Impact of Body Mass Index on Perioperative Complications and Oncologic Outcomes in Patients Undergoing Thermal Ablation for Renal Cell Carcinoma

PurposeTo determine effect of body mass index (BMI) on safety and cancer-related outcomes of thermal ablation for renal cell carcinoma (RRC).Materials and MethodsThis retrospective study evaluated 427 patients (287 men and 140 women; mean [SD] age, 72 [12] y) who were treated with thermal ablation for RCC between October 2006 and December 2017. Patients were stratified by BMI into 3 categories: normal weight (18.5–24.9 kg/m²), overweight (25–29.9 kg/m²), and obese (≥ 30 kg/m²). Of 427 patients, 71 (16%) were normal weight, 157 (37%) were overweight, and 199 (47%) were obese. Complication rates, local recurrence, and residual disease were compared in the 3 cohorts.ResultsNo differences in technical success between normal-weight, overweight, and obese patients were identified (P = .72). Primary technique efficacy rates for normal-weight, overweight, and obese patients were 91%, 94%, and 93% (P = .71). There was no significant difference in RCC specific–free survival, disease-free survival, and metastasis-free survival between obese, overweight, and normal-weight groups (P = .72, P = .43, P = .99). Complication rates between the 3 cohorts were similar (normal weight 4%, overweight 2%, obese 3%; P = .71).ConclusionsCT-guided renal ablation is safe, feasible, and effective regardless of BMI.     

Safety and Efficacy of Multilevel Thoracolumbar Vertebroplasty in the Simultaneous Treatment of Six or More Pathologic Compression Fractures

PurposeTo assess the safety and efficacy of multilevel thoracolumbar vertebroplasty in the simultaneous treatment of ≥ 6 painful pathologic compression fractures.Materials and MethodsRetrospective review was conducted of 50 consecutive patients treated with vertebroplasty for ≥ 6 pathologic compression fractures in a single session for pain palliation at a tertiary single cancer center from 2015 to 2019. Outcomes measured included procedural safety according to Common Terminology Criteria for Adverse Events (CTCAE), change in 4-week postprocedure back pain by numeric rating scale (NRS), comparison of daily opioid medication consumption, and development of skeletal-related events.ResultsA total of 397 pathologic compression fractures were treated during 50 sessions (mean, 7.9 per patient ± 1.5). Mean procedure duration was 162 minutes ± 35, mean postoperative hospitalization duration was 1.6 days ± 0.9, and mean follow-up duration was 401 days ± 297. Seven complications were recorded, including 1 case of symptomatic polymethyl methacrylate pulmonary embolism. No major complications (CTCAE grade 4/5) were reported. NRS pain score was significantly decreased (5.0 ± 1.8 vs 1.7 ± 1.4; P < .0001), with a mean score decrease of 3.3 points (66%). Opioid agent use decreased significantly (76 mg/24 h ± 42 vs 45 mg/24 h ± 37; P = .0003), with a mean decrease of 30 mg/24 h (39%). Skeletal-related events occurred in 7 patients (14%).ConclusionsMultilevel vertebroplasty for ≥ 6 pathologic compression fractures is safe and provides significant palliative benefit when performed simultaneously.     

Value of 18F-FDG PET/MR Imaging in the Early Evaluation of Treatment Response following Radiofrequency Ablation of Liver Cancer in a Rabbit Model

PurposeTo test the hypothesis that ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and magnetic resonance (MR) imaging can detect early residual tumor following radiofrequency (RF) ablation of liver cancer using a VX2 tumor model.Materials and MethodsTwenty-four rabbits with VX2 liver tumors were randomly divided into 3 groups (n = 8/group): Group 1 without RF ablation treatment, Group 2 with complete ablation, and Group 3 with partial ablation. An ¹⁸F-FDG PET/MR imaging scan was obtained within 2 hours after RF ablation. The maximum standardized uptake values (SUV) of the nontreated liver tumor, benign periablational enhancement (BPE), residual tumor, ablated tumor, and adjacent liver parenchyma and mean SUV of the normal liver were measured. The ratios of maximum SUV for these targets to the mean SUV of the normal liver (TNR) were calculated and compared.ResultsThe mean TNR of the nontreated liver tumors in Group 1 was significantly greater than that of the adjacent liver parenchyma (8.68 ± 0.71 vs 1.89 ± 0.26, P < .001). In Group 2, the mean TNR of BPE was significantly greater than that of the adjacent liver parenchyma (2.85 ± 0.20 vs 1.86 ± 0.25, P < .001). In Group 3, the mean TNR of the residual tumor was significantly greater than that of BPE (8.64 ± 0.59 vs 2.78 ± 0.23, P < .001), which was significantly greater than that of completely ablated tumor (2.78 ± 0.23 vs 0.50 ± 0.06, P < .001).Conclusions¹⁸F-FDG PET/MR imaging may serve as a promising imaging tool for the early detection of viable residual tumors due to incomplete tumor ablation.     

Midterm Outcomes of Angioplasty for Pediatric Renovascular Hypertension

PurposeTo evaluate the midterm outcomes of percutaneous transluminal renal angioplasty (PTRA) for pediatric renovascular hypertension (RVH).Materials and MethodsThe clinical data of patients who underwent PTRA for RVH in the authors’ hospital from 2012 to 2019 were retrospectively analyzed. Postprocedural blood pressure, glomerular filtration rate (GFR) of the affected kidney, restenosis, and complications were closely monitored.ResultsPTRA was performed in a total of 30 children (20 boys and 10 girls), with a mean age of 7.3 years ± 0.7 (range, 40 days to 13.9 years) and a mean weight of 25.0 kg ± 2.3 (range, 3.4–53 kg). The median follow-up period was 26.5 months (range, 1 month to 7.5 years). Technical success was achieved in 26 (86.7%) of the 30 patients. Restenosis developed in 3 patients (10.0%). Only 1 patient underwent stent implantation, and the stent fractured 8 months later, requiring further intervention. There were no other complications. In terms of clinical benefit of blood pressure control after the initial PTRA procedure, 15 patients (50%) were cured and 7 patients (23.3%) showed improvement. There was no significant difference in the etiology, lesion location, and lesion length between patients with clinical benefit and failure (P = .06, P = .202, and P = .06, respectively). GFR of the affected kidney was significantly improved from 19.9 mL/min ± 11.2 to 38.1 mL/min ± 11.9 at the 6-month follow-up after PTRA (P < .001).ConclusionsThe overall results of PTRA for pediatric RVH caused by different etiologies are promising. PTRA not only provided a clinical benefit of blood pressure control in 73.3% of the patients but also significantly improved the function of the affected kidney.     

Preoperative Embolization of Metastatic Spinal Cord Compression with n-Butyl Cyanoacrylate: Safety and Effectiveness in Limiting Blood Loss

PurposeTo evaluate the safety and effectiveness of preoperative embolization with n-butyl cyanoacrylate (nBCA) performed for metastatic spinal cord compression (MSCC) in limiting blood loss (BL).Materials and MethodsIn this institutional review board–approved retrospective study, clinical records from 2017 to 2022 were reviewed. Twenty consecutive patients (11 men and 9 women; mean age, 65.8 years ± 10.0; range, 45–82 years) underwent 21 preoperative spine tumor embolizations with nBCA. Angiograms were used to calculate the percentage reduction in tumor vascularity, and relevant clinical data (levels studied and embolized, fluoroscopy time [FT], reference dose [RD], and Kerma area product [KAP]) and operative data (BL and operative time [OT]) were analyzed. Adverse events and outcomes were recorded.ResultsA median of 2 levels were embolized per procedure (range, 1–5) but 4.9 were studied (range, 1–10). After embolization, tumor blush was reduced by a median of 87.3% (range, 50%–90%). The mean FT was 41 minutes ± 15.4 (range, 16–67 minutes), the mean RD was 1,977.1 mGy ± 1,794.3 (range, 450.2–6,319 mGy), and the mean KAP was 180.5 Gy·cm² ± 166.2 (range, 30.4–504 Gy·cm²). The adverse event rate was 1 (4.7%) of the 21 embolizations because a weakness of lower extremities related to swelling was observed. Surgery was performed at a mean of 1.4 days ± 1 (range, 1–5 days) after embolization. The mean surgical estimated BL was 432.5 mL ± 328.5 (range, 25–1,100 mL), and the mean OT was 210.1 minutes ± 97.4 (range, 57–489 minutes).ConclusionsPreoperative embolization of tumors resected for MSCC with nBCA is a safe procedure allowing for performance of surgery with acceptable BL.     

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.     

Long-Term Survival after Percutaneous Radiofrequency Ablation of Pathologically Proven Renal Cell Carcinoma in 100 Patients

PurposeTo determine the long-term survival of patients treated with percutaneous radiofrequency (RF) ablation for pathologically proven renal cell carcinoma (RCC).Materials and MethodsIn this single-center retrospective study, 100 patients with 125 RCCs (100 clear-cell, 19 papillary, and 6 chromophobe) 0.8–8 cm in size treated with RF ablation were evaluated at a single large tertiary-care center between 2004 and 2015. Technical success, primary and secondary technique efficacy, and pre- and postprocedural estimated glomerular filtration rate (eGFR) at 3–6 months and 2–3 years were recorded. Overall survival, cancer-specific survival, and local tumor progression–free survival were calculated by Kaplan–Meier survival curves. Complications were classified per the Clavien–Dindo system. Statistical testing was done via χ² tests for proportions and paired t test for changes in eGFR. Statistical significance was set at α = 0.05.ResultsOverall technical success rate was 100%, and primary and secondary technique efficacy rates were 90% and 100%, respectively. Median follow-up was 62.8 months, ranging from 1 to 120 months. The 10-year overall, cancer-specific, and local progression–free survival rates were 32%, 86%, and 92%, respectively. The number of ablation probes used was predictive of residual unablated tumor (P < .001). There were no significant changes in preprocedure vs 2–3-years postprocedure eGFR (65.2 vs 62.1 mL/min/1.73 m²; P = .443). There was a 9% overall incidence of complications, the majority of which were grade I.ConclusionsImage-guided percutaneous RF ablation of RCCs is effective at achieving local control and preventing cancer-specific death within 10 years from initial treatment.     

Transarterial Embolization of Neovascularity for Refractory Nighttime Shoulder Pain: A Multicenter,Open-Label,Feasibility Trial

PurposeTo assess the feasibility of transarterial embolization (TAE) for recalcitrant nighttime shoulder pain in a multicentric study.Materials and MethodsThis prospective, open-label, feasibility trial included 100 patients treated at 5 institutions. TAE was performed in 76 patients with adhesive capsulitis (AC) and 24 patients with symptomatic rotator cuff tears (sRCTs). The ipsilateral radial artery was punctured, and imipenem/cilastatin sodium was infused as an embolic agent. Adverse events, 10 point pain numerical rating scale (NRS), range of motion (ROM) of the shoulder joint, and quality of life (via the EuroQol-5D [EQ-5D]) were evaluated.ResultsAll patients exhibited neovascularity on baseline angiography, and all TAE procedures were performed successfully. No patient experienced a major adverse event. The mean nighttime pain NRS scores at baseline and 1, 3, and 6 months after TAE were 6.4 ± 2.2, 3.4 ± 2.6, 2.3 ± 2.5, and 1.6 ± 2.2, respectively (for all, P < .001). The mean ROM of anterior elevation at baseline and 1, 3, and 6 months after TAE were 97° ± 29°, 119° ± 28°, 135° ± 27°, and 151° ± 17°, respectively (for all, P < .001). The mean EQ-5D scores at baseline and 1, 3, and 6 months after TAE were 0.63 ± 0.17, 0.73 ± 0.16, 0.80 ± 0.17, and 0.84 ± 0.17, respectively (for all, P < .001). There was no significant difference in the clinical success rate between the AC and sRCT groups.ConclusionsTAE for nighttime shoulder pain caused by AC and sRCTs was feasible with sufficient safety and efficacy.     

Idarubicin-Loaded ONCOZENE Drug-Eluting Bead Chemoembolization in a Rabbit Liver Tumor Model: Investigating Safety,Therapeutic Efficacy,and Effects on Tumor Microenvironment

PurposeTo investigate toxicity, efficacy, and microenvironmental effects of idarubicin-loaded 40-μm and 100-μm drug-eluting embolic (DEE) transarterial chemoembolization in a rabbit liver tumor model.Materials and MethodsTwelve male New Zealand White rabbits with orthotopically implanted VX2 liver tumors were assigned to DEE chemoembolization with 40-μm (n = 5) or 100-μm (n = 4) ONCOZENE microspheres or no treatment (control; n = 3). At 24–72 hours postprocedurally, multiparametric magnetic resonance (MR) imaging including dynamic contrast-enhanced (DCE), diffusion-weighted imaging (DWI), and biosensor imaging of redundant deviation in shifts (BIRDS) was performed to assess extracellular pH (pHe), followed by immediate euthanasia. Laboratory parameters and histopathologic ex vivo analysis included fluorescence confocal microscopy and immunohistochemistry.ResultsDCE MR imaging demonstrated a similar degree of devascularization of embolized tumors for both microsphere sizes (mean arterial enhancement, 8% ± 12 vs 36% ± 51 in controls; P = .07). Similarly, DWI showed postprocedural increases in diffusion across the entire lesion (apparent diffusion coefficient, 1.89 × 10⁻³ mm²/s ± 0.18 vs 2.34 × 10⁻³ mm²/s ± 0.18 in liver; P = .002). BIRDS demonstrated profound tumor acidosis at baseline (mean pHe, 6.79 ± 0.08 in tumor vs 7.13 ± 0.08 in liver; P = .02) and after chemoembolization (6.8 ± 0.06 in tumor vs 7.1 ± 0.04 in liver; P = .007). Laboratory and ex vivo analyses showed central tumor core penetration and greater increase in liver enzymes for 40-μm vs 100-μm microspheres. Inhibition of cell proliferation, intratumoral hypoxia, and limited idarubicin elution were equally observed with both sphere sizes.ConclusionsNoninvasive multiparametric MR imaging visualized chemoembolic effects in tumor and tumor microenvironment following DEE chemoembolization. Devascularization, increased hypoxia, coagulative necrosis, tumor acidosis, and limited idarubicin elution suggest ischemia as the predominant therapeutic mechanism. Substantial size-dependent differences indicate greater toxicity with the smaller microsphere diameter.     

Experimental High-Frequency Irreversible Electroporation Using a Single-Needle Delivery Approach for Nonthermal Pancreatic Ablation In Vivo

PurposeTo investigate the feasibility of single-needle high-frequency irreversible electroporation (SN-HFIRE) to create reproducible tissue ablations in an in vivo pancreatic swine model.Materials and MethodsSN-HFIRE was performed in swine pancreas in vivo in the absence of intraoperative paralytics or cardiac synchronization using 3 different voltage waveforms (1-5-1, 2-5-2, and 5-5-5 [on-off-on times (μs)], n = 6/setting) with a total energized time of 100 μs per burst. At necropsy, ablation size/shape was determined. Immunohistochemistry was performed to quantify apoptosis using an anticleaved caspase-3 antibody. A numerical model was developed to determine lethal thresholds for each waveform in pancreas.ResultsMean tissue ablation time was 5.0 ± 0.2 minutes, and no cardiac abnormalities or muscle twitch was detected. Mean ablation area significantly increased with increasing pulse width (41.0 ± 5.1 mm² [range 32–66 mm²] vs 44 ± 2.1 mm² [range 38–56 mm²] vs 85.0 ± 7.0 mm² [range 63–155 mm²]; 1-5-1, 2-5-2, 5-5-5, respectively; p < 0.0002 5-5-5 vs 1-5-1 and 2-5-2). The majority of the ablation zone did not stain positive for cleaved caspase-3 (6.1 ± 2.8% [range 1.8–9.1%], 8.8 ± 1.3% [range 5.5–14.0%], and 11.0 ± 1.4% [range 7.1–14.2%] cleaved caspase-3 positive 1-5-1, 2-5-2, 5-5-5, respectively), with significantly more positive staining at the 5-5-5 pulse setting compared with 1-5-1 (p < 0.03). Numerical modeling determined a lethal threshold of 1114 ± 123 V/cm (1-5-1 waveform), 1039 ± 103 V/cm (2-5-2 waveform), and 693 ± 81 V/cm (5-5-5 waveform).ConclusionsSN-HFIRE induces rapid, predictable ablations in pancreatic tissue in vivo without the need for intraoperative paralytics or cardiac synchronization.     

Safety and Effectiveness of Expandable Intravertebral Implant Use for Thoracolumbar Burst Fractures

PurposeTo determine the safety and effectiveness of an expandable intravertebral implant (Spinejack; Stryker, Kalamazoo, Michigan) as a treatment option for patients with thoracolumbar spine burst fractures without fracture-related neurologic deficit.Materials and MethodsImaging studies before and after expandable intravertebral implantation and medical records of 33 patients, 11 (33.3%) men and 22 (66.6%) women with an overall mean age of 71.7 years ± 8.3, were reviewed for 60 thoracolumbar Magerl Type A3 injuries secondary to osteoporosis, trauma, or malignancy. The mean follow-up time was 299 days.ResultsImplantation of an expandable intravertebral device resulted in a statistically significant reduction in bone fragment retropulsion (mean ± SD, 0.64 mm ± 16.4; P < .001), reduction in the extent of canal compromise (mean, 5.5%; P < .001), increased central canal diameter (mean ± SD, 0.71 mm ± 1.3; P < .001), and restoration of vertebral body height, with a mean increase of 5.0 mm (P < .001). However, the implantation did not result in a statistically significant kyphosis reduction (mean, 1.38°; P = .10). All patients except for 1 reported improvement in pain after surgery, with a mean improvement of 1.54 on a 4-point pain scale (P < .001). No clinically significant adverse events were reported.ConclusionsThis study suggests that expandable intravertebral device implantation is a safe and effective treatment for thoracolumbar vertebral burst fractures in patients without fracture-related neurologic deficit. Although implantation did not result in a statistically significant reduction in kyphotic angle, it offered significant improvement in pain, vertebral body height, fracture fragment retropulsion, and central canal diameter compromise.     

Computed Tomography Evaluation of In Vivo Pulmonary Cryoablation Zone Sizes

PurposeTo evaluate ablation zone sizes in patients undergoing pulmonary tumor cryoablation with 14-gauge cryoablation probes.Materials and MethodsA single-center retrospective analysis of all consecutive patients who underwent cryoablation of pulmonary tumors with 1 or more 14-gauge probes (August 2017 to June 2020) was performed. Intraprocedural and 1–2-month postprocedural chest computed tomography (CT) scans were evaluated to characterize pulmonary lesions, ice balls, and ablation zones. Single-probe 14-gauge ablation zone volumes were compared with manufacturer reference isotherms and single- and 2-probe ablation zones from a prior investigation of 17-gauge probes. Overall survival and local recurrence–free survival were calculated to 3 years.ResultsForty-seven pulmonary malignancies in 42 patients (women, 50%; mean age, 75.2 years ± 11.5) underwent cryoablation with 1 (n = 35), 2 (n = 10), or 3 (n = 2) cryoablation probes. One- to 2-month follow-up CT images were available for 30 of the 42 patients. The mean cryoablation zone volumes at 1–2 months when 1 (n = 21), 2 (n = 8), and 3 (n = 1) probes were used were 5.0 cm³ ± 2.3, 37.5 cm³ ± 20.5, and 28.4 cm³, respectively. The mean single-probe follow-up ablation zone volume was larger than that previously reported for 17-gauge probes (3.0 cm³ ± 0.3) (P < .001) but smaller than manufacturer-reported isotherms (11.6 cm³ for ?40 °C isotherm) and the 2-probe ablation zone volume with 17-gauge devices (12.9 cm³ ± 2.4) (for all, P < 001). The 3-year overall survival and local recurrence–free survival were 69% (95% confidence interval [CI], 53%–89%) and 87% (95% CI, 74%–100%), respectively.ConclusionsFourteen-gauge probes generate larger ablation volumes than those generated by 17-gauge probes. Manufacturer-reported isotherms are significantly larger than actual cryoablation zones. Cryoablation can attain low rates of local recurrence.     

Safety and Efficacy of Radiofrequency Ablation for Nonfunctioning Benign Thyroid Nodules in Children and Adolescents in 14 Patients over a 10-Year Period

PurposeTo evaluate the efficacy and safety of radiofrequency (RF) ablation for nonfunctioning benign thyroid nodules in children and adolescents.Materials and MethodsFourteen pediatric patients (10 female, 4 male; mean age 15.7 ± 2.3 years, range 12–19 years) with nonfunctioning benign thyroid nodules (mean longest diameter 3.7 ± 1.1 cm, range 2.0–5.6 cm) treated with the use of RF ablation from 2005 to 2015 were evaluated. The inclusion criteria for RF ablation therapy were (i) age <20 years, (ii) benign cytological confirmation by ≥2 separate fine-needle aspiration or core needle biopsies, (iii) pressure symptoms or cosmetic problems caused by thyroid nodules, (iv) absence of any suspicious feature as determined with the use of ultrasound (US), (v) normal serum levels of thyroid hormone and thyrotropin, and (vi) follow-up of >6 months. RF ablation was performed with the use of an RF generator and an 18-gauge internally cooled electrode. RF ablation was performed under local anesthesia without conscious sedation or general anesthesia. Changes in nodules on follow-up US, changes in symptomatic and cosmetic scores, and complications arising during or after RF ablation were evaluated.ResultsMean follow-up period was 36.9 ± 21.7 months (range 6–69 months). At last follow-up visits, mean longest nodule diameter and volume had decreased significantly (3.7 ± 1.1 cm vs 1.4 ± 0.9 cm and 14.6 ± 13.3 mL vs 1.7 ± 4.4 mL; P < 0.001). Both cosmetic and compressive symptoms significantly improved (3.8 ± 0.6 vs 1.4 ± 0.6 and 3.4 ± 1.0 vs 0.1 ± 0.4; P < 0.001). The mean number of ablation sessions was 2.1 ± 1.2 (range 1–5 sessions) and no major complication was encountered during or after RF ablation.ConclusionsRF ablation might be a safe and effective treatment modality for nonfunctioning benign thyroid nodules in children and adolescents.     

MR Imaging–Based In Vivo Macrophage Imaging to Monitor Immune Response after Radiofrequency Ablation of the Liver

PurposeTo establish molecular magnetic resonance (MR) imaging instruments for in vivo characterization of the immune response to hepatic radiofrequency (RF) ablation using cell-specific immunoprobes.Materials and MethodsSeventy-two C57BL/6 wild-type mice underwent standardized hepatic RF ablation (70 °C for 5 minutes) to generate a coagulation area measuring 6–7 mm in diameter. CD68⁺ macrophage periablational infiltration was characterized with immunohistochemistry 24 hours, 72 hours, 7 days, and 14 days after ablation (n = 24). Twenty-one mice were subjected to a dose-escalation study with either 10, 15, 30, or 60 mg/kg of rhodamine-labeled superparamagnetic iron oxide nanoparticles (SPIONs) or 2.4, 1.2, or 0.6 mg/kg of gadolinium-160 (¹⁶⁰Gd)-labeled CD68 antibody for assessment of the optimal in vivo dose of contrast agent. MR imaging experiments included 9 mice, each receiving 10-mg/kg SPIONs to visualize phagocytes using T2¹-weighted imaging in a horizontal-bore 9.4-T MR imaging scanner, ¹⁶⁰Gd-CD68 for T1-weighted MR imaging of macrophages, or 0.1-mmol/kg intravenous gadoterate (control group). Radiological-pathological correlation included Prussian blue staining, rhodamine immunofluorescence, imaging mass cytometry, and immunohistochemistry.ResultsRF ablation–induced periablational infiltration (206.92 μm ± 12.2) of CD68⁺ macrophages peaked at 7 days after ablation (P < .01) compared with the untreated lobe. T2¹-weighted MR imaging with SPION contrast demonstrated curvilinear T2¹ signal in the transitional zone (TZ) (186 μm ± 16.9), corresponsing to Iron Prussian blue staining. T1-weighted MR imaging with ¹⁶⁰Gd-CD68 antibody showed curvilinear signal in the TZ (164 μm ± 3.6) corresponding to imaging mass cytometry.ConclusionsBoth SPION-enhanced T2¹-weighted and ¹⁶⁰Gd-enhanced T1-weighted MR imaging allow for in vivo monitoring of macrophages after RF ablation, demonstrating the feasibility of this model to investigate local immune responses.     

False Lumen Stent-Grafts for Repair of Postdissection Aortic Aneurysms

PurposeTo evaluate the safety and efficacy of false lumen (FL) stent-grafts in the treatment of postdissection aortic aneurysms.Materials and MethodsEleven patients who underwent endovascular repair using FL stent-grafts from January 2016 to June 2019 were included. Among them, 2 patients had a prior history of type A aortic dissection, whereas 9 had undergone a prior endovascular repair for type B aortic dissection. Computed tomography angiography was performed to evaluate the reintervention and technical success rate, aortic remodeling, and other related aortic complications.ResultsThe mean age of patients was 55.6 ± 10.4 years. Technical success was achieved in all patients, and neither early mortality nor paralysis occurred. In total, 8 visceral branch arteries originating from the FL were reconstructed. The true lumen areas at the celiac axis, superior mesenteric artery, renal artery, and abdominal aortic bifurcation were significantly increased from 230.1 mm² to 312.3 mm², 212.1 mm² to 277.5 mm², 209.1 mm² to 291.6 mm², and 214.4 mm² to 300.6 mm², respectively (P < .05). The total diameter of the aorta at the 4 designated levels was stable or had shrunk in all patients. At a mean follow-up of 18.9 ± 7.6 months, 1 patient received re-intervention owing to iliac stent-graft occlusion. No aortic-related mortality occurred.ConclusionsFL stent-grafts can safely and effectively treat patients with postdissection aortic aneurysms. This strategy can be used to promote thrombosis of the FL and aortic remodeling. A larger sample and an extended follow-up period are needed to produce more conclusive results.     

Dynamic Contrast-Enhanced MR Imaging Evaluation of Perfusional Changes and Ablation Zone Size after Combination Embolization and Ablation Therapy

PurposeThe objectives of this study were to assess the utility of dynamic contrast-enhanced magnetic resonance (MR) imaging in quantifying parenchymal perfusional changes after embolization and to characterize the association between pharmacokinetic (PK) parameters and final microwave ablation volume.Materials and MethodsPK parameters from dynamic contrast-enhanced MR imaging were used to quantify perfusional changes in the liver after transarterial embolization of the right or left lobe in a swine liver model (n = 5). Each animal subject subsequently underwent microwave ablation (60 W for 5 minutes) of the embolized and nonembolized liver lobes. Changes in PK parameters from dynamic contrast-enhanced MR imaging were correlated with their respective final microwave ablation volumes in each liver lobe.ResultsMicrowave ablation volumes of embolized liver lobes were significantly larger than those of nonembolized liver lobes (28.0 mL ± 6.2 vs 15.1 mL ± 5.2, P < .001). PK perfusion parameters were significantly lower in embolized liver lobes than in nonembolized liver lobes (K^trans = 0.69 min^?1 ± 0.15 vs 1.52 min^?1 ± 0.37, P < .001; k_ep = 0.69 min^?1 ± 0.19 vs 1.54 min^?1 ± 0.42, P < .001). There was a moderate but significant correlation between normalized k_ep and ablation volume, with each unit increase in normalized k_ep corresponding to a 9.8-mL decrease in ablation volume (P = .035).ConclusionsPK-derived parameters from dynamic contrast-enhanced MR imaging can be used to quantify perfusional changes after transarterial embolization and are directly inversely correlated with final ablation volume.     

Diffusion-Weighted MR Imaging of Primary and Secondary Lung Cancer: Predictive Value for Response to Transpulmonary Chemoembolization and Transarterial Chemoperfusion

PurposeTo examine predictive value of apparent diffusion coefficient (ADC) in diffusion-weighted imaging (DWI) for response of patients with primary and secondary lung neoplasms undergoing transpulmonary chemoembolization (TPCE) and transarterial chemoperfusion (TACP) treatment.Materials and MethodsThirty-one patients (mean age ± SD 64 ± 12.4 y) with 42 lung target lesions (13 primary and 29 secondary) underwent DWI and subsequent ADC analysis on a 1.5T MR imaging scanner before and 30.3 days ± 6.4 after first session of TPCE or TACP. After 3.1 treatment sessions ± 1.4 performed in 2- to 4-week intervals, morphologic response was analyzed by comparing tumor diameter and volume before and after treatment on unenhanced T1-weighted MR images. On a per-lesion basis, response was classified according to Response Evaluation Criteria In Solid Tumors.ResultsThreshold ADC increase of 20.7% indicated volume response with 88% sensitivity and 78% specificity (area under the curve [AUC] = 0.84). Differences between ADC changes in volume response groups were significant (P = .002). AUC for volume response predicted by ADC before treatment was 0.77. Median ADC before treatment and mean ADC change were 1.09 × 10⁻³ mm²/second and 0.36 × 10⁻³ mm²/second ± 0.23, 1.45 × 10⁻³ mm²/second and 0.14 × 10⁻³ mm²/second ± 0.16, and 1.30 × 10⁻³ mm²/second and 0.06 × 10⁻³ mm²/second ± 0.19 in partial response, stable disease, and progressive disease groups. In primary lung cancer lesions, strong negative correlation of ADC change with change in diameter (ρ = −.87, P < .001) and volume (ρ = −.66, P = .016) was found. In metastases, respective correlation coefficients were ρ = −.18 (P = .356) and ρ = −.35 (P = .061).ConclusionsADC quantification shows considerable diagnostic value for predicting response and monitoring TPCE and TACP treatment of patients with primary and secondary lung neoplasms.     

Hypertensive Crisis during Microwave Ablation of Adrenal Neoplasms: A Retrospective Analysis of Predictive Factors

PurposeTo identify risk factors for hypertensive crisis (HC) during ultrasound-guided percutaneous microwave (MW) ablation of adrenal neoplasms.Materials and MethodsPatients who underwent MW ablation for adrenal tumors between April 2006 and November 2017 were retrospectively identified for this study (51 consecutive patients; 35 males, 16 females; mean age, 55 years; range, 15–85 years). A total of 77 MW ablation treatments were performed for 67 tumors (24 primary [9 pheochromocytomas, 8 adenomas, and 7 cortical carcinomas]; and 43 metastases [22 hepatocellular carcinoma, 8 renal cell carcinoma, 5 non-small cell lung cancer, 4 colorectal cancer, 3 liposarcoma, and 1 malignant fibrous histiocytoma]). The mean diameter of the adrenal tumors was 4.6 cm (range, 1.2–16.2 cm). Information about patient demographics, imaging studies, pathology and laboratory results, procedure records, and clinical outcomes was retrieved and analyzed. Statistical analysis was then performed to determine potential risk factors for HC.ResultsOf the 77 MW ablation procedures, HC occurred in 13 (16.9%). A significantly higher risk of HC was observed in patients with pheochromocytoma (odds ratio [OR], 9.037; 95% confidence interval [CI], 1.731–47.172; P = .009), body mass index <24 kg/m² (OR, 5.167; 95% CI, 1.060–25.194; P = .042), dominant tumor size ≤4.5 cm (OR, 4.023; 95% CI, 1.011–16.005; P = .048), and pre-procedural systolic blood pressure ≥130 mmHg (OR, 0.242; 95% CI, 0.068–0.861; P = .029).ConclusionHC can occur during MW ablation in patients with either primary or metastatic adrenal tumors. Pheochromocytoma, body mass index, tumor size, and pre-procedural systolic blood pressure appear to be significant risk factors for the occurrence of HC.     

Yttrium-90 Radiation Segmentectomy of Hepatocellular Carcinoma: A Comparative Study of the Effectiveness,Safety, and Dosimetry of Glass-Based versus Resin-Based Microspheres

PurposeTo evaluate the differences in safety, effectiveness, and dosimetry between glass-based and resin-based ablative yttrium-90 (⁹⁰Y) transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC).Materials and MethodsUsing the modified Response Evaluation Criteria in Solid Tumors and Common Terminology Criteria for Adverse Events, both tumor response and adverse events (AEs) were assessed at 3 months after ⁹⁰Y-TARE. Post procedure ⁹⁰Y-bremsstrahlung single-photon emission computed tomography/computed tomography voxel-based dosimetry analysis was used to create tumor dose (TD) and normal tissue dose (NTD) volume histograms, and to calculate tumor particle loading and specific activity. The TD and NTD receiver operating characteristic curves evaluated the dose threshold able to predict objective (partial or complete) and complete tumor responses in addition to any-grade and grade ≥3 AE incidences. The chi-square test and Student t-test were used to assess variable differences where appropriate.ResultsBetween 2019 and 2020, 81 patients with HCC (20 in the resin-based cohort and 61 in the glass-based cohort) underwent ablative ⁹⁰Y-TARE. The resin-based cohort had more males (89% vs 65%, P = .03), lower tumor-to-normal ratio (1.81 ± 0.39 vs 2.22 ± 0.94, P = .03), higher tumor particle loading (40,172 particles/mL ± 28,039 vs 17,081 particles/mL ± 12,555, P = .0001), lower specific activity (158 Bq/particle ± 3 vs 1,058 Bq/particle ± 331, P = .001), and lower mean TD (308 Gy ± 210 vs 794 Gy ± 523, P = .0002) than the glass-based cohort. No significant differences in baseline characteristics or posttreatment AEs were noted. The overall objective and complete response rates were 85% (95% resin-based vs 82% glass-based; P = .1) and 65% (95% resin-based vs 56% glass-based; P = .003), respectively. The mean TD thresholds able to predict the objective and complete responses were 176 Gy and 247 Gy for resin-based radioembolization and 290 Gy and 481 Gy for glass-based radioembolization, respectively. A maximum NTD of 999 Gy predicted any-grade AEs in glass-based ablative ⁹⁰Y-TARE.ConclusionsCompared with glass-based ablative ⁹⁰Y-TARE, resin-based ablative ⁹⁰Y-TARE can offer comparable safety and effectiveness profiles for patients with HCC. The impact of the significantly different tumor particle loading, particle specific activities, and delivered TDs on tumor response outcomes merits further investigation.     

Nerve Injury and Regeneration after Neurolysis: Ethanol Alone versus Ethanol with Brachytherapy in Rabbits

PurposeThis study aimed to prove the hypothesis that neurolysis based on ethanol injection in combination with iodine-125 (¹²⁵I) radioactive seed implantation could prolong the nerve regeneration time compared with that based on ethanol injection alone. The grade of nerve injury was assessed for both methods.Materials and MethodsTwenty female rabbits (mean weight, 2.8 kg ± 0.2) were randomly assigned to group A (neurolysis of the left brachial plexus nerve based on ethanol injection in combination with ¹²⁵I radioactive seed implantation, n = 10) and group B (neurolysis using ethanol injection alone, n = 10). The right brachial plexus nerve was used as a control. Injury and regeneration of the brachial plexus nerve were analyzed using electromyography. Statistical tests were performed using the Mann-Whitney U test and repeated-measures analysis of variance. The results were verified with histopathological examinations.ResultsThe overall postprocedural amplitude was significantly lower in group A than in group B (P = .01), particularly in the second month after the procedure (P = .036). However, no statistical difference in latency was observed between the 2 groups (P = .103). Histopathological examination of both groups revealed Sunderland third-degree peripheral nerve injury (PNI), which was mainly characterized by axonal disintegration. The degree of nerve regeneration was significantly lower in group A than in group B.ConclusionsNeurolysis based on ethanol injection in combination with ¹²⁵I radioactive seed implantation can prolong the nerve regeneration time compared with that based on ethanol injection alone, although both methods resulted in Sunderland third-degree PNI.