Radiofrequency Ablation Of Hepatic Tumors Research Articles

Gastrointestinal tract perforation after radiofrequency ablation for hepatic tumor: Incidence and risk factors

ObjectiveWe analyzed the incidence and mortality rate of gastrointestinal (GI) tract perforation after radiofrequency ablation (RFA) for hepatic tumors and assess its risk factors. MethodsThis retrospective cohort study included 4799 patients with malignant tumors who underwent RFA (n = 7206). Sixty-nine cases of thermal injury to the GI tract were identified via a search of the electronic medical record system using index terms and divided into two groups according to the thermal injury with (n = 8) or without (n = 61) GI tract perforation based on follow-up CT reports. The risk factors for GI tract perforation were identified via multivariable logistic regression analysis using clinical, technical, and follow-up CT findings. ResultsThe incidence of thermal injury to the GI tract and GI tract perforation was 0.96 % (69/7206) and 0.11 % (8/7206), respectively. The type of adjacent GI tract and history of diabetes mellitus differed significantly between the two groups (p < 0.05). The index tumor being located around the small intestine was the only significant risk factor for GI tract perforation after ablation (Odds ratio, 22.69; 95 % confidence interval, 2.59–198.34; p = 0.005 [reference standard, stomach]). All perforations were not identified on CT images immediately after RFA. The median time to detection was 20 days (range, 3–41 days). Two patients (25 %, 2/8) died due to perforation-related complications. ConclusionGI tract perforation after RFA for hepatic tumors is rare; however, it is associated with high mortality. Thus, careful follow-up is required after RFA if the index tumor is located around the small intestine.

Hemostasis using re-radiofrequency ablation for hepatic tract bleeding after ultrasound-guided percutaneous radiofrequency ablation of hepatic tumors

To evaluate the hemostatic efficacy of re-radiofrequency ablation (re-RFA) for hepatic tract bleeding after ultrasound-guided RFA of hepatic tumors. A total of 4679 percutaneous ultrasound-guided RFA procedures were performed for hepatic tumors at Samsung Medical Center between January 2012 and December 2020. We identified patients who had hepatic tract bleeding after RFA by reviewing radiologic reports and ultrasound images and investigated the measures taken to control the bleeding and their outcomes. We also identified patients who had a significant peritoneal hematoma on immediate post-RFA CT or underwent transarterial embolization to control hepatic bleeding after RFA of hepatic tumors. In total, 91 patients with tract bleeding after RFA were identified. As initial measures to control the bleeding, external compression, re-RFA, and observation were performed in 71 (78%), 17 (19%), and 3 (3%) patients, respectively. Hemostasis using re-RFA was attempted to control tract bleeding in 40 patients as an initial measure or an additional measure after other initial efforts. In all 40 patients, the bleeding stopped after re-RFA on Doppler ultrasound, and there was no active bleeding on the immediate follow-up CT. During the study period, in the years when re-RFA was performed frequently, the number of transarterial embolizations to control tract bleeding and significant peritoneal hematoma formation tended to be low. Hemostasis using re-RFA of the needle tract is effective in controlling tract bleeding after ultrasound-guided RFA of hepatic tumors. Re-RFA is a simple, safe, and effective method to control tract bleeding.

Percutaneous radiofrequency ablation for hepatic tumors: factors affecting baseline impedance.

We aimed to evaluate factors that affect baseline impedance of percutaneous radiofrequency ablation. In this retrospective study, we analyzed 51 patients with 55 hepatic tumors from November 2015 until April 2018. We measured the baseline impedance nine times with three adjustable tip sizes (2 cm, 2.5 cm, 3 cm) and three different pad locations (two pads attached on the thigh, four on the thigh, two on the back). The first roll-off time was measured with two grounding pads attached on the back. Body mass index, cirrhotic or non-cirrhotic liver parenchyma, previous procedure, tumor location, artificial ascites, active tip size, and the pad location were evaluated as potential factors affecting baseline impedance using the Mann-Whitney U test, t-test and analysis of variance test. Complete radiofrequency ablation was achieved in 51 patients. Body mass index (p = 0.897), cirrhotic or non-cirrhotic liver parenchyma (p = 0.767), previous procedure (p = 0.957), tumor location (p = 0.906), and artificial ascites (p = 0.882) did not significantly affect baseline impedance. Grounding pads located on the back showed the lowest baseline impedance (p < 0.001). Increase in active tip size showed gradual decrease in baseline impedance (p = 0.016). The factors affecting baseline impedance were the pad location and the tip size. Positioning pads on the back lowers the baseline impedance and can shorten the first roll-off time, ultimately resulting in reduced total ablation time.

Manual versus automated image fusion of real-time ultrasonography and MR/CT images for radiofrequency ablation of hepatic tumors: results of a randomized prospective trial (NCT02705118).

PurposeThis study compared the technical parameters and clinical outcomes of manual and automatic image fusion techniques of ultrasonography and magnetic resonance imaging/computed tomography for radiofrequency ablation (RFA) of hepatic tumors.MethodsSeventy consecutive patients (male:female=47:23, 67.1±10.9 years old) who underwent RFA for hepatic tumors were prospectively enrolled and randomly assigned to the manual or automatic registration group. Two operators performed RFA with one of two imaging fusion techniques. Technical parameters (the registration error, time required for image registration, number of point registrations) and clinical outcomes (technical success, technical effectiveness, local tumor progression [LTP]-free survival, and progression-free survival [PFS]) were compared.ResultsThe automatic group contained 35 patients with hepatocellular carcinoma, while the manual group included 34 hepatocellular carcinoma patients and a patient with colon cancer liver metastasis. The registration error, time required for registration, and number of point registrations were 5.7±4.3 mm, 147.8±78.2 seconds, and 3.26±1.20 in the automatic group, and 6.3±5.0 mm, 150.3±89.7 seconds, and 3.20±1.13 in the manual group, respectively. The technical success and effectiveness rates were both 97.1% in the automatic group and both 100.0% in the manual group. The above differences were not significant. The LTP-free survival and PFS (28.3 and 21.2 months in the automatic group, and 29.0 and 24.9 months in the manual group, respectively) showed no significant between-group differences during a median 20.1-month follow-up period.ConclusionThe technical parameters and clinical outcomes of automatic image fusion were not significantly different from those of manual image fusion for RFA of hepatic tumors.

Finite-Element Gaussian Belief Propagation Solver for Multi-Physics Modeling of Radiofrequency Tumor Ablation

A new finite-element Gaussian belief propagation (FGaBP) algorithm for multi-physics applications is presented in this paper. The FGaBP method is first modified for solving the heat-transfer problem and then verified against an analytical solution. Combined with a Gauss–Seidel algorithm, FGaBP is used to solve the coupled electrical–thermal problem that emerges in radiofrequency ablation of hepatic tumors while the extent of the ablated zone is computed for a simplified model. The multi-physics FGaBP algorithm preserves the parallel scalability of FGaBP as in previous uni-physics works.

4:20 PM Abstract No. 398 Radiofrequency ablation of hepatic tumors: does heat sink affect the outcome?

4:20 PM Abstract No. 398 Radiofrequency ablation of hepatic tumors: does heat sink affect the outcome?

The Effectiveness of Ultrasound-Guided Thoracic Paravertebral Block for Percutaneous Radiofrequency Ablation of Hepatic Tumors: A Pilot Study

The Effectiveness of Ultrasound-Guided Thoracic Paravertebral Block for Percutaneous Radiofrequency Ablation of Hepatic Tumors: A Pilot Study

Radiofrequency Ablation of Hepatic Tumor: Subjective Assessment of the Perilesional Vascular Network on Contrast-Enhanced Computed Tomography Before and After Ablation Can Reliably Predict the Risk of Local Recurrence.

To determine whether simple, subjective analysis of the perilesional vascular network can predict the risk of local recurrence after radiofrequency ablation (RFA) of liver malignancies on contrast-enhanced computed tomography (CECT). Contrast-enhanced computed tomography's 103 patients (59 men and 44 women; mean age, 63 years (range, 31-84 years) with 134 lesions who underwent RFA between 2000 and 2010 were retrospectively analyzed. The primary tumors include colorectal carcinoma (58 patients), hepatocellular carcinoma (n = 13), breast carcinoma (n = 8), neuroendocrine tumor (n = 5), and others (n = 19). Three blinded radiologists independently reviewed the CECT (a triple phase liver protocol for hypervascular tumors and a single phase for the hypovascular tumors) before and 6 weeks after RFA and subjectively estimated the width of the ablative margin on a 3-point scale (optimal, 1; suboptimal, 2; and residual tumor, 3). Local recurrence was determined on follow-up CECT. The consensus score was 1 in 94, 2 in 28, and 3 in 12 lesions. κ among readers was 0.75. Local recurrence occurred in 3 lesions with a score of 1 and 12 lesions with a score of 2. The consensus score was a significant univariate predictor of local recurrence. Subjective estimation of the width of ablative margin can reliably predict the risk of local recurrence.

Prevention and treatment of complications after radiofrequency ablation for hepatic tumors in high-risk locations

Prevention and treatment of complications after radiofrequency ablation for hepatic tumors in high-risk locations

Mo1411 - Radiofrequency Ablation of Hepatic Tumors: Does Heat Sink Affect the Outcome?

Mo1411 - Radiofrequency Ablation of Hepatic Tumors: Does Heat Sink Affect the Outcome?

Manual versus automatic image fusion of real-time ultrasonography and MR/CT images for radiofrequency ablation of hepatic tumors: A preliminary report of a randomized prospective trial

Manual versus automatic image fusion of real-time ultrasonography and MR/CT images for radiofrequency ablation of hepatic tumors: A preliminary report of a randomized prospective trial

Efficient Lattice Boltzmann Solver for Patient-Specific Radiofrequency Ablation of Hepatic Tumors.

Radiofrequency ablation (RFA) is an established treatment for liver cancer when resection is not possible. Yet, its optimal delivery is challenged by the presence of large blood vessels and the time-varying thermal conductivity of biological tissue. Incomplete treatment and an increased risk of recurrence are therefore common. A tool that would enable the accurate planning of RFA is hence necessary. This manuscript describes a new method to compute the extent of ablation required based on the Lattice Boltzmann Method (LBM) and patient-specific, pre-operative images. A detailed anatomical model of the liver is obtained from volumetric images. Then a computational model of heat diffusion, cellular necrosis, and blood flow through the vessels and liver is employed to compute the extent of ablated tissue given the probe location, ablation duration and biological parameters. The model was verified against an analytical solution, showing good fidelity. We also evaluated the predictive power of the proposed framework on ten patients who underwent RFA, for whom pre- and post-operative images were available. Comparisons between the computed ablation extent and ground truth, as observed in postoperative images, were promising (DICE index: 42%, sensitivity: 67%, positive predictive value: 38%). The importance of considering liver perfusion while simulating electrical-heating ablation was also highlighted. Implemented on graphics processing units (GPU), our method simulates 1 minute of ablation in 1.14 minutes, allowing near real-time computation.

Various complications of percutaneous radiofrequency ablation for hepatic tumors: radiologic findings and technical tips

Radiofrequency ablation is a safe and effective treatment for primary and secondary liver malignancies and has a low complication rate; however, there are various radiofrequency ablation-related complications which can occur from the thorax to the pelvis. Although most of these complications are usually minor and self-limited, they may become fatal if diagnosis and treatment are delayed. It is important for radiologists performing radiofrequency ablation to have a perspective regarding the possible radiofrequency ablation-related complications and their risk factors as well as the radiologic findings for their timely detection and increase of the treatment efficacy, and thereby encouraging the use of the radiofrequency ablation technique. This article illustrates the various imaging features of common and rare radiofrequency ablation-related complications as well as offers technical tips in order to avoid these complications.

Hospital-based, acute care encounters after radiofrequency ablation of hepatic tumours

BackgroundThe use of radiofrequency ablation (RFA) for cancer is increasing; however, post-discharge outcomes have not been well described. The aim of the present study was to determine rates of hospital-based, acute care utilization within 30 days of discharge after RFA. MethodsUsing state-level data from California, patients were identified who were at least 40 years of age who underwent RFA of hepatic tumours without a concurrent liver resection from 2007–2011. Our primary outcome was hospital readmissions or emergency department visits within 30 days of discharge. A multivariable regression model was constructed to identify patient factors associated with these events. ResultsThe final sample included 1764 patients treated at 100 centres. Hospital readmissions (11.3/100 discharges), emergency department visits (6.0/100 discharges) and overall acute care utilization (17.3/100 discharges) were common. Most encounters occurred within 10 days of discharge for diagnoses related to the procedure. Patients with renal failure [adjusted odds ratio (AOR) = 1.98 (1.11–3.53)], obesity [AOR = 1.69 (1.03–2.77)], drug abuse [AOR = 2.95 (1.40–6.21)] or those experiencing a complication [AOR = 1.52 (1.07–2.15)] were more likely to have a hospital-based acute care encounter within 30 days of discharge. ConclusionsHospital-based acute care after RFA is common. Patients should be counselled regarding the potential for acute care utilization and interventions targeted to high-risk populations.

Percutaneous radiofrequency ablation of hepatic tumours: Factors affecting technical failure of artificial ascites formation using an angiosheath

To evaluate the technical feasibility of artificial ascites formation using an angiosheath before percutaneous radiofrequency ablation (RFA) for hepatic tumours and to determine predictive factors affecting the technical failure of artificial ascites formation. This retrospective study was approved by the institutional review board. One hundred and thirteen patients underwent percutaneous RFA of hepatic tumours after trying to make artificial ascites using an angiosheath to avoid collateral thermal damage. The technical success rate of making artificial ascites using an angiosheath and conversion rate to other techniques after initial failure of making artificial ascites were evaluated. The technical success rate for RFA was assessed. In addition, potential factors associated with technical failure including previous history of transcatheter arterial chemoembolization (TACE) or RFA, type of abdominal surgery, and adjacent perihepatic structures were reviewed. Predictive factors for the technical failure of artificial ascites formation were analysed using multivariate analysis. The technical success rates of artificial ascites formation by angiosheath and that of RFA were 84.1% (95/113) and 97.3% (110/113), respectively. The conversion rate to other techniques after the failure of artificial ascites formation using an angiosheath was 15.9% (18/113). Previous hepatic resection was the sole independent predictive factor affecting the technical failure of artificial ascites formation (p<0.001, odds ratio=29.03, 95% confidence interval: 4.56-184.69). Making artificial ascites for RFA of hepatic tumours using an angiosheath was technically feasible in most cases. However, history of hepatic resection was a significant predictive factor affecting the technical failure of artificial ascites formation.

Thoracic paravertebral anesthesia for percutaneous radiofrequency ablation of hepatic tumors

Study ObjectiveTo present our preliminary experience using a thoracic paravertebral block (TPVB) as the sole anesthetic in percutaneous hepatic radiofrequency ablation (RFA). DesignRetrospective case series of 12 ASA physical status 1, 2, and 3 patients of average risk scheduled for RFA. SettingUniversity medical center. MeasurementsThe first 12 procedures performed using TPVB were analyzed to evaluate the efficacy and safety of this anesthetic technique. Data collected included patients’ characteristics, procedure, pain referred during paravertebral punctures, and RFA (verbal numerical scale; VNS). Anesthesia and medical records also were reviewed for any major complications that occurred during or after the RFA. Main ResultsTen of the 12 patients presented for hepatocellular carcinoma; the other two patients had melanoma metastasis. Nine patients were ASA physical status 1 or 2; the other three patients were ASA physical status 3. Nine had liver cirrhosis. All patients had normal coagulation profiles. The TPVBs were performed in a median time of 6.5 (4–15) minutes. Onset of sensory loss to pinprick test occurred approximately 15 to 20 minutes after the injections. No evidence of bilateral blockade was seen in any patient. In most cases, the extent of anesthesia ranged from T6 to T11 or T12. In one patient (no. 2), the stimulating needle elicited no sensory or motor response at the T7 level; the local anesthetic was then injected one cm beyond the transverse process. All patients were very pleased with their anesthetic care; all were discharged from the hospital with no procedure-related complications. ConclusionThe use of thoracic paravertebral block as the sole anesthetic for RFA of liver produced satisfactory unilateral anesthesia and minor adverse events.

Complications of radiofrequency ablation of hepatic tumors: Frequency and risk factors

Radiofrequency ablation (RFA) has become an important option in the therapy of primary and secondary hepatic tumors. Surgical resection is still the best treatment option, but only a few of these patients are candidates for surgery: multilobar disease, insufficient liver reserve that will lead to liver failure after resection, extra-hepatic disease, proximity to major bile ducts and vessels, and co-morbidities. RFA has a low mortality and morbidity rate and is considered to be safe. Thus, complications occur and vary widely in the literature. Complications are caused by thermal damage, direct needle injury, infection and the patient's co-morbidities. Tumor type, type of approach, number of lesions, tumor localization, underlying hepatic disease, the physician's experience, associated hepatic resection and lesion size have been described as factors significantly associated with complications. The physician in charge should promptly recognize high-risk patients more susceptible to complications, perform a close post procedure follow-up and manage them early and adequately if they occur. We aim to describe complications from RFA of hepatic tumors and their risk factors, as well as a few techniques to avoid them. This way, others can decrease their morbidity rates with better outcomes.

Citation Classics in Radiology Journals: The 100 Top-Cited Articles, 1945–2012

The number of citations an article receives after its publication reflects its impact in the scientific community. The aim of this study was to identify and characterize the 100 top-cited articles published in radiology journals. The top-cited articles published in 12 radiology journals were identified using the database of Science Citation Index Expanded (1945-2012). The 100 top-cited articles were selected and analyzed with regard to the number of citations, year of publication, publishing journal, authorship, institution and country of origin, type of article, radiologic subspecialty, main topic, and radiologic technique. The 100 top-cited articles were published in eight radiology journals, led by Radiology (n=67) and followed by the American Journal of Roentgenology (n=11). These articles were published between 1939 and 2006 with a mean of 664.3 citations per article (range, 371-6931). Seventy-eight articles were published after 1979, 57 originated from the United States, and 69 were original articles. The most common subspecialties of study were interventional radiology (n=19), neuroradiology (n=15), and breast imaging (n=11). The main topics of articles were radiofrequency ablation of hepatic tumors (n=9), followed by receiver operating characteristic curves (n=6). Our study presents a detailed list and analysis of the 100 top-cited articles published in radiology journals, which provides insight into historical developments in the field of radiology.

Imaging After Percutaneous Radiofrequency Ablation of Hepatic Tumors: Part 1, Normal Findings

The purpose of this article is to review the spectrum of early and delayed normal cross-sectional imaging findings after percutaneous radiofrequency ablation of hepatic tumors. Knowledge of postablation imaging changes is vital not only for the interventionalist who performs the procedure but also for the diagnostician who interprets the postablation imaging. Recognition of normal postprocedural changes and differentiation from abnormal imaging findings prevent overcalling benign changes as abnormal and can thus avoid needless treatment.

Imaging After Percutaneous Radiofrequency Ablation of Hepatic Tumors: Part 2, Abnormal Findings

The purpose of this article is to review the spectrum of early and delayed abnormal cross-sectional imaging findings after radiofrequency ablation (RFA) of hepatic tumors. Recognition of abnormal post-RFA imaging findings and differentiation of abnormal findings from normal postprocedural changes are important for diagnostic and interventional radiologists. Early identification of residual or recurrent disease and complications can facilitate timely retreatment, management, and follow-up care.