Sequential Radiofrequency Ablation Research Articles

Significance of radiofrequency ablation in large solid benign thyroid nodules.

The aim of this study is to explore efficacy and safety for radiofrequency ablation (RFA) among cases attacked by large benign solid thyroid nodules, mainly focusing on volume reduction, complication rate, and thyroid function. From June 2015 to November 2019, 24 patients with 25 large benign solid thyroid nodules (more than 25 ml) underwent single or sequential RFA in our institution. Eleven nodules achieved complete ablation after single RFA, whereas the other 14 nodules received sequential RFA. Volume reduction in large nodules was evaluated. Following single or sequential RFA, all patients received clinical and ultrasound evaluations, and the median follow-up duration among them was 23.5 months. Technical success, complication rate, and recurrence rate were assessed as well. In single RFA group, volume reduction ranged from 62.6% to 99.4% (mean ± SD, 93.6 ± 9.9%) 6 months after RFA. In sequential RFA group, volume reduction ranged from 30.6% to 92.9% (mean ± SD, 67.4 ± 17.8%) after the first RFA and was between 83.4% and 98.4% (mean ± SD, 94.8± 3.8%) 6 months after the second RFA. The concentrations of FT3 and FT4 increased slightly 1 day after RFA and returned to normal level 1 month after. Single or sequential RFA is safe and effective in treating large benign solid thyroid nodules (more than 25 ml) that cause obvious compressive symptoms. Hence, compression symptoms and cosmetic conditions could be effectively improved through single or sequential RFA without marginal recurrence.

Sequential transarterial chemoembolization and early radiofrequency ablation improves clinical outcomes for early-intermediate hepatocellular carcinoma in a 10-year single-center comparative study

BackgroundTransarterial chemoembolization (TACE) and radiofrequency ablation (RFA) are effective treatment methods for unresectable hepatocellular carcinoma (HCC). However, there is still a lack of clinical research on whether early sequential RFA, compared with late combination therapy, can improve the long-term efficacy of initial TACE treatment.MethodsThis retrospective study investigated a cohort of patients who underwent combination therapy using TACE and RFA (TACE followed by RFA) from January 2010 to January 2020 at our medical centre. A total of 96 patients underwent TACE combined with early RFA (usually during the first hospitalization), which was called TACE + eRFA. Thirty-four patients received 1–2 palliative TACE treatments first and then underwent TACE treatment combined with late RFA (TACE + lRFA). All patients continued to receive palliative TACE treatments after intrahepatic lesion progression until reaching intolerance. The overall survival (OS) rate, time to tumour progression (TTP), tumour response rate and major complication rates were compared between the two groups.ResultsThere were significant differences in the median OS (46 months vs 33 months; P = 0.013), median TTP (28 months vs 14 months; P < 0.00), objective response rate (ORR) (89.6% vs 61.8%, P = 0.000) and disease control rate (DCR) (94.8% vs 73.5% P = 0.002) between the two groups. Multivariable analysis revealed that the Barcelona Clinic Liver Cancer stage was an independent risk factor for OS. Meanwhile, multivariable analysis revealed that TACE + eRFA was associated with an enhanced TTP.ConclusionEarly sequential RFA treatment in patients with early-intermediate HCC can improve local tumour control and clinical outcomes while reducing the frequency of TACE treatment. In clinical practice, in HCC patients initially treated with TACE, it is recommended to combine RFA as soon as possible to obtain long-term survival.

Clinical value of (125)I radioactive seed implantation plus transcatheter arterial chemoembolization combined with radiofrequency ablation in treating patient with sub-capsular hepatocellular carcinoma

Objective: To analyze the clinical efficacy and safety of (125)I radioactive seed implantation in the treatment of sub-capsular hepatocellular carcinoma (sub-HCC) with sequential radiofrequency ablation and transcatheter arterial chemoembolization (TACE). Methods: The clinical data of 76 cases with advanced HCC with sub-capsular nodules including 68 males and 8 females, with an average age of (58±9) years, ranging from 33 to 78 years, enrolled in Lishui Central Hospital from January 2010 to December 2016 were collected.The average maximum diameter of tumor is (5.7±2.3) cm, ranging from 3.1 cm to 12.0 cm.The patients were divided into TACE+ RFA group and (125)I + TACE+ RFA group with 38 cases in each group.The overall survival (OS) and progression free survival(PFS) were calculated.The clinical efficiency and adverse events were evaluated. Results: The disease control rate were 84.2%(32/38) in (125)I + TACE+ RFA group and 63.2% (24/38) in TACE+ RFA group, χ(2)=4.34, P= 0.04.The median PFS were 18 months in (125)I + TACE+ RFA group and 11 months in TACE+ RFA group, χ(2)=4.84, P=0.03.The FPS cumulative rate in (125)I + TACE+ RFA group were higher than that in TACE+ RFA group at 6 months (94.7%±3.6% vs 81.3%±6.4%, Z=24.1>2.58, P=0.00), 1 year (89.2%±5.1% vs 40.7%±8.3%, Z=13.3>2.58, P=0.00) and 2 year (55.9%±8.6% vs 29.6%±8.2%, Z=7.2>2.58, P=0.00). The median OS were 42 months in (125)I + TACE+ RFA group and 30 months in TACE+ RFA group, χ(2)=4.76, P=0.029.The survival cumulative rate in (125)I+ TACE+ RFA group were higher than that in TACE+ RFA group at 1 year (92.1%±4.4% vs 83.8%±6.1%, Z=23.5>2.58, P=0.00), 2 year (75.8%±7.0% vs 59.8%±8.4%, Z=12.43>2.58, P=0.00), 3 year (59.0%±8.2% vs 41.7%±8.9%, Z=8.3>2.58, P=0.00), 5 year (34.2%±8.2% vs 18.2%±8.1%, Z=5.5>2.58, P=0.00). In addition, there was no statistical difference in liver function and complications between TACE+ RFA group and (125)I+ TACE+ RFA group. Conclusion: (125)I radioactive seed implantation plus TACE combined with RFA treatment is an effective and safe treatment for sub-capsular hepatocellular carcinoma.

Combined Radiofrequency Ablation and Transarterial Chemoembolization in Treatment of Unresectable Primary Liver Cancer

HCC is the fifth most common cancer worldwide. Surgical therapy, as a curative option, is indicated only in patients with single HCC without portal hypertension and preserved liver function. Hepatic resection of HCC in patients with cirrhosis is associated with significant peri-operative mortality and morbidity. Cirrhotic patients with non-respectable HCC have a poor prognosis influenced by hepatic reserve function and tumor staging [1]. Surgical resection is the standard of care because it has been shown to provide survival benefits, while systemic chemotherapy and radiotherapy are ineffective, Liver transplantation seems to be the choice for mono-focal HCC less than 5 cm in diameter and in selected cases of multifocal HCC, but may be limited by availability of donor organs and a long waiting time [1]. TACE has been shown to reduce systemic toxicity and increase local effects and thus improve therapeutic results. The core concept includes selective embolization of tumour-feeding arteries with a chemotherapeutic agent in an emulsion with iodized oil and subsequent embolization with a particulate agent, The chemotherapeutic regime varies considerably between centers, as does the choice of embolization agent including non-permanent embolic material such as absorbable gelatine powder or polyvinyl alcohol particles, gelatine-coated tri-acryl embospheres or biocompatible polyvinyl alcohol hydro-gels (bead block). Doxorubicin is the most commonly used agent [2]. Because blood flow promotes heat loss, and heat loss may reduce the effectiveness of RFA, a possible way to increase the ablation size of RFA thermal lesions would be to reduce or eliminate the heat loss that is mediated by tissue perfusion, Blood flow to hepatocellular carcinoma lesions can be substantially reduced by the arterial embolization effect of TACE treatment. Moreover, TACE has a strong antitumor effect on hepatocellular carcinoma lesions. However, both TACE and RFA have some well-known limitations. In particular, neither results in adequate control of hepatocellular carcinoma tumors larger than 3 cm. Consequently, multimodal combined treatment is an appealing alternative, especially for patients with large hepatocellular carcinoma [2]. Background: In this study, the outcome of the combination of RFA with TACE was retrospectively evaluated and the effectiveness of this combination treatment on large unresectable primary liver cancer. We carried out a prospective, randomized controlled trial to assess the benefits of combined TACE-RFA for large unresectable hepato-cellular carcinoma. Method: In the present work, 20 patient with single unresectable HCC from Cairo between 35-50 years will be investigated, Patients were randomized into two groups: Group (1): starting by radiofrequency ablation followed by TACE after 4 weeks then follow up by TACE, Group (2): starting by chemo-embolization followed by sequential radiofrequency ablation after 2 weeks from TACE

Case of Successful Radiofrequency Ablation of Multiple Bilateral Renal Cell Carcinomas in von Hippel-Lindau Disease

Von Hippel-Lindau (VHL) disease is an inherited, autosomal dominant syndrome that manifests as a variety of benign and malignant tumors in various organs. Notably, renal cell carcinoma (RCC) in patients with VHL disease tends to be multifocal and bilateral, and tends to recur or new tumors develop after removal. Radiofrequency ablation (RFA) has recently been introduced as a minimally invasive treatment for small hereditary RCCs with a low complication rate and a minimal decrease in renal function. We present a case of successful RFA of multiple bilateral RCCs in a 24-year-old female with VHL. Computed tomography (CT) of the abdomen revealed multiple bilateral RCCs. The patient received sequential RFA for the bilateral RCCs, resulting in a complete response. At the time of writing, there was no sign of recurrence or renal failure. In conclusion, percutaneous RFA is a promising treatment for VHL patients who cannot undergo surgery, with excellent treatment outcomes and minimal change in renal function. (Korean J Med 2014;87:603-608)

Hypertonic saline-enhanced radiofrequency versus chemoembolization sequential radiofrequency in the treatment of large hepatocellular carcinoma

Large hepatocellular carcinoma (HCC) appears to be a major obstacle for radiofrequency ablation (RFA); therefore, attempts to increase the volume of coagulation by injecting hypertonic saline before and/or during RFA have been made. Transarterial chemoembolization (TACE) combines the effect of targeted chemotherapy with ischemic necrosis and eliminates heat loss if combined with RFA. Our aim was to compare the efficacy of hypertonic saline-enhanced RFA versus TACE sequential RFA in the treatment of medium and large nodular HCC. This prospective study was carried out on 40 patients with 40 HCCs between 2008 and 2010 in the Tropical Medicine and Hepatology Department, Faculty of Medicine, Cairo University. They were divided into two groups (20 patients each): the first group received hypertonic saline-enhanced RFA (RFA+HS) and the second group underwent transarterial chemoembolization, followed by RFA (TACE+RFA). Triphasic computed tomography 1 month after the procedure showed that 17 (85%) patients in each group achieved complete ablation, whereas three (15%) in each group achieved partial ablation. In the RFA+HS group, 12/13 (92%) of medium HCC and 5/7 (71%) of large HCC were successfully ablated. In the TACE+RFA group, 8/8 (100%) medium HCC and 9/12 (75%) of large lesions were successfully ablated. The relation between success rate and lesion diameter was statistically significant only in RFA+HS group. After 6 months, 73.7% of patients in the RFA+HS group and 83.3% of patients in the TACE+RFA group showed maintained ablation (P=0.86). RFA+HS and TACE+RFA are safe and equally effective treatments for medium to large HCC.

Sequential radiofrequency ablation and surgical debulking for unresectable colorectal carcinoma: Thermo‐surgical ablation

Despite decreasing frequency, local recurrences of unresectable colorectal cancer (CRC) remain difficult problems. These patients have few treatment options with conventional therapy. Preliminary results of sequential radiofrequency ablation (RFA) and surgical debulking (thermo-surgical ablation) suggest this technique may have benefit. We reviewed a prospective database of patients undergoing thermo-surgical ablation for unresectable colorectal carcinoma from 2003 to 2011. Sixteen patients were treated with unresectable, recurrent abdomino-pelvic colorectal carcinoma: 11 in pelvis; 4 with isolated aortic/retroperitoneal disease; and 1 with pelvic and peri-adrenal/retroperitoneal disease. Eleven patients had recurrent rectal cancer and five had recurrent colon cancer. Median overall and 3-year actuarial survivals were 15 months and 24%, respectively. Median and 3-year PFS was 12 months and 19%, respectively. Three patients without disease have survived 0.75, 4.0, and 7.0 years. Two patients died at 5.0 and 5.5 years. A disease-free interval (DFI) of >24 months after initial resection was associated with longer overall survival (60 months vs. 4 months; P = 0.001). Thermo-surgical debulking appears to have a role in the treatment of some patients with recurrent, unresectable CRC; those patients with DFI >24 months after initial surgery benefited the most.

Radiofrequency Ablation of Concomitant and Recurrent Pulmonary Metastases after Surgery for Colorectal Liver Metastases

To evaluate our experience of radiofrequency ablation (RFA) of pulmonary metastases in patients with resected colorectal liver metastases who had concomitant or recurrent pulmonary metastases. Clinical and treatment variables of patients undergoing RFA were collected, and their association with survival was examined. Survival analysis was performed by the Kaplan-Meier method. RFA was performed as concomitant sequential treatment of extrahepatic pulmonary metastases after hepatectomy in 19 patients (30%) and as salvage treatment for pulmonary recurrences after hepatectomy in 45 patients (70%). Patients undergoing sequential treatment had a median survival of 31 (95% confidence interval [CI] 21.8-40.6) months compared to 59 (95% CI 35.0-82.0) months in the salvage treatment group (P=0.142). The disease-free survival (DFS) was 9 (95% CI 1.0-18.8) months in the sequential treatment group and 16 (95% CI 8.1-23.1) months in the salvage treatment group (P=0.023). Liver metastases occurring within 12months of the primary tumor negatively influenced overall survival (OS) and DFS in the sequential treatment group (P=0.003 and P=0.091). Poorly differentiated tumor (P=0.001) was associated with a poorer OS, and prehepatectomy carcinoembryonic antigen>200ng/ml (P=0.017) and bilateral pulmonary metastases (P=0.030) were associated with a shorter DFS in the salvage treatment group. The DFS and OS of patients undergoing sequential RFA of extrahepatic pulmonary metastases after hepatectomy appeared shorter when compared to patients who underwent RFA as salvage treatment for pulmonary recurrences after hepatectomy. It nonetheless remains better than the historical results of chemotherapy alone and thus supports the use of RFA as an ablative technology to achieve tumor control.

An Acute Experimental Model Demonstrating 2 Different Forms of Sustained Atrial Tachyarrhythmias

The objective of this study was to develop an acute experimental model showing both focal and macroreentrant sustained atrial fibrillation (AF). In 31 anesthetized dogs, bilateral thoracotomies allowed the attachment of electrode catheters at the right and left superior pulmonary veins, atrial free walls, and atrial appendages. Acetylcholine, 100 mmol/L, was applied topically to either appendage. Sequential radiofrequency ablation was achieved for the ganglionated plexi (GP), found adjacent to the 4 pulmonary veins. In 12 separate studies, a propafenone bolus, 2 mg/kg, was given before and after GP ablations at the start of acetylcholine-induced AF. Acetylcholine caused abrupt onset of AF (n=22) or induced AF by burst pacing (n=9) that lasted > or = 10 minutes. Rapid, regular, or fractionated atrial electrograms were consistently seen (average cycle length, 37+/-7 ms) at the appendages versus cycle lengths of 114+/-23 ms at other atrial sites. After ablations of GP, AF abruptly terminated (n=25). In 6 dogs, sustained atrial tachyarrhythmias continued. Pacing at specific atrial sites organized electrograms of one atrium or also captured the other atrium. The latter resulted in termination when pacing was stopped in 4 of these 6 experiments. Propafenone did not change the duration of focal AF before GP ablation (17+/-9 versus 14+/-8 minutes; control, P=0.6) but terminated reentrant atrial tachyarrhythmias (12+/-3 versus 2+/-1 minutes, P=0.0009). Before GP ablation, acetylcholine (100 mmol/L) induced sustained AF characterized by rapid, focal firing. GP ablations were associated with loss of focal firing and regularization of electrograms in both atria before termination. Propafenone failed to terminate focal AF but rapidly terminated entrainable macroreentrant atrial tachyarrhythmias.

Isolated Atrial Segment Pacing: An Alternative to His Bundle Pacing After Atrioventricular Junctional Ablation

This study was designed to investigate a practical alternative to His bundle pacing after atrioventricular (AV) junctional ablation by pacing a small area of isolated atrial tissue surrounding the AV node. His bundle pacing is preferred after AV junctional ablation in patients with refractory atrial fibrillation. However, it is technically difficult and not clinically useful at the present time. This study was conducted in an isolated working swine heart model (n = 5), with real-time imaging capabilities. A small area of atrial tissue surrounding the AV node and the His bundle was isolated using sequential radiofrequency ablation lesions. Complete AV block created by segmental atrial isolation was achieved in 5 of 5 experiments. The isolated atrial segment was bordered by the ablation lines, the tricuspid annulus, and the AV node-His bundle. The AV conduction was characterized using a pacing electrode implanted into the isolated atrial segment. Pacing from the atria, the ventricles, and the isolated atrial segment at different rates confirmed complete bidirectional block between the atria and isolated area, whereas antegrade and retrograde AV nodal conduction between the isolated atrial segment and the ventricles remained intact. Pacing from the isolated area produced minimal changes in systolic left ventricular pressure compared with baseline sinus rhythm (mean -2 mm Hg). Isolation of a small area of atrial tissue surrounding the AV node is feasible by transcatheter radiofrequency ablation. This procedure may be a useful alternative to conventional AV junctional ablation because it can create complete AV block, while in effect permitting the equivalent of His bundle pacing after AV junctional ablation.

Histologic Evaluation and Treatment Outcome after Sequential Radiofrequency Ablation and Hepatic Resection for Primary and Metastatic Tumors

Operative manipulation during hepatic resection (HR) causes tumor cell shedding which is a factor in disease recurrence. Radiofrequency ablation (RFA) causes coagulative necrosis and was used to destroy the tumor before HR. We evaluated tumor necrosis and recurrence of hepatic malignancies treated by sequential RFA/HR. A retrospective review of patients treated with sequential RFA/HR from April 1999 to January 2002 was performed. A Radionics 500-kW RF generator was used to ablate lesions via H2O-cooled electrodes under ultrasound guidance. Segmental HR was performed after RFA. Resected specimens were reviewed with hematoxylin and eosin staining and for apoptosis. Patient follow-up ranged from 10 to 33 months with evaluation of salient clinical, radiologic, and laboratory parameters. Seven patients (four male and three female) ages 62.1 +/- 10.3 years had sequential RFA/HR. Four patients had hepatocellular carcinoma (HCC) and three had colorectal metastases (CRm). The tumors were unifocal right-lobe lesions measuring 4.1 +/- 0.9 cm with a resection margin of 0.4 to 2.5 cm. Extensive necrosis was noted but intact nests of tumor cells occurred in all specimens with minimal apoptosis. Three of seven patients (two HCC and one CRm) developed pulmonary metastases at 3 to 20 months with one HCC patient developing concurrent liver metastases. Two deaths occurred in the HCC group. Sequential RFA/HR may minimize local recurrence; however, the high incidence of pulmonary metastases raises concern of transvenous migration. The histologic findings demonstrate foci of intact tumor cells after RFA. Controlled study of additional patients with long-term follow-up is necessary to better understand these findings.

Effect of sequential radiofrequency ablation lesions at fast and slow atrioventricular nodal pathway positions in patients with paroxysmal atrial fibrillation.

To examine the hypothesis that the anatomic equivalents of the fast and slow pathways identified in patients with atrioventricular (AV) nodal tachycardia may be universal and represent the principal sites of atrial input into the normal compact AV node. 15 patients undergoing complete AV junction ablation for paroxysmal atrial fibrillation were studied. Radiofrequency energy was delivered first in the anterior "fast pathway" position so as to prolong the atrium to bundle of His (AH) interval by over 50% of baseline (protocol 1) and then to the "slow pathway" position using the anatomical technique (protocol 2). Ablation protocol 1 resulted in prolongation of AH interval in all patients. Subsequent lesions at the level of the coronary sinus produced complete heart block in four patients, and in five caused a further increase in AH interval above that produced by protocol 1. Four of these latter patients developed complete block after delivery of RF energy slightly anterior to the level of the coronary sinus os, as did three further patients in whom ablation at the level of the coronary sinus had no effect. In four patients complete heart block could not be achieved by protocol 2. A discrete anterior "fast" pathway and a posterior "slow" pathway or network of posterior pathways form the principal inputs to the compact AV node in most patients with atrial fibrillation. The absence of dual AV nodal physiology in the majority of these patients may be related to the functional properties of the individual components of this posterior network.