2,205/2,689) regained function at 6 and 12 months, respectively. In the base model, age, BMI and ASA score were significant predictors of continence at 6 or 12 months on univariate analysis (P < 0.005). Among the preoperative MRI measurements, membranous urethral length, which showed great significance, was incorporated into the base model to create the full model. For continence recovery at 6 months, the addition of membranous urethral length increased the area under the curve (AUC) to 0.664 for the validation set, an increase of 0.064 over the base model. For continence recovery at 12 months, the AUC was 0.674, an increase of 0.085 over the base model. CONCLUSION: Using our model, the likelihood of continence recovery increases with membranous urethral length and decreases with age, BMI and ASA score. This model could be used for patient counselling and for the identification of patients at high risk for urinary incontinence in whom to study changes in operative technique that improve urinary function after RP.

Interobserver variability of R.E.N.A.L., PADUA, and centrality index nephrometry score systems.

PURPOSE: To assess interobserver variability of R.E.N.A.L., preoperative aspects and dimensions used for an anatomical classification system (PADUA), and centrality index (C-Index) systems among observers with varying degrees of clinical experience and each system's subscale correlation with surgical outcome metrics. METHODS: Computed tomography images of 90 patients who underwent open, laparoscopic, or robot-assisted laparoscopic partial nephrectomy were scored by one radiology fellow, two urology fellows, one radiology resident, and one secondary school student. Agreement among readers was determined calculating intraclass correlation coefficients. Associations between radiology fellow scores (reference standard as reader with greatest clinical experience), ischemia time, and percent change in postoperative estimated glomerular filtration rate (eGFR) were evaluated using Spearman's correlation. RESULTS: Agreement using C-Index method (ICC = 0.773) was higher than with PADUA (ICC = 0.677) or R.E.N.A.L (ICC = 0.660). Agreement between reference and secondary school student was lower than with other physicians, although the differences were not statistically significant. The reference's scores were significantly (p < 0.05) associated with ischemia time on all three scoring systems and with percent change in eGFR at 6 weeks using C-Index (p = 0.016). Tumor size, nearness to sinus, and location relative to polar lines (R.E.N.A.L.) and tumor size, renal sinus involvement, and collecting system involvement (PADUA) correlated with ischemia time (all p ≤ 0.001). No R.E.N.A.L. or PADUA subscales significantly correlated with percent change in postoperative eGFR. CONCLUSIONS: Clinical experience reduces interobserver variability of existing nephrometry systems though not significantly and less so when using directly measureable anatomic variables. Consistently, only measures of tumor size and distance to intrarenal structures were useful in predicting clinically relevant outcomes.