Time conditioning for arbitrary contrast phase generation in interventional computed tomography.

Minimally invasive ablation techniques for renal cancer are becoming more popular due to their low complication rate and rapid recovery period. Despite excellent visualisation, one drawback of the use of computed tomography (CT) in these procedures is the requirement for iodine-based contrast agents, which are associated with adverse reactions and require a higher x-ray dose. The purpose of this work is to examine the use of time information to generate synthetic contrast enhanced images at arbitrary points after contrast agent injection from non-contrast CT images acquired during renal cryoablation cases. To achieve this, we propose a new method of conditioning generative adversarial networks with normalised time stamps and demonstrate that the use of a HyperNetwork is feasible for this task, generating images of competitive quality compared to standard generative modelling techniques. We also show that reducing the receptive field can help tackle challenges in interventional CT data, offering significantly better image quality as well as better performance when generating images for a downstream segmentation task. Lastly, we show that all proposed models are robust enough to perform inference on unseen intra-procedural data, while also improving needle artefacts and generalising contrast enhancement to other clinically relevant regions and features.

Comparing Sonazoid contrast-enhanced ultrasound to contrast-enhanced CT and MRI for differentially diagnosing renal lesions: a prospective multicenter study.

PURPOSE: To evaluate the diagnostic performance of contrast-enhanced (CE) ultrasound using Sonazoid (SNZ-CEUS) by comparing with contrast-enhanced computed tomography (CE-CT) and contrast-enhanced magnetic resonance imaging (CE-MRI) for differentiating benign and malignant renal masses. MATERIALS AND METHODS: 306 consecutive patients (from 7 centers) with renal masses (40 benign tumors, 266 malignant tumors) diagnosed by both SNZ-CEUS, CE-CT or CE-MRI were enrolled between September 2020 and February 2021. The examinations were performed within 7 days, but the sequence was not fixed. Histologic results were available for 301 of 306 (98.37%) lesions and 5 lesions were considered benign after at least 2 year follow-up without change in size and image characteristics. The diagnostic performances were evaluated by sensitivity, specificity, positive predictive value, negative predictive value, and compared by McNemar's test. RESULTS: In the head-to-head comparison, SNZ-CEUS and CE-MRI had comparable sensitivity (95.60 vs. 94.51%, P = 0.997), specificity (65.22 vs. 73.91%, P = 0.752), positive predictive value (91.58 vs. 93.48%) and negative predictive value (78.95 vs. 77.27%); SNZ-CEUS and CE-CT showed similar sensitivity (97.31 vs. 96.24%, P = 0.724); however, SNZ-CEUS had relatively lower than specificity than CE-CT (59.09 vs. 68.18%, P = 0.683). For nodules > 4 cm, CE-MRI demonstrated higher specificity than SNZ-CEUS (90.91 vs. 72.73%, P = 0.617) without compromise the sensitivity. CONCLUSIONS: SNZ-CEUS, CE-CT, and CE-MRI demonstrate desirable and comparable sensitivity for the differentiation of renal mass. However, the specificity of all three imaging modalities is not satisfactory. SNZ-CEUS may be a suitable alternative modality for patients with renal dysfunction and those allergic to gadolinium or iodine-based agents.

Utility of Chemical Shift Imaging and Diffusion-weighted Images/Apparent Diffusion Coefficient Maps as a Tool for Evaluation of Solid Renal Tumors.

OBJECTIVES: To study the utility of chemical shift imaging (CSI) and diffusion-weighted images (DWI)/apparent diffusion coefficient (ADC) maps for the evaluation of solid renal tumors. METHODS: Magnetic resonance imaging (MRI) has an equivalent application as computerized tomography (CT) in the characterization of renal masses. It offers a radiation-free imaging technique and has a better soft tissue contrast than CT. Also, MRI is favored in patients with chronic kidney disease. MRI is useful when findings on CT are equivocal. The role of DWI in characterizing solid renal lesions as malignant is encouraging, and DWI can be particularly useful when gadolinium is contraindicated. CSI is useful in differentiating angiomyolipoma (AML) from clear cell (cc) renal cell carcinoma (RCC). We did a cross-sectional study on 24 patients with solid renal masses. MRI of the upper abdomen (from the dome of the diaphragm to the iliac crest) will be done on an MRI machine in our department (1.5T, ACHIEVA, Phillips medical system) using the torso coil. RESULT: There was no significant association seen in terms of ADC values and histological subtypes (χ2 = 11.222, p = 0.082). In our study, 50% (one out of two) of AML showed a signal drop, whereas 40% of cases (6 out of 15) of ccRCC and 66% (two out of three) of papillary RCC showed a signal drop. CONCLUSION: In this article, we concluded CSI, although a useful tool to look for microscopic fat, can't be used as a reliable marker to rule in cc-carcinoma as both AML and papillary cell carcinoma have microscopic fat. Further, no histological classification can be done on the basis of DWI/ADC images.

Automated segmentation and volume prediction in pediatric Wilms' tumor CT using nnu-net.

BACKGROUND: Radiologic volumetric evaluation of Wilms' tumor (WT) is an important indicator to guide treatment decisions. However, due to the heterogeneity of the tumors, radiologists have main-guard differences in diagnosis that can lead to misdiagnosis and poor treatment. The aim of this study was to explore whether CT-based outlining of WT foci can be automated using deep learning. METHODS: We included CT intravenous phase images of 105 patients with WT and double-blind outlining of lesions by two radiologists. Then, we trained an automatic segmentation model using nnUnet. The Dice similarity coefficient (DSC) and 95th percentile Hausdorff distance (HD95) were used to assess the performance. Next, we optimized the automatic segmentation results based on the ratio of the three-dimensional diameter of the lesion to improve the performance of volumetric assessment. RESULTS: The DSC and HD95 was 0.83 ± 0.22 and 10.50 ± 8.98 mm. The absolute difference and percentage difference in tumor size was 72.27 ± 134.84 cm3 and 21.08% ± 30.46%. After optimization according to our method, it decreased to 40.22 ± 96.06 cm3 and 10.16% ± 9.70%. CONCLUSION: We introduce a novel method that enhances the accuracy of predicting WT volume by integrating AI automated outlining and 3D tumor diameters. This approach surpasses the accuracy of using AI outcomes alone and has the potential to enhance the clinical evaluation of pediatric patients with WT. By intertwining AI outcomes with clinical data, this method becomes more interpretive and offers promising applications beyond Wilms tumor, extending to other pediatric diseases.

Detection of two synchronous histologically different renal cell carcinoma subtypes in the same kidney: a case report and review of the literature.

INTRODUCTION: Renal cell carcinoma (RCC) is the dominant primary renal malignant neoplasm, encompassing a significant portion of renal tumors. The presence of synchronous yet histologically distinct ipsilateral RCCs, however, is an exceptionally uncommon phenomenon that is rather under-described in the literature regarding etiology, diagnosis, management, and later outcomes during follow-up. CASE PRESENTATION: We aim to present the 9th case of a combination chromophobe RCC (ChRCC) and clear cell RCC (ccRCC) in literature, according to our knowledge, for a 69-year-old North African, Caucasian female patient who, after complaining of loin pain and hematuria, was found to have two right renal masses with preoperative computed tomography (CT) and underwent right radical nephrectomy. Pathological examination later revealed the two renal masses to be of different histologic subtypes. CONCLUSION: The coexistence of dissimilar RCC subtypes can contribute to diverse prognostic implications. Further research should focus on enhancing the complex, yet highly crucial, preoperative detection and pathological examination to differentiate multiple renal lesions. Planning optimal operative techniques (radical or partial nephrectomy), selecting suitable adjuvant regimens, and reporting long-term follow-up outcomes of patients in whom synchronous yet different RCC subtypes were detected are of utmost importance.

Contrast-enhanced ultrasound for differentiating benign from malignant focal solid renal lesions in pediatric patients.

The contrast-enhanced ultrasound (CEUS) has been mainly applied to adults to differentiate benign and malignant renal lesions, however, the characteristics of CEUS in pediatric has not been as well studied as in adults. In the present work, the eligible pediatric patients who underwent renal CEUS between March 2016 and February 2023 were retrospectively analyzed. It included 20 lesions (median diameter, 8.4 cm; range, 1.8-18.0 cm) from 20 patients (median age, 28.0 months; range, 3.0-212.0 months; 9 boys) in malignant group and 5 lesions (median diameter, 3.8 cm; range, 1.3-7.5 cm) from 5 patients (median age, 25.0 months; range, 0.7-216.0 months; 2 boys) in benign group. The diagnostic performance was assessed. Nonparametric and Chi-square tests were performed. With hyperenhancement plus wash-out, CEUS showed a sensitivity of 95.0% [95% confidence interval (CI): 75.1%, 99.9%], a specificity of 80.0% (CI: 28.4%, 99.5%), a positive predictive value of 95.0% (CI: 75.1%, 99.9%) and a negative predictive value of 80.0% (CI: 28.4%, 99.5%). It suggested that CEUS is a valuable technique for identifying between malignant and benign renal lesions in children.

Deep Learning Assessment of Small Renal Masses at Contrast-enhanced Multiphase CT.

Background Accurate characterization of suspicious small renal masses is crucial for optimized management. Deep learning (DL) algorithms may assist with this effort. Purpose To develop and validate a DL algorithm for identifying benign small renal masses at contrast-enhanced multiphase CT. Materials and Methods Surgically resected renal masses measuring 3 cm or less in diameter at contrast-enhanced CT were included. The DL algorithm was developed by using retrospective data from one hospital between 2009 and 2021, with patients randomly allocated in a training and internal test set ratio of 8:2. Between 2013 and 2021, external testing was performed on data from five independent hospitals. A prospective test set was obtained between 2021 and 2022 from one hospital. Algorithm performance was evaluated by using the area under the receiver operating characteristic curve (AUC) and compared with the results of seven clinicians using the DeLong test. Results A total of 1703 patients (mean age, 56 years ± 12 [SD]; 619 female) with a single renal mass per patient were evaluated. The retrospective data set included 1063 lesions (874 in training set, 189 internal test set); the multicenter external test set included 537 lesions (12.3%, 66 benign) with 89 subcentimeter (≤1 cm) lesions (16.6%); and the prospective test set included 103 lesions (13.6%, 14 benign) with 20 (19.4%) subcentimeter lesions. The DL algorithm performance was comparable with that of urological radiologists: for the external test set, AUC was 0.80 (95% CI: 0.75, 0.85) versus 0.84 (95% CI: 0.78, 0.88) (P = .61); for the prospective test set, AUC was 0.87 (95% CI: 0.79, 0.93) versus 0.92 (95% CI: 0.86, 0.96) (P = .70). For subcentimeter lesions in the external test set, the algorithm and urological radiologists had similar AUC of 0.74 (95% CI: 0.63, 0.83) and 0.81 (95% CI: 0.68, 0.92) (P = .78), respectively. Conclusion The multiphase CT-based DL algorithm showed comparable performance with that of radiologists for identifying benign small renal masses, including lesions of 1 cm or less. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Development and validation of a clinical and ultrasound features-based nomogram for preoperative differentiation of renal urothelial carcinoma and central renal cell carcinoma.

PURPOSE: This study aimed to develop and validate an ultrasound (US)-based nomogram for the preoperative differentiation of renal urothelial carcinoma (rUC) from central renal cell carcinoma (c-RCC). METHODS: Clinical data and US images of 655 patients with 655 histologically confirmed malignant renal tumors (521 c-RCCs and 134 rUCs) were collected and divided into training (n = 455) and validation (n = 200) cohorts according to examination dates. Conventional US and contrast-enhanced US (CEUS) tumor features were analyzed to determine those that could discriminate rUC from c-RCC. Least absolute shrinkage and selection operator regression was applied to screen clinical and US features for the differentiation of rUC from c-RCC. Using multivariate logistic regression analysis, a diagnostic model of rUC was constructed and visualized as a nomogram. The diagnostic model's performance was assessed in the training and validation cohorts by calculating the area under the receiver operating characteristic curve (AUC) and calibration plot. Decision curve analysis (DCA) was used to assess the clinical usefulness of the US-based nomogram. RESULTS: Seven features of both clinical features and ultrasound imaging were selected to build the diagnostic model. The nomogram achieved favorable discrimination in the training (AUC = 0.996, 95% CI: 0.993-0.999) and validation (AUC = 0.995, 95% CI: 0.974, 1.000) cohorts, and good calibration (Brier scores: 0.019 and 0.016, respectively). DCA demonstrated the clinical usefulness of the US-based nomogram. CONCLUSION: A noninvasive clinical and US-based nomogram combining conventional US and CEUS features possesses good predictive value for differentiating rUC from c-RCC.

Multimodal Approach in the Diagnosis of Urologic Malignancies: Critical Assessment of ChatGPT-4V's Image-Reading Capabilities.

ChatGPT-4V model with image interpretation tested for distinguishing kidney & prostate tumors from normal tissue.

FDG PET/CT in the Diagnosis and After Sunitinib Follow-up of Synchronous Base of Tongue and Thyroid Metastases From Renal Cell Carcinoma.

ABSTRACT: Renal cell carcinoma (RCC) is a leading cause of mortality among genitourinary malignancies with limited therapeutic options. The hematogenous route, lymphatic spread, and direct invasion have been documented in RCC. Usually, metastases are regional lymph nodes, lungs, bone, liver, adrenal glands, contralateral kidney, and brain. Metastases to the rare sites such as skin, breast, head and neck were documented in the literature. In the present case, we describe the synchronous metastases to the base of the tongue and thyroid gland in RCC and the response to sunitinib therapy on 18F-FDG PET/CT.

Renal Metastasis Arising From a Pulmonary Adenoid Cystic Carcinoma: A Rare Case Report and Literature Review.

Adenoid cystic carcinoma (ACC), a rare malignancy, typically originates in salivary glands and is rarely found in other locations. In this case report, we describe a 54-year-old male patient who was presented to the Urology Department of Yantai Yuhuangding hospital with right-sided waist pain. The patient underwent percutaneous ultrasound-guided biopsies of lesions in the kidney and lung, which were histologically confirmed as primary adenoid cystic carcinoma of the lung and metastatic renal adenoid cystic carcinoma, respectively. Given the presence of multiple metastases, the patient received systemic palliative chemotherapy, which was well-tolerated and effectively controlled the tumor. At the last follow-up, there was no evidence of tumor progression in the patient.

Al18F-NOTA-Octreotide outperforms 18F-FDG in identifying rare renal metastases from pancreatic neuroendocrine tumor.

We presented a case involving a 56-year-old man who had been experiencing shoulder and back pain for over a year, with extensive bone metastases revealed by a bone scan. To identify the primary source of these issues, the patients underwent a fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scan, which indicated moderate uptake in the right renal soft mass and low uptake in multiple osteolytic lesions. Pathological examination and immunohistochemical staining of the renal mass supported the diagnosis of neuroendocrine tumors. Subsequently, a novel somatostatin receptor imaging agent, Al18F-NOTA-octreotide (18F-OC), was performed to further investigate the source of metastatic lesions and to stage the tumor. The 18F-OC scan revealed a high-uptake lesion in the pancreatic head, as well as additional lymph node and bone metastases lesions. Compared to 18F-FDG, the 18F-OC demonstrated superior imaging capabilities and a significantly higher tumor-to-background ratio in neuroendocrine neoplasms, which contributed to improving the staging and treatment management.

Percutaneous Microwave Ablation Versus Robot-Assisted Partial Nephrectomy for Stage I Renal Cell Carcinoma: A Propensity-Matched Cohort Study Focusing Upon Long-Term Follow-Up of Oncologic Outcomes.

PURPOSE: To retrospectively compare long-term oncologic outcomes of percutaneous computed tomography-guided microwave ablation (MWA) and robot-assisted partial nephrectomy (RAPN) for the treatment of stage 1 (T1a and T1b) renal cell carcinoma (RCC) patients. MATERIALS AND METHODS: Institutional database research identified all T1 RCC patients who underwent either MWA or RAPN. Models were adjusted with propensity score matching. Kaplan-Meier log-rank test analyses and Cox proportional hazard regression models were used to compare the oncologic outcomes. Patient and tumor characteristics, technical success as well as oncologic outcomes were evaluated and compared between the 2 groups. RESULTS: After propensity score matching, a total of 71 patients underwent percutaneous MWA (mean age 70 ± 10 years) and 71 underwent RAPN (mean age 60 ± 9 years). At 8-year follow-up, the estimated survival rates for MWA cohort were 98% (95% confidence interval [CI] 95-100%) for overall survival, 97% (95% CI 93-100%) for recurrence-free survival, and 97% (95% CI 93-100%) for metastasis-free survival. The matched cohort that underwent RAPN exhibited survival rates of 100% (95% CI 100-100%) for overall survival, 98% (95% CI 94-100%) for recurrence-free survival, and 98% (95% CI 94-100%) for metastasis-free survival. After performing log-rank testing, these rates were not significantly different (p values of 0.44, 0.67, and 0.67, respectively). CONCLUSION: The results of the present study suggest that both MWA and RAPN are equally effective in terms of oncologic outcome for the treatment of T1 RCC.

Enhanced Theranostic Efficacy of 89Zr and 177Lu-Labeled Aflibercept in Renal Cancer: A Viable Option for Clinical Practice.

Vascular endothelial growth factor (VEGF) targeted therapy serves as an important therapeutic approach for renal cancer, but its clinical effectiveness is unsatisfactory. Moreover, there is a lack of reliable biomarkers for preoperative assessment of tumor VEGF expression. This study aimed to explore the potential for further applications of 177Lu/89Zr-labeled aflibercept (Abe), a VEGF-binding agent, in imaging visualization of VEGF expression and therapy for renal cancer. To determine specificity uptake in renal cancer, BALB/c mice with VEGF-expressing Renca tumor were intravenously injected with [89Zr]Zr-Abe, [177Lu]Lu-Abe, or Cy5.5-Abe and the blocking group was designed as a control group. PET, SPECT, and fluorescence images were acquired, and the biodistribution of [89Zr]Zr-Abe and [177Lu]Lu-Abe was performed. Additionally, the [177Lu]Lu-Abe, [177Lu]Lu-Abe-block, 177Lu only, Abe only, and PBS groups were compared for evaluation of the therapeutic effect. To assess the safety, we monitored and evaluated the body weight, blood biochemistry analysis, and whole blood analysis and major organs were stained with hematoxylin and eosin after [177Lu]Lu-Abe treatment. DOTA-Abe was successfully labeled with 177Lu and Df-Abe with 89Zr in our study. The uptake in tumor of [89Zr]Zr-Abe was significantly higher than that of [89Zr]Zr-Abe-block (P < 0.05) and provided excellent tumor contrast in PET images. [177Lu]Lu-Abe demonstrated promising tumor-specific targeting capability with a high and persistent tumor uptake. The standardized tumor volume of [177Lu]Lu-Abe was significantly smaller than those of other treatment groups (P < 0.05). [177Lu]Lu-Abe also had smaller tumor volumes and reduced expression of VEGF and CD31 compared to those of the control groups. Fluorescence images demonstrate higher tumor uptake in the Cy5.5-Abe group compared to the Cy5.5-Abe-block group (P < 0.05). In conclusion, [89Zr]Zr-Abe enables noninvasive analysis of VEGF expression, serving as a valuable tool for assessing the VEGF-targeted therapy effect. Additionally, all of the findings support the enhanced therapeutic efficacy and safety of [177Lu]Lu-Abe, making it a viable option for clinical practice in renal cancer.

Ablative Radioembolization (SIRT) of a Large Inoperable Renal Cell Carcinoma Invading the Liver That Resulted in Hematuria Control and Complete Necrosis by mRECIST Criteria.

ABSTRACT: We report the successful application of radioembolization (SIRT) in a 77-year-old man with end-stage renal disease on hemodialysis and repeated episodes of macroscopic hematuria due to a large renal cell carcinoma of the right kidney extending to liver segment VI. A compassionate SIRT therapy was performed with resin microspheres through the upper pole renal artery and the feeding segmental artery of liver segment VI. Hematuria was resolved after treatment, and 4 months later, a follow-up CT scan revealed tumor size reduction and complete tumor necrosis (Response Evaluation Criteria in Solid Tumors criteria). Ablative SIRT therapy could be a safe and efficient option in a large inoperable RCC.

Predicting the presence of adherent perinephric fat using MRI radiomics combined with machine learning.

OBJECTIVES: Adherent perinephric fat (APF) poses significant challenges to surgical procedures. This study aimed to evaluate the usefulness of machine learning algorithms combined with MRI-based radiomics features for predicting the presence of APF. MATERIALS AND METHODS: Patients with renal cell carcinoma who underwent surgery between April 2019 and February 2022 at Chonnam National University Hwasun Hospital were retrospectively screened, and 119 patients included. Twenty-one and seventeen patients were set aside for the internal and external test sets, respectively. Pre-operative T1-weighted MRI acquired at 60 s following a contrast injection (T1w-60) were collected. For each T1w-60 data, two regions of interest (ROIs) were manually drawn: the perinephric fat tissue and an aorta segment on the same level as the targeted kidney. Preprocessing steps included resizing voxels, N4 Bias Correction filtering, and aorta-based normalization. For each patient, 851 radiomics features were extracted from the ROI of perinephric fat tissue. Gender and BMI were added as clinical factors. Least Absolute Shrinkage and Selection Operator was adopted for feature selection. We trained and evaluated five models using a 4-fold cross validation. The final model was chosen based on the highest mean AUC across four folds. The performance of the final model was evaluated on the internal and external test sets. RESULTS: A total of 15 features were selected in the final set. The final model achieved the accuracy, sensitivity, specificity, and AUC of 81% (95% confidence interval, 61.9-95.2%), 72.7% (42.9-100%), 90% (66.7-100%), and 0.855 (0.615-1.0), respectively on the internal test set, and 88.2% (70.6-100%), 100% (100-100%), 80% (50%-100%), 0.971 (0.871-1.0), respectively on the external test set. CONCLUSIONS: Our study demonstrated the feasibility of machine learning algorithms trained with MRI-based radiomics features for APF prediction. Further studies with a multi-center approach are necessary to validate our findings.