Outcomes of Postprocedural Closeout Checklist Implementation to Prevent Adverse Events during Interventional Radiology Procedures: An Initiative to Improve Outcomes

PurposeTo assess whether adherence to a postprocedural closeout (PPC) checklist decreases adverse events during image-guided procedures.Materials and MethodsBased on the analysis of prior adverse events related to image-guided procedures, the Radiology Quality Committee developed a PPC checklist. The rates of serious reportable events related to image-guided procedures performed in the radiology department were recorded annually from 2015 to 2021. The rate of adverse events was normalized to the procedure volume in the corresponding periods. The number of patients requiring repeat procedures was recorded. The severity of impact was classified according to the Society of Interventional Radiology Adverse Event Classification System. The annual rates before (2015 and 2016) and after (2017–2021) the implementation of PPC were compared.ResultsSeventy-seven safety reports were identified in image-guided procedures over the study period, of which 43 cases were not related to the PPC, leaving 34 cases for the analysis. Radiology adverse events decreased from 0.069% (14/20,218, 7/y) before PPC implementation to 0.034% (20/58,793, 4/y) after implementation (P = .05, 43% decrease). Radiology repeat procedures decreased from 0.040% (8/20,218, 4/y) before PPC implementation to 0.007% (4/58,793, 0.8/y) after implementation (P = .0033, 80% decrease). Moreover, severity of adverse events decreased (P = .009).ConclusionsImplementation of a PPC checklist improved patient outcomes by decreasing the number of adverse events that occur from inadequate safety processes at the end of image-guided procedures by 43%, need for repeat procedures by 80%, and severity of impact of errors.     

Percutaneous CT-Guided Abdominal and Pelvic Biopsies: Comparison of an Electromagnetic Navigation System and CT Fluoroscopy

PurposeTo compare electromagnetic navigation (EMN) with computed tomography (CT) fluoroscopy for guiding percutaneous biopsies in the abdomen and pelvis.Materials and MethodsA retrospective matched-cohort design was used to compare biopsies in the abdomen and pelvis performed with EMN (consecutive cases, n = 50; CT-Navigation; Imactis, Saint-Martin-d’Hères, France) with those performed with CT fluoroscopy (n = 100). Cases were matched 1:2 (EMN:CT fluoroscopy) for target organ and lesion size (±10 mm).ResultsThe population was well-matched (age, 65 vs 65 years; target size, 2.0 vs 2.1 cm; skin-to-target distance, 11.4 vs 10.7 cm; P > .05, EMN vs CT fluoroscopy, respectively). Technical success (98% vs 100%), diagnostic yield (98% vs 95%), adverse events (2% vs 5%), and procedure time (33 minutes vs 31 minutes) were not statistically different (P > .05). Operator radiation dose was less with EMN than with CT fluoroscopy (0.04 vs 1.2 μGy; P < .001), but patient dose was greater (30.1 vs 9.6 mSv; P < .001) owing to more helical scans during EMN guidance (3.9 vs 2.1; P < .001). CT fluoroscopy was performed with a mean of 29.7 tap scans per case. In 3 (3%) cases, CT fluoroscopy was performed with gantry tilt, and the mean angle out of plane for EMN cases was 13.4°.ConclusionsPercutaneous biopsies guided by EMN and CT fluoroscopy were closely matched for technical success, diagnostic yield, procedure time, and adverse events in a matched cohort of patients. EMN cases were more likely to be performed outside of the gantry plane. Radiation dose to the operator was higher with CT fluoroscopy, and patient radiation dose was higher with EMN. Further study with a wider array of procedures and anatomic locations is warranted.     

Collar Badge Lens Dose Equivalent Values among United States Physicians Performing Fluoroscopically Guided Interventional Procedures

PurposeTo describe the range of occupational badge dose readings and annualized dose records among physicians performing fluoroscopically guided interventional (FGI) procedures using job title information provided by the same 3 major medical institutions in 2009, 2012, and 2015.Materials and MethodsThe Radiation Safety Office of selected hospitals was contacted to request assistance with identifying physicians in a large commercial dosimetry database. All entries judged to be uninformative of occupational doses to FGI procedure staff were excluded. Monthly and annualized doses were described with univariate statistics and box-and-whisker plots.ResultsThe dosimetry data set of interventional radiology staff contained 169 annual dose records from 77 different physicians and 698 annual dose records from 455 nonphysicians. The median annualized lens dose equivalent values among physicians (11.9 mSv; interquartile range [IQR], 6.9–20.0 mSv) was nearly 3-fold higher than those among nonphysician medical staff assisting with FGI procedures (4.0 mSv; IQR, 1.8–6.7 mSv) (P < .001). During the study period, without eye protection, 25% (23 of 93) of the physician annualized lens dose equivalent values may have exceeded 20 mSv; for nonphysician medical staff, this value may have been exceeded 3.5% (6 of 173) of the time. However, these values did not account for eye protection.ConclusionsThe findings from this study highlight the importance of mitigating occupational dose to the eyes of medical staff, particularly physicians, performing or assisting with FGI procedures. Training on radiation protection principles, the use of personal protective equipment, and patient radiation dose management can all help ensure that the occupational radiation dose is adequately controlled.     

Feasibility and Procedural Safety of alfapump System Implantation by IR: Experience from the MOSAIC Study,a Multicenter,Open-Label Prospective Study in Cirrhotic Patients with Refractory Ascites

PurposeTo evaluate feasibility, procedural outcomes, and safety aspects of implantation of the alfapump system for management of refractory ascites by interventional radiology (IR) methods.Materials and MethodsThe multicenter open-label prospective MOSAIC study included 29 patients (mean age 60.0 y ± 9.9; range, 32–72 y, 17 [56.7%] male) with cirrhotic refractory ascites who received an alfapump system implanted by IR. The fully subcutaneous alfapump system consists of a pump and 2 silicone catheters, whose distal ends are inserted in the peritoneum and the bladder, respectively. The device moves ascites from the peritoneum to the bladder, reducing the requirement of paracentesis. Pumped volume and speed can be customized as required. The implant procedure was performed under general or local anesthesia. Both catheters were placed under ultrasound guidance. The pump was inserted in a subcutaneous pocket on the upper abdomen. Incidence and severity of procedure-related serious adverse events up to 3 months after implantation were recorded.ResultsTechnical success was achieved in 29 (100%) IR implant procedures. The pump was usually implanted on the right abdomen (76.7%). In 5 patients, deviation from the Instructions for Use was required. Adverse events (requirement of additional incisions, postoperative bleed) occurred in 3 patients. At 3 months after implantation, 3 possibly procedure-related serious adverse events (ascites leakage, bacterial peritonitis, postoperative bleeding) had occurred. Two explantations (2/29; 6.8%) (cellulitis, pump pocket infection) and 4 reinterventions (pump or catheter replacement) were required, corresponding to an adverse event incidence rate of 9/29 (31.0%).ConclusionsPlacement of the alfapump using IR methods is both feasible and technically successful.     

Radiation Dose during Transarterial Radioembolization: A Dosimetric Comparison of Cone-Beam CT and Angio-CT Technologies

PurposeTo evaluate the radiation dose differences for intraprocedural computed tomography (CT) imaging between cone-beam CT and angio-CT acquired during transarterial radioembolization (TARE) therapies for hepatocellular carcinoma.Materials and MethodsA retrospective cohort of 22 patients who underwent 23 TARE procedures were selected. Patients were imaged in both cone-beam CT and angio-CT rooms as a part of their conventional treatment plan. Effective dose contributions from individual CT acquisitions as well as the cumulative dose contributions from procedural 3D imaging were evaluated. Angiography dose contributions were omitted. Cone-beam CT images were acquired on a C-arm Philips Allura system. Effective doses were evaluated by coupling previously published conversion factors (effective dose per dose-area product) to patient’s dose-area product meter readings after the procedure. Angio-CT images were acquired on a hybrid Canon Infinix-i Aquilion PRIME system. Effective doses from angio-CT scans were estimated using Radimetrics. Comparisons of a single patient’s dose differential between the 2 technologies were made.ResultsThe mean effective dose from a single CT scan was 6.42 mSv and 5.99 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .3224), despite the greater field of view and average craniocaudal scan coverage in angio-CT. The mean effective dose summed across all CTs in a procedure was 12.89 mSv and 34.35 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .0018).ConclusionsThe mean effective dose per CT scan is comparable between cone-beam CT and angio-CT when considered in direct comparison for a single patient.     

Computed Tomography Fluoroscopy–Guided Percutaneous Transhepatic Bleomycin/Ethiodized Oil Sclerotherapy for Symptomatic Giant Hepatic Hemangioma

PurposeTo determine the safety and efficacy of computed tomography (CT) fluoroscopy–guided percutaneous transhepatic sclerotherapy with a bleomycin/ethiodized oil emulsion for symptomatic giant hepatic hemangiomas.Materials and MethodsThe procedure was performed on 22 patients with symptomatic giant hepatic hemangiomas in an outpatient setting between 2018 and 2020. All patients were followed clinically and underwent contrast-enhanced magnetic resonance imaging after 1 month and again at a mean time of 15 months ± 2. Adverse events were classified according to the Common Terminology Criteria for Adverse Events (CTCAE, v5.0), in which a severe adverse event was defined as an adverse event with a grade of ≥3. The desired radiologic response (volume and index size) and improvement of pain intensity (visual analog scale [VAS]) and other symptoms were recorded as outcomes.ResultsOverall, patients showed a 36.4% ± 8.6 reduction in volume and a 14% ± 1.6 reduction in index size after 1 month, with P values of .002 and .001, respectively. The final follow-up volume and index size were 194.7 cm³ ± 25.8 and 77 mm ± 36, respectively. Moreover, a 53.0% ± 7 reduction in volume and 22% ± 3.7 reduction in index size during the final imaging were reported, with the P values of .001 and .001, respectively. Significant reductions in the mean pain intensity (90% of patients with lower VAS scores after intervention) and symptoms were reported. Four patients were classified as clinically unsuccessful, and were recommended further procedures for residual pain.ConclusionsCT fluoroscopy–guided transhepatic sclerotherapy is an effective, safe, and minimally invasive method to manage giant hepatic hemangiomas in an outpatient setting.     

Uterine Artery Embolization for Pedunculated Subserosal Fibroids: A Systematic Review and Meta-Analysis

PurposeTo provide a comprehensive overview of the literature assessing the safety and efficacy of uterine artery embolization (UAE) for patients with pedunculated subserosal fibroids.Materials and MethodsMEDLINE and Embase databases were searched without language or publication type restrictions for observational studies to estimate safety (adverse events) and efficacy (devascularization, fibroid volume reduction, and uterine volume reduction) outcomes. Case reports were included to qualitatively report adverse events. Meta-analysis was performed for single proportions and mean changes with random-effects modeling.ResultsOf 98 eligible articles, 11 studies were included in the final analysis. Of the adverse events detailed in these cases, 5 events were mild, 2 were moderate (torsion of pedunculated fibroid requiring laparoscopic myomectomy and persistent bleeding after embolization requiring hysterectomy), and 1 was severe (fibroid necrosis causing bowel obstruction requiring bowel resection and hysterectomy). There were no deaths reported in the literature. The pooled risk of adverse events was 1.7% (95% confidence interval [CI], 0.29%–9.2%; 4 of 181; I² = 0%). The pooled devascularization rate was 75.9% (95% CI, 62.4%–85.6%; 140 of 189; I² = 75%) at 3.91 months of follow-up. The percent volume reduction of the dominant pedunculated fibroid was 38.6% (95% CI, 33.0%–44.2%; I² = 0%) at 4.3 months of follow-up. The percent uterine volume reduction was 36.7% (95% CI, 30.3%–43.0%; I² = 47%) at 3.5 months of follow-up.ConclusionsUAE for pedunculated subserosal fibroids has a low risk of adverse events and effectively reduces fibroid and uterine size.     

Modified Surgical Drain–Guided Percutaneous Catheter Drainage of Postoperative Fluid Collection in Inaccessible Locations

PurposeTo investigate the feasibility and safety of a modified surgical drain–guided percutaneous catheter drainage technique for postoperative fluid collection in inaccessible locations.Materials and MethodsThe modified technique was used in 24 patients (age, 58.6 years ± 11.3; men, 58.3%) from September 2015 to March 2021. All fluid collections had no safe access route on preprocedural computed tomography (CT) images. Every patient had a long (>20 cm) and tortuous surgical drain, which prevented the use of conventional surgical drain exchange. A favorable midpoint of the surgical drain tract was punctured under either ultrasound or fluoroscopic guidance, and a guide wire was advanced into the fluid collection. Technical success was defined as the successful placement of a drainage catheter, and clinical success was defined as the complete evacuation of fluid collection without recurrence. Follow-up was performed using CT images and a chart review. Adverse events within 30 days of the procedure were evaluated.ResultsTarget fluid collections in the pelvic cavity (n = 9); subphrenic (n = 7), peripancreatic (n = 4), and subhepatic spaces (n = 3); and abdominal cavity (n = 1) were drained using catheters measuring 7–10.2 F in diameter and 25–30 cm in length. The technical success rate was 91.7% (22/24), and the clinical success rate was 90.9% (20/22). No procedure-related or catheter-related adverse events were observed. The median follow-up period was 8.2 months (range, 10–1,721 days).ConclusionsThe modified surgical drain–guided percutaneous catheter drainage technique is a useful alternative when conventional exchange techniques cannot be used because of long and tortuous surgical drain paths.     

Percutaneous Cryoablation of Plasmacytomas: Oncologic Effectiveness and Adverse Events

PurposeTo evaluate the oncologic outcomes and adverse events associated with cryoablation of plasmacytomas.Materials and MethodsRetrospective review of an institutional percutaneous ablation database showed that 43 patients underwent 46 percutaneous cryoablation procedures for treatment of 44 plasmacytomas between May 2004 and March 2021. The treatment of 25 (25 of 44, 56.8%) tumors was augmented with bone consolidation/cementoplasty. The median patient age was 64 years (interquartile range [IQR], 54–69), and 30 of 43 (69.8%) patients were men. The median maximum plasmacytoma diameter was 5.0 cm (IQR, 3.1–7.0). Thirty of 44 (68.2%) tumors were periacetabular, vertebral, or located in the iliac wing. Twenty-nine of 44 (65.9%) cryoablated plasmacytomas were recurrent tumors after prior external beam radiation therapy (EBRT). Survival analyses were performed using the Kaplan-Meier method. Adverse events were graded using Society of Interventional Radiology criteria.ResultsThe 5-year estimated local tumor recurrence–free survival was 85.3% (95% CI, 74.1%–98.1%), the 5-year estimated new plasmacytoma–free survival was 49.9% (95% CI, 33.9%–73.4%), and the 5-year estimated overall survival was 70.4% (95% CI, 56.9%–87.1%). Nine of 46 (19.6%) major adverse events occurred in 8 patients, including 3 of 46 (6.5%) new or progressive pathologic fractures at the ablation site requiring surgical intervention, 3 of 46 (6.5%) nerve injuries, 1 of 46 (2.2%) avascular necrosis and femoral head collapse, 1 of 46 (2.2%) septic arthritis, and 1 of 46 (2.2%) acute renal failure caused by rhabdomyolysis.ConclusionsPercutaneous cryoablation is a viable treatment option for patients with plasmacytomas, including those with recurrent plasmacytomas after EBRT. Postcryoablation adverse events are relatively common.     

CT-Guided Percutaneous Cryoablation in Patients with Lung Nodules Mainly Composed of Ground-Glass Opacities

PurposeTo assess the safety and efficacy of cryoablation in patients with lung nodules mainly composed of ground-glass opacities (GGOs).Materials and MethodsIn this retrospective study, 50 patients (mean age, 65.0 years ± 12.3; 28 women) with a diagnosis of lung GGO nodules who underwent cryoablation were included (from June 2016 to June 2021). The local recurrence rate, incidence of regional metastases to lymph nodes, incidence of distant metastases, adverse events, and lung function condition were analyzed.ResultsFollow-up computed tomography (CT) was performed at a mean of 33 months (range, 3–60 months) after the cryoablation procedure. Outcomes were only evaluated in 30 patients. A total of 20 patients were excluded. Of these 20 patients, 10 patients had no cancer detected by histopathological analysis and a diagnosis was made using CT or positron emission tomography (PET)-CT, The other 10 patients had nodules with a diameter of <10 mm and a consolidation-to-tumor ratio of >0.25; thus, histopathological analysis was not performed because of the small nodule size, and patients were diagnosed using CT or PET-CT. The local recurrence rate was 0% (0 of 30). Evidence of regional metastases of lymph nodes was not found in any patients (0%; 0 of 30), and the incidence of distant metastases was 0% (0 of 30). No major adverse events were noted. Lung function recovered to normal within 1 month after cryoablation in all patients.ConclusionsCryoablation may serve as a safe and feasible option for the treatment of lung nodules mainly composed of GGOs.     

Yttrium-90 Radiation Segmentectomy in Oligometastatic Secondary Hepatic Malignancies

PurposeTo evaluate the safety and efficacy of yttrium-90 (⁹⁰Y) radiation segmentectomy (RS) in the treatment of oligometastatic secondary hepatic malignancies.Materials and MethodsThis institutional review board–approved retrospective study evaluated 16 patients with oligometastatic secondary hepatic malignancies who were treated with RS. The median patient age was 61.9 years (range, 38.6–85.7 years). Of the 16 patients, 11 (68.8%) presented with solitary lesions. The median index tumor size was 3.1 cm (95% CI, 2.3–3.9). Primary outcomes were evaluation of clinical and biochemical toxicities using National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0, and imaging response using Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary outcomes were time to progression (TTP) and overall survival (OS) as estimated by the Kaplan-Meier method.ResultsClinical Grade 3 toxicities were limited to 1 (6.7%) patient who experienced fatigue, abdominal pain, nausea, and vomiting. Biochemical Grade 3 toxicities occurred in 1 (6.7%) patient who experienced lymphopenia. No Grade 4 clinical or biochemical toxicities were identified. Disease control was achieved in 14 (93.3%) of 15 patients. The median TTP of the treated tumor was 72.9 months (95% CI, 11.2 to no estimate). The median OS was 60.9 months (95% CI, 24.7 to no estimate).Conclusions⁹⁰Y RS displayed an excellent safety profile and was effective in achieving a high disease control rate in the treatment of oligometastatic secondary hepatic malignancies.     

Improved Utilization Following Conversion of a Fluoroscopy Suite to Hybrid CT/Angiography System

PurposeTo assess changes in operational utilization following conversion of a single IR suite to a hybrid CT/angiography (Angio-CT) system at an academic tertiary care center.Materials and MethodsThe total number of interventional procedures and diagnostic CT examinations performed in 29 rooms (20 diagnostic radiology, 7 IR, 2 shared between divisions) was calculated in the 24 months before conversion of an IR suite to Angio-CT and 12 months after conversion. The total number of IR procedures (global IR/month) and diagnostic CT scans per month (global CT/month) in both before and after conversion periods was calculated and defined as baseline institutional growth. This was compared against the change in the number of IR procedures performed in the before and after periods in the converted room (Angio-CT/month) as well as the number of diagnostic CT scans performed in the shared rooms (shared CT/month).ResultsThe percent change in global CT and global IR from the before to the after periods was 39.2% and 3.1%, respectively. Shared CT per month and Angio-CT per month increased by 46.7% and 12.0% across the same time periods, respectively. The ratio of the percent increase in Angio-CT per month to percent increase in global IR per month was 3.87. The ratio of the percent increase in shared CT per month to percent increase in global CT per month was 1.19.ConclusionsOperational utilization improved in both diagnostic radiology and IR sections following conversion of a conventional fluoroscopic IR suite to an Angio-CT room.     

Drug-Eluting Embolics Chemoembolization for the Management of Recurrent or Advanced Head and Neck Cancer

PurposeTo characterize the safety, tolerability, and efficacy of chemoembolization using drug-eluting embolic (DEE) microspheres in patients with recurrent and advanced head and neck cancer.Materials and MethodsIn this retrospective study, 32 patients (mean age, 57.2 years ± 2.8; 17 women) with recurrent (n = 16) and advanced (n = 16) head and neck cancer were treated with chemoembolization using DEE microspheres loaded with doxorubicin. Treatment response, overall survival, local progression-free survival, and adverse events were evaluated.ResultsAt 6 months after the procedure, the objective response and disease control rates were 25% and 69%, respectively. The median overall survival and local progression-free survival were 14.5 and 13.6 months, respectively. Seven (22%) patients experienced adverse events after the chemoembolization procedure. All the adverse events were related to postembolization syndrome, including vomiting and nausea (n = 1), pyrexia (n = 2), and localized pain (n = 7). No severe adverse events or procedure-related deaths were observed.ConclusionsChemoembolization using DEE microspheres was safe and tolerable in patients with recurrent and advanced head and neck cancer.     

Increasing Yttrium-90 Dose Conformality Using Proximal Radioembolization Enabled by Distal Angiosomal Truncation for the Treatment of Hepatic Malignancy

PurposeTo evaluate safety and feasibility of improving radiation dose conformality via proximal radioembolization enabled by distal angiosomal truncation where selective administration was not practical.Materials and MethodsHepatic malignancies treated via angiosomal truncation between January 2017 and March 2019 were retrospectively evaluated. Thirty-three patients (8 women, 25 men; mean age, 62.2 y; range, 36–78 y) underwent 39 treatments. Of treatments, 74.3% (n = 29) were for hepatocellular carcinomas, 10.2% (n = 4) were for cholangiocarcinomas, and 15.4% (n = 6) were for metastatic tumors (1 colorectal adenocarcinoma, 1 pancreatic adenocarcinoma, 3 melanomas, and 1 endometroid carcinoma). Truncation was achieved using temporary embolic devices including a microvascular plug, detachable coil, gelatin slurry, and balloon microcatheter, after which proximal radioembolization was performed. Range of treatment activity was 0.47–5.75 GBq. Technetium-99m macroaggregated albumin and bremsstrahlung single photon emission computed tomography (CT)/CT threshold analysis was conducted to delineate and compare distribution of activity within the treatment angiosome before and after radioembolization.ResultsDosimetric analysis of 14 patients demonstrated a significant reduction in nontarget liver radiation exposure at 5, 20, and 40% thresholds (P = .002, P = .001, and P = .008, respectively). There were no grade 3 or higher adverse events. There was no significant change in Albumin-Bilirubin grade and Eastern Cooperative Oncology Group Performance Status (P = .09 and P = .74) before and 3 months after the procedure. Truncated arteries were patent on subsequent angiography in 11 cases and on MR angiography or CT angiography in 38 of 39 cases.ConclusionsProximal radioembolization enabled by distal angiosomal truncation is safe and decreases nontarget parenchymal radioembolization dose in cases not amenable to selective administration.     

Tumor and Ablation Margin Visibility during Cryoablation of Musculoskeletal Tumors: Comparing Intraprocedural PET/CT Images with CT-Only Images

PurposeTo compare tumor and ice-ball margin visibility on intraprocedural positron emission tomography (PET)/computed tomography (CT) and CT-only images and report technical success, local tumor progression, and adverse event rates for PET/CT-guided cryoablation procedures for musculoskeletal tumors.Materials and MethodsThis Health Insurance Portability and Accountability Act (HIPAA)–compliant and institutional review board–approved retrospective study evaluated 20 PET/CT-guided cryoablation procedures performed with palliative and/or curative intent to treat 15 musculoskeletal tumors in 15 patients from 2012 to 2021. Cryoablation was performed using general anesthesia and PET/CT guidance. Procedural images were reviewed to determine the following: (a) whether the tumor borders could be fully assessed on PET/CT or CT-only images; and (b) whether tumor ice-ball margins could be fully assessed on PET/CT or CT-only images. The ability to visualize tumor borders and ice-ball margins on PET/CT images was compared with that on CT-only images.ResultsTumor borders were fully assessable for 100% (20 of 20; 95% CI, 0.83–1) of procedures on PET/CT versus 20% (4 of 20; 95 CI, 0.057–0.44) of procedures on CT only (P < .001). The tumor ice-ball margin was fully assessable in 80% (16 of 20; 95% CI, 0.56–0.94) of procedures using PET/CT versus 5% (1 of 20; 95% CI, 0.0013–0.25) of procedures using CT only (P < .001). Primary technical success was achieved in 75% (15 of 20; 95% CI, 0.51–0.91) of procedures. There was local tumor progression in 23% (3/13; 95% CI, 0.050–0.54) of the treated tumors with at least 6 months of follow-up. There were 3 adverse events (1 Grade 3, 1 Grade 2, and 1 Grade 1).ConclusionsPET/CT-guided cryoablation of musculoskeletal tumors can provide superior intraprocedural visualization of the tumor and ice-ball margins compared with that provided by CT alone. Further studies are warranted to confirm the long-term efficacy and safety of this approach.     

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.     

Efficacy and Safety of Percutaneous Argon-Helium Cryoablation for Hepatocellular Carcinoma Abutting the Diaphragm

PurposeTo evaluate the efficacy and safety of percutaneous argon-helium cryoablation (CA) for hepatocellular carcinoma (HCC) abutting the diaphragm (<5 mm).Materials and MethodsA total of 61 consecutive patients (50 men, 11 women; mean age, 56.3 ± 12.1 years old; range, 32–83 years) with 74 HCC tumors (mean size, 3.3 ± 1.7 cm; range, 0.8–7 cm) who were treated with percutaneous argon-helium CA were enrolled in this retrospective study. Adverse events were evaluated according to Common Terminology Criteria for Adverse Events, version 5.0. Local tumor progression (LTP) and overall survival (OS) were analyzed using the Kaplan-Meier method and the log-rank test. The risk factors associated with OS and LTP were evaluated using univariate and multivariate Cox regression analysis.ResultsNo periprocedural (30-day) deaths occurred. A total of 29 intrathoracic adverse events occurred in 24 of the 61 patients. Major adverse events were reported in 5 patients (pleural effusion requiring catheter drainage in 4 patients and pneumothorax requiring catheter placement in 1 patient). Median follow-up was 18.7 months (range, 2.3–60.0 months). Median time to LTP after CA was 20.9 months (interquartile range [IQR], 14.1–30.6 months). Median times of OS after CA and diagnosis were 27.3 months (IQR, 15.1–45.1 months) and 40.9 months (interquartile range, 24.8–68.6 months), respectively. Independent prognostic factors for OS included tumor location (left lobe vs right lobe; hazard ratio [HR], 2.031; 95% confidence interval [CI], 1.062–3.885; P = .032) and number of intrahepatic tumors (solitary vs multifocal; HR, 2.684; 95% CI, 1.322–5.447; P = .006). Independent prognostic factors for LTP included age (HR, 0.931; 95% CI, 0.900–0.963; P < .001), guidance modality (ultrasound vs computed tomography and US; HR, 6.156 95% CI, 1.862–20.348; P = .003) and origin of liver disease.ConclusionsPercutaneous argon-helium CA is safe for the treatment of HCC abutting the diaphragm, with acceptable LTP and OS.     

Yttrium-90 Radioembolization to the Prostate Gland: Proof of Concept in a Canine Model and Clinical Translation

PurposeTo investigate the feasibility, safety, and absorbed-dose distribution of prostatic artery radioembolization (RE) in a canine model.Materials and MethodsFourteen male castrated beagles received dihydroandrosterone/estradiol to induce prostatic hyperplasia for the duration of the study. Each dog underwent fluoroscopic prostatic artery catheterization. Yttrium-90 (⁹⁰Y) microspheres (TheraSphere; Boston Scientific, Marlborough, Massachusetts) were delivered to 1 prostatic hemigland (dose escalation from 60 to 200 Gy), with the contralateral side serving as a control. Assessments for adverse events were performed throughout the follow-up (Common Terminology Criteria for Adverse Events v5.0). Positron emission tomography/magnetic resonance (MR) imaging provided a confirmation after the delivery of absorbed-dose distribution. MR imaging was performed before and 3, 20, and 40 days after RE. Tissue harvest of the prostate, rectum, bladder, urethra, penis, and neurovascular bundles was performed 60 days after RE.ResultsAll the animals successfully underwent RE. Positron emission tomography/MR imaging demonstrated localization to and good coverage of only the treated hemigland. No adverse events occurred. The MR imaging showed a significant dose-dependent decrease in the treated hemigland size at 40 days (25%–60%, P < .001). No extraprostatic radiographic changes were observed. Necropsy demonstrated no gross rectal, urethral, penile, or bladder changes. Histology revealed RE-induced changes in the treated prostatic tissues of the highest dose group, with gland atrophy and focal necrosis. No extraprostatic RE-related histologic findings were observed.ConclusionsProstate ⁹⁰Y RE is safe and feasible in a canine model and leads to focal dose-dependent changes in the gland without inducing unwanted extraprostatic effects. These results suggest that an investigation of nonoperative prostate cancer is warranted.     

First-in-Human Study with Eight Patients Using an Absorbable Vena Cava Filter for the Prevention of Pulmonary Embolism

PurposeTo prospectively evaluate the initial human experience with an absorbable vena cava filter designed for transient protection from pulmonary embolism (PE).Materials and MethodsThis was a prospective, single-arm, first-in-human study of 8 patients with elevated risk of venous thromboembolism (VTE). Seven absorbable IVC filters (made of polydioxanone that breaks down into H₂O and CO₂ in 6 mo) were placed prophylactically before orthopedic (n = 5) and gynecologic (n = 2) surgeries, and 1 was placed in a case of deep vein thrombosis. Subjects underwent CT cavography and abdominal radiography before and 5, 11, and 36 weeks after filter placement to assess filter migration, embolization, perforation, and caval thrombosis and/or stenosis. Potential PE was assessed immediately before and 5 weeks after filter placement by pulmonary CT angiography.ResultsNo symptomatic PE was reported throughout the study or detected at the planned 5-week follow-up. No filter migration was detected based on the fixed location of the radiopaque markers (attached to the stent section of the filter) relative to the vertebral bodies. No filter embolization or caval perforation was detected, and no caval stenosis was observed. Throughout the study, no filter-related adverse events were reported.ConclusionsImplantation of an absorbable vena cava filter in a limited number of human subjects resulted in 100% clinical success. One planned deployment was aborted as a result of stenotic pelvic veins, resulting in 89% technical success. No PE or filter-related adverse events were observed.     

Interventional Radiologists Achieve Equivalent Outcomes and Lower Costs for Totally Implantable Venous Access Device Placement Compared to Operating Room Placement

PurposeTo compare the cost and outcomes of surgical and interventional radiology (IR) placement of totally implantable venous access devices (TIVADs) within a large regional health system to determine the service line with better outcomes and lower costs to the health system.Materials and MethodsA retrospective review of all chest port placements performed in the operating room (OR) and IR suite over 12 months was conducted at a large, integrated health system with 6 major hospitals. Secondary electronic health record and cost data were used to identify TIVAD placements, follow-up procedures indicating port malfunction, early adverse events (within 1 month after the surgery), late adverse events (2–12 months after the procedure), and health system cost of TIVAD placement and management.ResultsFor 799 total port placements included in this analysis, the rate of major adverse events was 1.3% and 1.9% for the IR and OR groups, respectively, during the early follow-up (P = .5655) and 4.9% and 2.8% for the IR and OR groups, respectively, during the late follow-up (P = .5437). Malfunction-related follow-up procedure rates were 1.8% and 2.6% for the IR and OR groups, respectively, during the early follow-up (P = .4787) and 12.4% and 10.5% for the IR and OR groups, respectively, during the late follow-up (P = .4354). The mean cost of port placement per patient was $4,509 and $5,247 for the IR and OR groups, respectively. The difference in per-patient cost of port placement was $1,170 greater for the OR group (P = .0074).ConclusionsThe similar rates of adverse events and follow-up procedures and significant differences in insertion cost suggest that IR TIVAD placement may be more cost effective than surgical placement without affecting the quality.