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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., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).)

Purpose: To evaluate the coagulative performance of a 21-gauge (G) internally cooled radiofrequency (RF) electrode using ex vivo and in vivo rat liver., Materials and Methods: We developed a prototype of 21-G internally cooled monopolar RF electrode with 5.0 mm active tip length. The ablative zone size created by this electrode was evaluated in ex vivo and in vivo rat liver. Five RF powers (3 W, 5 W, 7 W, 9 W, and 11 W) were applied with and without circulation of chilled water within the electrode. The ablation zone sizes were compared. Histopathological evaluation of the ablation zone was also performed at 24 h and at 7 days after RF ablation., Results: From ex vivo experiments, the ablation volume was found to increase significantly when RF energy was applied with the chilled water circulation. Results of in vivo experiments demonstrate that the ablation volume reached its maximum value when RF power of 7 W was applied (532.3 ± 110.3 mm 3 ). Histopathological examination showed delineated coagulation necrosis at 24 h after RF ablation, which clarified the ablation zone border. Fibrotic change was also observed at 7 days after RF ablation., Conclusion: RF ablation using a 21-gauge electrode produced coagulation necrosis in the rat liver. The ablation volume became maximum when RF power of 7 W was applied with chilled water circulation.

Purpose: To determine the tumor immune cell landscape after transcatheter arterial bland embolization (TAE) in a clinically relevant rat hepatocellular carcinoma (HCC) model., Materials and Methods: Buffalo rats (n = 21) bearing syngeneic McArdle RH-7777 rat hepatoma cells implanted into the left hepatic lobe underwent TAE using 70-150 µm beads (n = 9) or hepatic artery saline infusion (n = 12). HCC nodules, peritumoral margin, adjacent non-cancerous liver, and splenic parenchyma were collected and disaggregated to generate single-cell suspensions for immunological characterization 14 d after treatment. Changes in tumor-infiltrating immune subsets including CD4 T cells (Th17 and Treg), CD8 cytotoxic T cells (IFNγ), and neutrophils were evaluated by multiparameter flow cytometry. Migration and colony formation assays were performed to examine the effect of IL-17, a signature cytokine of Th17 cells, on McArdle RH-7777 hepatoma cells under conditions simulating post-embolization environment (i.e., hypoxia and nutrient privation). Statistical significance was determined by the Student unpaired t test or one-way ANOVA., Results: TAE induces increased infiltration of Th17 cells in liver tumors when compared with controls 14 d after treatment (0.29 ± 0.01 vs. 0.19 ± 0.02; p = 0.02). A similar pattern was observed in the spleen (1.41 ± 0.13 vs. 0.57 ± 0.08; p < 0.001), indicating both local and systemic effect. No significant differences in the percentage of FoxP3 + Tregs, IFNγ-producing CD4 T cells, and CD8 T cells were observed between groups (p > 0.05). In vitro post-embolization assays demonstrated that IL-17 reduces McA-RH7777 cell migration at 24-48 h (p = 0.003 and p = 0.002, respectively)., Conclusion: Transcatheter hepatic arterial bland embolization induces local and systemic increased infiltration of Th17 cells and expression of their signature cytokine IL-17. In a simulated post-embolization environment, IL-17 significantly reduced McA-RH7777 cell migration.

Purpose: This phase II prospective study investigates possible benefits of radiofrequency ablation (RFA) combined with hepatic arterial chemoembolization using degradable starch microsphere (DSM) mixed with mitomycin C (MMC) in non-surgical candidates with colorectal liver metastases., Materials and Methods: This study, approved by the respective institutional review board, included non-surgical candidates with 3 or fewer liver tumors of 3 cm or smaller, or a single lesion 5 cm or smaller. Percutaneous RFA was performed immediately after chemoembolization using DSM-MMC. Primary and secondary endpoints were the local tumor control rate, safety, and 2-year recurrence-free and overall survival rates., Results: This study examined 25 patients (22 males, 3 females) with 38 tumors of mean maximum diameter of 2.2 ± 0.9 cm (standard deviation) (range 1.0-4.2 cm). Their mean age was 70.2 ± 8.2 years (range 55-82 years). Local tumor progression developed in 3 tumors (7.9%, 3/38) of 3 patients (12%, 3/25) during the mean follow-up of 34.9 ± 9.2 months (range 18.3-50.1 months). The 2-year local tumor control rates were 92.0% [95% confidence interval (CI), 81.4-100%] on a patient basis and 94.6% (95% CI, 87.3-100%) on a tumor basis. The respective 2-year overall and recurrence-free survival rates were 88.0% (95% CI, 75.3-98.5%) and 63.3% (95% CI, 44.2-82.5%), with median survival time of 48.4 months. Fever was the only adverse event requiring treatments in 2 patients (8%)., Conclusions: This combination therapy is safe, exhibiting strong anticancer effects on colorectal liver metastasis, which might contribute to patient survival.

Purpose: To evaluate long-term results of stent placement retrospectively in patients with outflow block after living-donor-liver transplantation (LDLT)., Materials and Methods: For this institutional review board approved retrospective study conducted during 2002-2012, stents were placed in outflow veins in 15 patients (11.3%, 15/133) (12 men; 3 female) in whom outflow block developed after LDLT. Their mean age was 52.3 years ± 15.3 (SD) (range, 4-69 years). Venous stenosis with a pressure gradient ≥5 mmHg (outflow block) was observed in the inferior vena cava in seven patients, hepatic vein in seven patients, and both in one patient. Technical success, change in a pressure gradient and clinical manifestations, and complications were evaluated. Overall survival of 15 patients undergoing outflow block stenting was compared with that of 116 patients without outflow block after LDLT., Results: Stents were placed across the outflow block veins without complications, lowering the pressure gradient ≤ 3 mmHg in all patients (100%, 15/15). Clinical manifestations improved in 11 patients (73.3%, 11/15), and all were discharged from the hospital. However, they did not improve in the other 4 patients (26.7%, 4/15) who died in the hospital 1.0-3.7 months after stenting (mean, 2.0 ± 1.2 months). No significant difference in 5-year survival rates was found between patients with and without outflow block after LDLT (61.1 vs. 72.2%, p = .405)., Conclusion: Stenting is a feasible, safe, and useful therapeutic option to resolve outflow block following LDLT, providing equal survival to that of patients without outflow block.

Purpose: The purpose of this study was to evaluate the efficacy of portal venous (PV) stent placement and find groups who benefit from this procedure among patients with symptomatic PV hypertension caused by malignant tumors., Materials and Methods: From October 2001 to January 2013, 13 patients underwent PV stent placement because of PV stenosis or occlusion caused by bile duct cancer (n = 7), pancreatic cancer (n = 5), or nodal metastasis (n = 1). Technical success, changes in PV pressure gradient and palliative prognostic index (PPI) scores before and after stent placement, clinical outcomes, and complications were evaluated., Result: Stent was successfully placed in all patients (100 %, 13/13), lowering the mean PV pressure gradient from 12.4 ± 4.5 mmHg (range 5-20 mmHg) to 0.5 ± 0.9 mmHg (range 0-3 mmHg, p < 0.000001). Symptoms were improved in all but one patient (92.3%, 12/13). Although 10 patients (76.9%, 10/13) with pre-stent placement PPI scores lower than 6 (mean 3.5 ± 1.7, range 0-5) were discharged from the hospital, the other 3 with the pre-stent placement PPI of 6 or more (mean 7.2 ± 1.6, range 6-9.5) died within 4 weeks (range 17-28 days) without discharge. The median survival time of discharged patients was 123 days, and it was 20 days in non-discharged patients (p = 0.0001). A major procedure-related complication of intraperitoneal hemorrhage occurred in one patient (7.7%, 1/13). No significant factor was detected for the occurrence of complication., Conclusion: PV stent placement is a feasible, safe, and effective technique to relieve symptomatic PV hypertension caused by malignant tumors. The PPI score might be useful to stratify patients who benefit from this procedure.

Purpose: To evaluate whether arterial injection of miriplatin-iodized oil suspension facilitates ablative zone expansion by radiofrequency (RF) ablation using a Cool-Tip electrode and to provide effective tissue platinum concentration in the normal swine liver., Materials and Methods: RF ablation was performed at three sites of each liver. RF ablation alone was performed in two animals (control). Ablation was performed after arterial injection of iodized oil (iodized-oil group) or a miriplatin-iodized oil suspension (miriplatin group) in two animals each. Long- and short-axis diameters of the ablative zone were measured. In the miriplatin group, tissue platinum concentrations were measured in the ablative, surrounding hyperemic rim, and nonablative zones., Results: The mean long- and short-axis diameters of ablative zones were 27.0 ± 3.1 and 18.0 ± 0.6 mm in the control. Although the long-axis diameter (30.2 ± 2.8 mm, p = 0.07) showed no significant expansion, the short-axis diameter (20.8 ± 2.6 mm, p = 0.04) was significantly expanded more in the iodized-oil group than in the control. Ablative zone sizes were largest in the miriplatin group. The long-axis diameter (33.5 ± 2.4 mm, p = 0.01) was significantly larger than that in the control. The short-axis diameter (27.2 ± 1.9 mm, p = 0.004) was significantly larger than that of the iodized-oil group. Tissue platinum concentrations showed an effective antitumor effect (≥9 μg/g) in ablative (16.5 ± 5.7 μg/g), surrounding hyperemic rim (18.0 ± 5.1 μg/g), and nonablative zones (mean 22.2 ± 5.7 μg/g) (p = 0.21)., Conclusion: Arterial injection of miriplatin-iodized oil suspension can expand the ablative zone size and provide effective tissue platinum concentration on tumor control in the ablative zones and their surrounding hyperemic rim.

This study evaluated the safety, feasibility, and clinical utility of hyaluronic acid gel injection to separate the gastrointestinal tract from the tumor during liver radiofrequency ablation (RFA). Eleven patients with liver tumors measuring 0.9-3.5 cm (mean ± standard deviation, 2.1 ± 0.8 cm) that were adjacent to the gastrointestinal tracts received RFA after the mixture of hyaluronic acid gel and contrast material (volume, 26.4 ± 14.5 mL; range, 10-60 mL) was injected between the tumor and the gastrointestinal tract under computed tomographic-fluoroscopic guidance. Each tumor was separated from the gastrointestinal tract by 1.0-1.5 cm (distance, 1.2 ± 0.2 cm) after injection of hyaluronic acid gel, and subsequent RFA was performed without any complications in all patients. Although tumor enhancement disappeared in all patients, local tumor progression was found in a patient (9.1%, 1 of 11) during the follow-up of 5.5 ± 3.2 months (range, 0.4-9.9 months). In conclusion, hyaluronic acid gel injection is a safe and useful technique to avoid thermal injury of the adjacent gastrointestinal tract during liver RFA.

Purpose: To evaluate the incidence and cause of hypertension prospectively during adrenal radiofrequency ablation (RFA)., Methods: For this study, approved by our institutional review board, written informed consent was obtained from all patients. Patients who received RFA for adrenal tumors (adrenal ablation) and other abdominal tumors (nonadrenal ablation) were included in this prospective study. Blood pressure was monitored during RFA. Serum adrenal hormone levels including epinephrine, norepinephrine, dopamine, and cortisol levels were measured before and during RFA. The respective incidences of procedural hypertension (systolic blood pressure >200 mmHg) of the two patient groups were compared. Factors correlating with procedural systolic blood pressure were evaluated by regression analysis., Results: Nine patients underwent adrenal RFA and another 9 patients liver (n = 5) and renal (n = 4) RFA. Asymptomatic procedural hypertension that returned to the baseline by injecting calcium blocker was found in 7 (38.9%) of 18 patients. The incidence of procedural hypertension was significantly higher in the adrenal ablation group (66.7%, 6/9) than in the nonadrenal ablation group (11.1%, 1/9, P < 0.0498). Procedural systolic blood pressure was significantly correlated with serum epinephrine (R (2) = 0.68, P < 0.0001) and norepinephrine (R (2) = 0.72, P < 0.0001) levels during RFA. The other adrenal hormones did not show correlation with procedural systolic blood pressure., Conclusion: Hypertension occurs frequently during adrenal RFA because of the release of catecholamine.

Purpose: A retrospective evaluation was done of clinical utility of lung radiofrequency (RF) ablation in recurrent non-small-cell lung cancer (NSCLC) after surgical intervention., Methods: During May 2003 to October 2010, 44 consecutive patients (26 male and 18 female) received curative lung RF ablation for 51 recurrent NSCLC (mean diameter 1.7±0.9 cm, range 0.6 to 4.0) after surgical intervention. Safety, tumor progression rate, overall survival, and recurrence-free survival were evaluated. Prognostic factors were evaluated in multivariate analysis., Results: A total of 55 lung RF sessions were performed. Pneumothorax requiring pluerosclerosis (n=2) and surgical suture (n=1) were the only grade 3 or 4 adverse events (5.5%, 3 of 55). During mean follow-up of 28.6±20.3 months (range 1 to 98), local tumor progression was found in 5 patients (11.4%, 5 of 44). The 1-, 3-, and 5-year overall survival rates were 97.7, 72.9, and 55.7%, respectively. The 1- and 3-year recurrence-free survival rates were 76.7 and 41.1%, respectively. Tumor size and sex were independent significant prognostic factors in multivariate analysis. The 5-year survival rates were 73.3% in 18 women and 60.5% in 38 patients who had small tumors measuring≤3 cm., Conclusion: Our results suggest that lung RF ablation is a safe and useful therapeutic option for obtaining long-term survival in treated patients.

Purpose: To evaluate changes in blood pressure during adrenal radiofrequency ablation (RFA) and analyze histopathologic outcomes in swine adrenal glands., Materials and Methods: Animal Care Committee approval was obtained for this study. After laparotomy, a single adrenal gland was ablated from each of six animals (six RF sessions total). An internally cooled-tip RF electrode was placed along the long axis of the adrenal gland, and RF energy was applied for 10 min in each adrenal gland. Blood pressure and heart rate were monitored, and serum epinephrine, norepinephrine, and cortisol levels were measured before, during, and after RFA. Histological study was performed using hematoxylin-eosin staining., Results: RFA was completed according to a planned protocol in all adrenal glands. Blood pressure increased to >200 mm Hg after an increase in heart rate during all six RF sessions. Mean serum epinephrine and norepinephrine levels increased significantly during RFA. However, mean cortisol levels showed no significant increase during or after RFA. Histological studies showed adrenal cell necrosis throughout the adrenal glands in all but one pig, with the mean necrosis rate being 99.1 ± 2.3% (range 94.3-100%)., Conclusion: Adrenal RFA causes extensive adrenal cell damage and causes catecholamine-induced hypertension.

A 47-year-old man presented with multiple lung metastases from parathyroid carcinoma that caused hyperparathyroidism and refractory hypercalcemia. Lung radiofrequency (RF) ablation was repeated to decrease the serum calcium and parathyroid hormone levels and improve general fatigue. Pulmonary resection was combined for lung hilum metastases. The patient is still alive 4 years after the initial RF session. He has received 20 RF sessions for 50 lung metastases during this period.

A 75-year-old man received lung radiofrequency (RF) ablation to treat lung metastases from hepatocellular carcinoma. Massive hemoptysis occurred 1 week after lung RF ablation. Emergent contrast-enhanced CT and pulmonary arteriography revealed a pulmonary artery pseudoaneurysm, which was embolized with coils. The postembolization course was uneventful. Hemoptysis did not recur for 5 months.

This study evaluated the safety, feasibility, and clinical utility of transhepatic drainage of inaccessible abdominal abscesses retrospectively under real-time computed tomographic (CT) guidance. For abdominal abscesses, 12 consecutive patients received percutaneous transhepatic drainage. Abscesses were considered inaccessible using the usual access route because they were surrounded by the liver and other organs. The maximum diameters of abscesses were 4.6-9.5 cm (mean, 6.7 +/- 1.4 cm). An 8-Fr catheter was advanced into the abscess cavity through the liver parenchyma using real-time CT fluoroscopic guidance. Safety, feasibility, procedure time, and clinical utility were evaluated. Drainage catheters were placed with no complications in abscess cavities through the liver parenchyma in all patients. The mean procedure time was 18.8 +/- 9.2 min (range, 12-41 min). All abscesses were drained. They shrank immediately after catheter placement. In conclusions, this transhepatic approach under real-time CT fluoroscopic guidance is a safe, feasible, and useful technique for use of drainage of inaccessible abdominal abscesses.

Purpose: To prospectively evaluate the feasibility, safety, and clinical utility of bone radiofrequency (RF) ablation with real-time monitoring of the spinal canal temperature for the treatment of spinal tumors adjacent to the spinal cord., Materials and Methods: Our Institutional Review Board approved this study. Patients gave informed consent. The inclusion criteria were (a) a painful spinal metastasis and (b) a distance of 1 cm or less between the metastasis and the spinal cord. The thermocouple was placed in the spinal canal under CT fluoroscopic guidance. When the spinal canal temperature reached 45 degrees C, RF application was immediately stopped. RF ablation was considered technically successful when the procedure was performed without major complications. Clinical success was defined as a fall in the visual analogue scale score of at least 2 points., Results: Ten patients with spinal tumors measuring 3-8 cm (mean, 4.9 +/- 1.5 cm) were enrolled. The distance between the tumor and the spinal cord was 1-6 mm (mean, 2.4 +/- 1.6 mm). All procedures were judged technically successful (100%). The spinal canal temperature did not exceed 45 degrees C in 9 of the 10 patients (90%). In the remaining patient, the temperature rose to 48 degrees C, resulting in transient neural damage, although RF application was immediately stopped when the temperature reached 45 degrees C. Clinical success was achieved within 1 week in all patients (100%)., Conclusion: Bone RF ablation with real-time monitoring of the spinal canal temperature is feasible, safe, and clinically useful for the treatment of painful spinal metastases adjacent to the spinal cord.

Arterial rupture subsequent to angioplasty occurs in about 5% of cases. Thrombolysis with re-establishment of flow without resolving underlying anatomic defects such as hepatic arterial stenosis leads to re-thrombosis. We present a case of arterial anastomotic rupture after thrombolysis and angioplasty of an underlying anastomotic hepatic arterial stenosis. Both the underlying anatomic defect and the rupture were resolved successfully with placement of a stent-graft, with a resultant patent artery for 1 year after the procedure.

The purpose of the study was to evaluate the feasibility, safety, and therapeutic effects of the combination of renal arterial embolization and radiofrequency (RF) ablation to reinforce the anticancer effect on renal cell carcinomas (RCCs) measuring 3.5 cm or larger. This study was undertaken to evaluate this combined therapy on large RCCs-based tumor geometry. Eleven patients with 12 RCCs 3.5 cm or larger in diameter (3.5-9.0 cm) underwent combined therapy. Two were exophytic tumors, and the remaining 10 tumors had components extending into the renal sinus fat. Tumor vessels were selectively embolized in nine patients and the renal artery was completely embolized in two patients with polyvinyl alcohol or ethanol mixed with iodized oil. RF ablation was percutaneously done under the computed tomographic (CT)-fluoroscopic guidance. Response to treatment was evaluated by dynamic contrast-enhanced CT and magnetic resonance (MR) imaging. Tumor enhancement was eliminated after a single RF session in nine tumors (75%), after two sessions in two tumors (17%), and after four sessions in one tumor (8%). Both exophytic tumors (100%) and 7 of 10 tumors having components in the renal sinus fat (70%) were completely ablated with a single RF session. All tumors remained controlled during a mean follow-up period of 13 months and showed significant reduction in tumor sizes (5.2 +/- 1.7 cm to 3.6 +/- 1.4 cm, p < 0.001). A delayed abscess developed in the ablated lesion in a patient, which was percutaneously drainaged. Combined therapy as described in this report is a feasible, relatively safe, and promising treatment method for large RCCs regardless of tumor geometry.

Five hepatocellular carcinomas and one liver metastasis located in the caudate lobe left of the inferior vena cava were successfully treated by radiofrequency (RF) ablation by placing the RF electrode into each tumor through the left lobe of the liver under the CT-fluoroscopic guidance. All tumors were free of enhancement on dynamic contrast-enhanced CT during the mean follow-up period of 6.3 months. There were no major complications related to the procedures.

Lung radiofrequency (RF) ablation was performed for the treatment of a primary lung cancer measuring 2.5 cm in maximum diameter in a 78-year-old man. A contrast-enhanced computed tomography (CT) study performed 3 months after RF ablation showed incomplete ablation of the lung tumor and the appearance of a chest wall tumor 4.0 cm in maximum diameter that was considered to be the result of needle-tract seeding. RF ablation was performed for the treatment of both the lung and the chest wall tumors. Although tumor enhancement was eradicated in both of the treated tumors, follow-up CT studies revealed diffuse intra-pulmonary metastases in both lungs 2 months after the second RF session. He is currently receiving systemic chemotherapy.