Metastatic renal cell carcinoma: radiologic findings and assessment of response to targeted antiangiogenic therapy by using multidetector CT

Vulvar Metastasis in Renal Cell Carcinoma: A Case Report Highlighting the Aggressive Nature of Clear Cell Renal Cell Carcinoma

Vulvar cancer is one of the rarest gynecological malignancies. The development of this condition can be associated with either dysplasia linked to human papillomavirus (HPV), primarily affecting younger women, or vulvar dermatoses such as lichen sclerosus, which predominantly affect older women. Over the last decade, the incidence of vulvar cancer has risen by 0.6% annually, while the relative survival rate has declined. Although metastasis to the vulva is uncommon, it can occur, particularly from cancers in nearby organs such as the cervix, bladder, rectum, or anus. More rarely, metastases from breast cancer and renal cell carcinoma have been reported in the vulva. Vaginal metastases from clear cell renal carcinoma are especially rare. In this article, we present the case of a 56-year-old patient diagnosed with clear cell renal carcinoma, who came to our clinic with a lesion on the right labia, which was identified as a metastasis originating from the kidney. Given the rarity of genital metastases in renal cancer, such cases should be examined and discussed to encourage further research and studies.

Prediction study of surrounding tissue invasion in clear cell renal cell carcinoma based on multi-phase enhanced CT radiomics

OBJECTIVE

To examine the effectiveness of a nomogram model that combines clinical-image features and CT radiomics in predicting surrounding tissue invasion (STI) in clear cell renal cell carcinoma (ccRCC) patients before surgery.

METHODS

Postoperative pathological data of 248 ccRCC patients from two centers were retrospectively collected. Univariate and multivariate regression analyses were used to identify clinical and image features of ccRCC patients to construct a clinical model. Radiomics features were extracted from three CT scans, including tumoral, intratumor, and peritumoral regions. A nomogram was developed by integrating clinical model with optimal radiomics signature. The Shapley Additive Explanations (SHAP) method was used for interpretation.

RESULTS

This study included 65 ccRCC patients with STI and 183 patients without STI. The AUC of the clinical model was 0.766, 0.765, and 0.698 in the training cohort, internal validation cohort, and external validation cohort, respectively. The AUCs were higher in the radiomics signature based on ROI4 in NP than other radiomics (training cohort: 0.837 vs. 0.775-0.847; internal validation cohort: 0.831 vs. 0.695-0.811; external validation cohort: 0.762 vs. 0.623-0.731). Integrating the optimal radiomics signature with the clinical model to construct a combined model resulted in an AUC of 0.890, 0.886, and 0.826 in the training cohort, internal validation cohort, external validation cohort, respectively. SHAP values analysis revealed the top three radiomics features to be Small Dependence Low Gray Level Emphasis, Maximum 3D Diameter, and Maximum Probability.

CONCLUSION

A nomogram based on preoperative CT and clinical image features is a reliable tool for predicting STI in ccRCC patients. The use of SHAP values can help popularize this tool.

Metastasis to jaw bones from renal cell carcinoma as the sole primary source: Systematic review

Renal cell carcinoma (RCC) has been known for its high propensity of metastasis to unusual locations, and jaw bones (JBs) are one among those sites. The literature has reported several studies analyzing metastatic tumors to the oral region, but very little research work has been published to date to analyze solely JB metastasis (JBM) via RCC. The goal of this study was to examine the published cases of metastasis to JBs from RCC as the sole primary source till date. An electronic search of the published literature was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines without publication year limitation in PubMed or MEDLINE, Scopus, Google Scholar, Web of Science, ScienceDirect, Embase, and Research Gate Databases, using MeSH keywords, such as ('Renal cancer', OR 'Renal carcinoma' OR 'Renal cell cancer' OR 'Renal cell carcinoma'), AND ('Metastasis' OR 'Metastases') And ('Jaw' OR 'Maxilla' OR 'Mandible') And ('Temporomandibular joint' OR 'Condyle' OR ' Ramus'). We also searched all related journals manually. The reference list of all articles was also checked. Our research revealed a total of 56 relevant papers with 66 patients. The papers included were from 1939 to 2022. The mandible was the most predominant jaw affected than the maxilla. 19.7% of patients died with a mean survival time of 8.5 months. From the current research, it can be concluded that metastasis to JBs from RCC is a rare occurrence. A careful evaluation of these cases is needed to raise awareness of these lesions and gain a better understanding of their characteristics.

MicroRNAs as promising diagnostic and prognostic markers for the human genitourinary cancer

Genitourinary cancer (GUC) represents more than one fifth of all human cancers. This makes the development of approaches to its early diagnosis an important task of modern biomedicine. Circulating microRNAs, short (17-25 nucleotides) non-coding RNA molecules found in human biological fluids and performing a regulatory role in the cell, are considered as promising diagnostic and prognostic biomarkers of cancers, including GUC. In this review we have considered the current state of research aimed at assessing microRNAs as biomarkers of such human GUC types as malignant tumors of the bladder, kidney, prostate, testicles, ovaries, and cervix. A special attention has been paid to studies devoted to the identification of microRNAs in urine as a surrogate "liquid biopsy" that may provide the simplest and cheapest approach to mass non-invasive screening of human GUC. The use of microRNA panels instead of single types of microRNA generally leads to higher sensitivity and specificity of the developed diagnostic tests. However, to date, work on the microRNAs assessment as biomarkers of human GUC is still of a research nature, and the further introduction of diagnostic tests based on microRNAs into practice requires successful clinical trials.

Utility of PSMA PET/CT in Staging and Restaging of Renal Cell Carcinoma: A Systematic Review and Metaanalysis

Prostate-specific membrane antigen (PSMA) is expressed in the neovasculature of multiple solid tumors, including renal cell carcinoma (RCC). Studies have demonstrated promising results on the utility of PSMA-targeted PET/CT imaging in RCC. This report aims to provide a systematic review and metaanalysis on the utility and detection rate of PSMA PET/CT imaging in staging or evaluation of primary RCC and restaging of metastatic or recurrent RCC. Methods: Searches were performed in PubMed, Embase, and abstract proceedings (last updated, August 2023). Studies that provided a lesion-level detection rate of PSMA radiotracers in staging or restaging of RCC were included in the metaanalysis. The overall pooled detection rate with a 95% CI was estimated, and subgroup analysis was performed when feasible. Results: Nine studies comprising 152 patients (133 clear cell RCC [ccRCC], 19 other RCC subtypes) were included in the metaanalysis. The pooled detection rate of PSMA PET/CT in evaluation of primary or metastatic RCC was estimated to be 0.83 (95% CI, 0.67-0.92). Subgroup analysis showed a pooled PSMA detection rate of 0.74 (95% CI, 0.57-0.86) in staging or evaluation of primary RCC lesions and 0.87 (95% CI, 0.73-0.95) in restaging of metastatic or recurrent RCC. Analysis based on the type of radiotracer showed a pooled detection rate of 0.85 (95% CI, 0.62-0.95) for 68Ga-based PSMA tracers and 0.92 (95% CI, 0.76-0.97) for 18F-DCFPyL PET/CT. Furthermore, in metastatic ccRCC, the available data support a significantly higher detection rate for 18F-DCFPyL PET/CT than for conventional imaging modalities (2 studies). Conclusion: Our preliminary results show that PSMA PET/CT could be a promising alternative imaging modality for evaluating RCC, particularly metastatic ccRCC. Large prospective studies are warranted to confirm clinical utility in the staging and restaging of RCC.

Update on Renal Cell Carcinoma Diagnosis with Novel Imaging Approaches

This review highlights recent advances in renal cell carcinoma (RCC) imaging. It begins with dual-energy computed tomography (DECT), which has demonstrated a high diagnostic accuracy in the evaluation of renal masses. Several studies have suggested the potential benefits of iodine quantification, particularly for distinguishing low-attenuation, true enhancing solid masses from hyperdense cysts. By determining whether or not a renal mass is present, DECT could avoid the need for additional imaging studies, thereby reducing healthcare costs. DECT can also provide virtual unenhanced images, helping to reduce radiation exposure. The review then provides an update focusing on the advantages of multiparametric magnetic resonance (MR) imaging performance in the histological subtyping of RCC and in the differentiation of benign from malignant renal masses. A proposed standardized stepwise reading of images helps to identify clear cell RCC and papillary RCC with a high accuracy. Contrast-enhanced ultrasound may represent a promising diagnostic tool for the characterization of solid and cystic renal masses. Several combined pharmaceutical imaging strategies using both sestamibi and PSMA offer new opportunities in the diagnosis and staging of RCC, but their role in risk stratification needs to be evaluated. Although radiomics and tumor texture analysis are hampered by poor reproducibility and need standardization, they show promise in identifying new biomarkers for predicting tumor histology, clinical outcomes, overall survival, and the response to therapy. They have a wide range of potential applications but are still in the research phase. Artificial intelligence (AI) has shown encouraging results in tumor classification, grade, and prognosis. It is expected to play an important role in assessing the treatment response and advancing personalized medicine. The review then focuses on recently updated algorithms and guidelines. The Bosniak classification version 2019 incorporates MRI, precisely defines previously vague imaging terms, and allows a greater proportion of masses to be placed in lower-risk classes. Recent studies have reported an improved specificity of the higher-risk categories and better inter-reader agreement. The clear cell likelihood score, which adds standardization to the characterization of solid renal masses on MRI, has been validated in recent studies with high interobserver agreement. Finally, the review discusses the key imaging implications of the 2017 AUA guidelines for renal masses and localized renal cancer.

Renal Cell Carcinoma Metastasizing to Oral Soft Tissues: Systematic Review

Background  Renal cancer metastasis to oral region is very rare. Studies have been published analyzing the cases of metastatic tumors to the oral cavity by many researchers. Very few research studies have been conducted till date to analyze the renal cancer metastasis as the sole primary source to the oral soft tissues. The goal of this study was to examine the published cases of oral soft tissue metastasis from renal cell carcinoma as the only primary source from 1911 to 2022. Materials and Methods  An electronic search of the published literature was performed without publication year limitation in PubMed/Medline, Scopus, Google Scholar, Web of Science, Science Direct, Embase, and Research Gate databases, using mesh keywords like ("Renal cancer," or "Renal carcinoma" or "Renal cell cancer" or "Renal cell carcinoma"), and ("Metastasis" or "Metastases"), and ("Oral soft tissues" or "Tongue" or "Palate" or "Tonsil" or "Buccal mucosa" or "Salivary glands"). We also searched related journals manually and the reference lists. Results  Our research revealed a total of 226 relevant articles with 250 patients. Parotid glands and tongue were the most common sites of metastasis. 23% patients died with a survival time of 10 days to 4 years. Conclusions  Oral soft tissue metastasis from renal cell carcinoma has a bad prognosis. More cases need to be published in order to raise awareness of these lesions.

Renal cell carcinoma metastasizing to salivary glands: Systematic review

Distant metastasis to salivary glands is a very rare event. Renal cell carcinoma (RCC) has been known for its high propensity of metastasis to unusual locations and salivary glands are one among those sites. Approximately 0.1% of all salivary gland metastatic neoplasms originate from renal malignancies Literature has reported several studies analysing the metastatic tumors to the oral region. However, very little research work has been published to date to analyse solely the RCC metastasizing to the salivary glands. Thus, this review was conducted to examine the published cases of RCC metastasizing to salivary glands in the literature to date and to learn about their characteristics. An electronic search of the published literature was performed without publication year limitation in PubMed/ Medline, Scopus, Google Scholar, Web of Science, Science Direct, Embase, and Research Gate databases, using mesh keywords like ('Renal cancer', OR 'Renal carcinoma' OR 'Renal cell cancer' OR 'Renal cell carcinoma'), AND ('Metastasis' OR 'Metastases'), And ('Salivary glands' OR 'Parotid gland' OR 'Submandibular gland' OR 'Sublingual gland'). We also searched all related journals manually. The reference list of all articles was also checked. Our research revealed a total of 83 relevant papers (1965-2022) with 100 patients. Parotid was the most predominant gland affected. 8% of patients died with a mean survival time of 1.3 yr. From this research, it can be concluded that RCC metastasizing to salivary glands is a rare occurrence. Careful evaluation of these cases is needed in order to raise awareness of these lesions and gain a better understanding of their characteristics for clinical as well as global implications.

Clinical impact of Prostate-Specific Membrane Antigen Positron Emission Tomography (PET) on intensification or deintensification of advanced renal cell carcinoma management

PURPOSE

There is an emerging role of the use of Prostate-Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) in renal cell carcinoma. Herein, we report our experience in use of PSMA PET in recurrent or metastatic renal cell carcinoma (RCC).

METHODS

A retrospective analysis of all patients who underwent PSMA PET for suspected recurrent or de-novo metastatic RCC between 2015 and 2020 at three institutions was performed. The primary outcome was change in management (intensification or de-intensification) following PSMA PET scan. Secondary outcomes included histopathological correlation of PSMA avid sites, comparison of sites of disease on PSMA PET to diagnostic CT and time to systemic treatment.

RESULTS

A Large Genetic Causal Analysis of the Gut Microbiota and Urological Cancers: A Bidirectional Mendelian Randomization Study

BACKGROUND

Several observational studies and clinical trials have shown that the gut microbiota is associated with urological cancers. However, the causal relationship between gut microbiota and urological cancers remains to be elucidated due to many confounding factors.

METHODS

In this study, we used two thresholds to identify gut microbiota GWAS from the MiBioGen consortium and obtained data for five urological cancers from the UK biobank and Finngen consortium, respectively. We then performed a two-sample Mendelian randomization (MR) analysis with Wald ratio or inverse variance weighted as the main method. We also performed comprehensive sensitivity analyses to verify the robustness of the results. In addition, we performed a reverse MR analysis to examine the direction of causality.

RESULTS

Our study found that family Rikenellaceae, genus Allisonella, genus Lachnospiraceae UCG001, genus Oscillibacter, genus Eubacterium coprostanoligenes group, genus Eubacterium ruminantium group, genus Ruminococcaceae UCG013, and genus Senegalimassilia were related to bladder cancer; genus Ruminococcus torques group, genus Oscillibacter, genus Barnesiella, genus Butyricicoccus, and genus Ruminococcaceae UCG005 were related to prostate cancer; class Alphaproteobacteria, class Bacilli, family Family XI, genus Coprococcus2, genus Intestinimonas, genus Lachnoclostridium, genus Lactococcus, genus Ruminococcus torques group, and genus Eubacterium brachy group were related to renal cell cancer; family Clostridiaceae 1, family Christensenellaceae, genus Eubacterium coprostanoligenes group, genus Clostridium sensu stricto 1, and genus Eubacterium eligens group were related to renal pelvis cancer; family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum were related to testicular cancer. Comprehensive sensitivity analyses proved that our results were reliable.

CONCLUSIONS

Our study confirms the role of specific gut microbial taxa on urological cancers, explores the mechanism of gut microbiota on urological cancers from a macroscopic level, provides potential targets for the screening and treatment of urological cancers, and is dedicated to providing new ideas for clinical research.

Neurological applications of belzutifan in von Hippel-Lindau disease

Von Hippel-Lindau (VHL) disease is a tumor predisposition syndrome caused by mutations in the VHL gene that presents with visceral neoplasms and growths, including clear cell renal cell carcinoma, and central nervous system manifestations, such as hemangioblastomas of the brain and spine. The pathophysiology involves dysregulation of oxygen sensing caused by the inability to degrade HIFα, leading to the overactivation of hypoxic pathways. Hemangioblastomas are the most common tumors in patients with VHL and cause significant morbidity. Until recently, there were no systemic therapies available for patients that could effectively reduce the size of these lesions. Belzutifan, the first approved HIF-2α inhibitor, has demonstrated benefit in VHL-associated tumors, with a 30% response rate in hemangioblastomas and ~30%-50% reduction in their sizes over the course of treatment. Anemia is the most prominent adverse effect, affecting 76%-90% of participants and sometimes requiring dose reduction or transfusion. Other significant adverse events include hypoxia and fatigue. Overall, belzutifan is well tolerated; however, long-term data on dosing regimens, safety, and fertility are not yet available. Belzutifan holds promise for the treatment of neurological manifestations of VHL and its utility may influence the clinical management paradigms for this patient population.

Sarcomatoid renal cell carcinoma: MRI features and their association with survival

OBJECTIVE

To evaluate MRI features of sarcomatoid renal cell carcinoma (RCC) and their association with survival.

METHODS

This retrospective single-center study included 59 patients with sarcomatoid RCC who underwent MRI before nephrectomy during July 2003-December 2019. Three radiologists reviewed MRI findings of tumor size, non-enhancing areas, lymphadenopathy, and volume (and percentage) of T2 low signal intensity areas (T2LIA). Clinicopathological factors of age, gender, ethnicity, baseline metastatic status, pathological details (subtype and extent of sarcomatoid differentiation), treatment type, and follow-up were extracted. Survival was estimated using Kaplan-Meier method and Cox proportional-hazards regression model was used to identify factors associated with survival.

RESULTS

Forty-one males and eighteen females (median age 62 years; interquartile range 51-68) were included. T2LIAs were present in 43 (72.9%) patients. At univariate analysis, clinicopathological factors associated with shorter survival were: greater tumor size (> 10 cm; HR [hazard ratio] = 2.44, 95% CI 1.15-5.21; p = 0.02), metastatic lymph nodes (present; HR = 2.10, 95% CI 1.01-4.37; p = 0.04), extent of sarcomatoid differentiation (non-focal; HR = 3.30, 95% CI 1.55-7.01; p < 0.01), subtypes other than clear cell, papillary, or chromophobe (HR = 3.25, 95% CI 1.28-8.20; p = 0.01), and metastasis at baseline (HR = 5.04, 95% CI 2.40-10.59; p < 0.01). MRI features associated with shorter survival were: lymphadenopathy (HR = 2.24, 95% CI 1.16-4.71; p = 0.01) and volume of T2LIA (> 3.2 mL, HR = 4.22, 95% CI 1.92-9.29); p < 0.01). At multivariate analysis, metastatic disease (HR = 6.89, 95% CI 2.79-16.97; p < 0.01), other subtypes (HR = 9.50, 95% CI 2.81-32.13; p < 0.01), and greater volume of T2LIA (HR = 2.51, 95% CI 1.04-6.05; p = 0.04) remained independently associated with worse survival.

CONCLUSION

T2LIAs were present in approximately two thirds of sarcomatoid RCCs. Volume of T2LIA along with clinicopathological factors were associated with survival.

[SMALL RENAL CELL CARCINOMA METASTASIS TO THE IPSILATERAL PERIRENAL FAT SYNCHRONOUSLY: A CASE REPORT]

Small renal cell carcinoma with metastases is rare; thus, to the best of our knowledge, this is the first case of synchronous metastasis to the ipsilateral perirenal fat.A 70-year-old man visited our hospital because of early gastric carcinoma. Contrast-enhanced computed tomography revealed a right renal tumor and two small nodules in the ipsilateral perirenal fat. The renal tumor was 3 cm in diameter and consistent with clear cell renal cell carcinoma. The enhancement pattern of the nodules was similar to that of the renal tumor, we diagnosed cT1aN0M1. Transperitoneal laparoscopic radical nephrectomy of the right kidney was performed. Postoperative pathological analysis showed clear cell renal cell carcinoma of the right kidney, pT1a, G2>1, INFa, v0, ly0, and two nodules in ipsilateral perirenal fat had comparable pathological findings. At 11th month of postoperative follow-up, CT revealed multiple nodules in the left pleura. Pembrolizumab plus axitinib was administered every 3 weeks. Multiple pleural metastases disappeared 3 months after the therapy; however, grade 2 (CTCAE v5.0) diarrhea and hoarseness emerged. Owing to the persistence of symptoms despite axitinib cessation, pembrolizumab was also discontinued. After 2 months of withdrawal, the patient's symptoms resolved spontaneously. After consultation with the patient, he was followed up with no further treatment. He is alive with no evidence of recurrence 36 months after surgery.

Endobronchial ultrasound-guided transbronchial needle aspiration in intrathoracic lymphadenopathy with extrathoracic malignancy

BACKGROUND

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the diagnosis of mediastinal and hilar lymph is poorly studied in patients with extrathoracic malignancies.

AIM

To evaluate the value of EBUS-TBNA for the diagnosis of enlarged intrathoracic lymph nodes in patients with extrathoracic malignancies.

METHODS

This was a retrospective study of patients with extrathoracic malignancies who were referred to Peking University Cancer Hospital from January 2013 to December 2018 for EBUS-TBNA due to intrathoracic lymphadenopathy. The specimens were defined as positive for malignancy, negative for non-malignancy (tuberculosis, sarcoidosis, etc.), and without a definitive diagnosis. Sensitivity, negative predictive value (NPV) for malignancy, and overall accuracy were calculated. Complications were recorded.

RESULTS

A total of 80 patients underwent EBUS-TBNA and had a final diagnosis, among which 50 (62.5%) were diagnosed with extrathoracic malignancy with intrathoracic lymph nodes metastasis, 14 (17.5%) were diagnosed with primary lung cancer with nodal involvement, and 16 (20.0%) exhibited benign behavior including tuberculosis, sarcoidosis and reactive lymphadenitis or who had benign follow-up. The diagnostic sensitivity, NPV, and accuracy of EBUS-TBNA for intrathoracic lymphadenopathy in patients with extrathoracic malignancy were 93.8% (n = 60/64), 80.0% (n = 16/20), and 95.0% (n = 76/80), respectively. In the multivariate analysis, longer short axis of the lymph node (OR: 1.200, 95%CI: 1.024-1.407; P = 0.024) and synchronous lung lesion (OR: 19.449, 95%CI: 1.875-201.753; P = 0.013) were independently associated with malignant intrathoracic lymphadenopathy. No characteristics of the lymph nodes and EBUS-TBNA were associated with the location of malignant intrathoracic lymphadenopathy, and no major complication was observed.

CONCLUSION

EBUS-TBNA is a simple and accurate procedure for the diagnosis of intrathoracic lymphadenopathy with extrathoracic malignancy.

Should We Always Perform Preoperative Chest Computed Tomography in Patients with cT1a Renal Cell Carcinoma?

No definitive criteria regarding the performance of preoperative chest computed tomography (CT) in patients with cT1a renal cell carcinoma (RCC) exists. We aimed to establish an objective standard for the optimal timing of preoperative chest CT in patients with RCC. Data from 890 patients who underwent surgical treatment for RCC between January 2011 and December 2020 were retrospectively collected. The primary endpoint was detection of lung metastasis on chest CT before nephrectomy. A multivariable logistic regression model predicting positive chest CT scans was used. Predictors included preoperative cTN stage, presence of systemic symptoms, Charlson comorbidity index (CCI), platelet count/hemoglobin ratio, albumin/globulin ratio (AGR), and De Ritis ratio. The overall rate of positive chest CT scans before nephrectomy was 3.03% (27/890). Only one patient had lung metastasis before surgery for cT1a. cT stage (≥cT1b), CCI ≥4, and low AGR were associated with a higher risk of positive chest CT scans. The best cutoff value for AGR was 1.39. After 890-sample bootstrap validation, the concordance index was 0.80. The net benefit of the proposed strategy was superior to that of the select-all and select-none strategies according to decision curve analysis. Therefore, when chest CT scans were performed with a risk of a positive result ≥10%, 532 (59.8%) negative chest CT scans could be prevented. Only 24 (2.7%) potentially positive chest CT scans were misdiagnosed. Therefore, we recommend chest CT in patients with ≥cT1b disease, CCI ≥4, and low AGR.

An interdisciplinary consensus on the management of brain metastases in patients with renal cell carcinoma

Brain metastases are a challenging manifestation of renal cell carcinoma. We have a limited understanding of brain metastasis tumor and immune biology, drivers of resistance to systemic treatment, and their overall poor prognosis. Current data support a multimodal treatment strategy with radiation treatment and/or surgery. Nonetheless, the optimal approach for the management of brain metastases from renal cell carcinoma remains unclear. To improve patient care, the authors sought to standardize practical management strategies. They performed an unstructured literature review and elaborated on the current management strategies through an international group of experts from different disciplines assembled via the network of the International Kidney Cancer Coalition. Experts from different disciplines were administered a survey to answer questions related to current challenges and unmet patient needs. On the basis of the integrated approach of literature review and survey study results, the authors built algorithms for the management of single and multiple brain metastases in patients with renal cell carcinoma. The literature review, consensus statements, and algorithms presented in this report can serve as a framework guiding treatment decisions for patients. CA Cancer J Clin. 2022;72:454-489.

Importance of tumor subtypes in cancer imaging

Cancer therapy has evolved from being broadly directed towards tumor types, to highly specific treatment protocols that target individual molecular subtypes of tumors. With the ever-increasing data on imaging characteristics of tumor subtypes and advancements in imaging techniques, it is now often possible for radiologists to differentiate tumor subtypes on imaging. Armed with this knowledge, radiologists may be able to provide specific information that can obviate the need for invasive methods to identify tumor subtypes. Different tumor subtypes also differ in their patterns of metastatic spread. Awareness of these differences can direct radiologists to relevant anatomical sites to screen for early metastases that may otherwise be difficult to detect during cursory inspection. Likewise, this knowledge will help radiologists to interpret indeterminate findings in a more specific manner.

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Tumor subtypes can be identified based on their different imaging characteristics.

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Awareness of tumor subtype can help radiologists chose the appropriate modality for additional imaging workup.

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Awareness of differences in metastatic pattern between tumor subtypes can be helpful to identify early metastases.

Use of Circular RNAs in Diagnosis, Prognosis and Therapeutics of Renal Cell Carcinoma

Renal cell carcinoma is the most common type of kidney cancer, representing 90% of kidney cancer diagnoses, and the deadliest urological cancer. While the incidence and mortality rates by renal cell carcinoma are higher in men compared to women, in both sexes the clinical characteristics are the same, and usually unspecific, thereby hindering and delaying the diagnostic process and increasing the metastatic potential. Regarding treatment, surgical resection remains the main therapeutic strategy. However, even after radical nephrectomy, metastasis may still occur in some patients, with most metastatic renal cell carcinomas being resistant to chemotherapy and radiotherapy. Therefore, the identification of new biomarkers to help clinicians in the early detection, and treatment of renal cell carcinoma is essential. In this review, we describe circRNAs related to renal cell carcinoma processes reported to date and propose the use of some in therapeutic strategies for renal cell carcinoma treatment.

Origins and Timing of Emerging Lesions in Advanced Renal Cell Carcinoma

Renal cell carcinoma (RCC) with venous tumor thrombus (VTT) arising from the primary tumor occurs in approximately 10% of cases and is thought to represent more advanced disease. The intravascular nature of VTT suggests that it may serve as a source for hematogenous metastases. RCC with VTT and distant metastasis provides unique opportunities to examine the origins and emergence timing of these distinct tumor lesions, and to identify molecular correlates with disease state. We performed multi-region exome and RNA-sequencing analysis of 16 patients with RCC with VTT, with eight patients also having sequenced metastasis, to identify genomic alterations, biological pathways, and evolutionary processes contributing to VTT and metastasis, and to ask whether metastasis arises directly from or independent of VTT. No specific genomic alterations were associated with VTT. Hallmark copy-number alterations (deletions of 14q, 8p, and 4q) were associated with metastasis and disease recurrence, and secondary driver alterations tended to accumulate in metastatic lineages. Mismatch repair mutational signatures co-occurred across most tumors, suggesting a role for intracellular DNA damage in RCC. Robust phylogenetic timing analysis indicated that metastasis typically emerged before VTT, rather than deriving from it, with the earliest metastases predicted to emerge years before diagnosis. As a result, VTT in metastatic cases frequently derived from a metastatic lineage. Relative to the primary tumor, VTT upregulated immediate-early genes and transcriptional targets of the TNFα/NF-κB pathway, whereas metastases upregulated MTOR and transcriptional targets downstream of mTORC1 activation.

IMPLICATIONS

These results suggest that VTT and metastasis formation occur independently, VTT presence alone does not necessarily imply more advanced disease with inevitably poor prognosis.

Intrahepatic renal cell carcinoma implantation along a percutaneous biopsy and cryoablation probe tract

A man in his 60s underwent percutaneous biopsy and cryoablation of a right upper pole clear cell renal cell carcinoma followed by repeat cryoablation 8 months later for possible residual disease. The patient was followed with imaging with documented stability for 19 months after repeat ablation. However, imaging at 32 months demonstrated intrahepatic nodular enhancing lesions along the initial percutaneous biopsy and ablation tract, consistent with metastatic implantation. The patient underwent repeat percutaneous biopsy and two rounds of microwave ablation for treatment of the intrahepatic implants, with no residual disease at 10 months postablation. While needle tract seeding is a known complication of percutaneous manipulation of various abdominopelvic malignancies, there have been no prior reports of intrahepatic metastatic implants related to percutaneous renal cell carcinoma ablation. Awareness of this potential complication is important for treatment planning, informed consent and surveillance. This report shares our experience of the management of intrahepatic metastatic implants.

Application of 18F Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography in Monitoring Gastric Metastasis and Cancer Thrombi from Renal Cell Carcinoma

Background. Renal cell carcinoma (RCC) with gastric metastasis is rare, particularly accompanied by multiple cancer thrombi. Methods. We reported a 66-year-old man with a history of a right radical nephrectomy because of RCC. The patient underwent 18F prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) scanning after 6 months of targeted therapy because of gastric metastasis and cancer thrombi. We conducted a systematic review of the literature and identified 73 cases of RCC with gastric metastasis. We analyzed the clinicopathological characteristics, therapies, and outcomes of patients. Results. 18F-PSMA PET/CT showed a large mass in the gastric fundus and cancer thrombi in the right atrium, inferior vena cava, and splenic vein with intense tracer uptake. Other metastases with increased tracer uptake included multiple bones and abdominal lymph nodes. The majority of gastric metastasis of RCC were men (53/73, 72.6%), with a median age at presentation of 67 (from 48 to 87) years. Gastric metastasis of RCC was mainly metachronous, and presented with small polyps or mass appearance and often accompanied by multiple-site metastases and gastrointestinal symptoms. An overall median interval between nephrectomy and diagnosis of gastric metastasis was 6 (from 0.1 to 23) years, and an overall median survival time was 14 (from 0.25 to 72) months. The median interval time of solitary gastric metastasis was longer than gastric metastasis with multiple-site metastases (7 vs.5 years; $P=0.034$ ). Patients with gastric and multiple-site metastases had higher mortality than patients with solitary metastasis (17 vs.1; $P=0.028$ ). The patients with synchronous gastric metastasis had a shorter survival time than metachronous gastric metastasis (6 vs.17 months; $P=0.018$ ). Conclusions. Postoperative follow-up of multiple imaging modalities to monitor recurrence and metastasis is necessary and important. PSMA PET/CT can improve the detection sensitivity of RCC, especially in metastatic clear cell renal cell carcinoma (ccRCC), and could provide a basis for disease staging, restaging, and therapeutic efficacy evaluation.

Severe vaginal bleeding due to vaginal metastasis from renal cell carcinoma with inferior vena cava tumor thrombus: A case report

RATIONALE

Renal cell carcinoma (RCC) is the most common type of kidney cancer and is the second most common urologic neoplasm. Vaginal metastasis from RCC is extremely rare clinically.

PATIENT CONCERNS

A 56-year-old woman presented with intermittent vaginal bleeding that had persisted for 1 month. Enhanced computed tomography examination suggested a vaginal mass (3 × 2 × 2 cm), right kidney tumor (15 × 12 × 10 cm), and an inferior vena cava tumor thrombus. During gynecologic examination, the mass was necrotic and caused uncontrollable vaginal bleeding.

DIAGNOSES

Based on clinical and imaging examinations and the pathology, she was diagnosed as vaginal metastasis from RCC.

INTERVENTIONS

The patient received percutaneous transcatheter arterial embolization to stop uncontrollable vaginal bleeding, and then treated with targeted therapy.

OUTCOMES

Vaginal bleeding disappeared after interventional embotherapy. However, disease progressed, and the patient died 9 months later.

LESSONS

In cases of vaginal bleeding, the possibility of metastatic renal cell carcinoma should be considered. Percutaneous transcatheter arterial embolization is an effective and novel treatment for uncontrollable vaginal bleeding caused by vaginal metastasis of RCC.

Metastatic Renal Cell Carcinoma Manifesting as a Gastric Polyp on CT: A Case Report and Literature Review

Gastric metastasis from renal cell carcinoma (RCC) is extremely rare, occurring in 0.2% of all RCC cases. Owing to its low prevalence, metachronous gastric metastasis from RCC may be underdiagnosed, and the imaging findings have not been well-established. Herein we present a case of metastatic RCC manifesting as a gastric polyp in a 70-year-old female along with a literature review on the imaging findings of gastric metastases from RCC. In patients presenting with gastric hyper-enhancing polypoid masses, metastasis from RCC should be considered as a differential diagnosis.

A combined postoperative nomogram for survival prediction in clear cell renal carcinoma

PURPOSE

To investigate and validate the prognostic value of nomogram models for predicting disease-free survival (DFS) and overall survival (OS) in patients with clear cell renal cell carcinoma (ccRCC).

METHODS

In this retrospective study, 223 patients (age 54.38 ± 10.93 years) with pathologically confirmed ccRCC who underwent resection and lymph node dissection between March 2010 and September 2018 were investigated. All patients were randomly divided into training (n = 155) and validation (n = 68) cohorts. Radiomics features were extracted from computed tomography (CT) images in the unenhanced, corticomedullary, and nephrographic phases. Radiomic score was calculated and combined with clinicopathological factors for model construction and nomogram development. Clinicopathological factors and imaging features were collected at initial diagnosis. Univariate and multivariate Cox proportional hazards regression analyses were used to evaluate the relationship between the radiomics signature and prognosis outcomes.

RESULTS

There were four prognostic factors for predicting DFS and five factors for predicting OS in our nomogram model (P < 0.05). The radiomics signature correlated independently with DFS (hazard ratio = 27; P < 0.001) and OS (hazard ratio = 25; P < 0.001). The nomogram showed excellent performance (C-index = 0.825) for predicting DFS. The combined nomogram also showed the highest C-index for OS (C-index = 0.943), which was verified in the validation dataset.

CONCLUSION

The combined nomogram model based on radiomics, clinicopathological factors, and preoperative CT features can accurately perform prognosis and survival analysis and can potentially be used for preoperative non-invasive survival prediction in ccRCC patients.

Potential Clinical Value of Pretreatment De Ritis Ratio as a Prognostic Biomarker for Renal Cell Carcinoma

Background

We performed this study to explore the prognostic value of the pretreatment aspartate transaminase to alanine transaminase (De Ritis) ratio in patients with renal cell carcinoma (RCC).

Methods

PubMed, EMBASE, Web of Science, and Cochrane Library were searched to identify all studies. The hazard ratio (HR) with a 95% confidence interval (CI) for overall survival (OS) and cancer-specific survival (CSS) were extracted to evaluate their correlation.

Results

A total of 6,528 patients from 11 studies were included in the pooled analysis. Patients with a higher pretreatment De Ritis ratio had worse OS (HR = 1.41, p < 0.001) and CSS (HR = 1.59, p < 0.001). Subgroup analysis according to ethnicity, disease stage, cutoff value, and sample size revealed that the De Ritis ratio had a significant prognostic value for OS and CSS in all subgroups.

Conclusions

The present study suggests that an elevated pretreatment De Ritis ratio is significantly correlated with worse survival in patients with RCC. The pretreatment De Ritis ratio may serve as a potential prognostic biomarker in patients with RCC, but further studies are warranted to support these results.

Current Imaging Evaluation of Tumor Response to Advanced Medical Treatment in Metastatic Renal-Cell Carcinoma: Clinical Implications

The present review is focused on the role of diagnostic tomographic imaging such as computed tomography and magnetic resonance imaging to assess and predict tumor response to advanced medical treatments in metastatic renal cell carcinoma (RCC) patients. In this regard, antiangiogenic agents and immune checkpoint inhibitors (ICIs) have developed as advanced treatment options replacing the conventional therapy based on interferon-alpha and interleuchin-2 which had unfavorable toxicity profile and low response rates. In clinical practice, the imaging evaluation of treatment response in cancer patients is based on dimensional changes of tumor lesions in sequential scans; in particular, Response Evaluation Criteria in Solid Tumors (RECIST) have been defined for this purpose and also applied in patients with metastatic RCC. However, these new drugs with predominant cytostatic effect make RECIST insufficient to realize an adequate response imaging evaluation. Therefore, new imaging criteria (mCHOI and iRECIST) have been proposed to assess tumor response to advanced medical treatments of metastatic RCC, they correlate better than RECIST with the progression-free survival and overall survival. Finally, a potential role of radiomics and machine learning models has been suggested to predict tumor response.

Intraindividual Comparison of Compressed Sensing-Accelerated Cartesian and Radial Arterial Phase Imaging of the Liver in an Experimental Tumor Model

OBJECTIVES

The aim of this study was to intraindividually compare the performance of 2 compressed sensing (CS)-accelerated magnetic resonance imaging (MRI) sequences, 1 featuring Cartesian (compressed sensing volumetric interpolated breath-hold examination [CS-VIBE]) and the other radial (golden-angle radial sparse parallel [GRASP]) k-space sampling in continuous dynamic imaging during hepatic vascular phases, using extracellular and hepatocyte-specific contrast agents.

MATERIALS AND METHODS

Seven New Zealand white rabbits, with induced VX2 liver tumors (median number of lesions, 2 ± 0.83; range, 1-3), received 2 continuously acquired T1-weighted prototype CS-accelerated MRI sequences (CS-VIBE and GRASP) with high spatial (0.8 × 0.8 × 1.5 mm) and temporal resolution (3.5 seconds) in randomized order on 2 separate days using a 1.5-T scanner. In all animals, imaging was performed using first gadobutrol at a dose of 0.1 mmol/kg and, then 45 minutes later, gadoxetic acid at a dose of 0.025 mmol/kg.The following qualitative parameters were assessed using 3- and 5-point Likert scales (3 and 5 being the highest scores respectively): image quality (IQ), arterial and venous vessel delineation, tumor enhancement, motion artifacts, and sequence-specific artifacts. Furthermore, the following quantitative parameters were obtained: relative peak signal enhancement, time to peak, mean transit time, and plasma flow ratios. Paired sampled t tests and Wilcoxon signed rank tests were used for intraindividual comparison. Image analysis was performed by 2 radiologists.

RESULTS

Six of 7 animals underwent the full imaging protocol and obtained data were analyzed statistically. Overall IQ was rated moderate to excellent, not differing significantly between the 2 sequences.Gadobutrol-enhanced CS-VIBE examinations revealed the highest mean Likert scale values in terms of vessel delineation and tumor enhancement (arterial 4.4 [4-5], venous 4.3 [3-5], and tumor 2.9 [2-3]). Significantly, more sequence-specific artifacts were seen in GRASP examinations (P = 0.008-0.031). However, these artifacts did not impair IQ. Excellent Likert scale ratings were found for motion artifacts in both sequences. In both sequences, a maximum of 4 hepatic arterial dominant phases were obtained. Regarding the relative peak signal enhancement, CS-VIBE and GRASP showed similar results. The relative peak signal enhancement values did not differ significantly between the 2 sequences in the aorta, the hepatic artery, or the inferior vena cava (P = 0.063-0.536). However, significantly higher values were noted for CS-VIBE in gadoxetic acid-enhanced examinations in the portal vein (P = 0.031) and regarding the tumor enhancement (P = 0.005). Time to peak and mean transit time or plasma flow ratios did not differ significantly between the sequences.

CONCLUSIONS

Both CS-VIBE and GRASP provide excellent results in dynamic liver MRI using extracellular and hepatocyte-specific contrast agents, in terms of IQ, peak signal intensity, and presence of artifacts.

Consensus statements on the management of metastatic renal cell carcinoma from the Hong Kong Urological Association and the Hong Kong Society of Uro-Oncology 2019

BACKGROUND

To establish a set of consensus statements for the management of metastatic renal cell carcinoma, a total of 12 urologists and clinical oncologists from two professional associations in Hong Kong formed an expert consensus panel.

METHODS

Through a series of meetings and using the modified Delphi method, the panelists presented recent evidence, discussed clinical experiences, and drafted consensus statements on several areas of focus regarding the management of metastatic renal cell carcinoma. Each statement was eventually voted upon by every panelist based on the practicability of recommendation.

RESULTS

A total of 46 consensus statements were ultimately accepted and established by panel voting.

CONCLUSIONS

Derived from recent evidence and expert insights, these consensus statements were aimed at providing practical guidance to optimize metastatic renal cell carcinoma management and promote a higher standard of clinical care.

Society for Cardiovascular Magnetic Resonance 2019 Case of the Week series

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). The SCMR web site ( https://www.scmr.org ) hosts a case series designed to present case reports demonstrating the unique attributes of CMR in the diagnosis or management of cardiovascular disease. Each clinical presentation is followed by a brief discussion of the disease and unique role of CMR in disease diagnosis or management guidance. By nature, some of these are somewhat esoteric, but all are instructive. In this publication, we provide a digital archive of the 2019 Case of the Week series as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar search engine.

Update on the Role of Imaging in Clinical Staging and Restaging of Renal Cell Carcinoma Based on the AJCC 8th Edition, From the AJR Special Series on Cancer Staging

This article reviews the essential role of imaging in clinical staging and restaging of renal cell carcinoma (RCC). To completely characterize and stage an indeterminate renal mass, renal CT or MRI without and with IV contrast administration is recommended. The critical items for initial clinical staging of an indeterminate renal mass or of a known RCC according to the TNM staging system are tumor size, renal sinus fat invasion, urinary collecting system invasion, perinephric fat invasion, venous invasion, adrenal gland invasion, invasion of the perirenal (Gerota) fascia, invasion into other adjacent organs, the presence of enlarged or pathologic regional (retroperitoneal) lymph nodes, and the presence of distant metastatic disease. Larger tumor size is associated with higher stage disease and invasiveness, lymph node spread, and distant metastatic disease. Imaging practice guidelines for clinical staging of RCC, as well as the role of renal mass biopsy, are highlighted. Specific findings associated with response of advanced cancer to antiangiogenic therapy and immunotherapy are discussed, as well as limitations of changes in tumor size after targeted therapy. The accurate clinical staging and restaging of RCC using renal CT or MRI provides important prognostic information and helps guide the optimal management of patients with RCC.

Pancreatic metastasis of renal cell carcinoma filling into the duct of Santorini

A 78-year-old man who underwent right nephrectomy for renal cell carcinoma (RCC) 18 years ago visited our hospital complaining of abdominal pain. Imaging revealed that the pancreatic head tumor obstructed the Santorini duct. We suspected a pancreatic intraductal tumor, such as an intraductal tubulopapillary neoplasm or intraductal papillary mucinous neoplasm. Thus, the patient underwent subtotal stomach-preserving pancreaticoduodenectomy. Pathological findings confirmed the diagnosis of metastatic RCC. Herein, we report a case of pancreatic metastasis of an RCC that presented with a tumor in the pancreatic duct.

Isolated temporalis muscle metastasis of renal cell carcinoma

Isolated head and neck metastasis of renal cell carcinoma (RCC) is relatively rare and metastasis to the temple area is very rare. Here, we present the case of a 51-year-old man who was diagnosed with RCC 2 years earlier and had a contralateral metastatic temple area lesion. The patient who was diagnosed with renal cell cancer and underwent a nephrectomy 2 years ago was referred to the plastic surgery department for a temple mass on the contralateral side. In the operative field, the mass was located in the temporalis muscle with a red-to-purple protruding shape. Biopsy of the mass revealed a metastatic RCC lesion. Computed tomography imaging showed a lobulated, contoured enhancing lesion. Positron emission tomography/computed tomography imaging showed high-fluorodeoxyglucose uptake in the right temporalis muscle. The patient underwent wide excision of the metastatic RCC including the temporalis muscle at the plastic surgery department. Skeletal muscle metastasis of head and neck lesions is extremely rare in RCC. Isolated contralateral temporalis muscle metastasis in RCC has not been previously reported in the literature. If a patient has a history of malignant cancer, plastic surgeons should always consider metastatic lesions of head and neck tumors. Because of its high metastatic ability and poor prognosis, it is very important to keep this case in mind.

Identification of RCC Subtype-Specific microRNAs-Meta-Analysis of High-Throughput RCC Tumor microRNA Expression Data

Renal cell carcinoma (RCC) is one of the most common cancers worldwide with a nearly non-symptomatic course until the advanced stages of the disease. RCC can be distinguished into three subtypes: papillary (pRCC), chromophobe (chRCC) and clear cell renal cell carcinoma (ccRCC) representing up to 75% of all RCC cases. Detection and RCC monitoring tools are limited to standard imaging techniques, in combination with non-RCC specific morphological and biochemical read-outs. RCC subtype identification relays mainly on results of pathological examination of tumor slides. Molecular, clinically applicable and ideally non-invasive tools aiding RCC management are still non-existent, although molecular characterization of RCC is relatively advanced. Hence, many research efforts concentrate on the identification of molecular markers that will assist with RCC sub-classification and monitoring. Due to stability and tissue-specificity miRNAs are promising candidates for such biomarkers. Here, we performed a meta-analysis study, utilized seven NGS and seven microarray RCC studies in order to identify subtype-specific expression of miRNAs. We concentrated on potentially oncocytoma-specific miRNAs (miRNA-424-5p, miRNA-146b-5p, miRNA-183-5p, miRNA-218-5p), pRCC-specific (miRNA-127-3p, miRNA-139-5p) and ccRCC-specific miRNAs (miRNA-200c-3p, miRNA-362-5p, miRNA-363-3p and miRNA-204-5p, 21-5p, miRNA-224-5p, miRNA-155-5p, miRNA-210-3p) and validated their expression in an independent sample set. Additionally, we found ccRCC-specific miRNAs to be differentially expressed in ccRCC tumor according to Fuhrman grades and identified alterations in their isoform composition in tumor tissue. Our results revealed that changes in the expression of selected miRNA might be potentially utilized as a tool aiding ccRCC subclass discrimination and we propose a miRNA panel aiding RCC subtype distinction.

Solitary, Endobronchial Metastasis from Renal Cell Carcinoma 20 Years after Nephrectomy

Late recurrence over 10 years after surgery and endobronchial metastasis are some of the specific biological behaviors of renal cell carcinoma (RCC). The current report describes a case of solitary endobronchial metastasis at a subsegmental bronchus that developed 20 years after curative nephrectomy for RCC. A 71-year-old male was admitted to our hospital for pneumonia. Chest radiography showed multifocal ill-defined nodular opacities in the right lower lung zone, suggesting pneumonia. Subsequent chest CT confirmed pneumonic infiltration in the right lung. However, a 4.3-cm, well-defined, elongated mass with a branching pattern was also identified in the right lower lobe, and a right nephrectomy scar was detected on the covered upper abdomen. The patient had undergone right nephrectomy 20 years ago due to clear cell RCC. After right lower lobectomy, the postoperative pathological diagnosis was endobronchial metastatic clear cell RCC. Endobronchial metastasis should be considered in a patient with a history of RCC who presents with a suspected endobronchial tumor, even decades after curative surgery.

Solitary Metastasis in the Mediastinal Lymph Node After Radical Nephrectomy for Clear Cell Renal Cell Carcinoma: A Case Report and Literature Review

Background

Renal cell carcinoma can metastasize to virtually any anatomical site throughout the body, especially the lung, bone, lymph nodes, liver, and brain. However, it is extremely rare for renal cell carcinoma to metastasize solely to the mediastinal lymph node more than 15 years after radical nephrectomy.

Case Presentation

The case we present here is that of a 50-year-old Chinese male with an isolated posterior mediastinal lymph node metastasis of clear cell renal cell carcinoma 16 years after radical nephrectomy. However, based on imaging examination, the mass was clinically misdiagnosed as Castleman’s disease before operation. Following surgical excision of the mass, it was finally judged to be a metastasis from clear cell renal cell carcinoma according to the patient’s medical history and immunohistochemical findings. Currently, there is no clinical or radiological finding the recurrence of metastasis after 10 months of follow-up.

Conclusion

We report a case of solitary metastasis in the posterior mediastinal lymph node 16 years after radical nephrectomy for clear cell renal cell carcinoma. Given the long disease-free interval between primary renal cell carcinoma to isolated mediastinal lymph node metastasis, it is important to conduct a lifelong regular follow-up, including thoracic computed tomography. In addition, surgical resection remains the best method of treatment for mediastinal lymph node metastases from clear cell renal cell carcinoma if the metastatic lesion is limited.

T1 Stage Clear Cell Renal Cell Carcinoma: A CT-Based Radiomics Nomogram to Estimate the Risk of Recurrence and Metastasis

Objectives

To develop and validate a radiomics nomogram to improve prediction of recurrence and metastasis risk in T1 stage clear cell renal cell carcinoma (ccRCC).

Methods

This retrospective study recruited 168 consecutive patients (mean age, 53.9 years; range, 28–76 years; 43 women) with T1 ccRCC between January 2012 and June 2019, including 50 aggressive ccRCC based on synchronous metastasis or recurrence after surgery. The patients were divided into two cohorts (training and validation) at a 7:3 ratio. Radiomics features were extracted from contrast enhanced CT images. A radiomics signature was developed based on reproducible features by means of the least absolute shrinkage and selection operator method. Demographics, laboratory variables (including sex, age, Fuhrman grade, hemoglobin, platelet, neutrophils, albumin, and calcium) and CT findings were combined to develop clinical factors model. Integrating radiomics signature and independent clinical factors, a radiomics nomogram was developed. Nomogram performance was determined by calibration, discrimination, and clinical usefulness.

Results

Ten features were used to build radiomics signature, which yielded an area under the curve (AUC) of 0.86 in the training cohort and 0.85 in the validation cohort. By incorporating the sex, maximum diameter, neutrophil count, albumin count, and radiomics score, a radiomics nomogram was developed. Radiomics nomogram (AUC: training, 0.91; validation, 0.92) had higher performance than clinical factors model (AUC: training, 0.86; validation, 0.90) or radiomics signature as a means of identifying patients at high risk for recurrence and metastasis. The radiomics nomogram had higher sensitivity than clinical factors mode (McNemar’s chi-squared = 4.1667, p = 0.04) and a little lower specificity than clinical factors model (McNemar’s chi-squared = 3.2, p = 0.07). The nomogram showed good calibration. Decision curve analysis demonstrated the superiority of the nomogram compared with the clinical factors model in terms of clinical usefulness.

Conclusion

The CT-based radiomics nomogram could help in predicting recurrence and metastasis risk in T1 ccRCC, which might provide assistance for clinicians in tailoring precise therapy.

Multiparametric MR for Solid Renal Mass Characterization

Multiparametric MR provides a noninvasive means for improved differentiation between benign and malignant solid renal masses. Although most large, heterogeneous renal masses are due to renal cell carcinoma, smaller "indeterminate" renal masses are being identified on cross-sectional imaging. Although definitive diagnosis of a solid renal mass may not always be possible by MR imaging, integrated evaluation of multiple MR imaging parameters can result in concise differential diagnosis. Multiparametric MR should be considered a critical step in the triage of patients with a solid renal mass for whom treatment options are being considered in the context of morbidity, prognosis, and mortality.

Imaging for Metastatic Renal Cell Carcinoma

Patients with renal cell carcinoma may develop metastases after radical nephrectomy, and therefore monitoring with imaging for recurrent or metastatic disease is critical. Imaging varies with specific suspected site of disease. Computed tomography/MRI of the abdomen and pelvis are mainstay modalities. Osseous and central nervous system imaging is reserved for symptomatic patients. Radiologic reporting is evolving to reflect effects of systemic therapy on lesion morphology. Nuclear medicine studies compliment routine imaging as newer agents are evaluated for more accurate tumor staging. Imaging research aims to fill gaps in treatment selection and monitoring of treatment response in metastatic renal cell carcinoma.

A Review of Prostate-Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) in Renal Cell Carcinoma (RCC)

Metastatic renal cell carcinoma (mRCC) is a disease that portends poor prognosis despite an increasing number of novel systemic treatment options including new targeted therapies and immunotherapy. Ablative intervention directed at oligometastatic RCC has demonstrated survival benefit. Consequently, developing techniques for improved staging of mRCC on contemporary imaging modalities including X-ray computed tomography (CT), magnetic resonance imaging (MRI) and/or bone scan (BS) is a clinical priority. This is relevant for metastatic deposits too small to characterize or lymph nodes within physiological normality. Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein highly expressed on prostate cancer epithelial cells. Recently, small molecules targeting the PSMA receptor, linked to radioactive isotopes have been developed for use with positron emission tomography (PET). Despite its nomenclature, PSMA has also been found to be expressed in the neovasculature of non-prostate cancers such as renal cell carcinoma (RCC) and hence PSMA PET/CT imaging has been proposed as an alternative staging modality. Preliminary small studies involving the use of PSMA PET/CT imaging in mRCC have been encouraging with evidence of improved staging sensitivity which has directly led to change in management in some cases. Given these early encouraging reports, we performed a comprehensive narrative review on the available evidence, including the scientific basis for PSMA expression in RCC, the role of PSMA PET/CT imaging with potential clinical implications in mRCC, its limitations and future opportunities.

Molecular targeting of renal cell carcinoma by an oral combination

The 5-year survival rate of patients with metastatic renal cell carcinoma (mRCC) is <12% due to treatment failure. Therapeutic strategies that overcome resistance to modestly effective drugs for mRCC, such as sorafenib (SF), could improve outcome in mRCC patients. SF is terminally biotransformed by UDP-glucuronosyltransferase-1A9 (A9) mediated glucuronidation, which inactivates SF. In a clinical-cohort and the TCGA-dataset, A9 transcript and/or protein levels were highly elevated in RCC specimens and predicted metastasis and overall-survival. This suggested that elevated A9 levels even in primary tumors of patients who eventually develop mRCC could be a mechanism for SF failure. 4-methylumbelliferone (MU), a choleretic and antispasmodic drug, downregulated A9 and inhibited SF-glucuronidation in RCC cells. Low-dose SF and MU combinations inhibited growth, motility, invasion and downregulated an invasive signature in RCC cells, patient-derived tumor explants and/or endothelial-RCC cell co-cultures; however, both agents individually were ineffective. A9 overexpression made RCC cells resistant to the combination, while its downregulation sensitized them to SF treatment alone. The combination inhibited kidney tumor growth, angiogenesis and distant metastasis, with no detectable toxicity; A9-overexpressing tumors were resistant to treatment. With effective primary tumor control and abrogation of metastasis in preclinical models, the low-dose SF and MU combinations could be an effective treatment option for mRCC patients. Broadly, our study highlights how targeting specific mechanisms that cause the failure of “old” modestly effective FDA-approved drugs could improve treatment response with minimal alteration in toxicity profile.

Cavitating pulmonary metastases from a renal cell carcinoma

Cavitary lung lesions are quite common findings on chest imaging and often pose a diagnostic challenge to the clinicians. We describe a case of a 75-year-old male who presented to the emergency room with hemoptysis. Computed tomography of the chest demonstrated multiple cavitary pulmonary nodules with peripheral groundglass opacities. Bronchoscopy did not reveal any active bleeding source, and washings were negative for malignancy and infectious cause. Computed Tomography guided biopsy of the left lung nodule showed metastatic carcinoma consistent with papillary renal cell carcinoma. This case highlights the unusual presentation of metastatic renal cell carcinoma.

Signal changes in T2-weighted MRI of liver metastases under bevacizumab-A practical imaging biomarker?

OBJECTIVE

The purpose of this study was to investigate signal changes in T2-weighted magnetic resonance imaging of liver metastases under treatment with and without bevacizumab-containing chemotherapy and to compare these signal changes to tumor contrast enhancement.

MATERIALS AND METHODS

Retrospective analysis of 44 patients, aged 36-84 years, who underwent liver magnetic resonance imaging including T2-weighted and dynamic contrast enhancement sequences. Patients received bevacizumab-containing (n = 22) or conventional cytotoxic chemotherapy (n = 22). Magnetic resonance imaging was obtained at baseline and at three follow-ups (on average 3, 6 and 9 months after initial treatment). Three independent readers rated the T2 signal intensity and the relative contrast enhancement of the metastases on a 5-point scale.

RESULTS

T2 signal intensity of metastases treated with bevacizumab showed a significant (p<0.001) decrease in T2 signal intensity after initial treatment and exhibit compared to conventionally treated metastases significantly (p<0.001 for each follow-up) hypointense (bevacizumab: 0.70 ± 0.83 before vs. -1.55 ± 0.61, -1.91 ± 0.62, and -1.97 ± 0.52; cytotoxic: 0.73 ± 0.79 before vs. -0.69 ± 0.81, -0.71 ± 0.68, and -0.75 ± 0.65 after 3, 6, and 9 months, respectively). T2 signal intensity was strongly correlated with tumor contrast enhancement (r = 0.71; p<0.001). Intra-observer agreement for T2-signal intensity was substantial (κ = 0.75). The agreement for tumoral contrast enhancement between the readers was considerably lower (κ = 0.39).

CONCLUSION

Liver metastases exhibit considerably hypointense in T2-weighted imaging after treatment with bevacizumab, in contrast to conventionally treated liver metastases. Therefore, T2-weighted imaging seems to reflect the effect of bevacizumab.

Metastatic clear cell renal cell carcinoma in isolated retroperitoneal lymph node without evidence of primary tumor in kidneys: A case report

BACKGROUND

Retroperitoneal lymph node dissection (RPLND) plays a diagnostic, therapeutic, and prognostic role in myriad urologic malignancies, including testicular carcinoma, renal cell carcinoma (RCC), and upper urinary tract urothelial carcinoma. RCC represents 2% of all cancers with approximately 25% of patients presenting with advanced disease. Clear cell RCC (CCRCC) is the most common RCC, accounting for 75%-80% of all RCC.

CASE SUMMARY

A 71-year-old man presented with a history of benign prostatic hypertrophy. He was asymptomatic without any hematuria, pain, or other urinary symptoms. A computed tomography (CT) scan of the abdomen and pelvis showed a 1.8 cm left retroperitoneal lymph node. There was no evidence of renal pathology. A core biopsy was performed of the left para-aortic lymph node. Although the primary tumor site was unknown, the morphological and immunohistochemical features were most consistent with CCRCC. A RPLND was performed which revealed a single mass 5.5 cm in greatest dimension with extensive necrosis. The retroperitoneal lymph node was most compatible with CCRCC. A nephrectomy was not conducted as a renal mass had not been detected on any prior imaging studies. The patient did not receive any type of adjuvant therapy. The patient underwent surveillance with serial CT scans with contrast of the chest, abdomen, and pelvis for the next 5 years, all of which demonstrated no recurrent or metastatic disease and no evidence of retroperitoneal adenopathy.

CONCLUSION

Our unique case emphasizes the therapeutic role of metastasectomy in metastatic CCRCC even in the absence of primary tumor in the kidneys.

Automated Identification of Optimal Portal Venous Phase Timing with Convolutional Neural Networks

OBJECTIVES

To develop a deep learning-based algorithm to automatically identify optimal portal venous phase timing (PVP-timing) so that image analysis techniques can be accurately performed on post contrast studies.

METHODS

681 CT-scans (training: 479 CT-scans; validation: 202 CT-scans) from a multicenter clinical trial in patients with liver metastases from colorectal cancer were retrospectively analyzed for algorithm development and validation. An additional external validation was performed on a cohort of 228 CT-scans from gastroenteropancreatic neuroendocrine cancer patients. Image acquisition was performed according to each centers' standard CT protocol for single portal venous phase, portal venous acquisition. The reference gold standard for the classification of PVP-timing as either optimal or nonoptimal was based on experienced radiologists' consensus opinion. The algorithm performed automated localization (on axial slices) of the portal vein and aorta upon which a novel dual input Convolutional Neural Network calculated a probability of the optimal PVP-timing.

RESULTS

The algorithm automatically computed a PVP-timing score in 3 seconds and reached area under the curve of 0.837 (95% CI: 0.765, 0.890) in validation set and 0.844 (95% CI: 0.786, 0.889) in external validation set.

CONCLUSION

A fully automated, deep-learning derived PVP-timing algorithm was developed to classify scans' contrast-enhancement timing and identify scans with optimal PVP-timing. The rapid identification of such scans will aid in the analysis of quantitative (radiomics) features used to characterize tumors and changes in enhancement with treatment in a multitude of settings including quantitative response criteria such as Choi and MASS which rely on reproducible measurement of enhancement.

Using a single abdominal computed tomography image to differentiate five contrast-enhancement phases: A machine-learning algorithm for radiomics-based precision medicine

PURPOSE

The clinical adoption of quantitative imaging biomarkers (radiomics) has established the need for high quality contrast-enhancement in medical images. We aimed to develop a machine-learning algorithm for Quality Control of Contrast-Enhancement on CT-scan (CECT-QC).

METHOD

Multicenter data from four independent cohorts [A, B, C, D] of patients with measurable liver lesions were analyzed retrospectively (patients:time-points; 503:3397): [A] dynamic CTs from primary liver cancer (60:2359); [B] triphasic CTs from primary liver cancer (31:93); [C] triphasic CTs from hepatocellular carcinoma (121:363); [D] portal venous phase CTs of liver metastasis from colorectal cancer (291:582). Patients from cohort A were randomized to training-set (48:1884) and test-set (12:475). A random forest classifier was trained and tested to identify five contrast-enhancement phases. The input was the mean intensity of the abdominal aorta and the portal vein measured on a single abdominal CT scan image at a single time-point. The output to be predicted was: non-contrast [NCP], early-arterial [E-AP], optimal-arterial [O-AP], optimal-portal [O-PVP], and late-portal [L-PVP]. Clinical utility was assessed in cohorts B, C, and D.

RESULTS

The CECT-QC algorithm showed performances of 98 %, 90 %, and 84 % for predicting NCP, O-AP, and O-PVP, respectively. O-PVP was reached in half of patients and was associated with a peak in liver malignancy density. Contrast-enhancement quality significantly influenced radiomics features deciphering the phenotype of liver neoplasms.

CONCLUSIONS

A single CT-image can be used to differentiate five contrast-enhancement phases for radiomics-based precision medicine in the most common liver neoplasms occurring in patients with or without liver cirrhosis.

Vaginal bleeding as primary presentation of renal cell carcinoma

Vaginal metastases from renal cell carcinoma has been recorded as extremely rare. We present a patient with vaginal bleeding as primary manifestation of renal cell carcinoma. A 40-year-old woman presented to a local private clinic with intermittent vaginal bleeding for approximately one month. Gynecological examination revealed a mass on the vaginal wall at approximately 8 o'clock. She underwent dilation and curettage (D&C) and mass excision. Microscopic histopathology and immunohistochemical stains showed vaginal metastases of clear cell RCC. The patient was referred to our urology clinic. Magnetic Resonance Imaging (MRI) of abdomen and pelvic showed a well-defined solid mass lesion measuring 16 × 12 × 11 cm in left kidney. Patient underwent left side radical nephrectomy through a left subcostal intraperitoneal incision. Histopathological results and metastasis workup confirmed the diagnosis of RCC with solitary metastatic vaginal lesion. After radical nephrectomy, she was treated with Sunitinib. No local relapse or distant metastasis was recognized 5 months after radical nephrectomy. In conclusion, the incidence of RCC metastasis to the vagina is extremely rare; but, in cases of vaginal bleeding or lesions we have to keep in mind the possibility of metastatic RCC.

Eligibility and Radiologic Assessment for Adjuvant Clinical Trials in Kidney Cancer

Purpose

To harmonize the eligibility criteria and radiologic disease assessment definitions in clinical trials of adjuvant therapy for renal cell carcinoma (RCC).

Method

On November 28, 2017, US-based experts in RCC clinical trials, including medical oncologists, urologic oncologists, regulators, biostatisticians, radiologists, and patient advocates, convened at a public workshop to discuss eligibility for trial entry and radiologic criteria for assessing disease recurrence in adjuvant trials in RCC. Multiple virtual meetings were conducted to address the issues identified at the workshop.

Results

The key workshop conclusions for adjuvant RCC therapy clinical trials were as follows. First, patients with non-clear cell RCC could be routinely included, preferably in an independent cohort. Second, patients with T3-4, N+M0, and microscopic R1 RCC tumors may gain the greatest advantages from adjuvant therapy. Third, trials of agents not excreted by the kidney should not exclude patients with severe renal insufficiency. Fourth, therapy can begin 4 to 16 weeks after the surgical procedure. Fifth, patients undergoing radical or partial nephrectomy should be equally eligible. Sixth, patients with microscopically positive soft tissue or vascular margins without gross residual or radiologic disease may be included in trials. Seventh, all suspicious regional lymph nodes should be fully resected. Eighth, computed tomography should be performed within 4 weeks before trial enrollment; for patients with renal insufficiency who cannot undergo computed tomography with contrast, noncontrast chest computed tomography and magnetic resonance imaging of the abdomen and pelvis with gadolinium should be performed. Ninth, when feasible, biopsy should be undertaken to identify any malignant disease. Tenth, when biopsy is not feasible, a uniform approach should be used to evaluate indeterminate radiologic findings to identify what constitutes no evidence of disease at trial entry and what constitutes radiologic evidence of disease. Eleventh, a uniform approach for establishing the date of recurrence should be included in any trial design. Twelfth, patient perspectives on the use of placebo, conditions for unblinding, and research biopsies should be considered carefully during the conduct of an adjuvant trial.

Conclusions and Relevance

The discussions suggested that a uniform approach to eligibility criteria and radiologic disease assessment will lead to more consistently interpretable trial results in the adjuvant RCC therapy setting.

Metachronous renal cell carcinoma with metastasis to the urinary bladder, and distant organs, 28 years after radical nephrectomy: a case report

BACKGROUND

Metachronous renal cell carcinoma after radical nephrectomy is extremely rare. Renal cell carcinoma commonly metastasizes to distant organs. However, metastasis to the urinary bladder is very uncommon.

CASE PRESENTATION

Herein, we report a case of metachronous renal cell carcinoma with metastasis to the urinary bladder, left acetabulum, left rib, lungs, thyroid, right renal vein and inferior vena cava. The patient had undergone a left-sided radical nephrectomy 28 years ago. The pathological diagnosis of a fragment of the bladder tumor was consistent with Fuhrman grade 2 clear cell renal cell carcinoma.

CONCLUSIONS

Although metachronous renal cell carcinoma after radical nephrectomy is rare, active surveillance should be still considered. Renal cell carcinoma has shown to unusually metastasize to the urinary bladder, a rarely reported organ of metastasis. Treatment options, such as immunotherapy, are available to patients with such metastasis and long-term survivorship can be achieved.

[Influence of immunomodulators on urological imaging]

BACKGROUND

Immune checkpoint inhibitors (ICI) have led to great advances in the therapy of metastatic renal cell and urothelial carcinoma. Currently ICI are approved for the first-line therapy of cisplatin-unfit patients (Atezolizumab, Pembrolizumab) and second-line therapy in patients with metastasized urothelial cancer (Atezolizumab, Nivolumab, Pembrolizumab). For the therapy of metastasized RCC, Nivolumab is approved as a second-line therapy and in combination with the CTLA‑4 antibody Ipilimumab as a first-line therapy.

OBJECTIVES

What does the optimized radiological follow-up and therapy response assessment for ICI, which differ in their pathways from common chemotherapeutics and anti-angiogenetic drugs, look like? What strategies are needed to meet the upcoming challenges concerning interpretation of the acquired images?

METHODS

A systematic literature search was carried out for urothelial and renal cell carcinoma.

RESULTS

Immune-related response criteria have been introduced to better characterize the imaging changes occurring under ICI, as monitoring response to immunotherapy still relies on RECIST.

CONCLUSIONS

To properly identify and predict response after treatment with ICI, additional studies with long-term follow-ups are needed. Because of the growing use of ICI, radiologists and urologist should be familiar with common imaging findings (such as pseudo progress) under immunotherapy to correctly interpret these findings in daily routine.