Radiofrequency ablation

Radiofrequency Ablation of Small Thyroid Cancer–A Solution Looking for a Problem?

Posted by

0


Fortunately, most thyroid cancers are indolent and their treatment is de-escalating. What was once uniformly managed with total thyroidectomy, adjuvant radioactive iodine, and thyrotropin suppression is now individualized, involving less or even no surgery—for the right patients. Matching the right treatment to the right cancer biology for the right patient is fundamental to providing the best care. Discerning thyroid tumor biology, however, currently depends on characteristics of disease presentation (eg, extent) and pathologic information obtained after surgery. When considering innovative surgery-free treatment strategies, such as radiofrequency ablation (RFA), an intrinsic question remains: how, without surgery, can we obtain the best and most comprehensive information about thyroid tumor biology?

Li and colleagues1 reported their retrospective and single-center experience of using RFA to treat 1613 patients with T1a (1 cm or less, intrathyroidal; 88% of cohort) or T1b (more than 1 cm and 2 cm or less, intrathyroidal; 12% of cohort) low-risk, differentiated thyroid carcinoma who were ineligible or refused either surgery or active surveillance. Over an average 5-year follow up, local tumor progression occurred in 4% of patients, of whom 39% had persistent disease, primarily occurring with larger or multifocal carcinomas in a subcapsular location, and 86% required RFA retreatment. Carcinomas with BRAF V600E mutations were up to 6 times more likely to develop local tumor progression, though the finding did not achieve statistical significance.

Could a more comprehensive molecular profile improve patient selection for RFA? Over the last 3 decades, significant strides in understanding the biology of thyroid carcinoma, especially its molecular underpinnings, have been made. Though the current study reported BRAF V600E status, this somatic abnormality is only 1 mutational feature of thyroid carcinomas.2 Studies increasingly report the connection of molecular profiling results with thyroid tumor biology and outcomes,3,4 offering important prognostic information from a fine-needle biopsy alone and, thus, perfectly suited to improve patient selection for nonoperative strategies. The use of molecular profiling for prognosis is common in other cancers5,6 and its application routinely guides clinical care of breast cancer7—why should thyroid cancer care lag behind?

The authors1 should be commended for their large series, which moves the field toward a better understanding of the safety of RFA for small thyroid carcinomas. Like active surveillance, RFA may be another possible nonoperative option for patients who desire further treatment of small (less than 1 cm) thyroid cancers. Avoiding surgery is a welcome change in a disease process where opportunities to de-escalate care are important, but it is still unclear whether RFA is a patient-centered, cost-effective alternative. Though future comparative studies are necessary, molecular profiling should be considered to optimize risk stratification and individualize treatment. For now, we must ask ourselves whether RFA is a solution that has yet to find its problem.

Coronary Artery Spasm During Pulsed Field vs Radiofrequency Catheter Ablation of the Mitral Isthmus

Posted by

0


Abstract

Importance  In treating atrial fibrillation, pulsed field ablation (PFA) is a novel energy modality with comparable efficacy to conventional thermal ablation, such as radiofrequency ablation (RFA), but with the benefit of some preferentiality to myocardial tissue ablation. Studies have demonstrated important safety advantages, including the absence of esophageal injury or pulmonary vein stenosis and only rare phrenic nerve injury. However, there is emerging evidence of coronary artery vasospasm provoked by PFA.

Objective  To compare the incidence and severity of left circumflex arterial vasospasm between PFA and RFA during adjacent ablation along the mitral isthmus.

Design, Setting, and Participants  This prospective cohort study enrolled consecutive adult patients receiving first-ever PFA or RFA of the mitral isthmus during catheter ablation of atrial fibrillation in 2022 with acute follow-up at a single referral European center.

Exposure  A posterolateral mitral isthmus line was created using either a multielectrode pentaspline PFA catheter (endocardial ablation) or a saline-irrigated RFA catheter. Simultaneous diagnostic coronary angiography was performed before, during, and after catheter ablation. Nitroglycerin was planned for spasm persisting beyond 20 minutes or for significant electrocardiographic changes.

Main Outcomes and Measures  The frequency and severity of left circumflex arterial vasospasm was assessed and monitored, as were time to remission and any need for nitroglycerin administration.

Results  Of 26 included patients, 19 (73%) were male, and the mean (SD) age was 65.5 (9.3) years. Patients underwent either PFA (n = 17) or RFA (n = 9) along the mitral isthmus. Coronary spasm was observed in 7 of 17 patients (41.2%) undergoing PFA: in 7 of 9 (77.8%) when the mitral isthmus ablation line was situated superiorly and in 0 of 8 when situated inferiorly. Conversely, coronary spasm did not occur in any of the 9 patients undergoing RFA. Of 5 patients in whom crossover PFA was performed after RFA failed to achieve conduction block, coronary spasm occurred in 3 (60%). Most instances of spasm (9 of 10 [90%]) were subclinical, with 2 (20%) requiring nitroglycerin administration. The median (range) time to resolution of spasm was 5 (5-25) minutes.

Conclusion and Relevance  When creating a mitral isthmus ablation line during catheter ablation of atrial fibrillation, adjacent left circumflex arterial vasospasm frequently occurred with PFA and not RFA but was typically subclinical.

Introduction

Pulsed field ablation (PFA) has engendered substantial interest, as it minimizes damage to periatrial tissue during atrial fibrillation (AF) ablation while retaining clinical effectivness.1–7 However, there is emerging evidence that PFA can cause subtotal coronary arterial spasm during cavotricuspid isthmus (CTI) ablation. Indeed, right coronary spasm occurred in 100% of patients undergoing PFA at the CTI using a multielectrode pentaspline catheter, albeit the spasm was subclinical—no ST-segment elevation, arrhythmias, or ventricular wall motion abnormalities—and attenuated by prophylactic administration of nitroglycerin.8 Furthermore, 2 patients undergoing PFA of the CTI developed symptomatic ST-segment elevation responsive to nitroglycerin, in one case degenerating to ventricular fibrillation requiring defibrillation.6,9

While CTI ablation is typically not technically demanding, with the option of switching to conventional radiofrequency ablation (RFA), it is difficult to achieve bidirectional mitral isthmus conduction block with thermal ablation.10 We performed systematic coronary angiography during PFA at the posterolateral mitral isthmus to assess the frequency and severity of vasospasm of the adjacent left circumflex artery and to compare this response with RFA.

Discussion

During mitral isthmus ablation, (1) left circumflex artery vasospasm occurred during PFA at the posterolateral mitral isthmus, but only with lesions situated superiorly; (2) RFA at this superior mitral isthmus location did not induce spasm; (3) during crossover PFA after failed RFA, spasm again occurred; and (4) spasm was severe in a minority of patients, with 1 instance of dynamic ST-segment changes without hemodynamic instability. Mitral isthmus ablation is often considered to fortify against perimitral flutters, but its utility is tempered by the technical difficulty in achieving durable bidirectional conduction block with RFA.10 This difficulty appears related to the epicardial cooling effect of the blood in the CS, the complex topography with associated annular movement, and the involvement of epicardial tissue sleeves. Additional strategies may be necessary for bidirectional mitral isthmus block, including ablation from within the CS itself, use of a CS balloon to displace blood during endocardial left atrial ablation, and infusion of alcohol into the vein of Marshall.10 This challenge is further compounded by the fact that incomplete linear ablation can be proarrhythmic by creating conduits of slow conduction, thereby potentiating macro-reentrant perimitral flutter.

The pentaspline PFA catheter studied herein was designed for pulmonary vein isolation, but after regulatory approval, it has been used for mitral isthmus ablation.6 Most cases of PFA-related spasm, even severe spasm, are subclinical or, when clinically evident, cause only transient ST-segment changes.8 Spasm was not observed during PFA inferiorly along the mitral isthmus. It is possible that at this location, the petals of the PFA catheter may not be oriented sufficiently parallel to the tissue for the energy field to affect the left circumflex artery. However, to our knowledge, there is 1 reported case of left circumflex artery spasm—manifesting as inferior ST-segment elevation requiring nitroglycerin—occurring during PFA inferiorly at the mitral isthmus.11 Interestingly, spasm in this case was likely accentuated by the fact that the left circumflex supplied collaterals to the right coronary arterial territory, as this vessel had in-stent stenosis. Thus, while vasospasm is not frequent with PFA situated inferiorly, it certainly is possible.

While not studied here, we previously demonstrated that nitroglycerin pretreatment during PFA at the CTI eliminated severe vasospasm.8 This is consistent with spasm resulting from temporary membrane permeabilization of smooth muscle, local release of calcium or inflammatory mediators, or stimulation of ganglionated plexi causing autonomic imbalance.12 Additional studies should assess whether routine prophylactic nitroglycerin pre-PFA is superior to expectant administration only when vasospasm occurs.

Significant (50% to 84%) left circumflex spasm was previously observed in 5 of 53 patients (9%) undergoing RFA of the mitral isthmus.13 In our study, RFA induced no discernable spasm, perhaps because of less frequent application of RF energy directly within the CS. This suggests that vasospasm during mitral isthmus ablation may be less related to the energy modality but rather a function of the energy field’s proximity to the vessel.

Limitations

This study has limitations. This study was nonrandomized; however, patients were treated consecutively—first PFA, then RFA. Furthermore, crossover PFA caused spasm in 3 of 5 patients after RFA induced no spasm. Also, left circumflex spasm only occurred during mitral isthmus ablation superiorly and not at all inferiorly, again highlighting the improbability of differential spasm being pure coincidence. Only 1 PFA catheter was studied, so these results may not apply to other catheters with different contact, maneuverability, and stability.

While the observed vasospasm was largely subclinical, overt clinical effects may be more common if there is preexisting coronary artery disease. Similarly, the long-term sequelae of spasm are unknown. In preclinical porcine studies, when PFA was applied immediately adjacent to coronary arteries, tunica media fibrosis and neointimal hyperplasia were observed 4 to 12 weeks later, albeit causing only minimal to mild stenosis.14,15 Whether chronic coronary injury occurs late after PFA adjacent to coronary arteries remains to be determined.

Conclusions

When creating a mitral isthmus ablation line during catheter ablation of atrial fibrillation, unlike for RFA, PFA caused spasm of the adjacent left circumflex artery, albeit typically without clinical manifestations.

Radiofrequency ablation effective for most children with benign thyroid nodules

Posted by

0


Most children who undergo image-guided radiofrequency ablation for treatment of benign nonfunctional thyroid nodules have at least a 50% reduction in nodule volume 4 years after treatment, according to study data published in Thyroid.

“Radiofrequency ablation was effective in reducing the volume of benign nonfunctional thyroid nodules in children, providing significant symptomatic relief with a good safety profile during short- and long-term follow-up,” Xinguang Qiu, MD, of the department of thyroid surgery at The First Affiliated Hospital of Zhengzhou University in China, and colleagues wrote. “Radiofrequency ablation should be considered as a beneficial, minimally invasive treatment modality for selected pediatric patients.”

Radiofrequency ablation reduces mean volume of benign thyroid nodules by more than 50% in children
Children undergoing radiofrequency ablation for the treatment of benign thyroid nodules had a mean volume reduction ratio of 65% or more at 3 months, 6 months and 1 year of follow up. Data were derived from Li L, et al. Thyroid. 2022;doi:10.1089/thy.2021.0454.

Researchers reviewed data from 62 patients aged 18 years or younger with benign thyroid nodules treated with radiofrequency ablation at The First Affiliated Hospital of Zhengzhou University from July 2014 to August 2017 (75.8% girls; mean age, 14.4 years). Participants underwent an ultrasonography prior to the procedure to evaluate thyroid nodule composition and symptoms and had follow-up 3, 6 and 12 months after treatment. After 1 year, follow-up visits were performed annually. Ultrasonography and laboratory tests were repeated at each follow-up visit. Volume reduction ratio was calculated to assess the extent of nodule volume reduction.

Of the study cohort, 54 children had one thyroid nodule requiring treatment, and eight had two thyroid nodules. At 3 months, the mean volume reduction ratio was 65.1%, and increased to 74.7% at 6 months and to 77.5% at 1 year. The mean volume reduction ratio was 60.3% at 2 years, 68.5% at 3 years and 55.1% at 4 years. Thirty-six nodules had strong echogenicity or hyperechogenicity at 3 months, and six retained these characteristics at 6 months.

Sixteen of the 70 nodules began to regrow after initial treatment. Of the regrowing nodules, 56.3% had a volume reduction ratio below 50%, indicating a loss in treatment efficacy. Of those that lost treatment efficacy, 66.7% became larger than before treatment. Three nodules underwent a second radiofrequency ablation and surgery was performed on two other nodules.

Children requiring treatment of bilateral nodules had a lower volume reduction rate (13.6% vs. 74.1%; P < .001), lower technical efficacy (56.3% vs. 90.7%; P = .001) and higher regrowth rate (68.8% vs. 9.3%; P < .001) compared with unilateral nodules.

“We found that bilateral nodules requiring treatment had lower volume reduction rates, lower therapeutic efficacy and higher rates of regrowth, and the presence of bilateral nodules was an independent factor related to efficacy and regrowth,” the researchers wrote. “The specific reason for these associations is unclear. In addition, such results have not been reported in adult studies. Thus, radiofrequency ablation may not be appropriate for the treatment of bilateral thyroid nodules in children.”

Nodules with a higher cystic component had a higher volume reduction ratio than those with a lower cystic component (72.4% vs. 46.7%; P = .001). Nodules with higher vascularity had a lower regrowth rate than those with low vascularity (12.1% vs. 32.4%; P = .043). In all, 4.8% of patients had complications from the procedure.

The researchers wrote that radiofrequency ablation provides benefits for many patients, but those who undergo the procedure require long-term follow-up and the lack of a pathological exam means providers can not rule out malignancy.

“This treatment requires specialized treatment centers, specialized equipment, and highly skilled and experienced physicians, so access to radiofrequency ablation may also be a barrier to its use,” the researchers wrote. “Therefore, we believe that radiofrequency ablation is more likely to be a complementary treatment modality to surgical treatment.”

Radiofrequency ablation effective for most children with benign thyroid nodules

Posted by

0


Most children who undergo image-guided radiofrequency ablation for treatment of benign nonfunctional thyroid nodules have at least a 50% reduction in nodule volume 4 years after treatment, according to study data published in Thyroid.

“Radiofrequency ablation was effective in reducing the volume of benign nonfunctional thyroid nodules in children, providing significant symptomatic relief with a good safety profile during short- and long-term follow-up,” Xinguang Qiu, MD, of the department of thyroid surgery at The First Affiliated Hospital of Zhengzhou University in China, and colleagues wrote. “Radiofrequency ablation should be considered as a beneficial, minimally invasive treatment modality for selected pediatric patients.”

Radiofrequency ablation reduces mean volume of benign thyroid nodules by more than 50% in children
Children undergoing radiofrequency ablation for the treatment of benign thyroid nodules had a mean volume reduction ratio of 65% or more at 3 months, 6 months and 1 year of follow up. Data were derived from Li L, et al. Thyroid. 2022;doi:10.1089/thy.2021.0454.

Researchers reviewed data from 62 patients aged 18 years or younger with benign thyroid nodules treated with radiofrequency ablation at The First Affiliated Hospital of Zhengzhou University from July 2014 to August 2017 (75.8% girls; mean age, 14.4 years). Participants underwent an ultrasonography prior to the procedure to evaluate thyroid nodule composition and symptoms and had follow-up 3, 6 and 12 months after treatment. After 1 year, follow-up visits were performed annually. Ultrasonography and laboratory tests were repeated at each follow-up visit. Volume reduction ratio was calculated to assess the extent of nodule volume reduction.

Of the study cohort, 54 children had one thyroid nodule requiring treatment, and eight had two thyroid nodules. At 3 months, the mean volume reduction ratio was 65.1%, and increased to 74.7% at 6 months and to 77.5% at 1 year. The mean volume reduction ratio was 60.3% at 2 years, 68.5% at 3 years and 55.1% at 4 years. Thirty-six nodules had strong echogenicity or hyperechogenicity at 3 months, and six retained these characteristics at 6 months.

Sixteen of the 70 nodules began to regrow after initial treatment. Of the regrowing nodules, 56.3% had a volume reduction ratio below 50%, indicating a loss in treatment efficacy. Of those that lost treatment efficacy, 66.7% became larger than before treatment. Three nodules underwent a second radiofrequency ablation and surgery was performed on two other nodules.

Children requiring treatment of bilateral nodules had a lower volume reduction rate (13.6% vs. 74.1%; P < .001), lower technical efficacy (56.3% vs. 90.7%; P = .001) and higher regrowth rate (68.8% vs. 9.3%; P < .001) compared with unilateral nodules.

“We found that bilateral nodules requiring treatment had lower volume reduction rates, lower therapeutic efficacy and higher rates of regrowth, and the presence of bilateral nodules was an independent factor related to efficacy and regrowth,” the researchers wrote. “The specific reason for these associations is unclear. In addition, such results have not been reported in adult studies. Thus, radiofrequency ablation may not be appropriate for the treatment of bilateral thyroid nodules in children.”

Nodules with a higher cystic component had a higher volume reduction ratio than those with a lower cystic component (72.4% vs. 46.7%; P = .001). Nodules with higher vascularity had a lower regrowth rate than those with low vascularity (12.1% vs. 32.4%; P = .043). In all, 4.8% of patients had complications from the procedure.

The researchers wrote that radiofrequency ablation provides benefits for many patients, but those who undergo the procedure require long-term follow-up and the lack of a pathological exam means providers can not rule out malignancy.

“This treatment requires specialized treatment centers, specialized equipment, and highly skilled and experienced physicians, so access to radiofrequency ablation may also be a barrier to its use,” the researchers wrote. “Therefore, we believe that radiofrequency ablation is more likely to be a complementary treatment modality to surgical treatment.”

Cryoballoon Ablation is Noninferior to Radiofrequency Ablation

Posted by

0


Cryoballoon ablation was found to be noninferior to radiofrequency ablation with respect to efficacy for the treatment of patients with drug-refractory paroxysmal atrial fibrillation, and there is no significant difference between the two procedures in regard to patient safety, according to late-breaking clinical trial research presented as part of ACC.16 in Chicago and simultaneously published in The New England Journal of Medicine.

The FIRE AND ICE trial, conducted by Karl-Heinz Kuck, MD, FACC, et al, is the largest randomized trial of its kind, and included participants from 16 centers in eight European countries. “The FIRE AND ICE trial demonstrated that the cryoballoon, a newer, easier-to-use ablation catheter, worked as well as the established technology, which ultimately means that more patients can be treated for atrial fibrillation without having [to go to a] specialized cardiac center,” said Kuck. “In addition, there was, in general, a low risk of procedural complications in both groups, demonstrating that catheter ablation has become much safer over the years.”

The authors wanted to compare the effectiveness of point-by-point mode applied radiofrequency ablation to that of cryoballoon ablation applied in a single step mode, a newer and less complex technique. The primary efficacy endpoint of the trial was time to first documented recurrence of AF/atrial tachycardia/atrial flutter, prescription of antiarrhythmic drugs or repeat ablation.

The multicenter, randomized, noninferior open-label trial analyzed data gathered from patients ranging from 18 to 75 years old, with symptomatic paroxysmal AF and prior antiarrhythmic drug failure. After exclusions for previous left atrial (LA) ablation, percutaneous coronary intervention or myocardial infarction within three months of enrollment, and other clinical issues, 693 patients undergoing pulmonary vein isolation were randomly assigned in a 1:1 ratio; 352 underwent radiofrequency ablation and 341 underwent cryoballoon ablation.

In-office visits were scheduled at three, six, and 12 months and every six months after. The primary efficacy endpoint occurred in 138 patients in the cryoballoon group and in 143 patients in the radiofrequency group. A pre-specified superiority test performed for the primary efficacy endpoint did not indicate a significant difference between the treatment groups. The most common treatment-related serious adverse events were groin site complication and atrial flutter or atrial tachycardia.

The authors did see significant procedural differences between the two groups. Radiofrequency ablation required less fluoroscopy time (17 vs. 22 minutes). Procedure time was shorter in the cryoballoon group, (124 minutes vs. 141 minutes). LA dwell time in the cryoballoon group was shorter as well (92 vs. 109 minutes). A favorable safety profile was observed in both groups.

“The procedure time was interesting because there are more cost pressures on the health care system for more efficient tools that keep procedures short and predictable,” Kuck said.

According to Kuck, the findings could help inform future medical guidelines on the use of different catheter ablation techniques for treating atrial fibrillation. One limitation of the study is that it did not investigate ablation for treating patients with more advanced stages of atrial fibrillation. A separate trial would be needed to assess the ablation techniques’effectiveness and safety for that patient population, he said.

– See more at: http://www.acc.org/latest-in-cardiology/articles/2016/03/23/18/25/mon-8am-fire-and-ice-effective-afib-ablation-acc-2016?wt.mc_id=twitter#sthash.M0E66Z4X.dpuf

4 Top Questions About Radiofrequency Ablation for Afib Answered

Posted by

0


If medications you’re taking for atrial fibrillation (afib) aren’t working anymore, there is another option: radiofrequency ablation.

human heart illustration

In most patients, rapid electrical activity that starts in the pulmonary vein and spreads to the atrium of the heart triggers afib. Radiofrequency ablation is a procedure that applies electrical energy to the area around the pulmonary vein.

“What radiofrequency ablation does is create roadblocks at the pulmonary vein to shield the atrium from the electrical activity that causes afib,” says cardiologist Walid Saliba, MD, Medical Director of the Center for Atrial Fibrillation at Cleveland Clinic.

Although radiofrequency ablation has been used as a treatment method for afib since the late 1990s, it is now being more widely accepted as a first-line therapy, or first treatment.

“Traditionally, afib has been treated with medications to slow the heartbeat or antiarrhythmics to suppress the afib,” says Dr. Saliba. “But medications have limitations and also side effects, and they only work to a certain extent. The likelihood of a particular medication still working after one year is about 50 percent at best.”

Here are the answers to the most common questions about radiofrequency ablation for afib:

1. Am I a good candidate for radiofrequency ablation?

Doctors use radiofrequency ablation to treat patients with afib who have already tried medications that either didn’t work or are no longer working. Patients who are unable to tolerate the medications or prefer not to take them may also be candidates for the procedure.

Radiofrequency ablation can be used as a stand-alone treatment or in combination with medications.

2. Does radiofrequency ablation cure afib?

There is currently no cure for afib, but the results of radiofrequency ablation can sometimes last for a long period of time.

“The goal of treatment is to decrease the frequency of afib occurrence as much as possible,” Dr. Saliba says. “In some patients, we can get it down to zero, but there’s no guarantee that it won’t come back. In others, we can decrease the incidence to where the symptoms aren’t nearly as frequent. When people are in afib, they don’t feel well. So the goal is to make them feel better, which improves their quality of life.”

3. How many treatments will I need?

Some patients will not have symptoms of afib for years after a single radiofrequency ablation treatment. Others may need additional treatments if they continue to have significant episodes of afib.

Lifestyle changes, such as weight loss and exercise, can help decrease the incidence of afib. Sleep apneaand thyroid disease can increase the occurrence of afib, so seeking treatment for those conditions will also help to decrease the frequency of your symptoms.

4. Will I be able to stop taking blood thinners?

After radiofrequency ablation, patients often ask if they can stop taking their blood thinners because they feel like they have been cured. The answer depends on your individual situation.

“It’s possible to still have episodes of afib and not have any symptoms,” says Dr. Saliba. “So even if you feel great, you may still be at risk for stroke.”

Whether or not you need blood thinners is determined by your baseline risk for stroke in the setting of afib, which is determined by your CHADSVasc score:

C = Congestive heart failure

H = Hypertension

A = Age >65

D = Diabetes

S = History of stroke

Vasc = Vascular disease

If you have more than one of the above, you will still need to take blood thinners.

Be sure to ask your doctor if you have questions about your treatment. And keep taking your medications unless your doctor tells you to stop.

Hepatic resection combined with radiofrequency ablation for initially unresectable colorectal liver metastases after effective chemotherapy is a safe procedure with a low incidence of local recurrence.

Posted by

0


Abstract

Background

Chemotherapy can lead to tumor down-staging in patients with initially unresectable colorectal liver metastases (CRLM); however, more than half of such cases are still considered to be unresectable because of disease progression, including multiple or bilobar CRLM, and an insufficient predicted remnant liver volume. In addition, there is little evidence supporting the use of radiofrequency ablation (RFA) for patients with CRLM. This study compared the safety and efficacy of hepatic resection (HR) combined with RFA versus HR alone after effective chemotherapy in patients with initially unresectable CRLM.

Methods

Data were prospectively collected on 118 consecutive patients with initially unresectable CRLM who received FOLFOX ± bevacizumab as the first-line chemotherapy. 48 of these patients (41 %) underwent HR or HR + RFA after the chemotherapy. HR was performed in 35 patients (HR group), and HR + RFA in 13 (HR + RFA group).

Results

There was no mortality in either group. Postoperative morbidity rates in the HR group and the HR + RFA group were 17 and 23 %, respectively (P = 0.640). Local recurrence at the RFA site occurred in only one tumor (1.6 % per lesion, 7.7 % per patients). The 3-year progression-free survival was 45.3 % in the HR group and 12.8 % in the HR + RFA group (P = 0.472). The 3-year overall survival rate was 70.4 % in the HR group and 77.1 % in the HR + RFA group (P = 0.627).

Conclusions

These results suggest that HR + RFA after effective chemotherapy is a safe procedure with low local recurrence at the RFA site and is a potentially effective treatment option for patients with initially unresectable CRLM.

Source: International Journal of Clinical Oncology

Radiofrequency superior to laser ablation in large thyroid nodules.

Posted by

2


When compared with laser ablation, radiofrequency ablation yielded greater reductions in volume in large, benign thyroid nodules and allowed more rapid decompression in a single session, according to data presented during a late-breaking session here.

“The bottom line is we want to treat large, benign nodules,” Roberto Valcavi, MD, FACE, of the endocrinology division and thyroid disease center at Arcispedale Santa Maria Nuova in Reggio, Emilia, Italy, said during his presentation. “There have been many papers on reducing nodules with radiofrequency or laser ablation, but so far, there has been no comparison between the two techniques in large nodules.”

To study to the effects of laser vs. radiofrequency ablation in nodules >35 mL, Valcavi and colleagues randomly assigned 108 patients with benign nodules to laser ablation (n=54; mean age, 51 years) or radiofrequency (n=54; mean age, 47 years). Mean nodule volume was approximately 40 mL in both groups.

Results revealed clear differences between the two treatment groups at 1, 3 and 6 months. At 1 month post-procedure, nodule volume was 31.9 mL in patients who underwent laser ablation vs. 28.9 mL in those who underwent radiofrequency ablation (P<.03). At 3 months, compared with the laser ablation group, reductions in nodule volume remained greater in the radiofrequency ablation group (27.8 mL vs. 26.6 mL; P<.04). At 6 months, the difference in nodule reduction became even more apparent (22.6 mL vs. 16.9 mL; P<.01), according to Valcavi.

“We have a faster and greater effect in the radiofrequency group, with a 70% reduction in nodule volume at 6 months vs. a 50% reduction, which is also a lot, with laser ablation,” he said.

A greater decrease in compressive symptoms was also noted in the radiofrequency ablation group, according to the study abstract. Symptoms declined from 5.1 at baseline to 2.5 at 6 months post-procedure in patients who underwent laser vs. from 5.3 to 0.8 in those who underwent radiofrequency ablation (P<.01).

Additionally, the researchers observed tissue carbonization in patients treated with laser ablation, but they found none in patients treated with a cool-tip radiofrequency ablation device.

“This is extremely important because we think the absence of carbonization may speed up nodule reabsorption, which is, on the other hand, ‘foxilized’ by the extremely high temperatures achieved by laser ablation,” Valcavi said.

He also noted that radiofrequency ablation is less expensive than laser ablation in which you need the proper equipment.

“We demonstrated that, in a single, well-done session, we can shrink the nodule and potentially cure the patient,” Valcavi said. “My final message is that, if you are confident enough with finding aspirates on ultrasound, you may have a new, very effective instrument to cure your patients.”

Source: Endocrine Today