Project description:Radiofrequency ablation (RFA) is a well-known, effective, and safe method for treating benign thyroid nodules and recurrent thyroid cancers. Thyroid-dedicated devices and basic techniques for thyroid RFA were introduced by the Korean Society of Thyroid Radiology (KSThR) in 2012. Thyroid RFA has now been adopted worldwide, with subsequent advances in devices and techniques. To optimize the treatment efficacy and patient safety, understanding the basic and advanced RFA techniques and selecting the optimal treatment strategy are critical. The goal of this review is to therefore provide updates and analysis of current devices and advanced techniques for RFA treatment of benign thyroid nodules and recurrent thyroid cancers.
Project description:PurposeRadiofrequency ablation is a curative treatment option for very early-stage or earlystage hepatocellular carcinoma (HCC). However, percutaneous radiofrequency ablation (PRFA) for subphrenic tumors is technically challenging. Laparoscopic radiofrequency ablation (LRFA) has been used to overcome this disadvantage. This study compared the treatment outcomes between LRFA and PRFA for subphrenic HCC.MethodsThis retrospective study screened patients who underwent PRFA or LRFA for subphrenic HCC between 2013 and 2018. Therapeutic outcomes, including local tumor progression (LTP), intrahepatic distant recurrence (IDR), extrahepatic metastasis (EM), disease-free survival (DFS), and overall survival (OS), were compared between the two groups.ResultsThirty patients in the PRFA group and 23 patients in the LRFA group were included. LTP was observed in six patients in the PRFA group (20%), but in no patients in the LRFA group. The cumulative LTP rates at 1, 3, and 5 years were 3.7%, 23.4%, and 23.4%, respectively, in the PRFA group and 0.0% in the LRFA group (P=0.015). The IDR, EM, and DFS rates were not significantly different between the two groups (P=0.304, P=0.175, and P=0.075, respectively). The OS rates at 1, 3, and 5 years were 96.6%, 85.7%, and 71.6%, respectively, in the PRFA group and 100%, 95.7%, and 95.7%, respectively, in the LRFA group (P=0.049).ConclusionLRFA demonstrated better therapeutic outcomes than did PRFA for subphrenic tumors in terms of LTP and OS. Therefore, LRFA can be considered as the first-line treatment option for subphrenic HCC.
Project description:ObjectivesThis study aimed to evaluate the therapeutic outcomes of transarterial chemoembolization combined with radiofrequency ablation (TACE + RFA) for hepatocellular carcinomas (HCC) measuring ≤3 cm infeasible for ultrasound (US)-guided percutaneous RFA.MethodsTwenty-four patients who underwent fluoroscopy-guided TACE + RFA for single HCC between January 2012 and December 2016 were screened. To evaluate the TACE + RFA outcomes compared with those of US-guided RFA, 371 patients who underwent US-guided RFA during the same period were screened. We compared local tumor progression (LTP) and intrahepatic distant recurrence (IDR) between the two groups before and after propensity score (PS) matching, and performed univariable and multivariable Cox proportional hazard regression analyses for all patients.ResultsPS matching yielded 21 and 42 patients in the TACE + RFA and US-guided RFA groups, respectively. Cumulative LTP rates after PS matching were not significantly different between the two groups at 1 (0.0% vs. 7.4%, p = 0.072), 2 (10.5% vs. 7.4%, p = 0.701), and 5 years (16.9% vs. 10.5%, p = 0.531). IDR rates did not differ significantly between the two groups at 1 (20.6% vs. 10%, p = 0.307), 2 (25.9% vs. 25.9%, p = 0.999), or 5 years (49.9% vs. 53%, p = 0.838). Multivariable analysis showed that treatment type was not a significant factor for LTP or IDR.ConclusionThe outcomes of TACE + RFA for HCC were similar to those of general US-guided RFA. Fluoroscopy-guided TACE + RFA may be an effective treatment when US-guided RFA is not feasible.
Project description:INTRODUCTION AND AIM: Radiofrequency ablation (RFA) is effective in the treatment of unresectable hepatic tumors and promising results have also been described in tumors of kidney, lung, brain, prostate, and breast. The radiofrequency destruction of solid pancreatic tumors sounds logical but also seems risky due to the friable pancreatic parenchyma, the fear of pancreatitis and the prejudiced myth of 'the pancreas is not your friend'. PATIENTS AND METHODS: We present our initial experience and we describe our technique during intraoperative RFA in four patients with locally advanced and unresectable pancreatic adenocarcinoma (head of pancreas, three; body-tail, one; diameter, 3-12 cm). In all the patients, the RFA was followed by bypass palliative procedures (cholecystojejunostomy and Brown's anastomosis and/or gastrojejunostomy). A drainage tube was left close to the ablated area. Serum amylase and fluid amylase (drain) were measured for 5-7 days postoperatively. Sandostatin was also administered prophylactically for 3-5 days. RESULTS: The postoperative period was uneventful in all the patients, without complications or evidence of pancreatitis. The post RFA CT scan showed remarkable changes in the density and the characteristics of the tumors in all the patients. All the patients are alive, at 12, 8, 5 and 3 months postoperatively, respectively. In one patient (with cancer of the body of the pancreas) who was receiving morphine because of intolerable pain, significant pain relief has been observed. CONCLUSIONS: From our initial results, RFA seems to be a feasible, potentially safe and promising option in patients with locally advanced and unresectable pancreatic cancer. Nevertheless, larger series of cases are needed to secure our encouraging results.
Project description:BackgroundThe delayed effect of radiofrequency (RF) ablation was described in cases of accessory pathway and premature ventricular contraction ablation, as well as delayed atrioventricular (AV) block after slow pathway ablation.Case summaryWe report a case of a female patient with AV nodal re-entry tachycardia (AVNRT), in whom the first electrophysiology study ended with acute failure of slow pathway ablation, despite using long steerable sheath, both right and left-sided ablation with >15 min of RF energy application and repeatedly achieving junctional rhythm. Six weeks afterwards, during scheduled three-dimensional electroanatomical mapping procedure, there was no proof of dual AV nodal conduction nor could the tachycardia be induced. Also, the patient did not have palpitations between the two procedures nor during the 12-month follow-up period.DiscussionThis case illustrates that watchful waiting for delayed RF ablation efficacy in some cases of AVNRT ablation could be reasonable, in order to reduce the risk of complications associated with slow pathway ablation.
Project description:PurposeTo compare the size of the coagulation (CZ) and periablational (PZ) zones created with two commercially available devices in clinical use for radiofrequency (RFA) and microwave ablation (MWA), respectively.MethodsComputer models were used to simulate RFA with a 3-cm Cool-tip applicator and MWA with an Amica-Gen applicator. The Arrhenius model was used to compute the damage index (Ω). CZ was considered when Ω > 4.6 (>99% of damaged cells). Regions with 0.6<Ω < 2.1 were considered as the PZ (tissue that has undergone moderate sub-ablative hyperthermia). The ratio of PZ volume to CZ volume (PZ/CZ) was regarded as a measure of performance, since a low value implies achieving a large CZ while keeping the PZ small.ResultsTen-min RFA (51 W) created smaller periablational zones than 10-min MWA (11.3 cm3 vs. 17.2-22.9 cm3, for 60-100 W MWA, respectively). Prolonging duration from 5 to 10 min increased the PZ in MWA more than in RFA (2.7 cm3 for RFA vs. 8.3-11.9 cm3 for 60-100 W MWA, respectively). PZ/CZ for RFA were relatively high (65-69%), regardless of ablation time, while those for MWA were highly dependent on the duration (increase of up to 25% between 5 and 10 min) and on the applied power (smaller values as power was raised, 102% for 60 W vs. 81% for 100 W, both for 10 min). The lowest PZ/CZ across all settings was 56%, obtained with 100 W-5 min MWA.ConclusionsAlthough RFA creates smaller periablational zones than MWA, 100 W-5 min MWA provides the lowest PZ/CZ.
Project description:Radiofrequency (RF) ablation has been increasingly utilized as a minimally invasive treatment for primary and metastatic liver tumors, as well as tumors in the kidneys, bones, and adrenal glands. The development of high-current RF ablation has subsequently led to an increased risk of thermal skin injuries at the grounding pad site. The incidence of skin burns in recent studies ranges from 0.1-3.2% for severe skin burns (second-/third-degree), and from 5-33% for first-degree burns.(1-3).
Project description:Accurate monitoring of treatment is crucial in minimally-invasive radiofrequency ablation in oncology and cardiovascular disease. We investigated alterations in optical properties of ex-vivo bovine tissues of the liver, heart, muscle, and brain, undergoing the treatment. Time-domain diffuse optical spectroscopy was used, which enabled us to disentangle and quantify absorption and reduced scattering spectra. In addition to the well-known global (1) decrease in absorption, and (2) increase in reduced scattering, we uncovered new features based on sensitive detection of spectral changes. These absorption spectrum features are: (3) emergence of a peak around 840 nm, (4) redshift of the 760 nm deoxyhemoglobin peak, and (5) blueshift of the 970 nm water peak. Treatment temperatures above 100 °C led to (6) increased absorption at shorter wavelengths, and (7) further decrease in reduced scattering. This optical behavior provides new insights into tissue response to thermal treatment and sets the stage for optical monitoring of radiofrequency ablation.
Project description:IntroductionBreast cancer (BC) is the most common malignancy in women. Various studies [5,6] have shown that surgical resection of single liver or lung metastases in patients with metastases from BC increases survival. Radiofrequency ablation (RFA) can be an alternative to resection in some patients when resection is not feasible.Materials and methodsFrom January 2002 to December 2008, 491 patients with liver metastases underwent US-guided percutaneous RFA. Of these patients 5 (5/491; 1%) had BC. In the same period, 32 patients with pulmonary metastases underwent CT-guided RFA. Of these patients 3 (3/32; 9%) had BC. Mean age was 61.3 years. All patients were postmenopausal and receiving polychemotherapy according to international guidelines. Inclusion criteria for RFA treatment of metastases from BC applied are identical or in some cases more restrictive than those reported in the literature.ResultsThere were no deaths or severe complications and no treatment failures. Disease free and overall median survival were respectively 7.65 and 25.7 months after US-guided RFA and 13.4 and 34.8 months after CT-guided RFA. During follow-up (mean follow-up 26 months, range 4-63 months) 5/8 (62.5%) patients exhibited recurrence: 3/5 (60%) had local recurrence and 2/5 (40%) had non-local recurrence; 4/5 patients with recurrence were re-treated.DiscussionThe authors' experience confirms that RFA is an effective, safe and repeatable technique in the treatment of metastases from BC. Metastatic recurrence rate confirms that metastatic BC is a disease which requires a multidisciplinary approach and that the role of chemotherapy is indisputable. Effects on survival are promising but further confirmation is needed through prospective randomized studies.