Evaluation of the Benefit of Extended Catheter-Directed Thrombolysis with Serial Angiography for Acute Pulmonary Embolism

PurposeTo evaluate whether extended catheter-directed thrombolysis (CDT) with repeat visits to the angiography suite provide added benefit in treatment of acute pulmonary embolism (PE).Materials and MethodsThis was a retrospective review of CDT procedures performed for acute PE in 156 patients (age 56.1 y ± 15.3, 46.2% women) between 2009 and 2019. All patients underwent at least 1 follow-up visit to the angiography suite for evaluation of pulmonary artery pressure (PAP) and thrombus burden (Miller score) before termination (111/156, 71.2%) or continuation of CDT (45/156, 28.8%).ResultsPatients who had CDT extended beyond the first follow-up visit required a higher total dose of tissue plasminogen activator (40.7 mg ± 14.3 vs 22.6 mg ± 9.9, P < .001) to achieve a similar final Miller score (6.4 ± 3.8 vs 7.6 ± 3.9, P = .1) and a similar reduction in systolic PAP (?14.4 mm Hg ± 10.2 vs ?12.6 mm Hg ± 11.9, P = .6). The initial Miller scores were similar in both groups (19.7 ± 5.8 vs 19 ± 4, P = .4) but were significantly higher during the first follow-up visit (after 18 hours ± 5.5 vs 20 hours ± 4.8, P = .06) in patients requiring multiple follow-up visits (12.2 ± 5 vs 7.6 ± 3.9, P < .001). Multiple regression analyses identified heart rate > 100 beats/min and systolic PAP > 55 mm Hg as associated with the need for extended CDT. Extended CDT did not result in a higher hemorrhagic complication rate (1/45 vs 6/111, P = .7).ConclusionsPatients presenting with higher heart rates and systolic PAP may benefit from extended CDT to achieve similar reductions in PAP and thrombus burden, without clear added risk of hemorrhage.     

Benchmark Status of Women Interventional Radiologists in China

PurposeTo evaluate the current status of women interventional radiologists in China and discuss possible measures to boost their representation in this male-dominated field for a more diverse workplace environment in the future.Materials and MethodsThe list of Chinese interventional radiologists obtained from the Chinese College of Interventionalists was retrospectively reviewed. Key information was extracted from the database, including sex, chronologic trends of representation of women interventional radiologists, position, education level, geographic distribution, interventional radiology (IR) practice time, departmental affiliation, and hospital classification.ResultsOf the 13,855 entries, 7,324 (52.9%) were interventional radiologists having valid information. Among them, 684 (9.3%) were identified as women. The number of women interventional radiologists has continued to increase since the first woman registered in 1992. The average age of women interventional radiologists was 39.1 years ± 5.7 (range, 26–50). The majority of them were attending physicians (n = 280; 40.9%) with a bachelor’s degree (n = 363; 53.1%). Most women interventional radiologists (n = 215, 31.4%) joined this specialty 5–9 years after becoming physicians, whereas 128 (18.7%) started practicing IR from the very beginning. A total of 42.4% of women interventional radiologists were from the departments of IR and cardiology.ConclusionsAlthough the total number shows an upward trend, women interventional radiologists are still underrepresented. Education level, geographic areas, and other socioeconomic factors may simultaneously influence the population size of women interventional radiologists in China.     

Safety and Efficacy of Peripheral Embolization with EASYX Liquid Embolic Agent: A Multicenter Prospective Study

PurposeTo evaluate the clinical safety and efficacy of EASYX, a new nonadhesive precipitating liquid embolic agent based on a polyvinyl alcohol ether polymer labeled with iodine molecules, for peripheral embolization.Materials and MethodsThis open-label prospective multicenter study was conducted on 50 consecutive patients treated with embolization using EASYX in 3 academic hospitals from April 2018 to July 2019. Indications for embolization were symptomatic varicocele (n = 15), type II endoleak (n = 8), acute hemorrhage (n = 16), portal vein embolization (PVE; n = 9), or angiomyolipoma (AML; n = 2). Patient characteristics, technical and clinical success rates, pain at injection, and satisfaction of the interventional radiologists were assessed. Follow-up imaging was performed using ultrasound for varicoceles (at 1 month) and computed tomography (CT) for the other indications (at 3 or 6 months).ResultsThe immediate technical success rate was 98%. The clinical success rates were 100% for acute hemorrhage and type II endoleaks, 89% for PVE, 86% for varicoceles, and 50% for AMLs. Patients who underwent PVE showed significant hypertrophy of the future liver remnant at follow-up (P < .001), and 55.6% of patients proceeded to hepatectomy. The absence of artifacts on imaging allowed improved monitoring of the aneurysmal sac in patients with type II endoleaks. The satisfaction rate of the interventional radiologists was >90% for 5 of 7 items.ConclusionsEASYX as a novel copolymer liquid embolic agent was safe and efficient for peripheral embolization. The absence of tantalum allowed reduced CT artifacts on imaging follow-up, which was especially useful in patients with type II endoleaks.     

Prostatic Artery Embolization Using 100–300-μm Trisacryl Gelatin Microspheres to Treat Lower Urinary Tract Symptoms Attributable to Benign Prostatic Hyperplasia: A Single-Center Outcomes Analysis with Medium-Term Follow-up

PurposeTo report medium-term outcomes of prostatic artery embolization (PAE) using 100–300-μm trisacryl gelatin microspheres to treat lower urinary tract symptoms (LUTS) from benign prostatic hyperplasia (BPH) and to evaluate how cone-beam computed tomography-measured prostate gland volume (PGV), median lobe enlargement (MLE), age, and Charlson Comorbidity Index (CCI) affect these results.Materials and MethodsSeventy-four consecutive patients who underwent PAE from April 2014 through August 2018 were retrospectively reviewed. Patients had International Prostate Symptom Score (IPSS) >12, Quality of Life (QoL) score >2, prostate gland volume (PGV) >40 mL, age older than 45 years, and medical therapy failure. Twelve patients were excluded for bladder pathology or prostate cancer. Patients (n = 62, age = 71.8 ± 9.3 years, CCI = 3.5 ± 1.7, PGV = 174 ± 110 mL) had pre-procedure IPSS = 22.4 ± 5.6, QoL score = 4.4 ± 0.9, and post-void residual (PVR) = 172 ± 144 mL. Post-procedure values were compared to baseline at 1, 3, 6, 12, and 24 months. Associations between outcomes and PGV, MLE, age, and CCI were evaluated. Adverse event recording used Clavien-Dindo classification.ResultsOne month after PAE (n = 37), IPSS improved to 7.6 ± 5.2 (P < .0001) and QoL score improved to 1.7 ± 1.4 (P < .0001). At 3 months (n = 32), improvements continued, with IPSS = 6.4 ± 5.1 (P < .0001), QoL score = 1.2 ± 1.2 (P < .0001), PVR = 53 ± 41 mL (P < .001), and PGV = 73 ± 38 mL (P < .0001). Results were sustained at 6 months (n = 35): IPSS = 6.4 ± 4.1 (P < .0001), QoL score = 1.2 ± 1.2 (P < .0001), PVR = 68 ± 80 mL (P < .0001), PGV = 60 ± 19 mL (P < .001). At 12 months, patients (n = 26) had IPSS = 7.3 ± 5.5 (P < .0001), QoL score = 1.2 ± 0.8 (P <.0001), PVR = 89 ± 117 mL (P < .0001), PGV = 60 ± 48 mL (P < .01). At 24 months, patients (n = 8) had IPSS = 8.0 ± 5.4 (P < .0001), QoL score = 0.7 ± 0.5 (P < .0001), PVR = 91 ± 99mL (P = 0.17), and PGV = 30 ± 5mL (P = .11). Improvements were independent of PGV, MLE, age, and CCI. Two grade II urinary infections occurred.ConclusionsPAE with 100–300-μm microspheres produced sustained substantial improvements in LUTS, PGV, and PVR, which were independent of baseline PGV, MLE, age, or CCI.     

Intranodal Lymphangiography and Embolization for the Treatment of Early Postoperative Lymphatic Leaks after Pelvic Surgery

PurposeTo assess outcome and predictors of outcome after lymphatic embolization (LE) for early postoperative lymphatic leak after pelvic surgery.Material and MethodsLymphangiography (LG) procedures performed between May 2015 and February 2020 for postoperative intraperitoneal lymphatic leaks after pelvic surgery were reviewed. Treatment indication was lymphatic drainage of >500 mL/d persisting for >1 week. LE was performed by injecting glue into the iliac lymph node. Fisher exact and Wilcoxon rank-sum tests were used for comparative analysis, and logistic regression was used to assess predictors of outcome.ResultsLG was performed in 71 patients. A leak was demonstrated in 69 patients who underwent LE. The mean drainage was 1,329 mL/d ± 773. Catheters were removed in 49 (69.0%) patients after 1 procedure and in 69 (97.2%) patients after a mean of 1.3 procedures. The mean drainage at the time of catheter removal was 157 mL/d ± 100. Failure occurred in 12 (16.9%) cases, including 2 (2.8%) cases of unsuccessful catheter removal and 10 (14.1%) cases of catheter reinsertion owing to recurrent ascites (n = 3) and lymphoceles (n = 7). Older age and drainage of >1,500 mL/d were associated with failure (P = .004). Drainage of >1,500 mL/d was associated with a post-LE catheter dwell time of longer than 1 week (P = .024). Minor adverse events were noted in 4 (5.6%) patients who presented with transient leg swelling.ConclusionsLE was effective for treating pelvic surgery-related lymphatic leaks. Reintervention may be required. Drainage of >1,500 mL/d was associated with clinical failure and a post-LE catheter dwell time of longer than 1 week.     

Percutaneous Access of the Modified Hutson Loop for Retrograde Cholangiography,Endoscopy, and Biliary Interventions

PurposeThe purpose of this study was to present the institutional experience of performing endoscopy, cholangiography, and biliary interventions through the modified Hutson loop by interventional radiology.Materials and MethodsA total of 61 of 64 modified Hutson loop access procedures were successful. This single-center retrospective study included 61 successful procedures of biliary interventions using existing modified Hutson loops (surgically affixed subcutaneous jejunal limb adjacent to biliary anastomosis or anastomoses) for diagnostic or therapeutic purposes in 21 patients. Seventeen of 21 patients (81%) had undergone liver transplantation. Indications included biliary strictures (n = 18) and biliary leaks (n = 3). The clinical success and complications were evaluated.ResultsThere were 3 of 26 modified Hutson loop retrograde biliary intervention failures (12%) before introduction of endoscopy and no failures (0 of 38 [0%]) subsequently (P = .06). Endoscopy or cholangioscopy was performed in 19 procedures by interventional radiologists. Retrograde biliary interventions included diagnostic cholangiography (n = 26), cholangioplasty (n = 25), stent placement (n = 29), stent retrieval (n = 25), and biliary drainage catheter placement (n = 5). No procedure-related mortality occurred. There was 1 major complication (duodenal perforation) (1.6%) and 12 minor complications (19%). In the 9 patients undergoing therapeutic interventions for biliary strictures, there was a significant decrease in median alkaline phosphatase (288.5 to 174.5 U/L; P = .03). There was a trend toward decrease in median bilirubin levels (1.7 to 1 mg/dL; P = .06) at 1 month post-intervention.ConclusionsThe modified Hutson loop provided interventional radiologists a safe and effective alternative access to manage biliary complications in patients with biliary-enteric anastomoses. Introduction of the endoscope in interventional radiology has improved the success rate of these procedures.     

Single-Use versus Reusable Endoscopes for Percutaneous Biliary Endoscopy with Lithotripsy: Technical Metrics,Clinical Outcomes,and Cost Comparison

PurposeTo compare procedure and fluoroscopy time, technical and clinical success, and costs between single-use and reusable endoscopes in patients undergoing percutaneous biliary endoscopy (PBE) with lithotripsy.Material and MethodsThirty-four patients (67 procedures) were retrospectively included in the study. The patients were treated with PBE for gallstone removal from October 24, 2014, to February 12, 2020, using reusable (28 procedures) or single-use (39 procedures) endoscopes. The procedure time, fluoroscopy time, technical success rate (accessing the biliary system and locating the gallstone), clinical success rate (at least partial gallstone removal), complication rate, and cost of use were compared between the procedures.ResultsThe mean (± standard deviation) procedure time was not significantly different between single-use (136 minutes ± 45) and reusable endoscopes (136 minutes ± 51) (P = .47). The mean fluoroscopy time was significantly shorter for single-use endoscopes (11 minutes ± 8.4) than for reusable endoscopes (18 minutes ± 12) (P = .01). When comparing single-use versus reusable endoscopes, the technical success (95% [n = 37] vs 93% [n = 26]) and the clinical success (90% [n = 35] vs 75% [n = 21]) rates were not significantly different (both, P > .05). Only 1 complication was noted in the reusable endoscope group (P = .42). The cost per case was lower for single-use ($1,500) than for reusable ($3,987) endoscope procedures, primarily due to differences in capital costs and repair costs.ConclusionsSingle-use endoscopes offer the potential for lower patient radiation exposure and lower cost per case, which may reduce the financial barriers to offering PBE in interventional radiology practices. The clinical and technical success rates did not differ by endoscope type.     

The Role of Physician-Driven Device Preference in the Cost Variation of Common Interventional Radiology Procedures

PurposeTo analyze the impact of physician-specific equipment preference on cost variation for procedures typically performed by interventional radiologists at a tertiary care academic hospital.Materials and MethodsFrom October 2017 to October 2019, data on all expendable items used by 9 interventional radiologists for 11 common interventional radiology procedure categories were compiled from the hospital analytics system. This search yielded a final dataset of 44,654 items used in 2,121 procedures of 11 different categories. The mean cost per case for each physician as well as the mean, standard deviation, and coefficient of variation (CV) of the mean cost per case across physicians were calculated. The proportion of spending by item type was compared across physicians for 2 high-variation, high-volume procedures. The relationship between the mean cost per case and case volume was examined using linear regression.ResultsThere was a high variability within each procedure, with the highest and the lowest CV for radioembolization administration (56.6%) and transjugular liver biopsy (4.9%), respectively. Variation in transarterial chemoembolization cost was mainly driven by microcatheters/microwires, while for nephrostomy, the main drivers were catheters/wires and access sets. Mean spending by physician was not significantly correlated with case volume (P =.584).ConclusionsPhysicians vary in their item selection even for standard procedures. While the financial impact of these differences vary across procedures, these findings suggest that standardization may offer an opportunity for cost savings.     

Prevalence of Musculoskeletal Symptoms in Interventional Radiologists

PurposeTo investigate the prevalence of musculoskeletal symptoms, defined as aches, pains, discomfort, or numbness, by using a validated assessment tool among interventional radiologists.Materials and MethodsA Web-based survey using the Nordic Musculoskeletal Questionnaire was disseminated to interventional radiologist members by email in November 2015. Musculoskeletal symptoms were evaluated in 9 body areas. Information regarding participant demographics, practice details, use of radio-protective equipment, and exercise routines was also gathered. Univariate and multivariate analyses were performed to determine risk factors associated with more severe symptoms.ResultsOf 4,096 SIR members at the time of the survey, 640 completed the questionnaire in its entirety (16% response rate). Respondents consisted of 69 females (11%) and 571 males (89%), with a mean age of 47.5 ± 10.2 years old, a mean body mass index of 25.5 ± 3.9 kg/m², and a mean practice length of 17.1 ± 9.8 years. Prevalence of musculoskeletal symptoms was 88% in the 12 months preceding the survey. For those reporting musculoskeletal issues, 58% attributed the symptoms to work-related activities. Lower back (61%), neck (56%), and shoulder complaints (46%) were the most common. Symptoms prevented 21.2% of respondents from being able to work over the same time period. Multivariate analysis identified female gender, above-normal body mass index, and a practice length of 10 years or more as factors associated with a higher risk of moderate-to-severe symptoms.ConclusionsMusculoskeletal symptoms are prevalent among interventional radiologists, the majority of which are attributed to work-related causes.     

Angiographic Findings during Repeat Prostatic Artery Embolization

PurposeTo describe mechanisms of prostate revascularization based on imaging findings during repeat prostatic artery embolization (PAE; rPAE).Materials and MethodsThis is a retrospective analysis of 10 rPAEs performed between October 2012 and September 2018 in patients with recurrent lower urinary tract symptoms (LUTS) after PAE (mean age, 68.2 y ± 4.5). Two interventional radiologists reviewed PAE and rPAE images and defined 6 patterns of revascularization. Correlation between embolization of the posterolateral (PL) prostatic branch during previous PAE and prostate revascularization on rPAE was assessed by Fisher exact test. One hemiprostate was excluded because no detectable revascularization was observed.ResultsAll patients showed LUTS improvement after previous PAEs (P < .01 for 5 outcome measures) and had recurrence during follow-up. rPAEs were performed a mean of 40.9 months after previous PAEs (18–96 mo). Of 19 hemiprostates analyzed, 11 presented revascularization by 2 or more branches (57.9%). The PL branch (29.0%) and the recanalized main prostatic artery (25.8%) were the most frequent revascularizing branches observed, followed by distal branches of obturator (12.9%), internal pudendal (12.9%), superior vesical (12.9%), and contralateral arteries (6.5%). Embolization of the PL branch during previous PAE significantly reduced the incidence of revascularization by this branch (P = .002).ConclusionsMechanisms of revascularization in rPAE are diverse and complex. Revascularization by the PL branch and recanalization of the previously embolized prostatic artery were the most frequent patterns observed. Embolization of the PL branch may reduce the incidence of prostate revascularization and LUTS recurrence after PAE.     

Combination of Microwave Ablation and Percutaneous Osteoplasty for Treatment of Painful Extraspinal Bone Metastasis

PurposeTo evaluate the efficacy and safety of microwave (MW) ablation combined with percutaneous osteoplasty (POP) on painful extraspinal bone metastases.Materials and MethodsIn this retrospective study, 50 adult patients with 56 extraspinal bone metastasis lesions, who suffered from refractory moderate to severe pain, were treated with MW ablation and POP. Changes in quality of life were evaluated based on the Visual Analog Scale (VAS), daily morphine consumption, and the Oswestry Disability Index (ODI) before and immediately after the procedure and during follow-up times.ResultsTechnical success was achieved in all patients. Mean preoperative VAS score and morphine dose were 7.0 ± 2.6 (range, 3–10) and 66.7 ± 33.2 mg (range, 10–120 mg), respectively. Mean postoperative VAS scores and daily morphine doses were as follows: 1 day, 3.5 ± 2.1 and 36.1 ± 25.8 mg (P < .05); 1 week, 1.5 ± 1.7 and 12.2 ± 14.8 mg (P < .001); 1 month, 0.9 ± 1.4 and 5.7 ± 10.0 mg (P < .001); and 3 months, 0.6 ± 1.2 and 4.7 ± 8.4 mg (P < .001). A significant decrease in the ODI score was also observed (P < .05). Periprocedural death was not observed. A pathologic fracture occurred in 1 (2%) patient with femoral metastasis, and local infection was observed in 2 (4%) patients. Minor cement leakage occurred in 4 (8%) patients with no symptomatic or intra-articular extravasation. No local tumor progression occurred in patients with imaging follow-up.ConclusionsMW ablation combined with POP is an effective and safe treatment for painful extraspinal bone metastases, which can significantly relieve pain and improve quality of life.     

Computed Tomography‒Guided Microwave Ablation Combined with Osteoplasty for the Treatment of Bone Metastases: A Multicenter Clinical Study

PurposeTo evaluate the efficacy and safety of combined microwave ablation (MWA) and osteoplasty as a palliative therapy for painful bone metastases.Materials and MethodsAs an extension of a previous limited single-center study, a retrospective review was conducted for 147 patients (77 male, 70 female) with painful bone metastases who underwent MWA combined with osteoplasty. In total, 102 (69.4%), 41 (27.9%), and 4 (2.7%) patients had spinal metastases, extraspinal metastases, and both, respectively. Treatment efficacy was determined by comparing visual analog scale (VAS) scores, daily morphine equivalent opioid consumption, and Oswestry disability index (ODI) scores before treatment and during the follow-up period (mean follow-up, 9.8 months; range 3–16).ResultsThe mean VAS score significantly declined from 6.4 ± 2.3 before treatment to 3.2 ± 2.1, 1.9 ± 1.6, 1.8 ± 1.6, 1.8 ± 1.6, and 1.9 ± 1.6 at 24 hours, 1 week, 4 weeks, 12 weeks, and 24 weeks after treatment, respectively (P < .01). Furthermore, the mean daily morphine equivalent opioid consumption was significantly reduced from 81.5 ± 32.8 mg before treatment to 40.0 ± 20.6, 32.4 ± 10.2, 26.4 ± 10.0, 21.5 ± 8.3, and 19.3 ± 7.4 mg. The mean ODI score also declined after treatment (P < .0001). Major complications occurred in 4 of 147 patients, with 1 pathologic fracture, 1 nerve injury, and 2 mild skin infections. Minor cement leakages were observed at 69 sites (32.8%).ConclusionsMWA combined with osteoplasty is an effective and safe treatment for painful bone metastases.     

Liver Tumor Ablation Procedure Duration and Estimated Patient Radiation Dose: Comparing Positron Emission Tomography/CT and CT Guidance

PurposeTo compare procedure duration and patient radiation dose in positron emission tomography/computed tomography (PET/CT) and CT-guided liver tumor ablation procedures.Materials and MethodsIn this retrospective, case-control study, 275 patients underwent 368 image-guided ablation procedures to treat 537 tumors. Radiologists used PET/CT guidance for 117 procedures and CT guidance for 251 procedures. PET/CT-guided procedures were performed by one radiologist (C: P.B.S.). All 3 radiologists (A: J.G.S., B: a radiologist who is not an author on this article, and C: P.B.S.) performed CT-guided procedures. Potential confounders included patient demographics, clinical and tumor characteristics, and procedural variables.ResultsThe mean duration and estimated patient radiation dose of PET/CT-guided procedures performed by radiologist C were 21.5 ± 4.9 minutes longer and 0.7 ± 2.8 mSv higher than CT-guided procedures performed by all radiologists in an unadjusted comparison. Adjusting for confounding, mean duration and estimated dose of PET/CT-guided procedures performed by radiologist C were 28.3 ± 3.8 minutes longer (P < .0001) and 6.2 ± 2.9 mSv higher (P = .03) than CT-guided procedures performed by the same radiologist. Comparing CT-guided procedures performed by all 3 radiologists, adjusted mean durations and estimated patient doses of procedures by the least experienced radiologist, radiologist A, and the second most experienced radiologist, radiologist B, were 24.2 ± 5.1 (P < .0001) and 18.1 ± 8.9 (P = .04) minutes longer and 13.1 ± 3.7 (P < .001) and 14.5 ± 6.4 (P = .02) mSv higher, respectively, than procedures performed by the most experienced radiologist, radiologist C.ConclusionsPET/CT-guided liver ablations had a slightly longer duration with slightly higher estimated patient radiation dose than similar CT-guided liver ablations. Procedure duration and patient dose do not appear to be major impediments to the emerging field of PET/CT-guided tumor ablation.     

Digital Variance Angiography in Selective Lower Limb Interventions

PurposeTo evaluate the potential benefits of digital variance angiography (DVA) in selective lower limb angiography and to compare the performance of 2 DVA algorithms (conventional DVA1 and the recently developed DVA2) to that of digital subtraction angiography (DSA).Materials and MethodsFrom November 2019 to May 2020, 112 iodinated contrast media (ICM) and 40 carbon dioxide (CO₂) angiograms were collected from 15 and 13 peripheral artery disease patients, respectively. The DVA files were retrospectively generated from the same unsubtracted source file as DSA. The objectively calculated contrast-to-noise ratio (CNR) and the subjective visual image quality of DSA, DVA1, and DVA2 images were statistically compared using the Wilcoxon signed-rank test. The images were evaluated by 6 radiologists (R.P.T., S.V., A.M.K., S.S.A., O.E., and J.S.) from 2 centers using a 5-grade Likert scale.ResultsBoth DVA algorithms produced similar increase (at least 2-fold) in CNR values (P < .001) and significantly higher image quality scores than DSA, independent of the contrast agent used. The overall scores with ICM were 3.61 ± 0.05 for DSA, 4.30 ± 0.04 for DVA1, and 4.33 ± 0.04 for DVA2 (each P < .001 vs DSA). The scores for CO₂ were 3.10 ± 0.14 for DSA, 3.63 ± 0.13 for DVA1 (P < .001 vs DSA), and 3.38 ± 0.13 for DVA2 (P < .05 vs DSA).ConclusionsDVA provides higher CNR and significantly better image quality in selective lower limb interventions irrespective of the contrast agent used. Between DVA algorithms, DVA1 is preferred because of its identical or better image quality than DVA2. DVA can potentially help the interventional decision process and its quality reserve might allow dose management (radiation/ICM reduction) in the future.     

Screening of Polymer-Based Drug Delivery Vehicles Targeting Folate Receptors in Triple-Negative Breast Cancer

PurposeTo compare cellular uptake and cytotoxicity of fluorescein (FL)-labeled polyethylene glycols (PEGs) carrying 2 folate groups (targeted delivery vehicles [TDVs]) to non-PEGylated molecules with 1 or 2 folate groups.Materials and MethodsThree PEGylated TDVs and 2 non-PEGylated folic acid (FA)–fluorescein (FL) conjugates (FA-FL and FA-FL-FA) were synthesized. Two triple-negative breast cancer cell lines (MDA-MB-231and MDA-MB-468) were cultured to 70% confluency and incubated for 2 h in a folate-depleted medium. Folate receptor (FR) expression was confirmed by immunocytochemistry. Cellular uptake and cytotoxicity of compounds were measured by flow cytometry. Intracellular localization was confirmed using confocal microscopy.ResultsMDA-MB-231 demonstrated 40% more FR staining than MD-MB-468. Intracellular localization of the 2 non-PEGylated molecules (FA-FL and FA-FL-FA) and the 3 PEGylated TDVs was confirmed with confocal microscopy. Cellular uptake was independent of concentration for FA-FL, but there was 26.8% more cytotoxicity at 30 μg/mL compared with no treatment (P ≤ .05). Uptake was > 90% for FA-FL-FA at 10 μg/mL and 30 μg/mL without significant cytotoxicity (P ≤ .005). Cellular uptake was > 80% for all TDVs. The molecule containing monodispersed PEG with M_n = 1,000 g/mol had the highest uptake in both cell lines without cytotoxicity. Maximum toxicity was demonstrated by the molecule containing PEG_2,000 only at the highest dose of 30 μg/mL (8.66% ± 3.94% cytotoxicity; cut-off was 20%).ConclusionsThe molecule containing monodispersed PEG with M_n = 1,000 g/mol and 2 FA targeting groups demonstrated better targetability and cellular uptake as a TDV.     

Medicare Reimbursement Trends for Interventional Radiology Procedures: 2012 to 2020

PurposeTo investigate the reimbursement trends for interventional radiology (IR) procedures from 2012 to 2020.Materials and MethodsReimbursement data from the Physician Fee Schedule look-up tool from the Centers for Medicare and Medicaid Services was compiled for 20 common IR procedures. The authors then investigated compensation trends after adjusting for inflation and from the unadjusted data between 2012 and 2020.ResultsFrom 2012 to 2020, the mean unadjusted reimbursement for procedures decreased by ?6.9% (95% confidence interval [CI], ?13.5% to ?0.34%). This trend was even more profound after inflation was taken into account, with a mean decline in adjusted reimbursement of ?18.7% (95% CI, ?24.4% to ?12.9%) during the study period, with a mean yearly decline of ?2.8%. The difference between the mean unadjusted and adjusted payment amounts was significant (P = .012). Similarly, linear regression analysis of the adjusted average reimbursement across all procedures revealed an overall decline from 2012 to 2020 (R² = 0.97), indicating a steady decline in reimbursement over time.ConclusionsIn just under a decade, IR has experienced significant reimbursement cuts by Medicare, as demonstrated by both the unadjusted and inflation-adjusted payment trends. Knowledge of these trends is critically important for practicing interventional radiologists, leaders within the field, and legislators, who may play a role in formulating future reimbursement schedules for IR. These data may be used to help support more amenable reimbursement plans to sustain and facilitate the growth of the specialty.     

Outcomes of Stroke Thrombectomy Performed by Interventional Radiologists versus Neurointerventional Physicians

PurposeTo test the hypothesis that interventional radiologists (IRs) and neurointerventional (NI) physicians have similar outcomes of endovascular stroke thrombectomy (EVT), which could be used to improve the availability of thrombectomy.Materials and MethodsEight hospitals providing EVT performed by IRs and NI physicians at the same institution submitted sequential retrospective data limited to the era of modern devices. Good clinical outcomes (a 90-day modified Rankin score [mRS] of 0–2) and technically successful revascularization (a modified thrombolysis in cerebral infarction score of ≥2b) were compared between the specialties after adjusting for treating hospital, patient age, stroke severity, Alberta stroke program early computed tomography score, time from symptom onset to door, and clot location. Propensity score matching was used to compare the outcomes. A total of 1,009 patients were evaluated (622 treated by IRs and 387 treated by NI physicians).ResultsThe median time from stroke onset to puncture was 245 versus 253 minutes (P = .49), the technically successful revascularization rate was 81.8% versus 82.4% (P = .81), and the good clinical outcome rate was 45.5% versus 50.1% (P = .16). After adjusting, the physician specialty was not a significant predictor of good clinical outcomes (odds ratio, 1.028; 95% confidence interval, 0.760–1.390; P = .86). After matching, an mRS of 0–2 was present in 47.7% of IR treated patients and 51.1% of NI treated patients (P = .366).ConclusionsThere were no significant differences in the successful revascularization rate and good clinical outcomes between IRs and NI physicians. The outcomes of EVT performed by IRs were similar to those of EVT performed by NI physicians, as determined using previously published trials and registries. This may be useful for addressing coverage and access to stroke interventions.     

Experimental Analysis of Radiation Protection Offered by a Novel Exoskeleton-Based Radiation Protection System versus Conventional Lead Aprons

PurposeTo evaluate the radiation protection offered by an exoskeleton-based radiation protection system (Stemrad MD) and to compare it with that offered by conventional lead aprons.MethodsThe experimental setup involved 2 anthropomorphic phantoms, an operator, a patient, and a C-arm as the x-ray radiation source. Thermoluminescent detectors were used to measure radiation doses to different radiosensitive body parts on the operator phantom both with the exoskeleton and a conventional lead apron at the left radial and right femoral positions. Detected radiation doses for the exoskeleton and lead apron for different body parts and positions were compared.ResultsAt the left radial position, the mean radiation dose (mGy) reduction by the exoskeleton compared with that by the lead apron was >90% for the left eye lens (0.22 ± 0.13 vs 5.18 ± 0.08; P < .0001), right eye lens (0.23 ± 0.13 vs 4.98 ± 0.10; P < .0001), left head (0.11 ± 0.16 vs 3.53 ± 0.07; P < .0001), right head (0.27 ± 0.09 vs 3.12 ± 0.10; P < .0001), and left brain (0.04 ± 0.08 vs 0.46 ± 0.07; P < .0001). At the right femoral position, radiation reduction was >90% for the left eye lens (0.14 ± 0.10 vs 4.16 ± 0.09; P < .0001), right eye lens (0.06 ± 0.08 vs 1.90 ± 0.11; P < .0001), left head (0.10 ± 0.08 vs 4.39 ± 0.08; P < .0001), left brain (0.03 ± 0.07 vs 1.44 ± 0.08; P < .0001), right brain (0.00 ± 0.14 vs 0.11 ± 0.13; P = .06), and thyroid (0.04 ± 0.07 vs 0.27 ± 0.09; P < .0001). Protection of the torso was equivalent to that offered by conventional lead aprons.ConclusionsThe exoskeleton-based system provided superior radiation protection to the physician compared with that provided by conventional lead aprons. The effects are particularly impactful for the brain, eye lens, and head areas.     

Evaluation of Technical Performance of Ultrasound-Guided Procedures through Hand Motion Analysis: An Exploration of Motion Metrics

PurposeTo evaluate the ability of hand motion analysis using conventional and new motion metrics to differentiate between operators of varying levels of experience for central venous access (CVA) and liver biopsy (LB).Materials and MethodsIn the CVA task, 7 interventional radiologists (experts), 10 senior trainees, and 5 junior trainees performed ultrasound-guided CVA on a standardized manikin; 5 trainees were retested after 1 year. In the LB task, 4 radiologists (experts) and 7 trainees biopsied a lesion on a manikin. Conventional motion metrics (path length and task time), a refined metric (translational movements), and new metrics (rotational sum and rotational movements) were calculated.ResultsIn the CVA task, experts outperformed trainees on all metrics (P < .02). Senior trainees required fewer rotational movements (P = .02), translational movements (P = .045), and time (P = .001) than junior trainees. Similarly, on 1-year follow-up, trainees had fewer translational (P = .02) and rotational (P = .003) movements with less task time (P = .003). The path length and rotational sum were not different between junior and senior trainees or for trainees on follow-up. Rotational and translational movements had greater area under the curve values (0.91 and 0.86, respectively) than the rotational sum (0.73) and path length (0.61). In the LB task, experts performed the task with a shorter path length (P = .04), fewer translational (P = .04) and rotational (P = .02) movements, and less time (P < .001) relative to the trainees.ConclusionsHand motion analysis using translational and rotational movements was better at differentiating levels of experience and improvement with training than the conventional metric of path length.     

Endovascular Therapy for Ischemic Stroke Can Be Successfully Performed by Peripheral Vascular Interventionalists

PurposeTo describe interventionalist and workflow characteristics of an acute stroke endovascular thrombectomy (EVT) center without a dedicated interventional neuroradiology service and report clinical and radiologic outcomes.Materials and MethodsRetrospective review was performed of all patients receiving EVT at Christchurch Hospital, New Zealand, from June 2014 to the end of December 2019 from a prospective reperfusion registry. During the study period, 5 peripheral vascular interventional radiologists, 2 of whom had experience in other neuroendovascular procedures, performed 210 EVT procedures. Median age of patients was 76 years (interquartile range: 64–83 y), and 107 (51%) were men.ResultsThe most commonly occluded vessel was the M1 middle cerebral artery (n = 114; 54%). Successful reperfusion (Modified Treatment In Cerebral Ischemia score 2b–3) was achieved in 180 (86%) procedures. Favorable 90-day outcome (modified Rankin Scale score 0–2) was achieved in 102 (54%) patients with no disability before stroke. Symptomatic intracranial hemorrhage occurred in 3 (1.4%) patients. Treatment rates in the local catchment area increased from 6 per 100,000 population in 2017 to 15 per 100,000 in 2019.ConclusionsThe results of this study suggest peripheral vascular interventional radiologists with specific training can successfully perform EVT resulting in a significant increase in EVT provision.