Percutaneous Microwave Ablation for Treatment of Retroperitoneal Tumors.

Purpose To determine if microwave ablation (MWA) of retroperitoneal tumors can safely provide high rates of local tumor control. Materials and Methods This retrospective study included 19 patients (median age, 65 years [range = 46-78 years]; 13 [68.4%] men and six [31.

Imaging Genomics and Multiomics: A Guide for Beginners Starting Radiomics-Based Research.

Radiomics uses advanced mathematical analysis of pixel-level information from radiologic images to extract existing information in traditional imaging algorithms. It is intended to find imaging biomarkers related to the genomics of tumors or disease patterns that improve medical care by advanced detection of tumor response patterns in tumors and to assess prognosis. Radiomics expands the paradigm of medical imaging to help with diagnosis, management of diseases and prognostication, leveraging image features by extracting information that can be used as imaging biomarkers to predict prognosis and response to treatment.

Using F-DCFPyL Prostate-Specific Membrane Antigen-Directed Positron Emission Tomography/Magnetic Resonance Imaging to Define Intraprostatic Boosts for Prostate Stereotactic Body Radiation Therapy.

Purpose: The recently reported FLAME trial demonstrated a biochemical disease-free survival benefit to using a focal intraprostatic boost to multiparametric magnetic resonance imaging (mpMRI)-identified lesions in men with localized prostate cancer treated with definitive radiation therapy. Prostate-specific membrane antigen (PSMA)-directed positron emission tomography (PET) may identify additional areas of disease. In this work, we investigated using both PSMA PET and mpMRI in planning focal intraprostatic boosts using stereotactic body radiation therapy (SBRT).

Assessment of 18F-DCFPyL PSMA PET/CT and PET/MR quantitative parameters for reference standard organs: Inter-reader, inter-modality, and inter-patient variability.

Prostate specific membrane antigen (PSMA)-based radiotracers have shown promise for prostate cancer assessment. Evaluation of quantitative variability and establishment of reference standards are important for optimal clinical and research utility. This work evaluates the variability of PSMA-based [18F]DCFPyL (PyL) PET quantitative reference standards.

Reduced field-of-view and multi-shot DWI acquisition techniques: Prospective evaluation of image quality and distortion reduction in prostate cancer imaging.

Objectives: To prospectively compare image quality and apparent diffusion coefficient (ADC) quantification for reduced field-of-view (rFOV)- and multi-shot echo-planar imaging (msEPI)-based diffusion weighted imaging (DWI), using single-shot echo-planar-imaging (ssEPI) DWI as the reference.

Methods: Under IRB approval and after informed consent, msEPI, rFOV, and ssEPI DWI acquisitions were prospectively added to clinical prostate MRI exams at 3.0 T.

Improved free-breathing liver fat and iron quantification using a 2D chemical shift-encoded MRI with flip angle modulation and motion-corrected averaging.

Objectives: 3D chemical shift-encoded (CSE) MRI enables accurate and precise quantification of proton density fat fraction (PDFF) and R2*, biomarkers of hepatic fat and iron deposition. Unfortunately, 3D CSE-MRI requires reliable breath-holding. Free-breathing 2D CSE-MRI with sequential radiofrequency excitation is a motion-robust alternative but suffers from low signal-to-noise-ratio (SNR).

Contrast-enhanced CT immediately following percutaneous microwave ablation of cT1a renal cell carcinoma: Optimizing cancer outcomes.

Objective: To evaluate the effect of intra-procedural contrast-enhanced CT (CECT) and same-session repeat ablation (SSRA) on primary efficacy, the complete eradication of tumor after the first ablation session as confirmed on first imaging follow-up, of clinically localized T1a (cT1a) renal cell carcinoma (RCC).

Methods: 398 consecutive patients with cT1a RCC were treated with cryoablation between 10/2003 and 12/2017, radiofrequency (RFA) or microwave ablation (MWA) between 1/2010 and 12/2017. SSRA was performed for residual tumor identified on intra-procedural CECT.

Split-bolus CT urography after microwave ablation of renal cell carcinoma improves image quality and reduces radiation exposure.

Objective: To compare image quality and radiation dose between single-bolus 2-phase and split-bolus 1-phase CT Urography (CTU) performed immediately after microwave ablation (MWA) of clinically localized T1 (cT1) RCC.

Methods: Forty-two consecutive patients (30 M, mean age 67.5 ± 9.

Combined mpMRI/US fusion targeted and concurrent standard biopsies in the detection of prostate cancer: a retrospective study.

Unlabelled: In this retrospective study we compared the PCa detection rates between combined (combined MRI/US fusion targeted biopsy with concurrent standard biopsy) and standard systemic, combined and targeted (component), and targeted (component) and concurrent standard (component) biopsies.

Design: Two cohorts, totaling 735 cases, were selected from the University of Wisconsin Pathology archive. 390 cases (cohort 1) were combined biopsies from 2017-2020 and 345 cases (cohort 2) were part of the standard US-guided systematic biopsies from the same period.

Advanced CT techniques for hepatic microwave ablation zone monitoring and follow-up.

Purpose: To evaluate utility of advanced CT techniques including HighlY constrained back-projection and dual-energy CT for intra- and post-procedure hepatic microwave ablation zone monitoring.

Methods: 8 hepatic microwave ablations were performed in 4 adult swine (5 min/65 W). Low-dose routine CECT and dual-energy CT images were obtained every 1 min during ablation.

Efficacy of percutaneous image-guided biopsy for diagnosis of intrahepatic cholangiocarcinoma.

Purpose: To evaluate the efficacy of percutaneous biopsy for diagnosing intrahepatic cholangiocarcinoma (IHCCA).

Methods: Retrospective review of biopsy and pathology databases from 2006 to 2019 yielded 112 patients (54F/58 M; mean age, 62.9 years; 27 cirrhotic) with IHCCA who underwent percutaneous biopsy.

Effect of Metabolic Syndrome on Anatomy and Function of the Lower Urinary Tract Assessed on MRI.

Objective: To investigate the relationship between metabolic syndrome (MetS) and lower urinary tract symptoms (LUTS) with functional and anatomic changes of the lower urinary tract with MRI.

Materials And Methods: The bladder and prostate of 95 subjects (56M, 39F) were segmented on T2-weighted pelvic MRI using Materialize Mimics 3D software. Bladder wall volume (BWV), post-void residual (PVR) and prostate volume (PV) were quantified from the 3D renderings.

Microwave ablation for colorectal cancer metastasis to the liver: a single-center retrospective analysis.

Background: The purpose of this study is to evaluate the safety and intermediate-term efficacy of percutaneous microwave (MW) ablation for the treatment of colorectal liver metastases (CRLM) at a single institution.

Methods: A retrospective review was performed of all CRLM treated with MW ablation from 3/2011 to 7/2020 (102 tumors; 72 procedures; 57 patients). Mean age was 60 years (range, 36-88) and mean tumor size was 1.

Microwave Ablation of Renal Cell Carcinoma.

Management options for small renal masses include active surveillance, partial nephrectomy, radical nephrectomy, and thermal ablation. For tumors typically ≤3 cm in size, thermal ablation is a good option for those desiring an alternative to surgery or active surveillance, especially in patients who are considered high surgical risk. We favor microwave ablation because of the more rapid heating, higher temperatures that overcome the heat sink effect of vessels, reproducible cell kill, and a highly visible ablation zone formed by water vapor that corresponds well to the zone of necrosis.

Differential Imaging of Liver Tumors before and after Microwave Ablation with Electrode Displacement Elastography.

Liver cancer is a leading cause of cancer-related deaths; however, primary treatment options such as surgical resection and liver transplant may not be viable for many patients. Minimally invasive image-guided microwave ablation (MWA) provides a locally effective treatment option for these patients with an impact comparable to that of surgery for both cancer-specific and overall survival. MWA efficacy is correlated with accurate image guidance; however, conventional modalities such as B-mode ultrasound and computed tomography have limitations.

Evolution of the Interventional Radiology (IR) Pathway-Various Changes and Interrelation to Diagnostic Radiology (DR).

Interventional radiology continues to evolve into a more robust and clinically dynamic specialty underpinned by significant advancements in training, education, and practice. This article, prepared by members of the 2020-2021 Association of University Radiologists' task force of the Radiology Research Alliance, will review these developments, highlighting the evolution of interventional radiology pathways with attention to growing educational differences, interrelation to diagnostic radiology training, post-training practice patterns, distribution of procedures and future trends, amongst other key features important to those pursuing a career in interventional radiology as well as those in practice.

Effect of iodinated contrast material on post-operative eGFR when administered during renal mass ablation.

Objective: To evaluate the effect of intravenous iodinated contrast on estimated glomerular filtration rate (eGFR) when administered immediately after thermal ablation of clinically localized T1a (cT1a) renal cell carcinoma (RCC).

Methods: This HIPAA-compliant, dual-center retrospective study was performed under a waiver of informed consent. Three hundred forty-two consecutive patients with cT1a biopsy-proven RCC were treated with percutaneous ablation between January 2010 and December 2017.

Long-Term Outcomes and Prognostic Factors in Kidney Transplant Recipients with Polycystic Kidney Disease.

Background: Polycystic kidney disease (PKD) accounts for approximately 15% of kidney transplants, but long-term outcomes in patients with PKD who have received a kidney transplant are not well understood.

Methods: In primary recipients of kidney transplants at our center (1994-2014), we compared outcomes of underlying PKD (=619) with other native diseases (non-PKD, =4312). Potential factors influencing outcomes in PKD were evaluated using Cox proportional-hazards regression and a rigorous multivariable model.

Comprehensive non-invasive analysis of lower urinary tract anatomy using MRI.

Purpose: Anatomic changes that coincide with aging including benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) negatively impact quality of life. Use of MRI with its exquisite soft tissue contrast, full field-of-view capabilities, and lack of radiation is uniquely suited for quantifying specific lower urinary tract features and providing comprehensive measurements such as total bladder wall volume (BWV), bladder wall thickness (BWT), and prostate volume (PV). We present a technique for generating 3D anatomical renderings from MRI to perform quantitative analysis of lower urinary tract anatomy.

Patterns of Initial Metastatic Recurrence After Surgery for High-Risk Nonmetastatic Renal Cell Carcinoma.

Objective: To evaluate postoperative recurrence patterns for high-risk nonmetastatic renal cell carcinoma (RCC) and to identify prognostic factors associated with site-specific metastatic recurrence using a multi-institutional contemporary cohort.

Methods: Data for nonmetastatic ≥pT3a RCC patients treated with surgery at 4 independent centers was analyzed. Initial recurrence locations were identified, and imaging templates were defined by anatomic landmarks using radiologic definitions.

CT and MR imaging surveillance of stage 1 renal cell carcinoma after microwave ablation.

Objective: To describe the CT and MR imaging findings after microwave ablation of clinical stage 1 renal cell carcinoma (RCC).

Methods: This single-center retrospective study was performed under a waiver of informed consent. 49 patients (38 M/11F, mean age 66 ± 9.

Microwave Ablation of Adrenal Tumors in Patients With Continuous Intra-Arterial Blood Pressure Monitoring Without Prior Alpha-Adrenergic Blockade: Safety and Efficacy.

Purpose: Evaluate the safety and efficacy of adrenal microwave ablation performed with continuous intra-arterial blood pressure monitoring (IABPM) and without alpha-adrenergic blockade (AAB) as pretreatment.

Material And Methods: A single-center, retrospective review of all percutaneous adrenal microwave ablation performed between 2011 and 2018. Microwave ablation was completed on 11 patients, with a total of 15 adrenal tumors with a mean size of 3.

Stimulated-echo diffusion-weighted imaging with moderate b values for the detection of prostate cancer.

Objectives: Conventional spin-echo (SE) DWI leads to a fundamental trade-off depending on the b value: high b value provides better lesion contrast-to-noise ratio (CNR) by sacrificing signal-to-noise ratio (SNR), image quality, and quantitative reliability. A stimulated-echo (STE) DWI acquisition is evaluated for high-CNR imaging of prostate cancer while maintaining SNR and reliable apparent diffusion coefficient (ADC) mapping.

Methods: In this prospective, IRB-approved study, 27 patients with suspected prostate cancer (PCa) were scanned with three DWI sequences (SE b = 800 s/mm, SE b = 1500 s/mm, and STE b = 800 s/mm) after informed consent was obtained.

Pharmacokinetics of Ferumoxytol in the Abdomen and Pelvis: A Dosing Study with 1.5- and 3.0-T MRI Relaxometry.

Background The off-label use of ferumoxytol (FE), an intravenous iron preparation for iron deficiency anemia, as a contrast agent for MRI is increasing; therefore, it is critical to understand its pharmacokinetics. Purpose To evaluate the pharmacokinetics of FE in the abdomen and pelvis, as assessed with quantitative 1.5- and 3.

Comparing Outcomes for Patients with Clinical T1b Renal Cell Carcinoma Treated With Either Percutaneous Microwave Ablation or Surgery.

Objective: To compare perioperative and oncologic outcomes for patients with clinical T1b renal cell carcinoma following treatment with microwave ablation (MW), partial nephrectomy (PN), or radical nephrectomy (RN).

Methods: Comprehensive clinical and pathologic data were collected for nonmetastatic renal cell carcinoma patients with cT1b tumors following MW, PN, or RN from 2000 to 2018. Local recurrence-free, metastasis-free, cancer-specific and overall survival were estimated using Kaplan-Meier method.