Preoperative prediction of the stage, size, grade, and necrosis score in clear cell renal cell carcinoma using MRI-based radiomics.

PURPOSE: Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma. Currently, there is a lack of noninvasive methods to stratify ccRCC prognosis prior to any invasive therapies. The purpose of this study was to preoperatively predict the tumor stage, size, grade, and necrosis (SSIGN) score of ccRCC using MRI-based radiomics. METHODS: A multicenter cohort of 364 histopathologically confirmed ccRCC patients (272 low [< 4] and 92 high [≥ 4] SSIGN score) with preoperative T2-weighted and T1-contrast-enhanced MRI were retrospectively identified and divided into training (254 patients) and testing sets (110 patients). The performance of a manually optimized radiomics model was assessed by measuring accuracy, sensitivity, specificity, area under receiver operating characteristic curve (AUROC), and area under precision-recall curve (AUPRC) on an independent test set, which was not included in model training. Lastly, its performance was compared to that of a machine learning pipeline, Tree-Based Pipeline Optimization Tool (TPOT). RESULTS: The manually optimized radiomics model using Random Forest classification and Analysis of Variance feature selection methods achieved an AUROC of 0.89, AUPRC of 0.81, accuracy of 0.89 (95% CI 0.816-0.937), specificity of 0.95 (95% CI 0.875-0.984), and sensitivity of 0.72 (95% CI 0.537-0.852) on the test set. The TPOT using Extra Trees Classifier achieved an AUROC of 0.94, AUPRC of 0.83, accuracy of 0.89 (95% CI 0.816-0.937), specificity of 0.95 (95% CI 0.875-0.984), and sensitivity of 0.72 (95% CI 0.537-0.852) on the test set. CONCLUSION: Preoperative MR radiomics can accurately predict SSIGN score of ccRCC, suggesting its promise as a prognostic tool that can be used in conjunction with diagnostic markers.

Machine Learning Offers Exciting Potential for Predicting Postprocedural Outcomes: A Framework for Developing Random Forest Models in IR.

PURPOSE: To demonstrate that random forest models trained on a large national sample can accurately predict relevant outcomes and may ultimately contribute to future clinical decision support tools in IR. MATERIALS AND METHODS: Patient data from years 2012-2014 of the National Inpatient Sample were used to develop random forest machine learning models to predict iatrogenic pneumothorax after computed tomography-guided transthoracic biopsy (TTB), in-hospital mortality after transjugular intrahepatic portosystemic shunt (TIPS), and length of stay > 3 days after uterine artery embolization (UAE). Model performance was evaluated with area under the receiver operating characteristic curve (AUROC) and maximum F1 score. The threshold for AUROC significance was set at 0.75. RESULTS: AUROC was 0.913 for the TTB model, 0.788 for the TIPS model, and 0.879 for the UAE model. Maximum F1 score was 0.532 for the TTB model, 0.357 for the TIPS model, and 0.700 for the UAE model. The TTB model had the highest AUROC, while the UAE model had the highest F1 score. All models met the criteria for AUROC significance. CONCLUSIONS: This study demonstrates that machine learning models may suitably predict a variety of different clinically relevant outcomes, including procedure-specific complications, mortality, and length of stay. Performance of these models will improve as more high-quality IR data become available.

Basic neuroangiography: review of technique and perioperative patient care.

Neuroangiography (NA) is an important part of diagnosis and treatment of patients with neurological disease. Although NA may be performed for diagnostic purposes, in many instances NA is performed with the intent to treat. Indications for NA range from extracranial diseases (vertebrobasilar insufficiency from subclavian steal, extracranial carotid stenosis, cavernous-carotid fistula, neck trauma, epistaxis, tumor invasion of the carotid artery, and tumor embolization) to intracranial diseases (nontraumatic subarachnoid hemorrhage, cerebral aneurysms, cerebral arteriovenous malformations, cerebral vasospasm, acute stroke, tumor embolization, and WADA test). Similar to peripheral angiography, appropriate preprocedural assessment and postprocedural care, along with understanding of anatomy, catheter technique, and disease processes, are vital to successful outcomes. This article will review the basic technique, equipment, and patient management in NA. With appropriate skill and knowledge, interventional radiologists can perform NA with safe and successful results.

Interventional management of head and neck emergencies: carotid blowout.

Involvement of the carotid artery by malignant processes of the head and neck with compromise of vessel integrity and rupture-"carotid blowout syndrome" (CBS)-is one of the most devastating complications of malignancy. Most often, it is associated with squamous cell cancer and almost always in patients who have undergone prior radiation therapy. CBS is classified as threatened, impending, or acute. Bleeding into the oral cavity or from areas of skin breakdown is a frightening experience for patients and their families and often a terminal event. Prognosis is poor with up to 50% mortality and morbidity, and surgical options are limited and risky. Endovascular management with vessel sacrifice or stent placement has become the principle treatment option in this patient population, though still associated with procedural complications, often neurologic, that can occur acutely or in a delayed fashion. This article reviews techniques and outcomes associated with endovascular treatment of CBS.

Transcatheter embolization in the management of epistaxis.

A majority of the population will experience epistaxis at some time in their life. Most cases will be from an anterior source and can be treated with pressure, anterior nasal packing, or cautery. Intractable epistaxis is generally posterior in origin and may require endoscopic cautery, posterior packing, surgical ligation, or embolization. Embolization has been used to treat epistaxis for more than 30 years and success can be achieved in approximately 90% of patients, with major complications occurring in approximately 2%. These excellent results require thorough knowledge of the regional anatomy, familiarity with the equipment and various agents used to achieve this type of embolization, as well as attention to detail and meticulous technique. There remains debate on several aspects of embolization, including the agent of choice, preferred size of the embolic, and the number of vessels to embolize. Advances in endoscopic surgery have evolved to the point that similar success rates for embolization and modern surgical techniques in treating epistaxis may be expected. This detailed review of pertinent vascular anatomy, embolization technique, and surgical alternatives should allow practitioners to formulate treatment algorithms that result in optimal outcomes at their institutions.

Contemporary endovascular embolotherapy for meningioma.

Preoperative endovascular tumor embolization has been used for 40 years. Meningiomas are the most common benign intracranial tumor in which preoperative embolization has been most extensively described in the literature. Advocates of embolization report that it reduces operative blood-loss, and softens the tumor, thus making surgery safer and easier. Opponents suggest that it adds additional risk and cost for patients without controlled studies showing conclusive benefit. The literature suggests a 3 to 6% neurological complication rate related to embolization. The combined external and internal carotid artery blood supply and complex anastomoses of the meninges can make embolization challenging. Positive outcomes require thorough knowledge of the pertinent vascular anatomy, familiarity with the neurovascular equipment and embolics, and meticulous technique. There remains debate on several aspects of embolization, including tumors most appropriate for embolization, embolic agent of choice, ideal size of embolic, and the choice of vessel(s) to embolize. This detailed review of pertinent vascular anatomy, embolization technique, results, and complications should allow practitioners to maximize treatment outcomes in this setting.

Interventional management of vertebral body metastases.

Metastases to the vertebral column are often due to hypervascular primary tumors, the most common of which is renal cell carcinoma. Clinical symptoms attributed to vertebral body metastases include localized pain, mechanical instability of the vertebral column, and neurologic deficits resulting from mass effect. Treatment options include targeted radiotherapy, percutaneous vertebral augmentation with or without thermal ablation, and surgical resection with subsequent fusion. Overall, surgical resection of the tumor and stabilization of the vertebral column provide the best prognosis for the patient in terms of symptomatic improvement and long-term survival; however, resection of hypervascular vertebral body metastases can result in significant intraoperative blood loss that can add to the morbidity of the procedure. Preoperative embolization of hypervascular metastases of the vertebral column has been shown to significantly reduce intraoperative blood loss at the time of surgery. The goal of this manuscript is to describe the role of embolization therapy in the management of patients with vertebral body metastases.

Interventional management of arc of buhler aneurysm.

The Arc of Buhler (AOB) represents a persistence of the ventral anastomosis between the superior mesenteric artery (SMA) and the celiac arterial systems. The exact incidence of the AOB is not known, but it is believed to be ≤ 4%. Aneurysms of this rare anomaly are even more uncommon. We report a case of an aneurysm of the AOB with an intact pancreaticoduodenal artery arcade (PDAA) and near occlusive celiac origin stenosis. Stenoses or occlusions of the celiac origin have been reported in association with AOB aneurysms, as well as in patients with PDAA aneurysms. Transcatheter embolization (TCE) was successfully performed, thereby excluding the AOB aneurysm while preserving flow through the PDAA. To our knowledge, this is the first report of successful percutaneous treatment of an AOB aneurysm. The pathophysiology and management AOB and PDAA aneurysms are reviewed. Review of the literature suggests that TCE, when feasible, is at least as effective as conventional surgery in patients with PDAA aneurysms, but with lower morbidity and mortality. Based on this data and our experience, we believe that TCE should be the initial treatment of choice in patients with PDAA or AOB aneurysms.

Case of pseudomembranous necrotizing tracheobronchial aspergillosis in an immunocompetent host.

A 44-year-old Korean male died of rapidly progressive respiratory failure and refractory hypoxemia in 8 days after being admitted with a fever and dyspnea. The patient was diagnosed with pseudomembranous necrotizing tracheobronchial aspergillosis by fibroptic bronchoscopy and it was not related to an invasion of the pulmonary parenchyma. To the best of our knowledge, this case represents a patient with pseudomembranous necrotizing tracheobronchial aspergillosis that developed in an immunocompetent host, rapidly resulting in airway obstruction with acute respiratory failure and refractory hypoxemia without an invasion of the pulmonary parenchyma.