Initial Radiofrequency Ablation Research Articles

1712 Detection of Sub-Surface High-Grade Dysplasia Following Radiofrequency Ablation (RFA) of Barrett’s Esophagus

INTRODUCTION: Barrett's esophagus (BE) occurs when intestinal epithelium replaces squamous epithelium normally lining the distal esophagus. BE is associated with an increased risk of esophageal adenocarcinoma (EAC). While traditionally associated with Caucasian males, prevalence of BE and EAC in Asian populations is projected to rise, associated with increasing prevalence of gastroesophageal reflux disease (GERD), which is associated with obesity and hiatal hernia. Radiofrequency ablation (RFA) is an endoscopic treatment modality shown to be safe and effective in inducing reversion to squamous epithelium, with a treatment depth of 500-1000 microns. We present a case of BE with high-grade dysplasia identified on random forceps biopsy after RFA for BE with low grade dysplasia, after which significant sub-surface disease was detected by volumetric laser endomicroscopy (VLE). CASE DESCRIPTION/METHODS: A 72 yo Chinese male was diagnosed with short-segment BE containing low grade dysplasia, and was treated with 2 sessions of focal RFA 5 months apart. He was lost to follow up and re-established care two years later. At presentation, the patient denied any heartburn, dysphagia or weight loss. Surveillance endoscopy with white light and narrow band imaging (Figure 1) revealed short tongues of salmon-colored mucosa suspicious for residual BE. Forceps biopsy confirmed BE with high grade dysplasia at the 12:00 position. Repeat endoscopy using VLE demonstrated suspicious-appearing glands, primarily sub-surface, which were laser marked and resected with band ligation and snare instead of forceps biopsy (Figure 2). Pathology results confirmed high-grade dysplasia within BE (Figure 3). Due to the presence of dysplasia deeper into the epithelium, in the setting of prior RFA, the patient was referred for liquid nitrogen spray cryotherapy. DISCUSSION: Residual or recurrent BE following RFA is a relatively common finding, but it is uncommon to see disease with a higher dysplasia grade than what was found pre-treatment. In this case, the use of VLE to evaluate these findings identified deeper disease that may not have been amenable to initial RFA treatment, with the lesion becoming “buried” after incomplete ablation. VLE, which visualizes the esophageal wall to a depth of 3 mm, should be considered as part of the evaluation of residual BE, especially when dysplasia is present. Its use may improve patient outcomes by leading to an alternate approach to both tissue sampling and further treatment selection.

Efficacy of transarterial chemoembolization compared with radiofrequency ablation for the treatment of recurrent hepatocellular carcinoma after radiofrequency ablation

Purpose: To compare the efficacy and outcome of transarterial chemoembolization (TACE) with radiofrequency ablation (RFA) in the treatment of recurrent hepatocellular carcinoma (HCC) after initial RFA.Material and methods: From January 2008 to December 2014, 199 consecutive patients with primary HCC underwent percutaneous RFA as initial treatment. One hundred and fourteen patients developed intrahepatic recurrent HCC after initial RFA. The patients with recurrent tumor size ≤3 cm and tumor numbers ≤3 who underwent RFA (n = 47) or TACE (n = 31) were included in study. Progression-free survival (PFS), tumor response to treatment and overall survival (OS) were assessed. Prognostic factors for OS were analyzed using multivariate Cox proportional hazard models.Results: The baseline data of initial HCC and the first recurrence of HCC were comparable in both groups. The complete response (CR) rate in the RFA group and the TACE group was 95.7% and 50%, respectively (p < .001). The PFS time in the RFA group and the TACE group was 424 days and 275 days, respectively (p = .004). The one-year and three-year cumulative overall survival rate was 93.5% and 45% in the TACE group, 91.3% and 68.8% in the RFA group (p = .49), respectively. Significant predictive factors for OS were tumor size (HR = 1.951, 95%CI 1.061–3.687, p = .032), prothrombin time (HR = 1.59, 95%CI 1.012–2.498, p = .044) and response to treatment (HR = 0.267, 95%CI 0.092–0.78, p = .016).Conclusion: Repeated RFA is still considered to be the first treatment choice for patients with post-RFA intrahepatic recurrence. However, TACE should also be considered due to comparable overall survival benefits. The advantages of being less invasive and highly repeatable may render TACE to be a preferred treatment for some patients with recurrent HCC after RFA.

The association between alcohol consumption, cardiac biomarkers, left atrial size and re-ablation in patients with atrial fibrillation referred for catheter ablation.

BackgroundInformation on alcohol consumption in patients undergoing radiofrequency ablation (RFA) of atrial fibrillation (AF) is often limited by the reliance on self-reports. The aim of this study was to describe the long-term alcohol consumption, measured as ethyl glucuronide in hair (hEtG), in patients undergoing RFA due to AF, and to examine potential associations with cardiac biomarkers, left atrial size and re-ablation within one year after the initial RFA.MethodsThe amount of hEtG was measured in patients referred for RFA, and a cut-off of 7 pg/mg was used. N-terminal pro B-type natriuretic peptide (NT-proBNP) and the mid-regional fragment of pro atrial natriuretic peptide (MR-proANP) were examined and maximum left atrium volume index (LAVI) was measured. The number of re-ablations was examined up to one year after the initial RFA. Analyses were stratified by gender, and adjusted for age, systolic blood pressure, body mass index, presence of heart failure and heart rhythm for analyses regarding NT-proBNP, MR-proANP and LAVI and heart rhythm being replaced by type of AF for analyses regarding re-ablation.ResultsIn total, 192 patients were included in the study. Median (25th– 75th percentile) NT-proBNP in men with hEtG ≥ 7 vs. < 7 pg/mg was 250 (96–695) vs. 130 (49–346) pg/ml (p = 0.010), and in women it was 230 (125–480) vs. 230 (125–910) pg/ml (p = 0.810). Median MR-proANP in men with hEtG ≥ 7 vs. < 7 pg/mg was 142 (100–224) vs. 117 (83–179) pmol/l (p = 0.120) and in women it was 139 (112–206) vs. 153 (93–249) pmol/l (p = 0.965). The median of maximum LAVI was 30.1 (26.7–33.9) vs. 25.8 (21.4–32.0) ml/m2 (p = 0.017) in men, and 25.0 (18.9–29.6) vs. 25.7 (21.7–34.6) ml/m2 (p = 0.438) in women, with hEtG ≥ 7 vs. < 7 pg/ml, respectively. Adjusted analyses showed similar results, except for MR-proANP turning out significant in men with hEtG ≥ 7 vs. < 7 pg/mg (p = 0.047). The odds ratio of having a re-ablation was 3.5 (95% CI 1.3–9.6, p = 0.017) in men with hEtG ≥ 7 vs. < 7 pg/mg, while there was no significant difference in women.ConclusionsIn male patients with AF and hEtG ≥ 7 pg/mg, NT-proBNP and MR-proANP were higher, LA volumes larger, and there was a higher rate of re-ablations, as compared to men with hEtG < 7 pg/mg. This implies that men with an alcohol consumption corresponding to an hEtG-value ≥ 7, have a higher risk for LA remodelling that could potentially lead to a deterioration of the AF situation.

Whole tumor ablation of locally recurred hepatocellular carcinoma including retained iodized oil after transarterial chemoembolization improves progression-free survival.

To evaluate and compare clinical outcomes of two different radiofrequency ablation (RFA) methods for locally recurred hepatocellular carcinoma (LrHCC) after locoregional treatment. Our institutional review board approved this study with a waiver of informed consent. A total of 313 patients previously treated with transarterial chemoembolization (TACE) (n = 167) and RFA (n = 146) with a single LrHCC ≤ 3cm was included from five tertiary referral hospitals. RFA was done for LrHCCs using either viable tumor alone ablation (VTA) method (VTA: n = 61 in the TACE group and n = 127 in the RFA group) or whole tumor ablation (WTA) method which includes both viable tumor and retained iodized oil or previously ablated zone (WTA: n = 106 in the TACE group and n = 19 in the RFA group). Local tumor progression (LTP)-free survival as well as progression-free survival (PFS) were estimated using the Kaplan-Meier method, and prognostic factors were evaluated using the Cox proportional hazards regression model. In 167 patients with LrHCC who underwent TACE, the 5-year LTP-free survival after RFA was significantly higher with the VTA method than with the WTA method (26.9% vs. 87.8%; p < 0.001; hazard ratio (HR) = 8.53 [4.16-17.5]). The estimated 5-year PFS after RFA for LrHCC after TACE using the VTA method was 5.7%, which was significantly lower than that with the WTA method (26.4%) (p = 0.014; HR = 1.62 [1.10-2.38]). However, in 146 patients with LrHCC after initial RFA, there were no significant differences in cumulative incidence of LTP (p = 0.514) or PFS (p = 0.905) after RFA between the two ablation methods. For RFA of LrHCC after TACE, the WTA method including both viable tumor and retained iodized oil could significantly lower LTP and improve PFS than VTA. • Whole tumor ablation (WTA) could provide significantly better local tumor control for locally recurred HCC (LrHCC) after TACE than viable tumor alone ablation (VTA). • WTA for LrHCC after TACE could also provide significantly better progression-free survival than VTA. • Regarding LrHCC after RFA, VTA would provide a comparable clinical outcome to WTA.

Efficacy and safety of repeated use of lusutrombopag prior to radiofrequency ablation in patients with recurrent hepatocellular carcinoma and thrombocytopenia.

AimsThrombocytopenia is often associated with chronic liver disease. Lusutrombopag is a small molecule thrombopoietin receptor agonist designed to temporarily increase the platelet count in patients with chronic liver disease for whom elective invasive procedures are planned. In the present study, the efficacy and safety of repeated use of lusutrombopag prior to radiofrequency ablation (RFA) for recurrent hepatocellular carcinoma were examined.MethodsEight patients with hepatocellular carcinoma who had a platelet count <50 000/μL prior to both initial and repeat RFA at the time of recurrence received lusutrombopag (3 mg/day) orally for 7 days between March 2016 and August 2018. The following were compared: the effect of lusutrombopag to increase the platelet count as determined by the platelet count after the initial and repeated use of lusutrombopag, the rate of avoiding platelet transfusion, and the presence of any complications.ResultsThe platelet count increased to 103 100 ± 22 800/μL 14 days after the first treatment and to 110 700 ± 17 800/μL 14 days after the repeated use. None of the patients required platelet transfusion. None of the patients developed clinical symptoms such as thrombosis, fever, rash, portal vein thrombosis, bleeding, or any other serious adverse events.ConclusionsRepeated use of lusutrombopag increased the platelet count. It did not cause any serious adverse events and led to avoidance of platelet transfusion. Radiofrequency ablation was carried out safely in all patients. Future studies with more cases of repeated use are needed to examine the long‐term efficacy and safety of lusutrombopag.

US-Guided Radiofrequency Ablation for Low-Risk Papillary Thyroid Microcarcinoma: Efficacy and Safety in a Large Population.

To evaluate the efficacy and safety of radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC) in a large population. Cases of 152 biopsy-proven PTMCs from 133 patients who had undergone RFA for PTMC between May 2008 and January 2017 were included in this study. All patients were either of high surgical risk or refused to undergo surgery. They were followed up for at least 6 months after initial RFA. Ultrasonography (US) and computed tomography were performed to evaluate the PTMC and the presence of neck metastasis before treatment. RFA was conducted using an internally cooled thyroid-dedicated electrode system. Follow-up US was performed at 1 week, and 2, 6, and 12 months, after the initial RFA, and then at every 6-12 months. We evaluated serial changes of ablated tumors, newly developed cancers, lymph node (LN) or distant metastasis and complications. Complete disappearance was found in 91.4% (139/152) of ablated tumors. Among the 13 tumors in patients who did not show complete disappearance, no tumor displayed any regrowth of the residual ablated lesion during the follow-up period. The mean follow-up period was 39 months. During the follow-up period, there were no local recurrence, no LN or distant metastasis, and no newly developed thyroid cancers. No patients were referred to surgery. The overall complication rate was 3% (4/133) of patients, including one voice change. There were no life-threatening complications or procedure-related deaths. Our results suggest that RFA is an effective and safe option for treating low-risk PTMC patients who are of high surgical risk or refuse surgery.

Six-months success of radiofrequency ablation in cardiac arrhythmias treatment: Experience of our centre

Background/Aim. Numerous trials have shown a high success of radiofrequency ablation (RFA) in the treatment of the patients with cardiac arrhythmias. We aimed to examine the RFA initial success in treatment of different cardiac arrhythmias and the RFA success after 6 months of followup. Second aim was to evaluate influence of all clinical and echocardiography parameters on initial and 6-month success and failure of RFA. Methods. The present study included 320 consecutive patients with atrial and ventricular arrhythmias in which RFA was performed during 2014 in the Institute for Cardiovascular Diseases ?Dedinje?, Belgrade, Serbia. We evaluated the initial RFA success and success of this procedure after 6-month follow-up. We also investigated the prognostic role of clinical and echocardiography parameters on initial and 6-month success and failure of RFA. Results. The RFA initial success for RFA of atrioventriculas (AV) node and AV nodal reentrant tachycardia (AVNRT) was 100%, RFA of pulmonary veins 99%, RFA of atrial flutter 92%, RFA of premature ventricular complexes (PVC) and the Wolf-Parkinson-White (WPW) syndrome 87%, RFA of ventricular tachycardia 85% and RFA of atrial tachycardia 78%. The success of RFA after 6 months of follow-up for RFA of the AV node was 100%, RFA of AVNRT 94%, RFA of atrial flutter 90%, RFA of WPW syndrome 86%, RFA of pulmonary veins 79% (paroxysmal atrial fibrillation 88% and persistent atrial fibrillation 63% with a significant difference p &lt; 0.05), RFA of PVC 78%, RFA of ventricular tachycardia 77% and RFA of atrial tachycardia 67%. Conclusion. This study proved a very high RFA initial success in treatment of cardiac arrhythmias and a satisfactory RFA success after 6 months of follow-up. Only the prognostic value had the type of atrial fibrillation in the group with catheter ablated pulmonary veins: after 6-month follow-up, the patients with paroxysmal atrial fibrillation had a significantly better outcome than those with persistent form.

Long-term outcomes and prognostic analysis of percutaneous radiofrequency ablation in liver metastasis from breast cancer

Objective: To evaluate the long-term efficacy and prognostic factors of ultrasound-guided percutaneous radiofrequency ablation (RFA) for breast cancer liver metastasis (BCLM).Methods: Between 2000 and 2015, 69 patients who underwent ultrasound-guided percutaneous RFA for BCLM and had regular follow-up examinations were included. All patients had undergone resection of the primary breast cancer and had received chemotherapy, endocrine therapy or both after surgery. The sample included two males and 67 females with an average age of 50.3 ± 10.0 years (31–76 y). The mean maximum diameter of metastatic lesions in the liver was 2.9 ± 1.4 cm (1.0–6 cm). Thirty-five patients had a single metastasis, while 34 patients had multiple liver metastases (2–5 lesions). Survival results were generated using Kaplan-Meier estimates and a multivariate analysis was performed using the Cox regression model.Results: In total, 92 RFA sessions were performed and 135 BCLM lesions were treated. Major complications occurred in one of the 92 sessions (1.1%). Technical efficacy was achieved in 92.6% of lesions (125/135 lesions). Local tumor progression occurred in 11.6% (8/69) of patients and new intrahepatic metastasis occurred in 55.1% (38/69) of patients. From the time of initial RFA, the median overall survival was 26 months, and the one-, two-, three- and five -year survival rates were 81.8, 50.1, 25.3 and 11.0%, respectively. Based on the multivariate analysis, the following three factors were identified as independent prognostic factors for overall survival: tumor size (p = .017), positive estrogen receptor status (p = .009) and extrahepatic metastatic disease (p = .001). The median progression-free survival was 24 months, and the one-, two-, three- and five -year survival rates after RFA were 77.4, 47.0, 23.7 and 8.5%, respectively. Additionally, the independent prognostic factors for progression-free survival included tumor size (p = .011), ER positivity (p = .001), margin size (p = .017) and extrahepatic metastatic disease (p < .001).Conclusion: The results of this study showed that RFA is a safe and locally effective method for the treatment of BCLM, especially in patients with lesions measuring less than 3 cm in diameter, a single liver metastasis, positive estrogen receptor status and no extrahepatic metastases. Also, patients with margin size >10 mm had no local tumor progression.

9 - Wide-field radiofrequency ablation (RFA) of anal high-grade dysplasia (HSIL) decreases recurrence over targeted ablation

Background Recurrence post HSIL ablation is high primarily from development of metachronous HSIL. Trials of hemi-circumferential and circumferential RFA of anal HSIL demonstrated reduced HSIL in treated areas at one year. We now examine long-term treatment durability and safety. Methods A retrospective analysis of long-term treatment results in participants returning for follow-up HRA after hemi-circumferential and circumferential RFA trials. Participants had to have an HRA >1 year post completion of initial RFA trials. A non-HSIL biopsy or no lesion on HRA without biopsy was considered no recurrence. Results Twenty-two participants underwent hemi-circumferential and 10 underwent circumferential RFA and 15 (68%) and 9 (90%), respectively returned for follow-up. Eighteen (75%) were white, 1 was female and 8 (33%) were HIV+ (all treated circumferentially). Median age was 52.5 (range 32–74) years with duration of follow-up post RFA a median 3.2 (range 1–4.5) years. During post-study follow-up median number of HRA's was 1 (range 1–4). No participants developed HSIL within the RFA treatment zone after completion of the initial trial. One participant treated with hemi-circumferential RFA developed metachronous HSIL in the non-ablated area at 3.8 years. Another developed recurrence at 12 months, was retreated with targeted cautery ablation, and post-trial remains disease free for 2.5 years. At last follow-up 14/23 (61%) individuals tested were high-risk HPV negative (6 HIV+). No long-term treatment related adverse events were identified. Conclusions When compared to targeted ablation, wide-field RFA appears to reduce HSIL recurrence. No long-term adverse events related to treatment were identified. Further study is warranted.

Su1118 APPEARANCE OR PROGRESSION OF DYSPLASIA AND CANCER IN BARRETT’S ESOPHAGUS UNDERGOING RADIOFREQUENCY ABLATION

Barrett’s esophagus (BE) is a known risk factor for esophageal adenocarcinoma (EAC). Radiofrequency ablation (RFA) has been associated with a high rate of complete eradication for dysplasia and intestinal metaplasia. Data are limited on patients who have progression of dysplasia or development of EAC while undergoing RFA therapy. We aimed to better characterize these patients. This was a retrospective review of medical records at a tertiary academic medical center. We included patients with at least one RFA treatment for BE without EAC. Patients achieving complete eradication of dysplasia were excluded. Data collected included demographics, date of BE diagnosis, endoscopy findings, anatomic pathology, location of the newly developed dysplasia, length of BE, RFA adjuvant therapies, and date of death. A total of 475 patients underwent RFA, of which 39 (8.2%) progressed to low grade dysplasia (LGD), high grade dysplasia (HGD) or EAC while undergoing therapy. The distribution of these changes is depicted in Table 1. Only 1 patient was female. Patient demographic data is found in Table 2. For those with HGD receiving RFA, 12.6% progressed into cancer. The majority of cancer developed in the distal esophagus (13/23 = 56.5 %). Seven patients (30.4 %) had their original HGD distributed over the entire BE segment prior to initial RFA. The progression was observed after an average of 3.0 RFA sessions. Twenty patients had endoscopic mucosal resection (EMR) and 2 had esophagectomy. Four (17.4 %) patients died. Eight patients achieved complete remission of intestinal metaplasia. For those who underwent RFA for LGD, 6 patients progressed to cancer and 6 to HGD. The rate of progression into cancer was significantly lower (5.1%) than those undergoing treatment for HGD (12.6%) (p= 0.04). The average number of RFA sessions before progression was 2.6. All 6 developed cancer in the distal BE segment and 5 of these patients had original low grade dysplasia in the distal BE segment. All 6 patients received adjuvant EMR and 2 esophagectomy. Two of these patients died. The 2 patients with short segment BE (2cm and 2.75 cm) progressed to cancer. Of the 4 patients with non-dysplastic Barrett’s who progressed while receiving RFA, the dysplasia appeared in the distal BE segment in 2, in the proximal in 1 and in the mid distal in 1. One patient developed cancer, but ultimately achieved complete remission of intestinal metaplasia. Our study shows that 8.2% of patients receiving RFA for BE have progression of dysplasia or development of cancer. Those at highest risk for progression are patients initially treated for HGD with 12.6% progressing to cancer after an average of 3.0 RFA sessions. Further studies are needed to determine why this progression occurred and how it can be avoided.Tabled 1Table 1. Number of patients with progression of dysplasia or progression to cancer based on initial indication for RFA therapy.Progression to:RFA for NDBE/ID (175)RFA for LGD (117)RFA for HGD (183)Indefinite DysplasiaLow grade Dysplasia1High Grade Dysplasia26Cancer16*23*Total4 (2.3%)12 (10.3%)23 (12.6%)Abbreviations: non-dysplastic Barrett’s esophagus (NDBE), indefinite dysplasia (ID), low grade dysplasia (LGD), high grade dysplasia (HGD). *P = 0.04 for progression into cancer between LGD and HGD groups Open table in a new tab Tabled 1Table 2. Characteristics of patients who had progression of dysplasia or development of cancer after RFA.RFA for NDBE/IDRFA for LGDRFA for HGDMean Age First Dysplasia or Mean Age First BE for NDBE (Range)64.5 (60-74)68.5 (54-78)72.3 (52-84)Mean Age Diagnosis Highest Progression (Range)68.5 (61-76)71.6 (57-81)74.2 (52-82)Mean Length BE Segment cm (Range)3.8 (2-5)7.0 (2-17)7.0 (1-14)Mean Number RFA Sessions Before Progression (Range)2.0 (1-3)2.6 (1-5)3.0 (1-11)Original Site of Dysplasia in Barrett’s Segment Before RFANAProximal11Proximal Mid10Mid04Mid Distal11Distal67Entire27Unknown13Site of Progression In EsophagusProximal124Proximal Mid003Mid023Mid Distal110Distal2713Adjuvant TherapyEMR2720ESD001Chemo-radiation002Brachytherapy002Esophagectomy022Cryotherapy123Radiation001Rate of CRIM128Deaths114Abbreviations: non-dysplastic Barrett’s esophagus (NDBE), indefinite dysplasia (ID), low grade dysplasia (LGD), high grade dysplasia (HGD), not applicable (NA), complete remission of intestinal metaplasia (CRIM). Open table in a new tab

Initial radiofrequency ablation failure for hepatocellular carcinoma: repeated radiofrequency ablation versus transarterial chemoembolisation

To compare the long-term therapeutic outcomes of repeated radiofrequency ablation (RFA) with that of transarterial chemoembolisation (TACE) in patients with local tumour progression (LTP) after initial RFA treatment for hepatocellular carcinoma (HCC). This retrospective study was approved by the institutional review board and the requirement for informed consent was waived. Between July 2006 and February 2012, 713 patients underwent RFA for single HCC as a first-line treatment. Fifty-eight patients who showed LTP as initial tumour recurrence post-RFA treatment were included. Patients were treated with either repeated RFA (n=33) or TACE (n=25). TACE was performed as an alternative therapeutic option when repeated RFA was not feasible based on the planning ultrasonography. Recurrence-free and overall survival rates were estimated using the Kaplan-Meier method. Prognostic factors for outcomes were evaluated using the Cox proportional hazards model. Both groups did not show significant differences in terms of baseline characteristics, with the exception being the proportion of subphrenic tumours (p=0.031). The RFA and TACE groups did not differ significantly in their 5-year recurrence-free and overall survival rates (17% versus 10.7% and 72.7% versus 51.9%, respectively, with all p-values >0.05). In addition, multivariate analyses revealed that type of treatment was not associated with recurrence-free or overall survival in patients with post-RFA LTP. TACE is an effective treatment, comparable to repeated RFA, in patients with LTP after initial RFA when repeated RFA is not feasible.

Clinical outcomes of percutaneous radiofrequency ablation for small renal cancer.

Partial nephrectomy is the treatment of choice for small renal cell carcinoma (RCC) from the perspective of cancer management and renal function. However, when patients with RCC are of advanced age, exhibit severe comorbidities, including cardiovascular and pulmonary diseases, or have hereditary RCC, ablative therapies, including radiofrequency ablation (RFA) and cryoablation are useful treatment options. In the present study, the clinical outcomes of percutaneous RFA for treating small RCC were evaluated. Between December 2005 and March 2015, 40 patients (41 renal tumors in total) underwent RFA and a total of 50 sessions of RFA were performed. The average tumor size was 2.5 cm. A total of 18 tumors were exophytic and 23 were parenchymal. Of the 41 tumors, 85.4% were completely ablated by initial RFA and the rate of complete ablation following reablation for residual viable lesions was 95.1%. Local recurrence-free survival following complete ablation was 84.2% at 3 years. A patient with a 4.7 cm RCC tumor rapidly progressed following four RFA treatments until complete ablation was achieved. The metastasis-free survival rate following initial RFA was 95.7% at 3 years. The RCC-specific survival was 100% (mean follow-up, 38 months). Adverse events occurred in five sessions (10%); however, only 1 patient with arteriovenous fistula required intervention (transarterial embolization). The mean hospital stay following RFA was 3.2 days. The mean decrease in estimated glomerular filtration rate following RFA was 2.7%. The results of the present study indicate that percutaneous RFA was an effective treatment for small RCCs with respect to management of cancer, minimal invasiveness and minimal loss of renal function, particularly in patients for whom surgery would be a high risk and those at increased risk of deterioration of renal function.

Irrigated-tip vs. conventional-tip catheters for primary ablation of posteroseptal and right free-wall accessory pathways: a prospective randomized study.

The use of irrigated-tip catheters enables elimination of almost all accessory pathways (APs) resistant to standard radiofrequency ablation (RFA). However, efficacy of irrigation catheter technology in the initial AP ablation has not been studied systematically yet. We tested whether the externally irrigated-tip catheters are more effective than the conventional-tip catheters for initial RFA of the posteroseptal and right free-wall APs, i.e., where application of the conventional RFA is expected to have a lower success rate. Fifty consecutive patients (39 +/- 12 years, 32 males), who were subjected to primary catheter-ablation of the posteroseptal or right free-wall AP were randomly assigned to RFA with an externally irrigated-tip catheter (group I, n = 25; 45 degrees C/40 W outside the coronary sinus (CS) and 45 degrees C/30 W inside the CS) or a conventional-tip catheter (group C, n = 25; 60 degrees C/60 W outside and 55 degrees C/35 W inside the CS). No significant difference was identified between groups I and C with respect to acute success rate (88% vs. 96%), number of radiofrequency applications (6.8 +/- 4.7 vs. 6.1 +/- 4.3), RFA time (373 +/- 242 sec vs 365 +/- 241 sec), energy (11,022 +/- 7833 J vs. 12,870 +/- 11,414 J), fluoroscopy time (669 +/- 443 sec vs. 789 +/- 578 sec) and recurrence rate (18.2% vs. 16.7%). The only complication was encountered in group I, manifested as AV-block I-II degree after elimination of the right posteroseptal AP. Irrigated-tip catheters are not more efficient than conventional catheters in initial RFA of the posteroseptal and right free-wall APs. Therefore, the use of irrigated-tip catheters is justifiable only for ablation of the APs resistant to previously attempted conventional RFA.

Radiofrequency ablation of hepatocellular carcinoma as bridge therapy to liver transplantation: A 10-year intention-to-treat analysis.

RFA as a first-line stand-alone bridge therapy to LT achieves excellent long-term overall and tumor-specific survivals, with a low dropout rate from tumor progression despite long wait list times and a sustained low tumor recurrence rate upon post-LT follow-up of up to 10 years. (Hepatology 2017;65:1979-1990).

Presence of non‐hypervascular hypointense nodules on Gadolinium‐ethoxybenzyl‐diethylenetriamine pentaacetic acid‐enhanced magnetic resonance imaging in patients with hepatocellular carcinoma

Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) performed before curative therapy for hepatocellular carcinoma (HCC) can distinguish between intrahepatic distant recurrence and hypervascularization. This study aimed to retrospectively evaluate the presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI as a risk factor of the intrahepatic distant recurrence of early stage HCC following radiofrequency ablation (RFA). A total of 132 patients who underwent preprocedural Gd-EOB-DTPA-enhanced MRI followed by initial RFA were retrospectively analyzed. Post-RFA intrahepatic distant recurrence, which excluded the hypervascularization of non-hypervascular hypointense nodules detected by preprocedural Gd-EOB-DTPA-enhanced MRI, was evaluated according to the presence of non-hypervascular hypointense nodules on preprocedural Gd-EOB-DTPA-enhanced MRI. Intrahepatic distant recurrence rates following RFA were higher in patients with non-hypervascular hypointense nodules (1-year: 22.5%, 2-year: 52.1%, 5-year: 89.1%) compared with in patients without non-hypervascular hypointense nodules (1-year: 7.0%, 2-year: 28.8%, 5-year: 48.7%). The presence of non-hypervascular hypointense nodules was associated with markedly increased cumulative recurrence rates of both identical and different subsegment intrahepatic distant recurrence, being an independent risk factor for post-RFA identical and different subsegment intrahepatic distant recurrence (identical: HR=2.365, P=0.027; different: HR=3.276, P<0.001). The presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI obtained prior to RFA is an important predictive factor of intrahepatic distant recurrence following RFA of HCC.

Implication of Psoas Muscle Index on Survival for Hepatocellular Carcinoma Undergoing Radiofrequency Ablation Therapy.

Aims We aimed to retrospectively examine the impact of pretreatment psoas muscle index (PMI) as determined by computed tomography on survival for treatment naïve hepatocellular carcinoma (HCC) patients who underwent percutaneous radiofrequency ablation (RFA) therapy (n=182; 111 males and 71 females with median age of 70 years).Patients and methods Optimal cut-off points of PMI in male and female were calculated by receiver operating characteristic analysis for survival. We investigated parameters associated with overall survival (OS) in the univariate and multivariate analyses.Results The median follow-up period in this study was 4.28 years. For all cases, the 5-year cumulative OS rate after initial RFA was 69.2%. The median (range) value in PMI for male was 6.03 (1.63-9.90) cm2/m2 whereas that for female was 4.06 (1.21-7.32) cm2/m2. Maximum tumor size ranged from 0.7 cm to 3.5 cm (median, 1.5cm). There were 145 patients with single nodule and 37 with multiple nodules. The optimal cut-off point for PMI was 6.31 cm2/m2 in male and 3.91 cm2/m2 in female. The 5-year cumulative OS rates were 51.5% in the decreased PMI group (n=90) and 86.5% in the non-decreased PMI group (n=92) (P<0.0001). In patients with Child-Pugh A (n=137) and Child-Pugh B or C (n=45), similar results were obtained. In the multivariate analysis, presence of decreased PMI (P<0.0001), total bilirubin ≥1.2 mg/dl (P=0.0015) and des-γ-carboxy prothrombin ≥34 mAU/ml (P=0.0089) were found to be significant adverse predictors related to OS.Conclusion PMI can be useful for predicting outcomes in HCC patients undergoing percutaneous RFA therapy.

Radiofrequency ablation of spinal osteoid osteoma: a prospective study.

OBJECTIVE Surgery has been considered the standard treatment for spinal osteoid osteomas that are refractory to analgesic agents. Radiofrequency ablation (RFA) is a less invasive technique with established efficiency for the treatment of peripheral osteoid osteomas. The main objectives of this study are to evaluate the safety of RFA based on the results of a previous experimental study in rats conducted in the authors' laboratory and to identify its short- and long-term efficiency in the treatment of spinal osteoid osteomas. METHODS Between March 2009 and July 2016, 8 consecutive patients with spinal osteoid osteomas were enrolled in the study and underwent 9 CT-guided RFA procedures. All patients presented with spinal pain (median preoperative visual analog scale [VAS] score 7.55, range 6-8.8) predominantly during the night, and they all had normal neurological examination results before the procedure. Pain (according to the VAS score) and neurological status were reassessed immediately before discharge, with further follow-up at 1, 6, and 12 months after the procedure. At the final follow-up, VAS score, neurological examination, patient satisfaction, and a radiological control (CT scan) were documented (median 48 months, range 12-84 months). VAS scores before and after the procedure were compared during the 3 days before surgery (D0), on the day of the surgery, Day 1 (D1), and at the final follow-up. RESULTS No neurological deficit was documented following the procedure or at the final follow-up. A statistically significant reduction in the VAS score was observed on Day 1 (mean 2.56 ± 0.68, p = 0.005) compared with D0. At the final follow-up, all patients reported a VAS score of 0 and a satisfaction rate of 100%. Only 1 patient had recurrent symptoms (pain, VAS score 8.1) 6 months after the initial RFA. A second procedure was performed, and the patient was subsequently symptom free at the final follow-up. CT scanning performed in all patients (12-84 months post-RFA) showed residual sclerosis in 4 patients and complete resolution of the radiological lesion in the remaining 4 patients. CONCLUSIONS CT-guided RFA appears to be a safe and effective method for the management of spinal osteoid osteoma and can be safely performed for lesions close to the dura or exiting nerve root based on the motor response threshold testing performed during the procedure. It should be considered the treatment of choice for spinal osteoid osteomas refractory to conservative treatment, thus avoiding more aggressive spinal approaches with subsequent potential morbidity.

Erratum: Treatment Failure After Image-Guided Percutaneous Radiofrequency Ablation (RFA) of Renal Tumors - A Systematic Review with Description of Type, Frequency, Risk Factors and Management.

Background Radiofrequency ablation (RFA) is an established treatment for small renal tumors. The objective of this review is to systematically assess the type, frequency, risk factors and management of treatment failure after image-guided percutaneous RFA of renal tumors. Method 10 studies (967 patients, 1033 tumors) with a mean/median follow-up of ≥ 30 months were systematically identified and analyzed. Results and Conclusion Image-guided percutaneous RFA of localized renal tumors is very effective. The most common type of treatment failure is residual unablated tumor (5.9 %), followed by local tumor progression (4.7 %). De novo tumors in the kidneys occur in 1.3 % of cases and extra-renal metastases in 2.0 %. Local tumor progression, de novo tumors in the kidneys and extra-renal metastases occur predominantly later than 12 months after initial RFA. Tumor size > 3 cm and central tumor location are the major risk factors for treatment failure. In the case of treatment failure, repeated RFA shows high success rates (86.3 % for residual unablated tumors and 87.5 % for local tumor progression). Key Points: Citation Format

Catheter ablation for ventricular tachycardia following surgical treatment of pulmonary stenosis with intact ventricular septum.

This study was aimed to report the characteristics and treatment of ventricular tachycardia (VT) following surgical treatment of pulmonary stenosis with intact ventricular septum. Five patients underwent radiofrequency catheter ablation for sustained monomorphic left bundle branch block (LBBB) type VT who previously underwent surgical treatment of pulmonary stenosis. Except stimulation, voltage and activation mapping was performed using three-dimensional (3D) electro-anatomic mapping and ablation was applied accordingly. Four VTs were induced during EP study. Two VTs were focal and the earliest activity was targeted in the right ventricular apex (RVA). The other two VTs were reentrant and the critical isthmus located in the mid-lateral wall and anterior wall of right ventricle, respectively. Ablation abolished all inducible VTs in four patients. In the patient whose VT was non-inducible, radiofrequency (RF) energy was delivered to the RVA where pacing mapping matched the clinical VT. One focal VT recurred 60 months after the initial RF ablation. Repeat mapping and ablation was performed and no VT recurred over a 24-month period. The mechanism of VT following surgical treatment of pulmonary stenosis can be either focal or reentrant. Ablation of this subgroup of VT is feasible.

Radiofrequency Ablation Guided by Contrast-Enhanced Sonography versus B-Mode Sonography for Hepatocellular Carcinoma after Transcatheter Arterial Chemoembolization

Purpose: Contrast-enhanced sonography increases negative enhancement in the Kupffer phase after transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). We compared contrast-enhanced sonography with B-mode sonography for guidance of radiofrequency ablation (RFA) of HCC after TACE. Methods: After TACE was performed, 18 nodules in 12 patients were treated by B-mode sonography guided RFA, while 22 nodules in 18 patients were treated by contrast-enhanced sonography-guided RFA. Results: The success rate of initial RFA was 83.3% (15/18 nodules) in the B-mode sonography group. On the other hand, the success rate was 100% (22/22 nodules) in the contrast-enhanced sonography group and the difference was significant (p = 0.046). Conclusion: These findings suggest that RFA guided by Kupffer phase contrast-enhanced sonography after TACE is a promising therapeutic option for curing HCC.