Implications of Bias in Artificial Intelligence: Considerations for Cardiovascular Imaging

PURPOSE OF REVIEW

Bias in artificial intelligence (AI) models can result in unintended consequences. In cardiovascular imaging, biased AI models used in clinical practice can negatively affect patient outcomes. Biased AI models result from decisions made when training and evaluating a model. This paper is a comprehensive guide for AI development teams to understand assumptions in datasets and chosen metrics for outcome/ground truth, and how this translates to real-world performance for cardiovascular disease (CVD).

RECENT FINDINGS

CVDs are the number one cause of mortality worldwide; however, the prevalence, burden, and outcomes of CVD vary across gender and race. Several biomarkers are also shown to vary among different populations and ethnic/racial groups. Inequalities in clinical trial inclusion, clinical presentation, diagnosis, and treatment are preserved in health data that is ultimately used to train AI algorithms, leading to potential biases in model performance. Despite the notion that AI models themselves are biased, AI can also help to mitigate bias (e.g., bias auditing tools). In this review paper, we describe in detail implicit and explicit biases in the care of cardiovascular disease that may be present in existing datasets but are not obvious to model developers. We review disparities in CVD outcomes across different genders and race groups, differences in treatment of historically marginalized groups, and disparities in clinical trials for various cardiovascular diseases and outcomes. Thereafter, we summarize some CVD AI literature that shows bias in CVD AI as well as approaches that AI is being used to mitigate CVD bias.

Creating a Sustainable Foundation for Interventional Radiology Services and Training in Sub-Saharan Africa: Five-Year Update on the Road2IR Initiative

PURPOSE

To evaluate the growth and quality of an IR training model designed for resource-constrained settings and implemented in Tanzania, as well as its overall potential to increase access to minimally invasive procedures across the region.

MATERIALS AND METHODS

IR training in Tanzania began in 10/2018 through monthly deployment of visiting teaching teams for hands-on training combined with in-person and remote lectures. A competency-based two-year Master of Science (MSc) in IR curriculum was inaugurated at the nation's main teaching hospital in 10/2019, graduating its first two classes in 2021 and 2022. Procedural data, demographics, and clinical outcomes were collected and analyzed throughout the duration of this program.

RESULTS

From 10/2018 to 7/2022, 1,595 procedures were performed in Tanzania: 1,236 non-vascular and 359 vascular, all with local fellows as primary operators. 97.2% were technically successful, 95.2% were without complication, and 28.9% were performed independently by Tanzanian fellows and faculty with no difference in complication and technical success rates (p=0.63 and 0.90, respectively), irrespective of procedural class. Ten IR physicians graduated from this program during the study period, followed by another three per year going forward. Partner training programs in Uganda and Rwanda mirroring this model commenced in 2023 and 2024, respectively.

CONCLUSION

The reported training model offers a practical and effective solution to meet many of the challenges associated with the lack of access to IR in sub-Saharan Africa.

Percutaneous Robotics in Interventional Radiology

The accuracy of the robotic device not only relies on a reproducible needle advancement, but also on the possibility to correct target movement at chosen checkpoints and to deviate from a linear to a nonlinear trajectory. We report our experience in using the robotic device for the insertion of trocar needles in CT guided procedures. The majority of procedures were targeted organ biopsies in the chest abdomen or pelvis. The accuracy of needle placement after target adjustments did not significantly differ from those patients where a linear trajectory could be used. The steering capabilities of the robot allow correction of target movement of the fly.

Uterine artery embolization in Tanzania: a procedure with major public health implications

BACKGROUND

The burden of uterine fibroids is substantial in sub-Saharan Africa (SSA), with up to 80% of black women harboring them in their lifetime. While uterine artery embolization (UAE) has emerged as an effective alternative to surgery to manage this condition, the procedure is not available to the vast majority of women living in SSA due to limited access to interventional radiology (IR) in the region. One of the few countries in SSA now offering UAE in a public hospital setting is Tanzania. This study aims to assess the safety and effectiveness of UAE in this new environment.

METHODS

From June 2019 to July 2022, a single-center, retrospective cohort study was conducted at Tanzania's first IR service on all patients who underwent UAE for the management of symptomatic fibroids or adenomyosis. Patients were selected for the procedure based on symptom severity, imaging findings, and medical management failure. Procedural technical success and adverse events were recorded for all UAEs. Self-reported symptom severity and volumetric response on imaging were compared between baseline and six-months post-procedure using paired sample t-tests.

RESULTS

During the study period, 92.1% (n = 35/38) of patients underwent UAE for the management of symptomatic fibroids and 7.9% (n = 3/38) for adenomyosis. All (n = 38/38) were considered technically successful and one minor adverse event occurred (2.7%). Self-reported symptom-severity scores at six-months post-procedure decreased in all categories: abnormal uterine bleeding from 8.8 to 3.1 (-5.7), pain from 6.7 to 3.2 (-3.5), and bulk symptoms from 2.8 to 1 (-1.8) (p < 0.01). 100% of patients reported satisfaction with outcomes. Among the nine patients with follow-up imaging, there was a mean volumetric decrease of 35.5% (p = 0.109).

CONCLUSIONS

UAE for fibroids and adenomyosis can be performed with high technical success and low complication rates in a low-resource setting like Tanzania, resulting in significant symptom relief for patients. Building capacity for UAE has major public health implications not only for fibroids and adenomyosis, but can help address the region's leading cause of maternal mortality, postpartum hemorrhage.

Contemporary Management of Blunt Liver Trauma: An Analysis of the Trauma Quality Improvement Program Registry (2007-19)

PURPOSE

To evaluate the effectiveness of management strategies for blunt liver injuries in adult patients.

MATERIALS AND METHODS

Patients 18 years and older with blunt liver injuries registered via the Trauma Quality Improvement Program (2007-19) were identified. Management strategies initiated within 24 hours of hospital presentation were classified as non-operative management (NOM), embolization, surgery, or combination therapy. Patients were stratified by injury grade. Linear models estimated each strategy's effect on hospital length of stay (LOS), intensive care unit (ICU) LOS, ventilator dependence, and mortality.

RESULTS

Of 78,127 included patients, 88.7%, 8.7%, 1.8%, and 0.8% of patients received NOM, surgery, embolization, and combination therapy, respectively. Among patients with low- (n = 62,237) and high-grade (n = 15,890) injuries and compared to all other management strategies, NOM was associated with the shortest hospital LOS and ICU LOS. Among patients with low-grade injuries and compared to surgery, embolization was associated with a shorter hospital LOS (9.7 days, P < .001, Cohen's d = .32) and ICU LOS (5.3 days, P < .001, Cohen's d = .36). Among patients with high-grade injuries and compared to surgery, embolization was associated with a shorter ICU LOS (6.0 days, P < .01, Cohen's d = .24). Among patients with low- and high-grade injuries and compared to embolization, surgery was associated with higher odds of mortality (P < .001).

CONCLUSIONS

Among patients presenting with blunt liver injuries and compared to surgery, embolization was associated with a shorter ICU LOS and lower risk of mortality.

Patient Radiation Doses in IR Procedures: The American College of Radiology Dose Index Registry-Fluoroscopy Pilot

PURPOSE

To update normative data on fluoroscopy dose indices in the United States for the first time since the Radiation Doses in Interventional Radiology study in the late 1990s.

MATERIALS AND METHODS

The Dose Index Registry-Fluoroscopy pilot study collected data from March 2018 through December 2019, with 50 fluoroscopes from 10 sites submitting data. Primary radiation dose indices including fluoroscopy time (FT), cumulative air kerma (Ka,r), and kerma area product (PKA) were collected for interventional radiology fluoroscopically guided interventional (FGI) procedures. Clinical facility procedure names were mapped to the American College of Radiology (ACR) common procedure lexicon. Distribution parameters including the 10th, 25th, 50th, 75th, 95th, and 99th percentiles were computed.

RESULTS

Dose indices were collected for 70,377 FGI procedures, with 50,501 ultimately eligible for analysis. Distribution parameters are reported for 100 ACR Common IDs. FT in minutes, Ka,r in mGy, and PKA in Gy-cm2 are reported in this study as (n; median) for select ACR Common IDs: inferior vena cava filter insertion (1,726; FT: 2.9; Ka,r: 55.8; PKA: 14.19); inferior vena cava filter removal (464; FT: 5.7; Ka,r: 178.6; PKA: 34.73); nephrostomy placement (2,037; FT: 4.1; Ka,r: 39.2; PKA: 6.61); percutaneous biliary drainage (952; FT: 12.4; Ka,r: 160.5; PKA: 21.32); gastrostomy placement (1,643; FT: 3.2; Ka,r: 29.1; PKA: 7.29); and transjugular intrahepatic portosystemic shunt placement (327; FT: 34.8; Ka,r: 813.0; PKA: 181.47).

CONCLUSIONS

The ACR DIR-Fluoro pilot has provided state-of-the-practice statistics for radiation dose indices from IR FGI procedures. These data can be used to prioritize procedures for radiation optimization, as demonstrated in this work.

Fostering an inclusive workplace for LGBTQIA + people in radiology and radiation oncology

The inclusion and celebration of LGBTQIA+ staff in radiology and radiation oncology departments is crucial in developing a diverse and thriving workplace. Despite the substantial social change in Australia, LGBTQIA+ people still experience harassment and exclusion, negatively impacting their well-being and workplace productivity. We need to be proactive in creating policies that are properly implemented and translate to a safe and inclusive space for marginalised groups. In this work, we outline the role we all can play in creating inclusive environments, for both individuals and leaders working in radiology and radiation oncology. We can learn how to avoid normative assumptions about gender and sexuality, respect people's identities and speak out against witnessed discrimination or slights. Robust policies are needed to protect LGBTQIA+ members from discrimination and provide equal access across other pertinent parts of work life such as leave entitlements, representation in data collection and safe bathroom access. We all deserve to feel safe and respected at work and further effort is needed to ensure this extends to LGBTQIA+ staff in the radiology and radiation oncology workforces.

Patient Radiation Doses in Interventional Radiology Procedures: Comparison of fluoroscopy dose indices from the American College of Radiology Dose Index Registry-Fluoroscopy (DIR-Fluoro) Pilot to the RAD-IR study

PURPOSE

To compare interventional radiology fluoroscopically-guided intervention (FGI) radiation dose index distributions from the American College of Radiology (ACR) Fluoroscopy Dose Index Registry (DIR-Fluoro) pilot to the Radiation Doses in Interventional Radiology (RAD-IR) study.

MATERIALS AND METHODS

Individual and grouped ACR Common IDs (procedure types) from the DIR-Fluoro pilot were matched to procedure types in the RAD-IR study. Fifteen comparisons were made. Distribution parameters including the 10^th, 25^th, 50^th, 75^th, and 95^th percentiles were compared for fluoroscopy time (FT), cumulative air kerma (K_a,r), and kerma area product (P_KA). Two derived indices were computed using median dose indices. The procedure-averaged reference air kerma rate (K_a,r¯) was computed as K_a,r / FT. The procedure-averaged X-ray field size at the reference point (A_r¯) was computed as P_KA / (K_a,r * 1,000).

RESULTS

Median FT was equally likely to be higher or lower in the DIR-Fluoro pilot compared to RAD-IR, while maximum FT was almost twice as likely to be higher in DIR-Fluoro than RAD-IR. Median K_a,r was lower in the DIR-Fluoro pilot for all procedures, as was median P_KA. The maximum K_a,r and P_KA were more often higher in the DIR-Fluoro pilot compared to RAD-IR. K_a,r¯ followed the same pattern as K_a,r, while A_r¯ was often greater in DIR-Fluoro.

CONCLUSIONS

Median dose indices have decreased since the RAD-IR study. Typical K_a,r rates are lower, a result of the use of lower default dose rates. However, opportunities for quality improvement exist, including a renewed focus on tight collimation of the imaging field of view.

A Fusion NLP Model for the Inference of Standardized Thyroid Nodule Malignancy Scores from Radiology Report Text

Radiology reports are a rich resource for advancing deep learning applications for medical images, facilitating the generation of large-scale annotated image databases. Although the ambiguity and subtlety of natural language poses a significant challenge to information extraction from radiology reports. Thyroid Imaging Reporting and Data Systems (TI-RADS) has been proposed as a system to standardize ultrasound imaging reports for thyroid cancer screening and diagnosis, through the implementation of structured templates and a standardized thyroid nodule malignancy risk scoring system; however there remains significant variation in radiologist practice when it comes to diagnostic thyroid ultrasound interpretation and reporting. In this work, we propose a computerized approach using a contextual embedding and fusion strategy for the large-scale inference of TI-RADS final assessment categories from narrative ultrasound (US) reports. The proposed model has achieved high accuracy on an internal data set, and high performance scores on an external validation dataset.

Balancing the Scales: An Analysis of Social Determinants of Health, Radiology Report Acuity, and Radiology Staffing Models in an Academic Health System

PURPOSE

Social determinants of health, including race and insurance status, contribute to patient outcomes. In academic health systems, care is provided by a mix of trainees and faculty members. The optimal staffing ratio of trainees to faculty members (T/F) in radiology is unknown but may be related to the complexity of patients requiring care. Hospital characteristics, patient demographics, and radiology report findings may serve as markers of risk for poor outcomes because of patient complexity.

METHODS

Descriptive characteristics of each hospital in an urban five-hospital academic health system, including payer distribution and race, were collected. Radiology department T/F ratios were calculated. A natural language processing model was used to classify multimodal report findings into nonacute, acute, and critical, with report acuity calculated as the fraction of acute and critical findings. Patient race, payer type, T/F ratio, and report acuity score for hospital 1, a safety net hospital, were compared with these factors for hospitals 2 to 5.

RESULTS

The fraction of patients at hospital 1 who are Black (79%) and have Medicaid insurance (28%) is significantly higher than at hospitals 2 to 5 (P < .0001), with the exception of hospital 3 (80.1% black). The T/F ratio of 1.37 at hospital 1 as well as its report acuity (28.9%) were significantly higher (P < .0001 for both).

CONCLUSIONS

T/F ratio and report acuity are highest at hospital 1, which serves the most at-risk patient population. This suggests a potential overreliance on trainees at a site whose patients may require the greatest expertise to optimize care.

Challenges of Implementing Artificial Intelligence in Interventional Radiology

Artificial intelligence (AI) and deep learning (DL) remains a hot topic in medicine. DL is a subcategory of machine learning that takes advantage of multiple layers of interconnected neurons capable of analyzing immense amounts of data and "learning" patterns and offering predictions. It appears to be poised to fundamentally transform and help advance the field of diagnostic radiology, as heralded by numerous published use cases and number of FDA-cleared products. On the other hand, while multiple publications have touched upon many great hypothetical use cases of AI in interventional radiology (IR), the actual implementation of AI in IR clinical practice has been slow compared with the diagnostic world. In this article, we set out to examine a few challenges contributing to this scarcity of AI applications in IR, including inherent specialty challenges, regulatory hurdles, intellectual property, raising capital, and ethics. Owing to the complexities involved in implementing AI in IR, it is likely that IR will be one of the late beneficiaries of AI. In the meantime, it would be worthwhile to continuously engage in defining clinically relevant use cases and focus our limited resources on those that would benefit our patients the most.

Management of Splenic Trauma in Contemporary Clinical Practice: A National Trauma Data Bank Study

BACKGROUND

To evaluate the utilization and efficacy of various treatments for management of adult patients with splenic trauma, highlighting the evolving role of splenic artery embolization.

MATERIALS AND METHODS

The National Trauma Data Bank (NTDB) was queried for patients who sustained splenic trauma between 2007 and 2015, excluding those with death on arrival and selected nonsplenic high-grade injuries. Patients were categorized into (1) nonoperative management (NOM), (2) embolization, (3) splenectomy, (4) splenic repair, and (5) combined treatment groups. Evaluated outcomes included hospital length of stay (LOS), intensive care unit LOS, mortality, and NOM and embolization failures.

RESULTS

Overall, 117,743 patients with splenic predominant trauma were included in this study. Over the 9-year study period, 85,793 (72.9%) were treated with NOM, 21,999 (18.9%) with splenectomy, 3895 (3.3%) with embolization, and 2131 (1.8%) with splenic repair. From 2007 to 2015, mortality rates declined from 7.6% to 4.7%. The rate of NOM did not significantly change over time, while embolization increased 369% (1.3%-4.8%). Failure of NOM was 4.4% in 2007 and decreased to 3.4% in 2015. Across all injury grades, NOM had the shortest LOS (8.3 days), followed by splenic repair (12.3), embolization (12.6), and splenectomy (13.8) (p < 0.001). When adjusted for various clinical factors including severity of splenic injury, mortality rates were 7.1% for splenectomy, 3.2% for embolization, and 2.5% for NOM.

CONCLUSION

Most patients with splenic-dominant blunt trauma are managed with NOM. Over time, the use of embolization has increased while open surgery has declined, and mortality has improved for all treatment methods. Compared to splenectomy, embolization is associated with shorter hospital LOS but is still used relatively infrequently.

Comparing the Safety and Cost of Image-Guided Percutaneous Gastrostomy Tube Placement in the Outpatient Versus Overnight Observation Setting in a Single-Center Retrospective Study

RATIONALE AND OBJECTIVES

Historically, patients undergoing image-guided percutaneous gastrostomy tube placement have been admitted overnight with feeds commencing 12-24 hours postprocedure. With new expedited feeding protocols starting 3-4 hours postprocedure, same-day discharge is now possible. The purpose of this study was to evaluate the safety and cost of image-guided percutaneous gastrostomy tube placement as an outpatient procedure.

MATERIALS AND METHODS

In this retrospective study, 131 patients (age 63.9 ± 11.6; 34% female) underwent gastrostomy tube placement as an outpatient procedure with expedited feeding protocol versus 40 patients (age 61.3 ± 12.6; 38% female) who were hospitalized overnight with feeds starting at 12-24 hours, primarily based on operator preference. The two groups were compared regarding complications within 90 days of procedure. Using a subgroup of 33 consecutive patients, procedural costs (total combined insurer and patient payments for professional and hospital services) for outpatients vs. hospitalized patients were compared.

RESULTS

Complication rates were similar (p = 0.64) for gastrostomy tubes placed on outpatients (0.17 complications/procedure: 4 bleeding, 2 aspiration pneumonia, 1 abdominal abscess, 4 significant pain, 6 cellulitis, 1 surgical consult, 4 malpositioned/fractured tubes) and hospitalized patients (0.20 complications/procedure: 1 aspiration pneumonia, 1 significant pain, 3 cellulitis, 1 surgical consult, 2 fractured tubes). Total combined insurer and patient payments were similar ($2193/outpatient vs $2701/hospitalized patient; p= 0.52).

CONCLUSION

Outpatient image-guided percutaneous gastrostomy tube placement with an expedited feeding protocol is a safe and cost-comparable alternative to historic overnight hospitalization. Further prospective investigation with a larger sample is warranted.

Same day yttrium-90 radioembolization with single photon emission computed tomography/computed tomography: An opportunity to improve care during the COVID-19 pandemic and beyond

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has made it more challenging for patients to undergo yttrium-90 (Y-90) radioembolization (RE). Same day Y-90 RE provides an opportunity to minimize logistical challenges and infection risk associated with COVID-19, thus improving patient access.

AIM

To describe the use of same day Y-90 RE with routine single photon emission computed tomography/computed tomography (SPECT/CT) in order to optimize therapy.

METHODS

All patients were selected for Y-90 RE through a multidisciplinary tumor board, and were screened and tested for COVID-19 infection per institutional protocol. A same day procedure was developed, consisting of angiography, imaging, and Y-90 resin particle delivery. Routine SPECT/CT after technetium-99m macroaggregated albumin (Tc-99m MAA) administration was performed for assessment of arterial supply, personalized dosimetry, and extrahepatic activity. Post-treatment Y-90 bremsstrahlung SPECT/CT was performed for confirmation of particle delivery, by utilization of energy windowing to limit signal from previously administered Tc-99m MAA particles.

RESULTS

A total of 14 patients underwent same day Y-90 RE between March and June 2020. Mean lung shunt fraction was 6.13% (range 3.5%-13.1%). Y-90 RE was performed for a single lesion in 7 patients, while the remaining 7 patients had treatment of multifocal lesions. The largest lesion measured 8.3 cm. All patients tolerated the procedure well and were discharged the same day.

CONCLUSION

Same day Y-90 RE with resin-based microspheres is feasible, and provides an opportunity to mitigate infection risk and logistical challenges associated with the COVID-19 pandemic and beyond. We recommend consideration of SPECT/CT, especially among patients with complex malignancies, for the potential to improve outcomes and eligibility of patients to undergo same day Y-90 RE.

Uterine Artery Embolization for Secondary Postpartum Hemorrhage

Postpartum hemorrhage (PPH) affects approximately 14 million women yearly, accounts for 25% of delivery-related deaths in the world and is the main cause of emergency peripartum hysterectomy. Traditionally, PPH is defined as at least 500 mL of blood loss after vaginal delivery or 1000 mL of blood loss after cesarean-section. However, several authors have suggested a simpler definition to include women who experience hemodynamic instability after birth regardless of amount of blood loss. Secondary PPH is defined as bleeding that occurs after 24 hours to 12 weeks from delivery, and can fail medical management. It is imperative that the clinical team recognize the signs and symptoms of secondary PPH and, if necessary, consult the interventional radiology service for a minimally invasive option of uterine artery embolization, which has shown up to 95% success rate.

Contemporary Management of Pediatric Blunt Splenic Trauma: A National Trauma Databank Analysis

PURPOSE

To quantify changes in the management of pediatric patients with isolated splenic injury from 2007 to 2015.

MATERIALS AND METHODS

Patients under 18 years old with registered splenic injury in the National Trauma Data Bank (2007-2015) were identified. Splenic injuries were categorized into 5 management types: nonoperative management (NOM), embolization, splenic repair, splenectomy, or a combination therapy. Linear mixed models accounting for confounding variables were used to examine the direct impact of management on length of stay (LOS), intensive care unit (ICU) days, and ventilator days.

RESULTS

Of included patients (n = 24,128), 90.3% (n = 21,789), 5.6% (n = 1,361), and 2.7% (n = 640) had NOM, splenectomy, and embolization, respectively. From 2007 to 2015, the rate of embolization increased from 1.5% to 3.5%, and the rate of splenectomy decreased from 6.9% to 4.4%. Combining injury grades, NOM was associated with the shortest LOS (5.1 days), ICU days (1.9 days), and ventilator days (0.5 day). Moreover, splenectomy was associated with longer LOS (10.1 days), ICU days (4.5 days), and ventilator days (2.1 days) than NOM. The average failure rate of NOM was 1.5% (180 failures/12,378 cases). Average embolization failure was 1.3% (6 failures/456 cases). Splenic artery embolization was associated with lower mortality than splenectomy (OR: 0.10, P <.001). No statistically significant difference was observed in mortality between embolization and NOM (OR: 0.96, P = 1.0).

CONCLUSIONS

In pediatric splenic injury, NOM is the most utilized and associated with favorable outcomes, most notably in grades III to V pediatric splenic injury. If intervention is needed, embolization is effective and increasingly utilized most significantly in lower grade injuries.

Additional Magnetic Resonance or Nuclear Scintigraphy Imaging Influences Approach to Vertebral Augmentation: A Single Institution Experience

STUDY DESIGN

Retrospective review.

OBJECTIVE

To ascertain impact of preprocedural magnetic resonance imaging (MRI) or nuclear medicine Tc99m-DMP scintigraphy on the treatment plan when compared with plain films and/or computed tomography prior to vertebral augmentation procedures.

SUMMARY OF BACKGROUND DATA

Over 1 million vertebral compression fractures (VCFs) occur in the United States annually with over 150,000 individuals hospitalized each year. Physical examination and history are essential to the workup of VCFs, but imaging remains necessary for confirming the diagnosis. VCFs can be imaged with various modalities and there is limited data on the comparative effectiveness of different imaging modalities.

METHODS

Six hundred fifty consecutive patients treated with vertebral augmentation at a single institution between May of 2013 and April of 2018 were reviewed. Preprocedure imaging of the spine obtained within 30 days prior to the procedure were reviewed. Preprocedure imaging results were cross-referenced against the levels treated by vertebral augmentation to determine whether there was a change in the levels treated after receiving an MRI or NM imaging study.

RESULTS

Three hundred sixty-three patients had adequate imaging for inclusion. One hundred fifty-four of these 363 patients (42.4%) had an alteration of their treatment plan based upon the MR or NM imaging. Fewer vertebral levels were treated in 33, different levels were treated in 41, and more levels were treated in 80 patients.

CONCLUSION

MRI or nuclear medicine bone scan imaging prior to vertebral augmentation altered the location and number of levels treated in a large percentage of patients, adding specificity to treatment over findings on radiographs or computed tomography alone.

LEVEL OF EVIDENCE

3.

Meta-analysis of Intraprocedural Comparative Effectiveness of Vascular Plugs Vs Coils in Proximal Splenic Artery Embolization and Associated Patient Radiation Exposure

PURPOSE

To compare vascular plugs to coil embolization of the proximal splenic artery and evaluate differences in radiation exposure to the patients.

METHODS

An electronic literature search was performed for relevant studies from January 2000 to July 2018 that compared the efficacy of vascular plugs vs coils in splenic artery embolization. Only studies that investigated coil or vascular plug use, without combination with other embolic agents, were included. Meta-analysis was performed using a fixed effects model approach with the inverse variance-weighted average method to determine pooled differences in time to vessel occlusion, procedure time, fluoroscopy time, total number of devices used, and radiation exposure. Heterogeneity was assessed using the I square statistic. Pooled outcomes were compared, and quality assessments were evaluated using the Newcastle Ottawa Scale.

RESULTS

Eight studies met inclusion criteria. 81 patients were embolized with vascular plugs and 52 patients with coils only. The most common indication for splenic artery embolization was trauma. Time to vessel occlusion was shorter in the vascular plug group by 7.11 minutes (P = 0.003). Fluoroscopy time was shorter by 13.82 minutes in the vascular plug cohort, and these patients received less radiation (-439 mGy) compared to the coil group (P = 0.006 and P = 0.02, respectively). The number of devices was significantly fewer in the vascular plug group (-3.54; P < 0.001). Procedure time was not statistically significant.

CONCLUSION

Our data supports the vascular plug is superior to coils for embolization of the proximal splenic artery with respect to occlusion time, fluoroscopy time, patient radiation exposure, and number occlusive devices used.

Invasive Procedural Treatments for Symptomatic Uterine Fibroids: A Cost Analysis

PURPOSE

The aim of this study was to evaluate the contemporary use of procedural interventions to treat symptomatic uterine fibroids and assess associated health care system costs.

METHODS

Using the IBM Watson MarketScan Commercial Claims and Encounters database for 2009 to 2015 and relevant International Classification of Diseases diagnosis codes, women aged 18 to 55 years with clinically significant uterine fibroids were identified. Using Current Procedural Terminology codes, relevant procedural interventions were identified (hysterectomy, endometrial ablation, myomectomy, and uterine fibroid embolization [UFE]). Costs were defined as total actual payments by insurers and patients (per procedure and per episode of care) and were adjusted and compared using generalized linear models.

RESULTS

Of 241,757 invasive procedures for fibroids, hysterectomy was most common (76.5%), followed by endometrial ablation (14.5%), myomectomy (4.7%), and UFE (4.3%). Hysterectomy was more common in older women and those in rural areas (65.2% of patients <40 years of age, 77.6% of those 40-49 years of age, and 83.6% of those 50-55 years of age; 83.9% of patients outside versus 75.3% within metropolitan statistical areas). Per procedure, adjusted mean costs were $3,188 (95% confidence interval [CI], $3,114-$3,264) for hysterectomy, $2,781 (95% CI, $2,695-$2,870) for ablation, $4,436 (95% CI, $4,256-$4,623) for myomectomy, and $6,161 (95% CI, $5,736-$6,617) for UFE. Adjusted mean costs for entire episodes of care were $14,676 (95% CI, $14,496-$14,858) for hysterectomy, $6,702 (95% CI, $6,534-$6,875) for endometrial ablation, $14,791 (95% CI, $14,465-$15,125) for myomectomy, and $13,873 (95% CI, $13,182-$14,599) for UFE.

CONCLUSIONS

Of invasive procedures for symptomatic uterine fibroids, hysterectomy was used more frequently than endometrial ablation, myomectomy, and UFE combined. Per procedure and per episode, ablation was least costly. Costs per episode were similar for hysterectomy, myomectomy, and UFE.

Impact of Genomic Mutation and Timing of Y90 Radioembolization in Colorectal Liver Metastases

PURPOSE

To investigate timing of Yttrium-90 radioembolization (Y90) during treatment course, genomics, and other clinical factors as predictors of overall survival (OS) in colorectal liver metastasis (CRLM) that have progressed on at least one line of chemotherapy.

MATERIALS AND METHODS

This was a retrospective study from 2013 to 2018 of patients with CRLM and genomic analysis prior to Y90 at a multihospital tertiary referral center. OS from liver metastasis diagnosis and predictors of OS were analyzed using Kaplan-Meier estimation with log-rank and Cox regression analyses.

RESULTS

Overall, 58 patients with CRLM who progressed on at least one line of chemotherapy who had genomic analysis prior to Y90 were identified. Median OS after hepatic metastasis was 29.9 months. Of these, 16 (28%) patients received Y90 after failure of the first-line systemic chemotherapy. There was significantly prolonged OS in patients receiving Y90 immediately following failure of the first-line chemotherapy folinic acid, fluorouracil, oxaliplatin ((FOLFOX) ± bevacizumab) versus following multiple lines of chemotherapy (median OS of 46.3 vs. 26.6 months, P = 0.005). The presence of genetic mutation in tumor, MAPK pathway wild type, left-sided primary tumor, low MELD score, and non-diffuse unilobar disease were also found to be predictors prolonged survival on log-rank analysis (P's < 0.05). On multivariate analysis, receiving Y90 after failure of the first line of chemotherapy, low baseline MELD score, and baseline ECOG performance score of 0 were all found to be independent predictors of prolonged OS from the time of metastatic disease diagnosis (P's < 0.05).

CONCLUSION

In patients with CRLM, receiving Y90 after failing the first line of chemotherapy, lack of genetic mutation, low MELD score, and lower tumor burden appear to be independent predictors of prolonged OS.

LEVEL OF EVIDENCE

Level 4, case-control study.

Predictors of Survival after Yttrium-90 Radioembolization of Chemotherapy-Refractory Hepatic Metastases from Breast Cancer

PURPOSE

To determine predictors of survival after transarterial radioembolization of hepatic metastases from breast cancer.

MATERIALS AND METHODS

Twenty-four patients with chemotherapy-refractory hepatic metastases from breast cancer who underwent radioembolization from 2013 to 2018 were evaluated based on various demographic and clinical factors before and after treatment. Overall survival (OS) was estimated by Kaplan-Meier method. Log-rank analysis was performed to determine predictors of prolonged OS from the time of first radioembolization and first hepatic metastasis diagnosis.

RESULTS

Median OS times were 35.4 and 48.6 months from first radioembolization and time of hepatic metastasis diagnosis, respectively. Radioembolization within 6 months of hepatic metastasis diagnosis was a positive predictor of survival from first radioembolization, with median OS of 38.9 months vs 22.1 months for others (P = .033). Estrogen receptor (ER)-positive status predicted prolonged survival (38.6 months for ER⁺ vs 5.4 months for ER^-; P = .005). The presence of abdominal pain predicted poor median OS: 12.8 months vs 38.6 months for others (P < .001). The presence of ascites was also a negative predictor of OS (1.7 months vs 35.4 months for others; P = .037), as was treatment-related grade ≥ 2 toxicity at 3 months (5.4 months vs 38.6 months for others; P = .017).

CONCLUSIONS

In patients with metastatic breast cancer, radioembolization within 6 months of hepatic metastasis diagnosis and ER⁺ status appear to be positive predictors of prolonged survival. Conversely, baseline abdominal pain, baseline ascites, and treatment-related grade ≥ 2 toxicity at 3 months after treatment appear to be negative predictors of OS.

Contemporary Management of Hepatic Trauma: What IRs Need to Know

Trauma remains one of the leading causes of death in the United States in patients younger than 45 years. Blunt trauma is most commonly a result of high-speed motor vehicular collisions or high-level fall. The liver and spleen are the most commonly injured organs, with the liver being the most commonly injured organ in adults and the spleen being the most affected in pediatric blunt trauma. Liver injuries incur a high level of morbidity and mortality mostly secondary to hemorrhage. Over the past 20 years, angiographic intervention has become a mainstay of treatment of hepatic trauma. As there is an increasing need for the interventional radiologists to embolize active hemorrhage in the setting of blunt and penetrating hepatic trauma, this article aims to review the current level of evidence and contemporary management of hepatic trauma from the perspective of interventional radiologists. Embolization techniques and associated outcome and complications are also reviewed.

Predictors of Overall and Progression-Free Survival in Patients with Ocular Melanoma Metastatic to the Liver Undergoing Y90 Radioembolization

PURPOSE

To investigate predictors of overall survival (OS) and progression-free survival (PFS) in patients with ocular melanoma metastatic to the liver undergoing yttrium-90 (Y90) radioembolization, including the effect of concurrent immunotherapy.

METHODS

An IRB-approved retrospective review of 24 patients with ocular melanoma metastatic to the liver who underwent Y-90 treatment between June 2003 and January 2018 was performed. Data regarding patients' performance status at the time of Y90, intra-/extrahepatic tumor burden, and treatment response were evaluated. RECIST was used to determine objective tumor response. Kaplan-Meier analysis was used to calculate OS and PFS from the first Y90 therapy. Log-rank analysis was used to determine predictors of prolonged OS and PFS.

RESULTS

Median OS from primary diagnosis and diagnosis of liver metastases was 66 months (mo) and 26.3 mo, respectively. Median OS for those who received immunotherapy within 3 months of undergoing Y90 was prolonged at 26.0 mo versus 9.5 mo for others (p = 0.014). Median OS for patients with an ECOG performance status of 0 was prolonged at 26 mo versus 5.5 mo for others (p = 0.003). Median hepatic PFS was prolonged in patients treated with Y-90 on concurrent immunotherapy at 10.3 mo versus 2.7 mo for TARE only (p = 0.002). Patients with an ECOG performance status of 0 had prolonged PFS (p = 0.002).

CONCLUSIONS

Concurrent immunotherapy and an ECOG performance status of 0 at the time of Y90 therapy appear to be predictors of prolonged OS and PFS in patients with ocular melanoma metastatic to the liver.

Image-Guided Percutaneous Gastrostomy Tube Placement is Safe in Patients Requiring Aspirin 325 mg

RATIONALE AND OBJECTIVES

Requests for gastrostomy tube placement in patients on aspirin (ASA) 325 mg are common, particularly in patients following reconstructive surgery for head and neck cancer, but periprocedural guidelines and recommendations regarding management of high dose aspirin are inconsistent. The purpose of this study was to assess the bleeding risk of percutaneous gastrostomy tube placement in patients on ASA 325 mg.

MATERIALS AND METHODS

This retrospective study of 213 patients who underwent image-guided "push" percutaneous gastrostomy tube placement compared rates of significant bleeding and other secondary outcomes (including all-cause mortality within 30 days, procedure-related mortality, bowel perforation, abdominal abscess, peritonitis, aspiration pneumonia, intraprocedural airway complications, and tube dislodgement) between patients maintained on ASA 325 mg and patients not on antiplatelet or anticoagulation therapy.

RESULTS

No significant bleeding episodes occurred in patients on ASA 325 mg, compared to three episodes in patients not on ASA 325 mg (p = 0.37). A patient in each group had aspiration pneumonia possibly related to tube placement. There were no other notable secondary outcomes, including intraprocedural airway complications in this population with complex head and neck anatomy.

CONCLUSION

These findings suggest that holding ASA 325 mg in patients undergoing percutaneous gastrostomy tube placement is not necessary, especially in patients in whom holding ASA would pose considerable risk. Further multi-institutional longitudinal study is warranted to validate these results.

Postpartum haemorrhage requiring embolisation of a hypertrophied round ligament artery

A gravida 4 para 1021, 41-year-old woman postcaesarean section at 39 weeks and 1 day with clinically significant haemorrhage required embolisation of unique uterine arterial collaterals. She had persistent haemorrhage after initial bilateral uterine artery embolisation, and on further investigation she was found to have a hypertrophied right round ligament artery. Once successful embolisation of this abnormal right round ligament artery was completed using a combination of Gelfoam and coils, haemostasis was achieved. She had rapid clinical improvement, no complications and no further admissions on postprocedural follow-up over a year and a half later.

Systematic Review of Contemporary Evidence for the Management of T1 Renal Cell Carcinoma: What IRs Need to Know for Kidney Cancer Tumor Boards

Renal cell carcinoma is a relatively common malignancy, with 60 to 70 thousand cases a year in the United States alone. Increased utilization of cross-sectional imaging has led to an increase in the number of early renal cell cancers seen by the medical establishment. In addition, certain patient populations have an increased risk of developing kidney cancers which may mandate aggressive screening protocols. This article discusses the epidemiology of renal cell cancers; discusses the current management guidelines from multiple specialty societies; discusses some of the surgical and interventional techniques used in the treatment of such lesions; and provides a review of the literature regarding treatments of early-stage renal cell cancers.

Evaluation of Ki67 and other predictors of survival in metastatic neuroendocrine tumor (NET) to the liver treated with Y90 radioembolization

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Background: Ki67 index is a predictor of survival in patients with metastatic neuroendocrine tumor (NET). The purpose of this study is to evaluate Ki67 index and other potential predictors of overall survival (OS) in patients with NET metastases to the liver treated with Y90 radioembolization. Methods: In an institutional review board-approved retrospective study, consecutive patients with NET metastases to the liver who were treated with Y90 radioembolization from 2013-2018 at a single institution were evaluated. Patients with documented Ki67 index were stratified according to 2017 World Health Organization (WHO) grading based on Ki67 index (G1: < 3%, G2: 3-20%, G3: > 20%). Age, gender, and objective tumor response on post Y90 imaging were also evaluated as potential predictors of survival after Y90. Objective tumor response was evaluated at 1 and/or 3 months post Y90 with multiphase MRI utilizing Response Evaluation Criteria for Solid Tumors (RECIST). Overall survival (OS) from time of Y90 was analyzed using Kaplan-Meier estimation. Predictors of survival were evaluated using log-rank test with p < 0.05 as the statistically significant level. SPSS software v. 25 (IBM Corporation, Armonk, NY) was used for all statistical analysis. Results: A total of 77 patients were identified; 36 (47%) had a documented Ki67 index from either their primary tumor, liver metastasis, or both. Primary tumor site included pancreatic (n = 10), small bowel (n = 7), pulmonary (n = 5), gastric (n = 3), large bowel (n = 3), and renal (n = 1). A primary site was not identified in several patients (n = 7).G1 tumors comprised 31% (n = 11) of patients, while G2 and G3 tumors made up 50% (n = 18) and 19% (n = 7) of the cohort, respectively. Median overall survival (OS) of the entire cohort was 51.1 months. Median OS in patients was 63.0 months in G1 tumors, 51.1 months in G2 tumors, and 3.1 months in G3 tumors (p < 0.001). Objective response on initial MRI follow-up after Y90 radioembolization also predicted prolonged OS (51.2 months versus 17.9 months, p < 0.001). Age at time of diagnosis and gender were not predictors of survival after Y90 radioembolization. Conclusions: WHO grading based on KI67 index and objective tumor response appear to be predictors of prolonged survival in patients with metastatic NET to the liver treated with Y90 radioembolization.

Predictors of survival in chemorefractory colorectal liver metastases treated with Y90 radioembolization

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Background: The aim of the study was to evaluate molecular signatures and timing of yttrium-90 (Y90) as prognostic factors of survival following Y90 radioembolization (RE) in patients with chemorefractory colorectal liver metastases (CRLM). Methods: In a retrospective single-institution study, patients with unresectable, chemorefractory CRLM who had undergone genomic analysis prior to Y90 RE from 2013 to 2018 were identified. Timing of Y90 (following failure of first line vs following multiple lines of chemotherapy) and oncogenic mutation status (MAPK and PI3K pathways) were evaluated as predictors of survival length following Y-90. Survival was measured from first Y90 using Kaplan-Meier estimation and predictors of outcome were identified using log-rank analysis. Results: Overall, 58 patients with chemorefractory CRLM who underwent genomic analysis prior to Y-90 were identified. Of these, 26 (44.8%) had MAPK mutations, and 2 (3.5%) had PI3K mutations. Median survival after first Y-90 RE was 12.9 months. There was significantly prolonged overall survival (OS) in patients receiving Y90 immediately following failure of the first line of chemotherapy (FOLFOX ± bevacizumab) versus patients who underwent multiple lines of chemotherapy prior to Y90 (median OS of 16.9 vs 11.4 months for others; p = 0.023). When stratifying the cohort based on the timing of Y90, patients with WT-MAPK (n = 8) had prolonged OS if they underwent Y-90 following failure of the first line of chemotherapy (median OS of 22.3 vs 12.9 mo; p = 0.019). Patients with WT-PI3K (n = 19) had prolonged OS if they underwent Y90 following failure of the first line of chemotherapy (median OS of 16.9 vs 12 mo; p = 0.037). When analyzing the entire cohort non-stratified by timing of Y90, genetic mutation was not found to be a predictor of prolonged OS. Conclusions: Y90 RE after failure of first line of chemotherapy in CRLM appears to confer prolonged survival specifically for WT-MAPK and WT-PI3K oncogenes. Conversely, the prognosis of more favorable genetic status appears to be negated if Y90 RE is performed after failure of second or third line chemotherapies.