Faculty Bibliography

Patients with pancreatic ductal adenocarcinoma (PDAC) frequently present with liver metastases, which severely limit treatment options and prognosis. In other cancers, treatment of liver disease can improve outcomes and similar approaches are being explored in PDAC. Clinical data for locoregional control of pancreatic cancer liver metastases (PCLM) are limited, and histotripsy offers a new noninvasive tool for disease control. This study evaluates the preliminary safety, efficacy, and imaging findings of histotripsy in patients with PCLM.

Knee osteoarthritis (OA) is a major cause of pain and disability. Genicular artery embolization (GAE) is a promising alternative for patients unresponsive to conservative treatment or unsuitable for total knee replacement. GAE may alleviate knee pain by reducing synovitis and by causing ischemia to pathologic knee nerves. However, outcomes vary based on baseline MRI and radiographic findings, making patient selection challenging. Recently, reduction in synovitis on contrast-enhanced MRI has been associated with pain relief post-GAE. Novel OA phenotypes (inflammatory, cartilage, bone, and atrophic) can aid in patient selection by using imaging and molecular biomarkers. Moreover, imaging features such as cartilage defects, bone marrow lesions, and synovitis may predict symptomatic outcomes. This review explores OA pathophysiology, focusing on radiographic, biochemical, and imaging biomarkers in evaluating GAE for knee OA treatment.

PURPOSE/OBJECTIVE:To characterize the effect of embolic particle size on outcomes of uterine artery embolization (UAE) for mixed adenomyosis/fibroids. MATERIALS AND METHODS/METHODS:A single-center retrospective database was compiled of all patients with mixed adenomyosis/fibroids who underwent UAE with particles (Embosphere, Merit, USA; Embozene, Varian, UK) from September 2015 to May 2022 (n=76, mean age: 46.7 ± 5.7). Demographic, clinical, imaging, procedural, and follow-up data were collected. Intraprocedurally, initial particle size was chosen according to proceduralist judgment and subsequently upsized as needed until near-stasis was achieved. Initial particle size was categorized as either small (Embosphere 300-500μm, Embozene 500μm) or large (Embosphere 500-700μm, Embozene 700μm). The effect of initial particle size on patient-reported symptomatic improvement was assessed with logistic regression, with pre-procedural uterine volume, presence of focal adenomyoma, and total number of vials of embolic material as regression covariates. RESULTS:Pre-procedural symptoms included menorrhagia (89.5%), pelvic pain (53.9%), and bulk symptoms (60.5%). Baseline mean uterine volume was 748.5 ± 543.9 mL. Post-procedurally, 89.1%, 92.3%, and 97.4% reported improvement in menorrhagia, pelvic pain, and bulk symptoms, respectively. Initial embolic particle sizing was not significantly associated with patient-reported improvement in menorrhagia (p=0.134), pelvic pain (p=0.598), or bulk symptoms (p=0.151), when controlling for covariates. CONCLUSION/CONCLUSIONS:When controlling for covariates, smaller calibrated microspheres had similar post-procedural pain outcomes as larger particles, with similar target outcomes in UAE for mixed adenomyosis/fibroids.

BACKGROUND/UNASSIGNED:The aim of this study was to examine the impact of early versus delayed catheter-based therapies (CBTs) on clinical outcomes in patients with acute intermediate-risk pulmonary embolism (PE). METHODS/UNASSIGNED:This retrospective cohort study analyzed data from 2 academic centers involving patients with intermediate-risk PE from January 2020 to January 2024. Patients were divided into early (<12 hours) and delayed CBT (≥12 hours) groups. The primary outcome was a composite of 30-day mortality, resuscitated cardiac arrest, hemodynamic instability, and 90-day readmission. Secondary outcomes included a composite of 30-day mortality, resuscitated cardiac arrest, and hemodynamic instability. Inverse probability of treatment weighting was used to balance covariates. RESULTS/UNASSIGNED:=0.046). When patients were stratified by timing of CBT (early/late) and the composite PE shock score (high ≥3; low <3), all 16 patients who experienced the primary composite outcome had a high composite PE shock score, with 14/16 (87.5%) having a high composite PE shock score and delayed intervention. CONCLUSIONS/UNASSIGNED:Early CBT was associated with improved clinical outcomes in patients with acute intermediate-risk PE. The composite PE shock score may help identify patients who will benefit from early CBT. Further prospective studies are needed to validate these findings.

BACKGROUND:The recently published PEERLESS trial compared catheter-directed thrombolysis (CDT) and catheter-based thrombectomy (CBT) in acute pulmonary embolism (PE). However, it included a low proportion of patients with contraindications to thrombolytic therapy (4.4%), leaving uncertainty about how CDT would perform relative to CBT in a real-world cohort with higher bleeding risk. AIMS/OBJECTIVE:This study aims to address this gap by comparing real-world outcomes of CDT and CBT in patients with acute PE. METHODS:This retrospective analysis included patients who underwent CDT and CBT at two tertiary care centers from January 2020 to January 2024. The primary outcome was a composite of 30-day mortality, resuscitated cardiac arrest, or hemodynamic decompensation. Secondary outcomes included major bleeding and intracranial hemorrhage (ICH). Inverse probability treatment weighting (IPTW) was used to adjust for baseline variables. RESULTS:A total of 162 (mean age 58 years, 45.7% women, 17.3% high-risk, 28% contraindication to lytics, 28% CDT, 72% CBT) patients were included, with 12.4% patients experiencing the primary outcome. There was no difference in the rates of the primary outcome between CBT versus CDT (11.2% vs. 15.2%, IPTW HR: 0.80; 95% CI: 0.27-2.38, p = 0.69). CBT was associated with a lower risk of hemodynamic decompensation (5% vs. 21.7%, p = 0.036), major bleeding (7.8% vs. 17.4%, IPTW HR 0.26; 95% CI: 0.07-0.95, p = 0.042) and ICH (0 vs. 4.3%, p = 0.024) compared to CDT. CONCLUSION/CONCLUSIONS:Among a real-world cohort of patients with acute PE with higher bleeding risk than PEERLESS undergoing catheter-based therapies, CBT was associated with a lower rate of hemodynamic deterioration, major bleeding, and ICH with similar rate of primary composite outcome when compared with CDT. Additional randomized controlled trials are needed to validate these findings.

Genicular artery embolization (GAE) is an emerging, minimally invasive therapy to address the global burden of knee osteoarthritis (OA) and the unmet needs for medically refractory disease. Although total knee arthroplasty has been a standard intervention for severe cases, GAE is developing into a promising alternative, particularly for patients ineligible for or unwilling to undergo surgery. GAE targets the inflammatory cascade underlying OA pathophysiology by arresting neoangiogenesis and preventing pathological neoinnervation, offering potential pain relief. Although early studies have established safety and short-term effectiveness, ensuing studies are needed to validate long-term safety, durability, and comparative effectiveness and to optimize patient selection, embolic agent selection, and administration techniques. Standardized reporting guidelines are therefore essential to enhance transparency and reproducibility across clinical trials, facilitating data aggregation and comparison. This Society of Interventional Radiology (SIR)-endorsed reporting standards consensus document provides a framework to harmonize future research efforts and to improve the interpretation of outcomes.

Genicular artery embolization is increasingly recognized as a safe and effective treatment option for symptomatic knee osteoarthritis and recurrent hemarthrosis following total knee arthroplasty. Genicular arteries are an essential vascular supply for the knee joint and demonstrate considerable variability. Familiarity with the anatomy and common variations is critical for pre-procedural planning, accurate target selection, and minimizing adverse events in trans-arterial embolization procedures. This review aims to provide a detailed discussion of the genicular artery anatomy that is relevant to interventional radiologists performing genicular artery embolization.

PURPOSE/OBJECTIVE:To characterize how the adoption of virtual residency interviews (2020-2021 cycle) has impacted the geographic distribution of radiology resident matches. METHODS:University-based interventional (IR) and diagnostic radiology (DR) residency programs from 2017 to 2021 were identified using a national residency database (FRIEDA). Public applicant data were obtained from official residency program websites. Medical schools and residency programs were categorized by US census regions. Geographic applicant distribution before and after the initiation of virtual interviews was statistically assessed using Chi-square tests. The effect of virtual interviews on the probability of matching within the same geographic region as one's medical school was evaluated with multivariate logistic regression. RESULTS:4358 radiology residents (88% diagnostic, 12% interventional) matched at 102 radiology programs during the study period. 71% (n = 3115 residents) had data available for analysis. 56.3% of DR and 49.3% of IR residents matched in the same geographic region as their medical school. The geographic distribution of applicants who matched at Southern IR residency programs significantly changed after implementation of virtual interviews (p < 0.0001). Virtual interviews did not increase the odds of matching in the same region as one's medical school for IR (OR 1.11, p = 0.08) or DR (OR 1.01, p = 0.58) applicants. Top-20 ranked DR programs had lower odds of in-region matches (OR 0.87, p < 0.001). CONCLUSION/CONCLUSIONS:With few exceptions, shifting to virtual residency interviews did not significantly affect the geographic distribution of IR or DR residency matches. Top-ranked DR programs match more regionally diverse applicants.