Differentiating mixed epithelial and stromal tumor family from predominantly cystic renal cell carcinoma using magnetic resonance imaging-based Bosniak classification system version 2019.

PURPOSE: To differentiate mixed epithelial and stromal tumor family (MESTF) of the kidney from predominantly cystic renal cell carcinoma (RCC) using the magnetic resonance imaging (MRI)-based Bosniak classification system version 2019 (v2019). MATERIALS AND METHODS: The study included 36 consecutive patients with MESTF and 77 with predominantly cystic RCC who underwent preoperative renal MRI. One radiologist evaluated and documented the clinical and MRI characteristics (age, sex, laterality, R.E.N.A.L. Nephrometry Score [RNS], surgical approach, the signal intensity on T2-weighted imaging, restricted diffusion and enhancement features in corticomedullary phase). Blinded to clinical and pathological information, another two radiologists independently evaluated Bosniak category of all masses. Interobserver agreement based on Bosniak classification system v2019 was measured by the weighted Cohen/Conger's Kappa coefficient. Furthermore, predominantly cystic RCCs and MESTFs were divided into low (categories I, II, and IIF) and high-class (categories III, and IV) tumors. The independent sample t test (Mann-Whitney U test) or Pearson Chi-square test (Fisher's exact probability test) was utilized to compare clinical and imaging characteristics between MESTFs and predominantly cystic RCCs. The performance of the Bosniak classification system v2019 in distinguishing MESTF from predominantly cystic RCC was investigated via receiver operating characteristic curve analysis. RESULTS: MESTF and predominantly cystic RCC groups significantly differed in terms of age, lesion size, RNS, restricted diffusion, and obvious enhancement in corticomedullary phase, but not sex, laterality, surgical approach, and the signal intensity on T2WI. Interobserver agreement was substantially based on the Bosniak classification system v2019. There were 24 low-class tumors and 12 high-class tumors in the MESTF group. Meanwhile, 13 low-class tumors and 64 high-class tumors were observed in the predominantly cystic RCC group. The distribution of low- or high-class tumors significantly differed between the MESTF and predominantly cystic RCC groups. Bosniak classification system v2019 had excellent discrimination (cutoff value = category III), and an area under curve value was 0.81; accuracy, 80.5%; sensitivity, 87.0%; and specificity, 66.7%. CONCLUSION: The MRI-based Bosniak classification system v2019 can effectively distinguish MESTF from predominantly cystic RCC if category III was used as a cutoff reference.

Diagnostic Value of Clear Cell Likelihood Score v1.0 and v2.0 for Common Subtypes of Small Renal Masses: A Multicenter Comparative Study.

BACKGROUND: Clear cell likelihood score (ccLS) is reliable for diagnosing small renal masses (SRMs). However, the diagnostic value of Clear cell likelihood score version 1.0 (ccLS v1.0) and v2.0 for common subtypes of SRMs might be a potential score extension. PURPOSE: To compare the diagnostic performance and interobserver agreement of ccLS v1.0 and v2.0 for characterizing five common subtypes of SRMs. STUDY TYPE: Retrospective. POPULATION: 797 patients (563 males, 234 females; mean age, 53 ± 12 years) with 867 histologically proven renal masses. FIELD STRENGTH/SEQUENCES: 3.0 and 1.5 T/T2 weighted imaging, T1 weighted imaging, diffusion-weighted imaging, a dual-echo chemical shift (in- and opposed-phase) T1 weighted imaging, multiphase dynamic contrast-enhanced imaging. ASSESSMENT: Six abdominal radiologists were trained in the ccLS algorithm and independently scored each SRM using ccLS v1.0 and v2.0, respectively. All SRMs had definite pathological results. The pooled area under curve (AUC), accuracy, sensitivity, and specificity were calculated to evaluate the diagnostic performance of ccLS v1.0 and v2.0 for characterizing common subtypes of SRMs. The average κ values were calculated to evaluate the interobserver agreement of the two scoring versions. STATISTICAL TESTS: Random-effects logistic regression; Receiver operating characteristic analysis; DeLong test; Weighted Kappa test; Z test. The statistical significance level was P < 0.05. RESULTS: The pooled AUCs of clear cell likelihood score version 2.0 (ccLS v2.0) were statistically superior to those of ccLS v1.0 for diagnosing clear cell renal cell carcinoma (ccRCC) (0.907 vs. 0.851), papillary renal cell carcinoma (pRCC) (0.926 vs. 0.888), renal oncocytoma (RO) (0.745 vs. 0.679), and angiomyolipoma without visible fat (AMLwvf) (0.826 vs. 0.766). Interobserver agreement for SRMs between ccLS v1.0 and v2.0 is comparable and was not statistically significant (P = 0.993). CONCLUSION: The diagnostic performance of ccLS v2.0 surpasses that of ccLS v1.0 for characterizing ccRCC, pRCC, RO, and AMLwvf. Especially, the standardized algorithm has optimal performance for ccRCC and pRCC. ccLS has potential as a supportive clinical tool. EVIDENCE LEVEL: 4. TECHNICAL EFFICACY: Stage 2.

Renal cell carcinoma and venous tumor thrombus: predicting sarcomatoid dedifferentiation through preoperative IVIM-based MR imaging.

PURPOSE: To evaluate the value of preoperative intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and conventional MRI indicators in identifying sarcomatoid dedifferentiation in renal cell carcinoma (RCC) and tumor thrombus. METHODS: From September 2016 to April 2023, consecutive patients with RCC and tumor thrombus who received routine MRI examination and IVIM-DWI before radical resection were enrolled prospectively. Kaplan-Meier method with log-rank test was used to calculate and compare the survival probability. The preoperative imaging features were analyzed. Univariate and multivariable logistic regression analyses were employed to identify independent predictors of sarcomatoid dedifferentiation. The predictive ability was evaluated by receiver operating characteristic (ROC) curves. RESULTS: Twenty-two patients (15.3%) of the 144 patients in the training set (median age, 58.0 years [IQR, 52.0-65.0 years]; 108 men) and 11 patients (22.4%) of the 49 patients in the test set (median age, 58.0 years [IQR, 53.0-63.0 years]; 38 men) had sarcomatoid dedifferentiated tumors. Patients with sarcomatoid-differentiated tumors had poor progress-free survival in the training set and test set (P < 0.001 and P = 0.007). f value (P = 0.011), mN stage (P = 0.007), and necrosis (P = 0.041) were independent predictors for predicting sarcomatoid dedifferentiation in the training set. The model combining conventional MRI features and f value had AUCs of 0.832 (95% CI 0.755-0.909) and 0.825 (95% CI 0.702-0.948) in predicting sarcomatoid dedifferentiation in the training set and test set. CONCLUSION: It is feasible to preoperatively identify sarcomatoid dedifferentiation based on IVIM-DWI and conventional MR imaging indicators.

Multiparametric MRI-Based Machine Learning Models for the Characterization of Cystic Renal Masses Compared to the Bosniak Classification, Version 2019: A Multicenter Study.

RATIONALE AND OBJECTIVE: Accurate differentiation between benign and malignant cystic renal masses (CRMs) is challenging in clinical practice. This study aimed to develop MRI-based machine learning models for differentiating between benign and malignant CRMs and compare the best-performing model with the Bosniak classification, version 2019 (BC, version 2019). METHODS: Between 2009 and 2021, consecutive surgery-proven CRM patients with renal MRI were enrolled in this multicenter study. Models were constructed to differentiate between benign and malignant CRMs using logistic regression (LR), random forest (RF), and support vector machine (SVM) algorithms, respectively. Meanwhile, two radiologists classified CRMs into I-IV categories according to the BC, version 2019 in consensus in the test set. A subgroup analysis was conducted to investigate the performance of the best-performing model in complicated CRMs (II-IV lesions in the test set). The performances of models and BC, version 2019 were evaluated using the area under the receiver operating characteristic curve (AUC). Performance was statistically compared between the best-performing model and the BC, version 2019. RESULTS: 278 and 48 patients were assigned to the training and test sets, respectively. In the test set, the AUC and accuracy of the LR model, the RF model, the SVM model, and the BC, version 2019 were 0.884 and 75.0%, 0.907 and 83.3%, 0.814 and 72.9%, and 0.893 and 81.2%, respectively. Neither the AUC nor the accuracy of the RF model that performed best were significantly different from the BC, version 2019 (P = 0.780, P = 0.065). The RF model achieved an AUC and accuracy of 0.880 and 81.0% in complicated CRMs. CONCLUSIONS: The MRI-based RF model can accurately differentiate between benign and malignant CRMs with comparable performance to the BC, version 2019, and has good performance in complicated CRMs, which may facilitate treatment decision-making and is less affected by interobserver disagreements.

Assessment of the Added Value of Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging in Identifying Non-Diabetic Renal Disease in Patients With Type 2 Diabetes Mellitus.

BACKGROUND: Identification of non-diabetic renal disease (NDRD) in patients with type 2 diabetes mellitus (T2DM) may help tailor treatment. Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) is a promising tool to evaluate renal function but its potential role in the clinical differentiation between diabetic nephropathy (DN) and NDRD remains unclear. PURPOSE: To investigate the added role of IVIM-DWI in the differential diagnosis between DN and NDRD in patients with T2DM. STUDY TYPE: Prospective. POPULATION: Sixty-three patients with T2DM (ages: 22-69 years, 17 females) confirmed by renal biopsy divided into two subgroups (28 DN and 35 NDRD). FIELD STRENGTH/SEQUENCE: 3 T/ T2 weighted imaging (T2WI), and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI). ASSESSMENT: The parameters derived from IVIM-DWI (true diffusion coefficient [D], pseudo-diffusion coefficient [D*], and pseudo-diffusion fraction [f]) were calculated for the cortex and medulla, respectively. The clinical indexes related to renal function (eg cystatin C, etc.) and diabetes (eg diabetic retinopathy [DR], fasting blood glucose, etc.) were measured and calculated within 1 week before MRI scanning. The clinical model based on clinical indexes and the IVIM-based model based on IVIM parameters and clinical indexes were established and evaluated, respectively. STATISTICAL TESTS: Student's t-test; Mann-Whitney U test; Fisher's exact test; Chi-squared test; Intraclass correlation coefficient; Receiver operating characteristic analysis; Hosmer-Lemeshow test; DeLong's test. P < 0.05 was considered statistically significant. RESULTS: The cortex D*, DR, and cystatin C values were identified as independent predictors of NDRD in multivariable analysis. The IVIM-based model, comprising DR, cystatin C, and cortex D*, significantly outperformed the clinical model containing only DR, and cystatin C (AUC = 0.934, 0.845, respectively). DATA CONCLUSION: The IVIM parameters, especially the renal cortex D* value, might serve as novel indicators in the differential diagnosis between DN and NDRD in patients with T2DM. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Assessment of Ki-67 proliferation index in prognosis prediction in patients with nonmetastatic clear cell renal cell carcinoma and tumor thrombus.

PURPOSE: To determine the optimal cut-off value of Ki-67 for predicting the survival of patients with clear cell renal cell carcinoma (ccRCC) and tumor thrombus and to explore the correlation between Ki-67 expression and pathological features. PATIENTS AND METHODS: We retrospectively analyzed Ki-67 immunohistochemical staining of ccRCC and tumor thrombus resected from February 2006 to February 2022. The survival rate was evaluated using the Kaplan-Meier method. The optimal cut-off value of the Ki-67 expression for predicting survival was determined by the minimum P-value method. Clinicopathological data were compared based on Ki-67 status (low versus high expression). Univariate and multivariate Cox regression analysis was used to explore independent predictors. RESULTS: A total of 202 patients (median age, 58 years [IQR, 52-65 years], 147 men) with ccRCC and tumor thrombus were included in the study. The optimal cut-off value of Ki-67 for predicting survival was 30%. 159 (78.7%) and 43 (21.3%) patients were included in the low-expression and high-expression groups. Patients with Ki-67 high expression had significantly worse recurrence-free survival (P < 0.001) and cancer-specific survival (P < 0.001). Ki-67 high expression was associated with adverse pathological features, including tumor necrosis, ISUP nuclear grade, sarcomatoid differentiation, perirenal fat invasion, renal pelvis invasion, and inferior vena cava wall invasion (all P < 0.050). Ki-67 expression ≥ 30% (P = 0.016), tumor side (P = 0.003), diabetes (P = 0.040), blood loss (P = 0.016), inferior vena cava wall invasion (P = 0.016), and sarcomatoid differentiation (P = 0.014) were independent predictors of cancer-specific survival. CONCLUSION: The optimal cut-off level of Ki-67 in predicting the prognosis of ccRCC and tumor thrombus was 30%. The high expression of Ki-67 was associated with the aggressive pathological phenotype and poor prognosis.

Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging and Venous Tumor Thrombus Consistency in Renal Cell Carcinoma.

BACKGROUND: Venous tumor thrombus (VTT) consistency of renal cell carcinoma (RCC) is an important consideration in nephrectomy plus thrombectomy. However, evaluation of VTT consistency through preoperative MR imaging is lacking. PURPOSE: To evaluate VTT consistency of RCC through intravoxel incoherent motion-diffusion weighted imaging (IVIM-DWI) derived parameters (Dt , Dp , f, and ADC) and the apparent diffusion coefficient (ADC) value. STUDY TYPE: Retrospective. POPULATION: One hundred and nineteen patients (aged 55.8 ± 11.5 years, 85 male) with histologically-proven RCC and VTT who underwent radical resection. FIELD STRENGTH/SEQUENCES: 3.0-T; two-dimensional single-shot diffusion-weighted echo planar imaging sequence at 9 b-values (0-800 s/mm2 ). ASSESSMENT: IVIM parameters and ADC values of the primary tumor and the VTT were calculated. The VTT consistency (friable vs. solid) was determined through intraoperative findings of two urologists. The accuracy of VTT consistency classification based on the individual IVIM parameters of primary tumors and of VTT, and based on models combining parameters, was assessed. Type of operation, intra-operative blood loss, and operation length were recorded. STATISTICAL TESTS: Shapiro-Wilk test; Mann-Whitney U test; Student's t-test; Chi-square test; Receiver operating characteristic (ROC) analysis. Statistical significance level was P < 0.05. RESULTS: Of the enrolled 119 patients, 33 patients (27.7%) had friable VTT. Patients with friable VTT were significantly more likely to experience open surgery, have significantly more intraoperative blood loss, and significantly longer operative duration. The area under the ROC curve (AUC) values of Dt of the primary tumor and VTT in classifying VTT consistency were 0.758 (95% CI 0.671-0.832) and 0.712 (95% CI 0.622-0.792), respectively. The AUC value of the model combining Dp and Dt of VTT was 0.800 (95% CI 0.717-0.868). Furthermore, the AUC of the model combining Dp and Dt of VTT and Dt of the primary tumor was 0.886 (95% CI 0.814-0.937). CONCLUSION: IVIM-derived parameters had the potential to predict VTT consistency of RCC. EVIDENCE LEVEL: 3 Technical Efficacy: Stage 2.

Differentiation between renal epithelioid angiomyolipoma and clear cell renal cell carcinoma using clear cell likelihood score.

PURPOSE: Clear cell likelihood score (ccLS) may be a reliable diagnostic method for distinguishing renal epithelioid angiomyolipoma (EAML) and clear cell renal cell carcinoma (ccRCC). In this study, we aim to explore the value of ccLS in differentiating EAML from ccRCC. METHODS: We performed a retrospective analysis in which 27 EAML patients and 60 ccRCC patients underwent preoperative magnetic resonance imaging (MRI) at our institution. Two radiologists trained in the ccLS algorithm scored independently and the consistency of their interpretation was evaluated. The difference of the ccLS score was compared between EAML and ccRCC in the whole study cohort and two subgroups [small renal masses (SRM; ≤ 4 cm) and large renal masses (LRM; > 4 cm)]. RESULTS: In total, 87 patients (59 men, 28 women; mean age, 55±11 years) with 90 renal masses (EAML: ccRCC = 1: 2) were identified. The interobserver agreement of two radiologists for the ccLS system to differentiate EAML from ccRCC was good (k = 0.71). The ccLS score in the EAML group and the ccRCC group ranged from 1 to 5 (73.3% in scores 1-2) and 2 to 5 (76.7% in scores 4-5), respectively, with statistically significant differences (P < 0.001). With the threshold value of 2, ccLS can distinguish EAML from ccRCC with the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 87.8%, 95.0%, 73.3%, 87.7%, and 88.0%, respectively. The AUC (area under the curve) was 0.913. And the distribution of the ccLS score between the two diseases was not affected by tumor size (P = 0.780). CONCLUSION: The ccLS can distinguish EAML from ccRCC with high accuracy and efficiency.

Federated learning with hyper-network-a case study on whole slide image analysis.

Federated learning(FL) is a new kind of Artificial Intelligence(AI) aimed at data privacy preservation that builds on decentralizing the training data for the deep learning model. This new technique of data security and privacy sheds light on many critical domains with highly sensitive data, including medical image analysis. Developing a strong, scalable, and precise deep learning model has proven to count on a variety of high-quality data from different centers. However, data holders may not willing to share their data considering the restriction of privacy. In this paper, we approach this challenge with a federated learning paradigm. Specifically, we present a case study on the whole slide image classification problem. At each local client center, a multiple-instance learning classifier is developed to conduct whole slide image classification. We introduce a privacy-preserving federated learning framework based on hyper-network to update the global model. Hyper-network is deployed at the global center that produces the weights of the local network conditioned on its input. In this way, hyper-networks can simultaneously learn a family of the local client networks. Instead of communicating raw data with the local client, only model parameters injected with noise are transferred between the local client and the global model. By using a large scale of whole slide images with only slide-level labels, we mensurated our way on two different whole slide image classification problems. The results demonstrate that our proposed federated learning model based on hyper-network can effectively leverage multi-center data to develop a more accurate model which can be used to classify a whole slide image. Its improvements in terms of over the isolated local centers and the commonly used federated averaging baseline are significant. Code will be available.

Proportion of malignancy in Bosniak classification of cystic renal masses version 2019 (v2019) classes: systematic review and meta-analysis.

OBJECTIVES: Determine the proportion of malignancy within Bosniak v2019 classes. METHODS: MEDLINE and EMBASE were searched. Eligible studies contained patients with cystic renal masses undergoing CT or MRI renal protocol examinations with pathology confirmation, applying Bosniak v2019. Proportion of malignancy was estimated within Bosniak v2019 class. Risk of bias was assessed using QUADAS-2. RESULTS: We included 471 patients with 480 cystic renal masses. No class I malignant masses were observed. Pooled proportion of malignancy were class II, 12% (6/51, 95% CI 5-24%); class IIF, 46% (37/85, 95% CI 28-66%); class III, 79% (138/173, 95% CI 68-88%); and class IV, 84% (114/135, 95% CI 77-90%). Proportion of malignancy differed between Bosniak v2019 II-IV classes (p = 0.004). Four studies reported the proportion of malignancy by wall/septa feature. The pooled proportion of malignancy with 95% CI were class III thick smooth wall/septa, 77% (41/56, 95% CI 53-91%); class III obtuse protrusion ≤ 3 mm (irregularity), 83% (97/117, 95% CI 75-89%); and class IV nodule with acute angulation, 86% (50/58, 95% CI 75-93%) or obtuse angulation ≥ 4 mm, 83%, (64/77, 95% CI 73-90%). Subgroup analysis by wall/septa feature was limited by sample size; however, no differences were found comparing class III masses with irregularity to class IV masses (p = 0.74) or between class IV masses by acute versus obtuse angles (p = 0.62). CONCLUSION: Preliminary data suggest Bosniak v2019 class IIF masses have higher proportion of malignancy compared to the original classification, controlling for pathologic reference standard. There are no differences in proportion of malignancy comparing class III masses with irregularities to class IV masses with acute or obtuse nodules. KEY POINTS: • The proportion of malignancy in Bosniak v2019 class IIF cystic masses is 46% (37 malignant/85 total IIF masses, 95% confidence intervals (CI) 28-66%). • The proportion of malignancy in Bosniak v2019 class III cystic masses is 79% (138/173, 95% CI 68-88%) and in Bosniak v2019 class IV cystic masses is 84% (114/135, 95% CI 77-90%). • Class III cystic masses with irregularities had similar proportion of malignancy (83%, 97/117, 95% CI 75-89%) compared to Bosniak class IV masses (84%, 114/135, 95% CI 77-90%) overall (p = 0.74) with no difference within class IV masses by acute versus obtuse angulation (p = 0.62).

18 F-DCFPyL positron emission tomography/magnetic resonance imaging-guided ultrasound fusion biopsy is an identical pathway in prostate cancer diagnosis.

BACKGROUND: Prostate biopsy is still unavoidable in patients with a rising prostate-specific antigen even though multiparametric magnetic resonance imaging (MRI) is widely used. 18 F-DCFPyL positron emission tomography (PET)/MRI was proved to be promising both in sensitivity and specificity. But its guiding fusion biopsy and the advantages in the diagnosis of prostate disease is seldom reported. This study aimed to verify the feasibility and advantage of 18 F-DCFPyL PET/MRI-guided fusion targeted biopsy (TB) over whole-mount histopathology (WMH) for prostate cancer diagnosis. METHODS: A prospective study of 94 biopsy-naïve patients were conducted using 18 F-DCFPyL PET/MRI scans and scored on a scale of 1-4. Systematic biopsy was performed for all patients. Patients with suspicious lesions also underwent PET/MRI/transrectal ultrasound-guided fusion biopsy. Patients with pathologically confirmed cancer underwent surgery and WMH sections. Systematic biopsy was compared with TB for the detection of index tumors (ITs). Significant cancer was defined as Grade group (GG) 2 or higher no matter the length of the cancer core. RESULTS: 18 F-DCFPyL PET/MRI detected 30/94 (32%) patients with a score of 4, all of whom were verified to have prostate cancer. While it detected 10 patients with a score of 1 (10.6%), they were shown to have no cancer. The sensitivity and specificity of 18 F-DCFPyL PET/MRI were 94.4% and 75%, respectively, if images with a score of 3 are defined as positive. Systematic biopsy detected 18% (203/1128) samples as prostate cancer; conversely, TB detected 113 samples out of 259 scores (43.6%). A statistically significant difference was seen between the PCa detection rates by TB and SB (p < 0.001). All targeted lesions were pathologically proven to be the IT on WMH. CONCLUSIONS: In biopsy-naïve patients, the ultrasound fusion biopsy targeted by 18 F-DCFPyL PET/MRI is an identical pathway for the detection of prostate cancer.

Robotic Level IV Inferior Vena Cava Thrombectomy Using an Intrapericardial Control Technique: Is It Safe Without Cardiopulmonary Bypass?

PURPOSE: We introduce an intrapericardial control technique using a robotic approach in the surgical treatment of renal tumor with level IV inferior vena cava thrombus to decrease the severe complications associated with cardiopulmonary bypass and deep hypothermic circulatory arrest. MATERIALS AND METHODS: Eight patients with level IV inferior vena cava thrombi not extending into the atrium underwent transabdominal-transdiaphragmatic robot-assisted inferior vena cava thrombectomy obviating cardiopulmonary bypass/deep hypothermic circulatory arrest (cardiopulmonary bypass-free group) by an expert team comprising urological, hepatobiliary, and cardiovascular surgeons. The central diaphragm tendon and pericardium were transabdominally dissected until the intrapericardial inferior vena cava were exposed and looped proximal to the cranial end of the thrombi under intraoperative ultrasound guidance. As controls, 14 patients who underwent robot-assisted inferior vena cava thrombectomy with cardiopulmonary bypass (cardiopulmonary bypass group) and 25 patients who underwent open thrombectomy with cardiopulmonary bypass/deep hypothermic circulatory arrest (cardiopulmonary bypass/deep hypothermic circulatory arrest group) were included. Clinicopathological, operative, and survival outcomes were retrospectively analyzed. RESULTS: Eight robot-assisted inferior vena cava thrombectomies were successfully performed without cardiopulmonary bypass, with 1 open conversion. The median operation time and first porta hepatis occlusion time were shorter, and estimated blood loss was lower in the cardiopulmonary bypass-free group as compared to the cardiopulmonary bypass group (540 vs 586.5 minutes, 16.5 vs 38.5. minutes, and 2,050 vs 3,500 mL, respectively). Severe complications (level IV-V) were also lower in the cardiopulmonary bypass-free group than in cardiopulmonary bypass and cardiopulmonary bypass/deep hypothermic circulatory arrest groups (25% vs 50% vs 40%). Oncologic outcomes were comparable among the 3 groups in short-term follow-up. CONCLUSIONS: Pure transabdominal-transdiaphragmatic robot-assisted inferior vena cava thrombectomy without cardiopulmonary bypass/deep hypothermic circulatory arrest represents as an alternative minimally invasive approach for selected level IV inferior vena cava thrombi.

Multiparametric liver MRI for predicting early recurrence of hepatocellular carcinoma after microwave ablation.

BACKGROUND: High early recurrence (ER) of hepatocellular carcinoma (HCC) after microwave ablation (MWA) represents a sign of aggressive behavior and severely worsens prognosis. The aim of this study was to estimate the outcome of HCC following MWA and develop a response algorithmic strategy based on multiparametric MRI and clinical variables. METHODS: In this retrospective study, we reviewed the records of 339 patients (mean age, 62 ± 12 years; 106 men) treated with percutaneous MWA for HCC between January 2014 and December 2017 that were evaluated by multiparametric MRI. These patients were randomly split into a development and an internal validation group (3:1). Logistic regression analysis was used to screen imaging features. Multivariate Cox regression analysis was then performed to determine predictors of ER (within 2 years) of MWA. The response algorithmic strategy to predict ER was developed and validated using these data sets. ER rates were also evaluated by Kaplan-Meier analysis. RESULTS: Based on logistic regression analyses, we established an image response algorithm integrating ill-defined margins, lack of capsule enhancement, pre-ablative ADC, ΔADC, and EADC to calculate recurrence scores and define the risk of ER. In a multivariate Cox regression model, the independent risk factors of ER (p < 0.05) were minimal ablative margin (MAM) (HR 0.57; 95% CI 0.35 - 0.95; p < 0.001), the recurrence score (HR: 9.25; 95% CI 4.25 - 16.56; p = 0.021), and tumor size (HR 6.21; 95% CI 1.25 - 10.82; p = 0.014). Combining MAM and tumor size, the recurrence score calculated by the response algorithmic strategy provided predictive accuracy of 93.5%, with sensitivity of 92.3% and specificity of 83.1%. Kaplan-Meier estimates of the rates of ER in the low-risk and high-risk groups were 6.8% (95% CI 4.0 - 9.6) and 30.5% (95% CI 23.6 - 37.4), respectively. CONCLUSION: A response algorithmic strategy based on multiparametric MRI and clinical variables was useful for predicting the ER of HCC after MWA.

Mucinous tubular and spindle cell carcinomas of the kidney (MTSCC-Ks): CT and MR imaging characteristics.

PURPOSE: To strengthen the recognition of mucinous tubular and spindle cell carcinomas of the kidney (MTSCC-Ks) by analyzing CT and MR imaging findings of MTSCC-Ks. MATERIALS AND METHODS: This study retrospectively enrolled ten patients with pathologically confirmed MTSCC-Ks from 2007 to 2020. The main observed imaging characteristics included growth pattern, signal characteristics on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI), hemorrhage, necrosis, cystic degeneration, lipid component, pseudocapsule and the enhancement pattern. Apparent diffusion coefficient (ADC) value of MTSCC-Ks and normal renal cortex were measured, respectively. All imaging features were evaluated in consensus by two genitourinary radiologists. RESULTS: All patients (53.1 ± 6.5 years, male to female, 3:7) presented with a solitary renal tumor with the mean diameter of 3.5 ± 0.4 cm. All lesions showed iso- or slight hypoattenuation on non-contrast CT with no hemorrhage but cystic degeneration (10%) and necrosis (10%). On T2WI, all lesions showed predominantly slight hypointensity with focal hyperintensity. The ADC value of MTSCC-Ks was 0.845 ± 0.017 × 10-3 mm2/s, and ADCtumor-to-ADCrenal cortex value was 0.376 ± 0.084. Pseudocapsules existed in all MTSCC-Ks on MRI. There were seven lesions showed heterogeneous enhancement, while three lesions showed homogeneous enhancement. Among them, six MTSCC-Ks showed slight multiple patchy enhancement (60%) in the corticomedullary phase, while the remaining MTSCC-Ks showed homogeneously slight enhancement (30%) or slightly stratified enhancement (10%). All MTSCC-Ks exhibited slow and progressive enhancement in the late phases. CONCLUSION: Iso- or slight hypoattenuation on CT, slight hypointensity with focal hyperintensity on T2WI, marked diffusion restriction on DWI and ADC map, slight multiple patchy enhancement in the corticomedullary phase, and slow and progressive enhancement in the late phases are the imaging features of MTSCC-Ks, which may facilitate the diagnosis of MTSCC-Ks.

Progressive Obstruction of Inferior Vena Cava by Ameroid Constrictor: The Canine Model of Revealing Hemodynamic and Compensatory Patterns of Tumor Thrombus Formation at the Renal Hilus Level.

Background: To develop an efficient and stable canine model of inferior vena cava (IVC) progressive obstruction at the renal hilus level. Methods: The model was established in two beagles by encircling an ameroid constrictor (AC) on the IVC at the renal hilus level. Abdominal wall varicosity and animal weight variations were observed weekly after operation. Ultrasound examination was performed weekly after surgery to observe the AC position, the diameter, and the velocity in the IVC. Six weeks after surgery, IVC angiography and CT scan were performed to observe the collateral circulation establishment and internal organ variation. Blood samples were taken regularly to monitor for variation in critical biochemical parameters. Renal biopsy was performed at 0, 2, 4, and 6 weeks after surgery. Results: Superficial varicose veins were observed on the abdominal wall at 2 weeks after surgery. Four weeks after operation, the IVC diameter increased by ∼30%, whereas the IVC velocity decreased by more than 50%. Collateral circulation was observed by IVC angiography at 6 weeks through multiple dilated veins along with neovascularization. CT scan showed congestive alteration in the kidney. The body weight, kidney, and liver function were not significantly affected. Chronic congestive renal injury was detected in the renal tubular epithelium by kidney biopsy after surgery. Conclusions: A canine model of IVC progressive obstruction at the renal hilus level was stably and safely established for the first time by using an AC, which may be helpful for preserving pivotal collateral circulation and nontumor-side kidney function in the IVC thrombus surgery.

Application of Fluorescence Dye in Combination with Methylene Blue for Axillary Reverse Mapping in Patients with Modified Radical Mastectomy for Breast Cancer.

Background: Axillary reverse mapping (ARM) is a novel intraoperative technique developed in recent years. This study was aimed at determining the effect of combined use of fluorescence dye and methylene blue, as well as its feasibility of ARM in patients with breast cancers who undergo modified radical mastectomy. Method: From January 2016 to June 2017, 46 patients with primary breast cancer at stage I-IV (Tis-T3, N0-N3, and M0) who received modified radical mastectomy were enrolled in this study. The exclusion criteria included preoperative radiotherapy/chemotherapy or bilateral disease. Patients were divided into 2 groups: methylene blue group (22 patients, 47.8%) and methylene blue+indocyanine green (ICG) group (24 patients, 52.2%). ARM was performed before surgery. Results: The overall visualization rate of ARM nodes was 80.4% (37/46). The visualization rate was significantly increased in methylene blue+ICG group (91.67%, 22/24) than that in methylene blue group (63.64%, 14/22) (P = 0.032). There was a statistical difference of visualization rate between clinical groups of N0-N1 and N3-N4 (t = 2.431, P = 0.19 < 0.05). Although there was no significant difference found in the total drainage volume and arm perimeter of patients between the two groups (P > 0.05), the harden diameter of the injection site in methylene blue+ICG group was significantly longer than that in methylene blue group (P < 0.05). Among the 44 patients with different molecular profiling of breast cancer, there was no significant difference of visualization rate of ARM nodes in luminal A group (100%,5/5), luminal B group (75.0%, 18/24, P = 0.21), HER2 group (75.0%, 6/8, P = 0.22), and basal-like group (85.7%, 6/7, P = 0.37). Conclusions: ARM using methylene blue+ICG presented greater identification rate than that with methylene blue alone, especially in patients with more invasive breast cancer. Our finding offers support for the improvement of ARM in future breast cancer management.

CT and MRI features of sclerosing angiomatoid nodular transformation of the spleen: A report of 18 patients with pathologic correlation.

PURPOSE: The purpose of this study was to describe the computed tomography (CT) and magnetic resonance imaging (MRI) features of sclerosing angiomatoid nodular transformation (SANT) of the spleen and correlate imaging features with those obtained at histopathologic analysis. MATERIALS AND METHODS: A total of 18 patients (9 men, 9 women; mean age, 42.2±10.7 [standard deviation (SD)] years; range, 23-59 years) with histopathologically confirmed SANT were retrospectively evaluated. The presenting symptoms, gross pathologic changes, and histopathologic and correlative immunohistochemical results were recorded. CT (n=8) and MRI (n=12) features were analyzed by two radiologists and included number, size, shape, boundary, attenuation, signal intensity, and enhancement patterns. RESULTS: Seventeen patients (17/18; 94%) had a single SANT without specific clinical symptoms and one patient (1/18; 6%) had multiple SANTs with left-upper-quadrant bloating and pain. The largest lesion diameter exceeded 3cm. On plain CT images, SANTs were slightly hypoattenuating in seven patients (7/8; 88%), isoattenuating in one patient (1/8; 13%), and contained calcification in two patients (2/8; 25%). On T2-weighted MR images, SANTs displayed hypointensity in ten patients (10/12; 83.3%), isointensity in one patient (1/12; 8%) and hyperintensity in one patient (1/12; 8%). On T2-weighted images, stellate or scattered fibrous scars were observed in all patients (12/12; 100%). On diffusion-weighted images, SANTs appeared as heterogenous or homogeneous hypointense in 12 patients (12/12; 100%). Compared to out-of-phase images, SANTs displayed decreased local signal intensity on in-phase images in 12 patients (12/12; 100%). On enhanced CT and MRI images, SANTs had clear boundaries (17/18; 94%), oval (7/18; 39%) or lobular (7/18; 39%) shape, displayed progressive centripetal enhancement (18/18; 100%), spoke-wheel pattern (14/18; 78%), nodular enhancement (11/18; 61%), or delayed enhancement of central fibrous scar (9/18; 50%). CONCLUSIONS: SANT of the spleen predominantly manifests as a solid, single, oval or lobular, and well-defined lesion with a fibrous scar and occasional calcification. Typical enhancement characteristics include progressive and centripetal enhancement, spoke-wheel pattern, nodular enhancement, and delayed enhancement of central fibrous scar. Hypointensity on T2- and diffusion-weighted images are due to hemosiderin deposition and fibrous tissue.

MRI radiomics-based nomogram for individualised prediction of synchronous distant metastasis in patients with clear cell renal cell carcinoma.

OBJECTIVE: To evaluate the performance of a multiparametric MRI radiomics-based nomogram for the individualised prediction of synchronous distant metastasis (SDM) in patients with clear cell renal cell carcinoma (ccRCC). METHODS: Two-hundred and one patients (training cohort: n = 126; internal validation cohort: n = 39; external validation cohort: n = 36) with ccRCC were retrospectively enrolled between January 2013 and June 2019. In the training cohort, the optimal MRI radiomics features were selected and combined to calculate the radiomics score (Rad-score). Incorporating Rad-score and SDM-related clinicoradiologic characteristics, the radiomics-based nomogram was established by multivariable logistic regression analysis, then the performance of the nomogram (discrimination and clinical usefulness) was evaluated and validated subsequently. Moreover, the prediction efficacy for SDM in ccRCC subgroups of different sizes was also assessed. RESULTS: Incorporating Rad-score derived from 9 optimal MR radiomics features (age, pseudocapsule and regional lymph node), the radiomics-based nomogram was capable of predicting SDM in the training cohort (area under the ROC curve (AUC) = 0.914) and validated in both the internal and external cohorts (AUC = 0.854 and 0.816, respectively) and also showed a convincing predictive power in ccRCC subgroups of different sizes (≤ 4 cm, AUC = 0.875; 4-7 cm, AUC = 0.891; 7-10 cm, 0.908; > 10 cm, AUC = 0.881). Decision curve analysis indicated that the radiomics-based nomogram is of clinical usefulness. CONCLUSIONS: The multiparametric MRI radiomics-based nomogram could achieve precise individualised prediction of SDM in patients with ccRCC, potentially improving the management of ccRCC. KEY POINTS: • Radiomics features derived from multiparametric magnetic resonance images showed relevant association with synchronous distant metastasis in clear cell renal cell carcinoma. • MRI radiomics-based nomogram may serve as a potential tool for the risk prediction of synchronous distant metastasis in clear cell renal cell carcinoma.