Radiofrequency ablation in patients with interstitial lung disease and lung neoplasm: a retrospective multicenter study.

PURPOSE: To retrospectively investigate the safety and efficacy of percutaneous radiofrequency ablation (RFA) by analyzing results in patients with lung neoplasm accompanied by interstitial lung disease (ILD) on computed tomography (CT) in a multicenter study. MATERIALS & METHODS: Patients with lung neoplasm accompanied by ILD who underwent RFA between April 2002 and October 2017 at seven institutions were investigated. Technical success rate, and local tumor progression (LTP) of ablated tumors were evaluated. Adverse events including acute exacerbation of ILD were also evaluated. Univariate analyses were performed to identify factors associated with acute exacerbation. RESULTS: Forty-nine patients with 64 lung neoplasm (mean diameter, 22.6 mm; range, 4-58 mm) treated in 66 sessions were included. Usual interstitial pneumonia (UIP) pattern on CT was identified in 23 patients (47%). All patients underwent successful RFA. Acute exacerbations were seen in 5 sessions (8%: 7% with UIP pattern, 8% without) in 5 patients, all occurring on or after 8 days (median, 12 days; range, 8-30 days). Three of those 5 patients died of acute exacerbation. Treatment resulted in mortality after 5% of sessions, representing 6% of patients. Pleural effusion and fever ≥38°C after RFA were identified by univariate analysis (p = 0.0012, p = 0.02, respectively) as significant risk factors for acute exacerbation. The cumulative LTP rate was 43% at 1 year. CONCLUSIONS: RFA appears feasible for patients with lung neoplasm complicated by ILD. Acute exacerbation occurred in 8% of patients with symptoms occurring more than 8 days post-ablation and was associated with a 45% mortality rate.

Clinical Outcomes of Common Femoral Thromboendarterectomy with Bovine Pericardium Patch Angioplasty.

BACKGROUND: The purpose of the study is to evaluate the efficacy of thromboendarterectomy (TEA) for common femoral occlusive disease using bovine pericardium patch angioplasty. METHODS: The subjects were patients who underwent TEA for common femoral occlusive disease with bovine pericardium patch angioplasty from October 2020 to August 2021. The study had a prospective, multicenter, and observational design. The primary end point was primary patency (freedom from restenosis). The secondary end points were secondary patency, amputation-free survival (AFS), postoperative wound complication, hospital death within 30 days, and major adverse cardiovascular events (MACE) within 30 days. RESULTS: Forty-seven TEA procedures with a bovine patch were performed in 42 patients (34 males; median age, 78 years; diabetes mellitus, 57%; end-stage renal disease with hemodialysis, 19%). Clinical presentations were intermittent claudication (68%) and critical limb-threatening ischemia (32%). Sixteen (34%) limbs underwent TEA alone and 31 (66%) underwent a combined procedure. Surgical site infection (SSI) occurred in 4 limbs (9%) and lymphatic fistulas in 3 limbs (6%). One limb with SSI required surgical debridement 19 days after the procedure, and 1 limb (2%) without postoperative wound complications required additional treatment due to acute bleeding. Hospital death within 30 days occurred in 1 case due to panperitonitis. There was no MACE within 30 days. Claudication was improved in all cases. Postoperative ABI of 0.92 [0.72-1.00] was significantly higher than the preoperative value (P < 0.001). The median follow-up period was 10 months [9-13 months]. One limb (2%) required additional endovascular therapy due to stenosis at the endarterectomy site at 5 months postoperatively. Primary and secondary patencies were 98% and 100% at 12 months, respectively, and the AFS rate was 90% at 12 months. CONCLUSIONS: Common femoral TEA with bovine pericardium patch angioplasty has satisfactory clinical outcomes.

Lenvatinib Mitigates Transarterial Embolization-Induced Polarization of Tumor-Associated Macrophages in a Rat Hepatocellular Carcinoma Model.

PURPOSE: To investigate the effect of transarterial embolization (TAE) on macrophage polarization and the modulatory effect of lenvatinib when used in combination with TAE in a rat hepatocellular carcinoma model. MATERIALS AND METHODS: A N1S1-bearing orthotopic rat model was subjected to TAE and administered 5 mg/kg of lenvatinib. CD8+, CD68+, and CD206+ cells were examined in 4 groups: sham (n = 5), lenvatinib (n = 5), TAE (n = 5), and combination of TAE and lenvatinib (n = 5). Transcriptome analysis was performed to assess gene expression related to macrophage polarization in the sham, TAE, and combination groups. An in vitro coculture experiment with bone marrow-derived macrophages was performed to identify lenvatinib target in macrophage polarization. RESULTS: There were no significant differences in the number of CD8+ and CD68+ cells among the 4 groups. Tumor-associated macrophage positivity for CD206 was significantly higher in the TAE group (58.1 ± 20.9) than in the sham (11.2 ± 14.3; P < .001) and combination (27.1 ± 19.7; P = .003) groups. In the transcriptome analysis, compared with the genes in the sham group, 5 macrophage polarization-related genes, including St6gal1, were upregulated by more than 1.5 fold in the TAE group and downregulated by more than 1.5 fold in the combination group. The coculture experiment showed that lenvatinib did not affect macrophages but affected N1S1 cells, leading to macrophage polarization. CONCLUSIONS: TAE-induced M2 macrophage polarization. Lenvatinib administration with TAE could reprogram macrophage polarization, improving tumor immune microenvironment.

Impact of the Ablative Margin on Local Tumor Progression after Radiofrequency Ablation for Lung Metastases from Colorectal Carcinoma: Supplementary Analysis of a Phase II Trial (MLCSG-0802).

PURPOSE: To explore what extent of ablative margin depicted by computed tomography (CT) immediately after radiofrequency (RF) ablation is required to reduce local tumor progression (LTP) for colorectal cancer (CRC) lung metastases. MATERIALS AND METHODS: This retrospective study was undertaken as a supplementary analysis of a previous prospective trial. Seventy patients (49 men and 21 women; mean age ± standard deviation, 64.9 years ± 10.6 years) underwent RF ablation for CRC lung metastases, and 95 tumors that were treated in the trial and followed up with CT at least 12 months after RF ablation were evaluated. The mean tumor size was 1.0 cm ± 0.5 cm. The ablative margin was estimated as the shortest distance between the outer edge of the tumor and the surrounding ground-glass opacity on CT obtained immediately after RF ablation. The impact of the ablative margin on LTP was evaluated using logistic regression analysis. Multivariate logistic regression analysis was also performed to identify the risk factors for LTP. The result was validated with multivariate logistic regression applying a bootstrap method (1,000 times resampling). RESULTS: The mean ablative margin was 2.7 mm ± 1.3 (range, 0.4-7.3 mm). LTP developed in 6 tumors (6%, 6/95) 6-19 months after RF ablation. The LTP rate was significantly higher when the margin was less than 2 mm (P = .023). A margin of <2 mm was also found to be a significant factor for LTP (P = .048) on multivariate analysis and validated using the bootstrap method (P = .025). CONCLUSIONS: An ablative margin of at least 2 mm is important to reduce LTP after RF ablation for CRC lung metastases.

Clinicopathological features of radiological early malignant pleural mesothelioma with no apparent tumor or pleural thickening.

BACKGROUND: We occasionally encounter malignant pleural mesothelioma (MPM) of no apparent tumor or pleural thickening that is radiological early MPM. This study aimed to examine the clinicopathological outcomes of radiological early MPM. METHODS: Patients with MPM treated with neoadjuvant chemotherapy and planned surgery at the time of diagnosis between July 2004 and December 2019 were retrospectively examined. Pretreatment maximal pleural thickness of all patients was measured on chest computed tomography. We extracted and investigated the patients who exhibited a lack of pleural thickening or visible tumor, which was defined as radiological early MPM. Survival was analyzed by the Kaplan-Meier method. RESULTS: Of 296treated patients, 16 (5.4%) exhibited radiological early MPM. Fourteen (87.5%) of these patients underwent pleurectomy/decortication and 2 (12.5%) underwent extrapleural pneumonectomy. Pathological stage T1 disease was diagnosed in 14 (87.5%) patients; 2 (12.5%) exhibited pulmonary parenchymal invasion (pathological stage T2). Lymphatic invasion was detected in only 1 patient. Lymph node metastases and vascular invasion were not detected. Median follow-up was 42 months. Median progression-free survival and median overall survival were 40.7 and 56.1 months, respectively. The 3-year progression-free survival and overall survival rates were 84.8% and 83.6%, respectively. CONCLUSIONS: Radiological early MPM occurs in approximately 1 of every 20 patients treated with neoadjuvant chemotherapy and surgery planned at the time of diagnosis in an experienced center. Radiological early MPM was associated with early pathological stage and long-term survival.

Three-year Survival Rate after Radiofrequency Ablation for Surgically Resectable Colorectal Lung Metastases: A Prospective Multicenter Study.

Background Although radiofrequency ablation (RFA) is widely performed for the treatment of colorectal cancer (CRC) lung metastases, its efficacy for candidates with surgically resectable disease is unclear. Purpose To evaluate the prognosis after RFA in participants with resectable CRC lung metastases. Materials and Methods For this prospective multicenter study (ClinicalTrials.gov identifier: NCT00776399), participants with five or fewer surgically resectable lung metastases measuring 3 cm or less were included. Participants with CRC and a total of 100 lung metastases measuring 0.4-2.8 cm (mean, 1.0 cm ± 0.5) were chosen and treated with 88 sessions of RFA from January 2008 to April 2014. The primary end point was the 3-year overall survival (OS) rate, with an expected rate of 55%. The local tumor progression rate and safety were evaluated as secondary end points. The OS rates were generated by using the Kaplan-Meier method. Log-rank tests and Cox proportional regression models were used to identify the prognostic factors by means of univariable and multivariable analyses. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Events, version 3.0. Results Seventy participants with CRC (mean age, 66 years ± 10; 49 men) were evaluated. The 3-year OS rate was 84% (59 of 70 participants; 95% confidence interval [CI]: 76%, 93%). In multivariable analysis, factors associated with worse OS included rectal rather than colon location (hazard ratio [HR] = 7.7; 95% CI: 2.6, 22.6; P < .001), positive carcinoembryonic antigen (HR = 5.8; 95% CI: 2.0, 16.9; P = .001), and absence of previous chemotherapy (HR = 9.8; 95% CI: 2.5, 38.0; P < .001). Local tumor progression was found in six of the 70 participants (9%). A grade 5 adverse event was seen in one of the 88 RFA sessions (1%), and grade 2 adverse events were seen in 18 (20%). Conclusion Lung radiofrequency ablation provided a favorable 3-year overall survival rate of 84% for resectable colorectal lung metastases measuring 3 cm or smaller. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Gemmete in this issue.

Hepatic Artery Embolization Enhances Expression of Programmed Cell Death 1 Ligand 1 in an Orthotopic Rat Hepatocellular Carcinoma Model: In Vivo and in Vitro Experimentation.

PURPOSE: To evaluate the effects of hepatic artery embolization (HAE) on the expression of programmed cell death 1 ligand 1 (PD-L1) in an orthotopic rat hepatocellular carcinoma (HCC) model. MATERIALS AND METHODS: A rat HCC model was established in Sprague-Dawley rats with the RH7777 cell line. Six animals each were assigned to receive HAE or sham treatment. Liver tissues were harvested 24 h after the procedure. Immunohistochemistry (IHC) was used to compare expression of PD-L1 and hypoxia-inducible factor (HIF)-1α in the intratumoral and peritumoral regions and normal liver tissue. In vitro cell culture study was performed for 24 h under normoxic and hypoxic conditions, and protein expression of PD-L1 and HIF-1α and the effects of HIF-1α inhibitors were assessed. RESULTS: IHC showed that PD-L1- and HIF-1α-positive areas were significantly larger in the HAE group vs the sham group in intratumoral (P = .006 and P < .001, respectively) and peritumoral regions (both P < .001). The expression of PD-L1 positively correlated with HIF-1α expression in the intratumoral region (r2 = 0.551; P < .001). In vitro cell culture study revealed that protein expression of PD-L1 and HIF-1α were significantly higher when cells were incubated under hypoxic vs normoxic conditions (P = .028 and P = .010, respectively). PD-L1 expression was suppressed significantly when the HIF-1α inhibitor rapamycin was added to the culture medium (P = .024). CONCLUSIONS: HAE enhances intratumoral and peritumoral PD-L1 expression in a rat HCC model. The HIF-1α pathway is a possible mechanism underlying increased intratumoral PD-L1 expression after HAE.

Macrophage-secreted TGF-ß1 contributes to fibroblast activation and ureteral stricture after ablation injury.

Iatrogenic injury to the healthy ureter during ureteroscope-guided ablation of malignant or nonmalignant disease can result in ureteral stricture. Transforming growth factor (TGF)-ß1-mediated scar formation is considered to underlie ureteral stricture, but the cellular sources of this cytokine and the sequelae preceding iatrogenic stricture formation are unknown. Using a swine model of ureteral injury with irreversible electroporation (IRE), we evaluated the cellular sources of TGF-ß1 and scar formation at the site of injury and examined in vitro whether the effects of TGF-ß1 could be attenuated by pirfenidone. We observed that proliferation and α-smooth muscle actin expression by fibroblasts were restricted to injured tissue and coincided with proliferation of macrophages. Collagen deposition and scarring of the ureter were associated with increased TGF-ß1 expression in both fibroblasts and macrophages. Using in vitro experiments, we demonstrated that macrophages stimulated by cells that were killed with IRE, but not LPS, secreted TGF-ß1, consistent with a wound healing phenotype. Furthermore, using 3T3 fibroblasts, we demonstrated that stimulation with paracrine TGF-ß1 is necessary and sufficient to promote differentiation of fibroblasts and increase collagen secretion. In vitro, we also showed that treatment with pirfenidone, which modulates TGF-ß1 activity, limits proliferation and TGF-ß1 secretion in macrophages and scar formation-related activity by fibroblasts. In conclusion, we identified wound healing-related macrophages to be an important source of TGF-ß1 in the injured ureter, which may be a paracrine source of TGF-ß1 driving scar formation by fibroblasts, resulting in stricture formation.

High power microwave ablation of normal swine lung: impact of duration of energy delivery on adverse event and heat sink effects.

PURPOSE: The purpose of this study is to assess the impact of duration of energy delivery on adverse events (AEs) and heat sink effects during high power microwave ablation (MWA) of normal swine lung. MATERIALS AND METHODS: High power (100 W) MWA was performed with short (2 min, 18 ablations) or long (10 min, nine ablations) duration of energy delivery in unilateral lung of swine (n = 10). CT imaging was done prior to sacrifice at 2 or 28 d post-treatment, with additional imaging at 7 and 14 d for the latter cohort. Ablation zones were assessed with CT imaging and histopathology analysis. Differences in AEs and ablation characteristics between groups were compared with Fisher's exact test and Student's t-test, respectively. RESULTS: There were no significant differences in formation of air-filled needle tract, cavitation, and pneumonia (p > 0.5) between the treatment groups. Intra-procedural pneumothorax requiring chest tube placement occurred in three animals. Substantial (>20%, p = 0.01) intra-procedural ablation zone distortion was observed in both groups. The presence of large airways or blood vessels did not result in heat sink effect within the ablation zones and was not indicative of reduced ablation size. Increased energy delivery yielded larger (8.9 ± 3.1 cm3 vs. 3.4 ± 1.7 cm3, p < 0.001) spherical ablations (sphericity: 0.70 ± 0.10 vs. 0.56 ± 0.13, p = 0.01). CONCLUSIONS: High power MWA of normal lung with longer duration of energy delivery can create larger spherical ablations, without significant differences in post-procedure AEs when compared with shorter energy delivery time.

A Case of Anterolateral Papillary Muscle Rupture Caused by Isolated First Diagonal Branch Occlusion.

A 74-year-old man hospitalized due to acute myocardial infarction (AMI) of the first diagonal branch developed cardiogenic shock. Ultrasonography showed anterolateral papillary muscle rupture (PMR) which caused anterior mitral leaflet prolapse and severe mitral valve regurgitation, and he successfully underwent mitral valve replacement. Anterolateral PMR causing anterior mitral leaflet prolapse due to obstruction of the first diagonal branch is rare and should be considered in such an AMI case.

Preoperative Tissue Doppler Imaging-Derived Atrial Conduction Time Predicts Postoperative Atrial Fibrillation in Patients Undergoing Mitral Valve Surgery for Mitral Valve Regurgitation.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery and may result in stroke, heart failure and poor prognosis. This study evaluated a novel index of total atrial conduction time derived from the P-wave onset (lead II) to the peak A' wave on tissue Doppler imaging (PA-TDI duration) in patients undergoing mitral valve surgery (MVS) for mitral valve regurgitation. METHODS AND RESULTS: Seventy-three patients undergoing MVS had transthoracic echocardiography with tissue Doppler imaging preoperatively and were monitored postoperatively with continuous electrocardiographic telemetry for 14 days. Preoperative characteristics, echocardiographic data, operative data and postoperative findings were compared between patients with (n=44) and without (n=29) POAF. Postoperative cardiac events were higher in patients with than without POAF (12/44, 27% vs. 3/29, 10%; P=0.0798) and cerebral events occurred in only 2 POAF patients. On multivariate analysis the independent predictors of POAF were degenerative disease etiology (OR, 4.61; 95% CI: 1.41-15.0; P=0.0112) and PA-TDI duration (OR, 1.04; 95% CI: 1.01-1.07; P=0.0048). On ROC curve analysis a PA-TDI cut-off of 159.4 ms was optimal for predicting POAF. CONCLUSIONS: PA-TDI duration was an independent predictor of POAF after MVS. Patients with PA-TDI duration >159.4 ms should be considered high risk and treated appropriately to improve outcome.

Radiofrequency Ablation Using a Multiple-Electrode Switching System for Lung Tumors with 2.0-5.0-cm Maximum Diameter: Phase II Clinical Study.

PURPOSE: To prospectively evaluate the safety and effectiveness of radiofrequency ablation (RFA) by using a multiple-electrode switching system to treat 2.0-5.0-cm lung tumors. MATERIALS AND METHODS: The institutional review board approved this prospective phase II study. Written informed consent was obtained from all patients. Between September 2009 and July 2011, RFA using two or three radiofrequency (RF) electrodes and a multiple-electrode switching system was performed for malignant lung tumors with a maximum tumor diameter of 2.0-5.0 cm in nonsurgical candidates. The primary endpoint was safety, as evaluated using the Common Terminology Criteria for Adverse Events. Patients were observed for at least 1 year. Local tumor progression and overall survival were analyzed with the Kaplan-Meier method. RESULTS: Thirty-three patients (26 men, seven women; mean age, 70.5 years ± 10.0; age range, 46-87 years) with 35 lung tumors with a mean maximum diameter of 3.0 cm ± 0.7 (standard deviation; range, 2.0-4.4 cm) underwent treatment in 35 sessions. No procedure-related death or grade 4 adverse events (AEs) occurred. Grade 3 AEs occurred in four patients (12%), with pleural effusion requiring chest tube placement in two patients, pneumothorax requiring pleural adhesion in one patient, and pulmonary hemorrhage requiring pulmonary artery coil embolization in one patient. Grade 2 AEs were detected in 13 patients (39%). The 1-year local tumor progression and overall survival rates were 12.7% (95% confidence interval [CI]: 1.0, 25.5) and 81.2% (95% CI: 67.6, 94.8). CONCLUSION: RFA with a multiple-electrode switching system may be a safe therapeutic option with which to treat 2.0-5.0-cm lung cancer tumors.

Comparison of therapeutic results from radiofrequency ablation and stereotactic body radiotherapy in solitary lung tumors measuring 5 cm or smaller.

BACKGROUNDS: This retrospective study was conducted to compare the clinical outcomes of radiofrequency ablation (RFA) with those of stereotactic body radiotherapy (SBRT) in patients with lung tumors. METHODS: Local tumor progression, adverse events, and overall survival were compared in patients who underwent either RFA or SBRT for a single lung tumor measuring 5 cm or smaller. This study was approved by the institutional review boards of two institutions. Informed consent was waived. RESULTS: During September 2009 to June 2012, 48 patients [30 males and 18 females, with a mean age ± standard deviation (SD) of 75.0 ± 7.5 years] underwent RFA at one institution and 47 patients (21 males and 26 females, with a mean age ± SD of 77.0 ± 7.5 years) underwent SBRT in another. The mean maximum tumor diameter ± SD was 2.0 ± 0.8 cm (range 0.6-3.9 cm) in the RFA group, and 2.1 ± 0.9 cm (range 0.8-4.7 cm, p = 0.539) in the SBRT group. The RFA and SBRT groups showed similar 3-year local tumor progression [9.6%, 95% confidence interval (CI) 3.6-23.9% vs. 7.0%, 95% CI 0.2-20.2%, p = 0.746] and overall survival rates (86.4%, 95% CI 69.2-94.3% vs. 79.6%, 95% CI 60.6-90.1%, p = 0.738). No factor significantly affected local tumor progression. A maximum tumor size of 2 cm was identified as a prognostic factor in both univariate and multivariate analyses. No death was related to treatment procedures. Major complication rates (Grade 3 adverse events) of the RFA (10.4%, 5/48) and SBRT (8.5%, 4/47, p > 0.999) groups were similar. CONCLUSION: For lung tumor patients, lung RFA provided local tumor control and survival that were similar to those achieved using SBRT, with equal safety.

Radiofrequency ablation for ground-glass opacity-dominant lung adenocarcinoma.

PURPOSE: To evaluate retrospectively the clinical utility of lung radiofrequency (RF) ablation for the treatment of ground-glass opacity (GGO)-dominant lung adenocarcinoma. MATERIALS AND METHODS: From August 2004 through May 2012, 33 consecutive patients (14 men and 19 women; mean age, 71.1 y; age range, 46-84 y) with 42 lung tumors having ≥ 50% GGO component received lung RF ablation. The mean maximum tumor diameter was 1.6 cm ± 0.9 (range, 0.7-4.0 cm). Feasibility, safety, local tumor progression, and survival were evaluated. RESULTS: For the 42 RF sessions, after RF electrodes were placed in each target tumor, planned ablation protocols were completed in all sessions (100%; 42 of 42). No deaths related to the RF procedure occurred. Major and minor complication rates were 4.8% and 23.8%, respectively. Local tumor progression developed in 6 tumors (14.3%; 6 of 42) during a mean follow-up of 42 months ± 23 (range, 5-92 mo). Four of six tumors with local progression were controlled by repeated RF ablation. No evidence of disease was achieved in 31 of 33 patients (93.9%) at the end of the follow-up period. All but one patient (who died of brain hemorrhage) are alive today. Overall and cancer-specific survival rates were 100% and 100% at 1 year, 96.4% (95% confidence interval [CI], 77.5%-99.5%) and 100% at 3 years, and 96.4% (95% CI, 77.5%-99.5%) and 100% at 5 years, respectively. CONCLUSIONS: Lung RF ablation is a feasible, safe, and useful therapeutic option to control GGO-dominant lung adenocarcinoma.

Efficacy of Percutaneous Direct Puncture Biopsy of Malignant Lung Tumors Contacting to the Pleura.

BACKGROUND/AIM: This is a retrospective evaluation of whether percutaneous direct puncture biopsy of lung lesions contacting to the pleura is justified. PATIENTS AND METHODS: Between August 2016 and July 2021, 163 consecutive patients (100 males, 63 females with a median age of 73 years) who had malignant lung tumors measuring 0.6-12.4 cm (median, 2.9 cm) that contacted to the pleura and underwent percutaneous lung biopsy under computed tomography fluoroscopic guidance using an 18-gauge end-cut needle were examined. The trajectory was direct puncture in 80 patients (49.1%, 80/163), and trans-lung in 83 patients (50.9%, 83/163). Diagnostic yield and major adverse event rates of direct and trans-lung puncture biopsies were compared. RESULTS: No difference was found in diagnostic yield between direct puncture and trans-lung biopsies (93.8% vs. 98.8%, p=0.11). Major adverse events were major pneumothorax (n=13/163, 8.0%), pleural dissemination (n=18/163, 11.0%), and hemothorax requiring arterial embolization (n=1/163, 1.0%). Direct puncture caused major pneumothorax significantly less than trans-lung puncture did (0%, 0/80 vs. 15.7%, 13/83, p<0.001). No significant difference was found between the two biopsy methods regarding the incidence of pleural dissemination (11.0%, 11/80 vs. 8.4%, 7/83, p=0.32). CONCLUSION: Direct puncture biopsy of malignant lung tumors contacting to the pleura is justified.

Untangling a Knotted Angiographic Catheter Using a Balloon Catheter: A Case Report.

When a 66-year-old man with hepatocellular carcinoma underwent an angiographic examination, a 4-Fr catheter was inserted from the right femoral artery. It became tightly knotted in the descending aorta. To untangle the knotted catheter, a noncompliant balloon catheter was delivered into the knotted loop from the contralateral femoral artery. After the balloon catheter was inflated from the inside of the knotted loop, the knot became loose. Finally, the knotted catheter was untangled. Subsequently, the remainder of the examination was performed as initially planned.

Radioprotective Effects of a Semicircular X-ray Shielding Device for Operators During CT Fluoroscopy-Guided Interventional Procedures: Experimental and Clinical Studies.

PURPOSE: To evaluate, experimentally and clinically, the radioprotective effects of a semicircular X-ray shielding device for operators during CT fluoroscopy-guided IR procedures. MATERIALS AND METHODS: During experimentation, the reduction rates of scattered radiation rates from CT fluoroscopy were evaluated using a humanoid phantom. Two shielding device positions were tested: "shielding close to the CT gantry" and "shielding close to the operator". The scattered radiation rate without shielding was also evaluated. The clinical study retrospectively evaluated the operator's radiation exposure during 314 CT-guided IR procedures. With a semicircular X-ray shielding device (with shielding group, n = 119) or without it (no shielding group, n = 195), CT fluoroscopy-guided IR procedures were performed. Radiation dose measurements were taken using a pocket dosimeter placed near the operator's eye. For shielding and no shielding groups, the procedure time, dose length product (DLP), and the operator's radiation exposures were compared. RESULTS: Experimentation revealed the respective mean reduction rates of "shielding close to the CT gantry" and "shielding close to the operator" as 84.3% and 93.5% compared with the no-shielding setting. Although no significant differences were found in the procedure time and the DLP between "no shielding" and "with shielding" groups in the clinical study, the operators' radiation exposure in the "with shielding" group (0.03 ± 0.04 mSv) was significantly lower than in the "no shielding" group (0.14 ± 0.15 mSv; p < .001). CONCLUSION: The semicircular X-ray shielding device provides valuable radioprotective effects for operators during CT fluoroscopy-guided IR.

Radiofrequency Ablation Combined with Hepatic Artery Embolization Using a Tris-acryl Gelatin Microsphere for Colorectal Liver Metastases-Initial Experience.

Purpose: We aim to evaluate retrospectively the feasibility, safety, and initial therapeutic outcomes of radiofrequency ablation combined with hepatic artery embolization using a tris-acryl gelatin microsphere for colorectal liver metastases. Material and Methods: Six consecutive patients (4 men and 2 women) with median age of 68 years (range 57-78 years) underwent computed tomography fluoroscopy-guided radiofrequency ablation immediately after hepatic artery embolization using microspheres. This study evaluated tumor visibility on noncontrast-enhanced computed tomography immediately after hepatic artery embolization; analyzed local tumor progression; defined technical success as the coverage of the tumor by the ablative zone; and assessed adverse events based on Common Terminology Criteria for Adverse Events v5.0. Results: Ten tumors with median maximum diameter of 9 mm (range 5-52 mm) were treated in nine sessions. Eight tumors (80%, 8/10 tumors) were detected as high-attenuation nodules. One tumor was treated in two sessions because follow-up computed tomography revealed an insufficient ablative margin. Therefore, the primary and secondary technical success was 90% (9/10 tumors) and 100% (10/10 tumors), respectively. Grade 2 pneumothorax was observed in one session (11%, 1/9 sessions). No grade 3 or higher adverse event was observed. The local tumor progression rate was 20% (2/10 tumors) during the median follow-up of 14 months. Conclusions: Radiofrequency ablation following microsphere embolization may be a feasible, safe, and useful therapeutic option for controlling small colorectal liver metastases.

Clinical Utility of Bland Embolization Using Microspheres for Painful Malignant Musculoskeletal Tumors.

BACKGROUND/AIM: To evaluate retrospectively whether bland embolization using microspheres is safe and useful for relieving pain in patients with painful malignant musculoskeletal (MSK) tumors. PATIENTS AND METHODS: Bland embolization using microspheres was performed for 20 patients (11 women/9 men) with a median age of 69 years (range=40-89 years) who had 22 painful malignant MSK tumors. The maximum tumor diameters were 2.4-13.8 cm (median, 7.5 cm). Pain was evaluated using the visual analog scale. A decrease of this score by 2 or more after embolization was defined as clinically effective pain relief. Adverse events (AEs) were evaluated using CTCAE v5.0. Objective response, disease control rates, and overall survival were also evaluated. RESULTS: Effective pain relief was achieved in 18 patients (90.0%, 18/20). Grade-3 AEs developed in four patients (20.0%, 4/20): skin ulcer (n=2), skin ulcer and pain (n=1), and muscle weakness with dysesthesia (n=1). No grade-4 or grade-5 AEs developed. Objective response and disease control rates were 26.7% (4/15) and 86.7% (13/15), respectively. The 1-year survival rate was 43.8%, with median survival of 9.2 months (range=0.5-41.0 months). CONCLUSION: Although the survival benefit is equivocal, bland embolization is acceptably safe and useful for relieving pain by controlling tumor growth in patients with painful malignant MSK tumors.

[Breast Decompression Using Automatic Pressure Reduction Control Function: Relationship between Breast Thickness, Density, and Compression Pressure].

PURPOSE: This retrospective study was conducted to evaluate whether the breast density and initial compression pressure affected the compressed breast thickness (CBT) and compression pressure after decompression using compression control function (CCF) during mammography. METHODS: Consecutive 779 mammograms obtained from 392 patients between February and October 2019 were included. The initial compression was randomly performed at 110 N-140 N. CCF was set to stop decompression when the pressure decreased to 80 N or restoration of CBT reached 3 mm. If the CCF stopped due to 3 mm or more restoration of CBT, it was defined as goal unachieved. Mammograms were classified into non-dense and dense groups. CBT, ∆P (actual compression pressure after decompression-80 N), and the ratio of goal unachieved were compared between breast density subgroups and among initial compression pressure. RESULTS: CBT was significantly different between non-dense and dense groups both at initial compression (42.3±12.1 mm vs. 27.6±9.7 mm, p<0.001) and after decompression (44.6±12.3 mm vs. 29.7±9.9 mm, p<0.001), but not different based on initial compression pressure. The higher the initial compression pressure, the higher the ∆P. When the initial compression pressure was 130 N and 140 N, ∆P was significantly higher in the non-dense group, -0.1±3.7 N vs. -1.6±2.7 N (p=0.0018) and 2.9±5.8 N vs. 0.4±3.3 N (p<0.001), respectively. Goal unachieved was significantly frequent in the non-dense group (19.6% vs. 13.1%, p=0.016). CONCLUSION: Breast density and initial compression pressure affected the decompression using CCF. Especially with lower initial compression pressure to the dense breast, decompression using CCF was successfully performed.