Macrotrabecular-massive hepatocellular carcinoma: A distinctive histological subtype with clinical relevance

We recently identified a histological subtype of hepatocellular carcinoma (HCC), designated as "macrotrabecular-massive" (MTM-HCC) and associated with specific molecular features. In order to assess the clinical relevance of this variant, we investigated its prognostic value in two large series of patients with HCC treated by either surgical resection or radiofrequency ablation (RFA). We retrospectively included 237 HCC surgical samples and 284 HCC liver biopsies from patients treated by surgical resection and RFA, respectively. Histological slides were reviewed by pathologists specialized in liver disease, and the MTM-HCC subtype was defined by the presence of a predominant (>50%) macrotrabecular architecture (more than six cells thick). The main clinical and biological features were recorded at baseline. Clinical endpoints were early and overall recurrence. The MTM-HCC subtype was identified in 12% of the whole cohort (16% of surgically resected samples, 8.5% of liver biopsy samples). It was associated at baseline with known poor prognostic factors (tumor size, alpha-fetoprotein level, satellite nodules, and vascular invasion). Multivariate analysis showed that MTM-HCC subtype was an independent predictor of early and overall recurrence (surgical series: hazard ratio, 3.03; 95% confidence interval, 1.38-6.65; P = 0.006; and 2.76; 1.63-4.67; P < 0.001; RFA series: 2.37; 1.36-4.13; P = 0.002; and 2.19; 1.35-3.54; P = 0.001, respectively). Its prognostic value was retained even after patient stratification according to common clinical, biological, and pathological features of aggressiveness. No other baseline parameter was independently associated with recurrence in the RFA series.

CONCLUSION

The MTM-HCC subtype, reliably observed in 12% of patients eligible for curative treatment, represents an aggressive form of HCC that may require more specific therapeutic strategies. (Hepatology 2018;68:103-112).

Combined locoregional-immunotherapy for liver cancer

Locoregional therapies are commonly used to treat patients with hepatocellular carcinoma. It has been noted for many years that locoregional therapies may have additional systemic effects other than simple tumour elimination. Immunological "side effects" have been described in response to locoregional therapies in animal studies and in patients. With the advent of immunotherapy for hepatocellular carcinoma, there is increasing interest in determining the best way to combine immunotherapy with locoregional therapies. Herein, we provide a compact summary of answered and unanswered questions in the field, including: What animal model is best suited to test combined immune-locoregional treatments? How does tumour cell death affect immune responses? What type of immune responses have been observed in patients treated with different types of locoregional therapies? What can be surmised from the results of the first study testing the combination of locoregional therapy with immune checkpoint blockade? Finally, we discuss the outlook for this rapidly growing area of research, focussing on the issues which must be overcome to bridge the gap between interventional radiology and cancer immunology.

Long-term Effects of Repeat Hepatectomy vs Percutaneous Radiofrequency Ablation Among Patients With Recurrent Hepatocellular Carcinoma: A Randomized Clinical Trial

IMPORTANCE

Repeat hepatectomy and percutaneous radiofrequency ablation (PRFA) are most commonly used to treat early-stage recurrent hepatocellular carcinoma (RHCC) after initial resection, but previous studies comparing the effectiveness of the 2 treatments have reported conflicting results.

OBJECTIVE

To compare the long-term survival outcomes after repeat hepatectomy with those after PRFA among patients with early-stage RHCC.

DESIGN, SETTING, AND PARTICIPANTS

This open-label randomized clinical trial was conducted at the Eastern Hepatobiliary Surgery Hospital and the National Center for Liver Cancer of China. A total of 240 patients with RHCC (with a solitary nodule diameter of ≤5 cm; 3 or fewer nodules, each ≤3 cm in diameter; and no macroscopic vascular invasion or distant metastasis) were randomized 1:1 to receive repeat hepatectomy or PRFA between June 3, 2010, and January 15, 2013. The median (range) follow-up time was 44.3 (4.3-90.6) months (last follow-up, January 15, 2018). Data analysis was conducted from June 15, 2018, to September 28, 2018.

INTERVENTIONS

Repeat hepatectomy (n = 120) or PRFA (n = 120).

MAIN OUTCOMES AND MEASURES

The primary outcome was overall survival (OS). Secondary outcomes included repeat recurrence-free survival (rRFS), patterns of repeat recurrence, and therapeutic safety.

RESULTS

Among the 240 randomized patients (216 men [90.0%]; median [range] age, 53.0 [24.0-59.0] years), 217 completed the trial. In the intention-to-treat (ITT) population, the 1-year, 3-year, and 5-year OS rates were 92.5% (95% CI, 87.9%-97.3%), 65.8% (95% CI, 57.8%-74.8%), and 43.6% (95% CI, 35.5%-53.5%), respectively, for the repeat hepatectomy group and 87.5% (95% CI, 81.8%-93.6%), 52.5% (95% CI, 44.2%-62.2%), and 38.5% (95% CI, 30.6%-48.4%), respectively, for the PRFA group (P = .17). The corresponding 1-year, 3-year, and 5-year rRFS rates were 85.0% (95% CI, 78.8%-91.6%), 52.4% (95% CI, 44.2%-62.2%), and 36.2% (95% CI, 28.5%-46.0%), respectively, for the repeat hepatectomy group and 74.2% (95% CI, 66.7%-82.4%), 41.7% (95% CI, 33.7%-51.5%), and 30.2% (95% CI, 22.9%-39.8%), respectively, for the PRFA group (P = .09). Percutaneous radiofrequency ablation was associated with a higher incidence of local repeat recurrence (37.8% vs 21.7%, P = .04) and early repeat recurrence than repeat hepatectomy (40.3% vs 23.3%, P = .04). In subgroup analyses, PRFA was associated with worse OS vs repeat hepatectomy among patients with an RHCC nodule diameter greater than 3 cm (hazard ratio, 1.72; 95% CI, 1.05-2.84) or an α fetoprotein level greater than 200 ng/mL (hazard ratio, 1.85; 95% CI, 1.15-2.96). Surgery had a higher complication rate than did ablation (22.4% vs 7.3%, P = .001).

CONCLUSIONS AND RELEVANCE

No statistically significant difference was observed in survival outcomes after repeat hepatectomy vs PRFA for patients with early-stage RHCC. Repeat hepatectomy may be associated with better local disease control and long-term survival in patients with an RHCC diameter greater than 3 cm or an AFP level greater than 200 ng/mL.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00822562.

Chronic venous insufficiency and varicose veins of the lower extremities

Chronic venous insufficiency (CVI) of the lower extremities manifests itself in various clinical spectrums, ranging from asymptomatic but cosmetic problems to severe symptoms, such as venous ulcer. CVI is a relatively common medical problem but is often overlooked by healthcare providers because of an underappreciation of the magnitude and impact of the problem, as well as incomplete recognition of the various presenting manifestations of primary and secondary venous disorders. The prevalence of CVI in South Korea is expected to increase, given the possible underdiagnoses of CVI, the increase in obesity and an aging population. This article reviews the pathophysiology of CVI of the lower extremities and highlights the role of duplex ultrasound in its diagnosis and radiofrequency ablation, and iliac vein stenting in its management.

Current Management of Small Renal Masses, Including Patient Selection, Renal Tumor Biopsy, Active Surveillance, and Thermal Ablation

Renal cancer represents 2% to 3% of all cancers, and its incidence is rising. The increased use of ultrasonography and cross-sectional imaging has resulted in the clinical dilemma of incidentally detected small renal masses (SRMs). SRMs represent a heterogeneous group of tumors that span the full spectrum of metastatic potential, including benign, indolent, and more aggressive tumors. Currently, no composite model or biomarker exists that accurately predicts the diagnosis of kidney cancer before treatment selection, and the use of renal mass biopsy remains controversial. The management of SRMs has changed dramatically over the last two decades as our understanding of tumor biology and competing risks of mortality in this population has improved. In this review, we critically assess published consensus guidelines and recent literature on the diagnosis and management of SRMs, with a focus on patient treatment selection and use of renal mass biopsy, active surveillance, and thermal ablation. Finally, we highlight important opportunities for leveraging recent research discoveries to identify patients with SRMs at high risk for renal cell carcinoma-related mortality and minimize overtreatment and patient morbidity.

Efficacy of thermal ablation in benign non-functioning solid thyroid nodule: A systematic review and meta-analysis

BACKGROUND

Image-guided thermal ablations are commonly used in the treatment of thyroid nodules. Radiofrequency ablation (RFA) and laser ablation are the most commonly used. Here we aimed to obtain solid evidence of the long-term efficacy of RFA and laser ablation in benign non-functioning solid thyroid nodules (BNFSTN).

METHODS

PubMed, CENTRAL, Scopus, and Web of Science were searched until March 2019. Studies reporting the effectiveness of RFA or laser ablation in patients with BNFSTN in terms of volume reduction rate (VRR), compressive symptoms and cosmetic concerns were included. Complications were also assessed.

RESULTS

Out of 963 papers, 12 studies on RFA and 12 on laser ablation were included, assessing 1186 and 2009 BNFSTNs, respectively. Overall, VRR at 6, 12, 24, and 36 months was 60%, 66%, 62%, and 53%. VRR of RFA was 68%, 75%, and 87%, respectively. VRR of laser ablation was 48%, 52%, 45%, and 44%, respectively. Baseline volume of nodules undergone RFA was significantly smaller compared to laser ablation (20.1 ± 22.4 versus 24.6 ± 23.6 ml; p < 0.01). Nodules smaller than 30 ml obtained better outcomes than larger ones. A significant reduction in compressive symptoms and cosmetic concerns was found after RFA.

CONCLUSIONS

This meta-analysis showed that both RFA and laser ablation are able to obtain a significant volume reduction in BNFSTNs. A significant volume reduction is already evident at 6 months after thermal ablation and results are stable over the time.

Comparisons between radiofrequency ablation and stereotactic body radiotherapy for liver malignancies: Meta-analyses and a systematic review

INTRODUCTION

Radiofrequency ablation (RFA) is a standard ablative modality for small liver malignancies. Stereotactic body radiotherapy (SBRT) has emerged although yet suffers a lack of high-level evidence. We performed meta-analyses and a systematic review to integrate the literature and help in clinical decision-making.

METHODS

Systemic searches were performed of the PubMed, Medline, and EMBASE databases to identify controlled studies comparing RFA and SBRT.

RESULTS

Eleven studies involving 2238 patients were included. Among them, eight studies were for treating early hepatocellular carcinomas (HCCs) and three for liver metastases. Including HCCs and liver metastases studies, the pooled two-year local control (LC) rate was higher in the SBRT arm (83.8%, 95% confidence interval [CI]: 77.6-88.4) than that in the RFA arm (71.8%, 95% CI: 61.5-80.2) (p = 0.024). Among studies on liver metastases, the pooled two-year LC rate was higher in the SBRT arm (83.6% vs. 60.0%, p < 0.001). No significant difference was found between arms in HCC studies (SBRT vs. RFA: 84.5 vs. 79.5% p = 0.431). Pooled analysis of overall survival (OS) in HCC studies showed an odds ratio of 1.43 (95% CI: 1.05-1.95, p = 0.023), favoring RFA. Among the two liver metastases studies with comparative survival data, no significant difference was observed.

CONCLUSION

LC was equivalent between RFA and SBRT for HCC and better for SBRT for the treatment of liver metastases. RFA was associated with better OS for HCC, but discrepancy between LC and OS requires further investigation, as they are local modalities having comparable efficacy.

Long-Term Outcomes Following Thermal Ablation of Benign Thyroid Nodules as an Alternative to Surgery: The Importance of Controlling Regrowth

Thermal ablation (TA) procedures, such as radiofrequency ablation and laser ablation, are used for the treatment of benign thyroid nodules. Short-term studies (<2 years) have demonstrated that TA is an effective and safe procedure to improve cosmetic or symptomatic problems. However, studies including a longer follow-up period show that treated thyroid nodules can increase in size after 2 to 3 years. Several studies suggest that this results from regrowth at the undertreated nodule margins. Here, we review current data on regrowth after TA and describe factors related to it and possible approaches to prevent it.

Long-term outcomes after endoscopic treatment for Barrett's neoplasia with radiofrequency ablation ± endoscopic resection: results from the national Dutch database in a 10-year period

OBJECTIVE

Radiofrequency ablation (RFA)±endoscopic resection (ER) is the preferred treatment for early neoplasia in Barrett's oesophagus (BE). We aimed to report short-term and long-term outcomes for all 1384 patients treated in the Netherlands (NL) from 2008 to 2018, with uniform treatment and follow-up (FU) in a centralised setting.

DESIGN

Endoscopic therapy for early BE neoplasia in NL is centralised in nine expert centres with specifically trained endoscopists and pathologists that adhere to a joint protocol. Prospectively collected data are registered in a uniform database. Patients with low/high-grade dysplasia or low-risk cancer, were treated by ER of visible lesions followed by trimonthly RFA sessions of any residual BE until complete eradication of BE (CE-BE). Patients with ER alone were not included.

RESULTS

After ER (62% of cases; 43% low-risk cancers) and median 1 circumferential and 2 focal RFA (p25-p75 0-1; 1-2) per patient, CE-BE was achieved in 94% (1270/1348). Adverse events occurred in 21% (268/1386), most commonly oesophageal stenosis (15%), all were managed endoscopically. A total of 1154 patients with CE-BE were analysed for long-term outcomes. During median 43 months (22-69) and 4 endoscopies (1-5), 38 patients developed dysplastic recurrence (3%, annual recurrence risk 1%), all were detected as endoscopically visible abnormalities. Random biopsies from a normal appearing cardia showed intestinal metaplasia (IM) in 14% and neoplasia in 0%. A finding of IM in the cardia was reproduced during further FU in only 33%, none progressed to neoplasia. Frequent FU visits in the first year of FU were not associated with recurrence risk.

CONCLUSION

In a setting of centralised care, RFA±ER is effective for eradication of Barrett's related neoplasia and has remarkably low rates of dysplastic recurrence. Our data support more lenient FU intervals, with emphasis on careful endoscopic inspection. Random biopsies from neosquamous epithelium and cardia are of questionable value.

NETHERLANDS TRIAL REGISTER NUMBER

NL7039.

Radiofrequency ablation for benign thyroid nodules according to different ultrasound features: an Italian multicentre prospective study

Background The purpose of this study was to confirm the generalisation of radiofrequency ablation (RFA) in the treatment of benign thyroid nodules (BTN) and to look for a correlation between final shrinkage and some ultrasound (US) findings in a large Italian population data set. Methods This prospective study included 337 patients with solid cold BTN from six Italian institutions. Nodule volume, US pattern, thyroid function, symptom/cosmetic scores and complications were evaluated before treatment and at 6 and 12 months. The primary outcome was to find a correlation between basal volume and US pattern of the nodules and final shrinkage. The secondary outcome was to confirm the efficacy and safety of RFA in a large data set. Results The median basal volume was 20.7 mL, and this significantly decreased after RFA at 6 months (7.3 mL (-63.5%), P < 0.001) and at 12 months (6 mL (-70%), P vs 6 months = 0.009). A significant correlation was found for US structure (a spongiform pattern showing a 76% reduction vs 67 and 66% of mix and solid patterns respectively, P < 0.01) as well as for vascularity (intense peripheral and intranodal patterns showing 71 vs 68 and 67% of weak peripheral and intranodal and peripheral patterns respectively, P < 0.03), but not for macrocalcifications. A slight inverse correlation was found between nodule basal volume and shrinkage (Spearman: -0.23). Mean symptoms/cosmetic scores were significantly reduced. No major complications were encountered. Conclusions This multicentre study validated the efficacy and safety of RFA for treating BTN and showed a clear correlation between final shrinkage and some common US findings.

Volumetric assessment of the periablational safety margin after thermal ablation of colorectal liver metastases

OBJECTIVES

To retrospectively assess the periablational 3D safety margin in patients with colorectal liver metastases (CRLM) referred for stereotactic radiofrequency ablation (RFA) and to evaluate its influence on local treatment success.

METHODS

Forty-five patients (31 males; mean age 64.5 [range 31-87 years]) with 76 CRLM were treated with stereotactic RFA and retrospectively analyzed. Image fusion of pre- and post-interventional contrast-enhanced CT scans using a non-rigid registration software enabled a retrospective assessment of the percentage of predetermined periablational 3D safety margin and CRLM successfully ablated. Periablational safety zones (1-10 mm) and percentage of periablational zone ablated were calculated, analyzed, and compared with subsequent tumor growth to determine an optimal safety margin predictive of local treatment success.

RESULTS

Mean overall follow-up was 36.1 ± 18.5 months. Nine of 76 CRLMs (11.8%) developed local tumor progression (LTP) with mean time to LTP of 18.3 ± 11.9 months. Overall 1-, 2-, and 3-year cumulative LTP-free survival rates were 98.7%, 90.6%, and 88.6%, respectively. The periablational safety margin assessment proved to be the only independent predictor (p < 0.001) of LTP for all calculated safety margins. The smallest safety margin 100% ablated displaying no LTP was 3 mm, and at least 90% of a 6-mm circumscribed 3D safety margin was required to achieve complete ablation.

CONCLUSIONS

Volumetric assessment of the periablational safety margin can be used as an intraprocedural tool to evaluate local treatment success in patients with CRLM referred to stereotactic RFA. Ablations achieving 100% 3D safety margin of 3 mm and at least 90% 3D safety margin of 6 mm can predict treatment success.

KEY POINTS

• Volumetric assessment of the periablational safety margin can be used as an intraprocedural tool to evaluate local treatment success following thermal ablation of colorectal liver metastases. • Ablations with 100% 3D periablational safety margin of 3 mm and ablations with at least 90% 3D safety margin of 6 mm can be considered indications of treatment success. • Image fusion of pre- and post-interventional CT scans with the software used in this study is feasible and could represent a useful tool in daily clinical practice.

Long-term outcomes of radiofrequency ablation for unifocal low-risk papillary thyroid microcarcinoma: a large cohort study of 414 patients

OBJECTIVES

The purpose of this study was to evaluate the long-term efficacy and safety of radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC) in a large population.

METHODS

From June 2014 to December 2017, 414 patients (323 females, 91 males, mean age 43.56 ± 9.79 years, range 18-73 years) with unifocal low-risk PTMC confirmed by core-needle biopsy (CNB) were treated by RFA. Patients were followed up at 1, 3, 6, and 12 months and every 6-12 months thereafter by ultrasound and contrast-enhanced ultrasound (CEUS). The volume and the volume reduction ratio (VRR) were calculated. Recurrence and lymph node or distant metastasis were evaluated.

RESULTS

The mean initial volume was 92.74 ± 83.43 mm³ (range 4.19-490.07 mm³), which decreased significantly to 1.37 ± 7.94 mm³ (range 0-67.97 mm³) at a mean follow-up time of 42.15 ± 11.88 months (range 24-69 months) with a mean VRR of 98.81 ± 6.41% (range 50-100%). No life-threatening or delayed complications occurred. After RFA, 366 tumors (88.41%) completely disappeared. The overall incidence of local tumor progression rate was 3.62%. Among them, one patient (0.24%) was diagnosed to have residual cancer by CNB and underwent additional RFA. Four patients (0.97%) developed metastatic lymph node, and 10 patients (2.42%) had recurrent PTMC. A total of 13 patients underwent additional RFA, and 11 lesions completely disappeared during the follow-up.

CONCLUSIONS

RFA is an effective and safety treatment for low-risk PTMC after a long-term follow-up period for a large cohort with careful patient enrollment evaluation.

KEY POINTS

• Radiofrequency ablation is an effective and safe alternative for low-risk PTMC. • The overall incidence of local tumor progression rate was low. • No life-threatening or delayed complications occurred.

Worthy of further consideration: An updated meta-analysis to address the feasibility, acceptability, safety and efficacy of thermal ablation in the treatment of cervical cancer precursor lesions

Treatment of preinvasive lesions is critical to the success of secondary prevention of cervical cancer. In many settings, however, excision or ablation of preinvasive lesions can prove challenging. Thermal ablation (TA) is a form of treatment for cervical precancer that may present fewer logistical challenges in resource limited settings. In 2013, Dolman and colleagues wrote a meta-analysis of publications reporting cure rates from TA. This included only one article from a low or middle-income country (LMIC). We updated Dolman's meta-analysis to include more recent articles from LMICs. A formal review of the world literature was performed for the years 2014-2017. Article titles and abstracts were reviewed for relevance; full articles were assessed for quality. The primary endpoint was treatment outcome for cervical intraepithelial neoplasia grade 2 or higher (CIN2+). The I2 statistic was used to assess heterogeneity between studies. Studies were stratified by geographic region, decade that the study was published, World Bank economic classification of the country where the study was performed, and other factors. We reviewed 34 total reports and included 23 in our meta-analysis, including 10,995 and 6371 patients, respectively. A total of 7 studies were performed in LMICs, including 6 studies included in the meta-analysis. The overall response rate for TA treatment of biopsy proven CIN2+ was 93.8%. Consistent with the wide variety of settings and patient populations, there was significant heterogeneity between studies. TA appears to be an effective treatment for CIN2+ across a variety of settings, including in LMICs.

Endoscopic Ultrasound-guided Radiofrequency Ablation Versus Surgical Resection for Treatment of Pancreatic Insulinoma

BACKGROUND & AIMS

Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is emerging as a safe and effective treatment for pancreatic neuroendocrine tumors. We aimed to compare EUS-RFA and surgical resection for the treatment of pancreatic insulinoma (PI).

METHODS

Patients with sporadic PI who underwent EUS-RFA at 23 centers or surgical resection at 8 high-volume pancreatic surgery institutions between 2014 and 2022 were retrospectively identified and outcomes compared using a propensity-matching analysis. Primary outcome was safety. Secondary outcomes were clinical efficacy, hospital stay, and recurrence rate after EUS-RFA.

RESULTS

Using propensity score matching, 89 patients were allocated in each group (1:1), and were evenly distributed in terms of age, sex, Charlson comorbidity index, American Society of Anesthesiologists score, body mass index, distance between lesion and main pancreatic duct, lesion site, size, and grade. Adverse event (AE) rate was 18.0% and 61.8% after EUS-RFA and surgery, respectively (P < .001). No severe AEs were observed in the EUS-RFA group compared with 15.7% after surgery (P < .0001). Clinical efficacy was 100% after surgery and 95.5% after EUS-RFA (P = .160). However, the mean duration of follow-up time was shorter in the EUS-RFA group (median, 23 months; interquartile range, 14-31 months vs 37 months; interquartile range, 17.5-67 months in the surgical group; P < .0001). Hospital stay was significantly longer in the surgical group (11.1 ± 9.7 vs 3.0 ± 2.5 days in the EUS-RFA group; P < .0001). Fifteen lesions (16.9%) recurred after EUS-RFA and underwent a successful repeat EUS-RFA (11 patients) or surgical resection (4 patients).

CONCLUSION

EUS-RFA is safer than surgery and highly effective for the treatment of PI. If confirmed in a randomized study, EUS-RFA treatment can become first-line therapy for sporadic PI.

Endoscopic radiofrequency ablation plus plastic stent placement versus stent placement alone for unresectable extrahepatic biliary cancer: a multicenter randomized controlled trial

BACKGROUND AND AIMS

We sought to compare the efficacy and safety between endoscopic radiofrequency ablation (RFA) and stent placement alone in patients with unresectable extrahepatic biliary cancer (EBC).

METHODS

In this randomized controlled trial, patients with locally advanced or metastatic cholangiocarcinoma (CCA) or ampullary cancer who were unsuitable for surgery were recruited from 3 tertiary centers. Eligible patients were randomly assigned to RFA plus plastic stent placement (RFA group) or plastic stent placement alone (stent placement alone group) in a 1:1 ratio. Both groups underwent 2 scheduled interventions with an interval of approximately 3 months. The primary outcome was overall survival (OS).

RESULTS

Altogether, 174 participants completed the 2 index endoscopic interventions. No significant differences in baseline characteristics were noted between the 2 groups. The median OS was significantly higher in the RFA group (14.3 vs 9.2 months; hazard ratio, .488; 95% confidence interval, .351-.678; P < .001). A survival benefit was also shown in patients with CCA (13.3 vs 9.2 months; hazard ratio, .546; 95% confidence interval, .386-.771; P < .001). However, no significant between-group differences were found in jaundice control or stent patency duration. The postprocedural Karnofsky performance scores were significantly higher in the RFA group until 9 months (all P < .001). Adverse events were comparable between the 2 groups (27.6% vs 19.5%, P = .211), except for acute cholecystitis, which was more frequently observed in the RFA group (9 vs 0, P = .003).

CONCLUSIONS

Compared with stent placement alone, additional RFA may improve OS and quality of life of patients with inoperable primary EBC who do not undergo systemic treatments. (Clinical trial registration number: NCT01844245.).

Initial Ablation Ratio: Quantitative Value Predicting the Therapeutic Success of Thyroid Radiofrequency Ablation

BACKGROUND

The aims of this study were to determine a quantitative index, the initial ablation ratio (IAR), representing the amount of ablation, to predict therapeutic success and to evaluate the correlation between the IAR and volume reduction ratio (VRR).

METHODS

Among the patients who underwent radiofrequency ablation (RFA) for the treatment of benign thyroid nodules at the Withsim Clinic between April 2008 and December 2016, 130 patients with 134 nodules were included. The relationship between the IAR and VRR was analyzed at six months, 12 months, and the final follow-up. The relationship between the IAR and final VRR was also analyzed according to the initial nodule volumes.

RESULTS

The mean VRR was 78.7 ± 17.5% (range 23.3-100%) at a mean follow-up period of 22.6 ± 20.1 months (range 3-93 months). The mean IAR was 90.0 ± 11.6% (range 39.1-100%). The correlation coefficient between the IAR and final VRR was 0.65, which indicates a positive correlation (p < 0.001). When the IAR exceeded 70%, it tended to achieve 50% VRR in most cases.

CONCLUSIONS

The IAR is a quantitative indicator of how well the RFA procedures are performed, and it is highly correlated with the VRR. If the IAR is >70%, VRR of >50% may be expected after RFA.

Liver Transplantation for Intrahepatic Cholangiocarcinoma: Ready for Prime Time?

Cholangiocarcinoma (CCA) represents the second-most common primary liver malignancy after HCC and has risen in incidence globally in the past decades. Intrahepatic cholangiocarcinoma (iCCA) comprises 20% of all CCAs, with the rest being extrahepatic (including perihilar [pCCA] and distal CCA). Though long representing an absolute contraindication for liver transplantation (LT), recent analyses of outcomes of LT for iCCA have suggested that iCCA may be a potentially feasible option for highly selected patients. This has been motivated both by successes noted in outcomes of LT for other malignancies, such as HCC and pCCA, and by several retrospective reviews demonstrating favorable results with LT for a selected group of iCCA patients with small lesions. LT for iCCA is primarily relevant within two clinical scenarios. The first includes patients with very early disease (single tumor, ≤2 cm) with cirrhosis and are not candidates for liver resection (LR). The second scenario is patients with locally advanced iCCA, but where the extent of LR would be too extensive to be feasible. Preliminary single-center reports have described LT in a selected group of patients with locally advanced tumors who have responded to neoadjuvant therapy and have a period of disease stability. Currently, there are three prospective trials underway that will help clarify the role of LT in iCCA. This review seeks to explore the available studies involving LT for iCCA, the challenges of ongoing trials, and opportunities for the future.

Percutaneous microwave ablation of bone tumors: a systematic review

AIM

To systematically review microwave ablation (MWA) protocols, safety, and clinical efficacy for treating bone tumors.

MATERIALS AND METHODS

A systematic literature search was conducted using PubMed, the Cochrane Library, EMBASE, and Web of Science database. Data concerning patient demographics, tumor characteristics, procedure, complications, and clinical outcomes were extracted and analyzed.

RESULTS

Seven non-comparative studies (6 retrospective, 1 prospective) were included accounting for 249 patients and 306 tumors (244/306 [79.7%] metastases; 25/306 [8.2%] myelomas, and 37/306 [12.1%] osteoid osteomas [OO]). In malignant tumors, MWA power was 30-70 W (except in one spinal tumors series where a mean power of 13.3 W was used) with pooled mean ablation time of 308.3 s. With OO, MWA power was 30-60 W with mean ablation time of 90-102 s. Protective measures were very sporadically used in 5 studies. Additional osteoplasty was performed in 199/269 (74.0%) malignant tumors. Clinically significant complications were noted in 10/249 (4.0%) patients. For malignant tumors, estimated pain reduction on the numerical rating scale was 5.3/10 (95% confidence intervals [95%CI] 4.6-6.1) at 1 month; and 5.3/10 (95% CI 4.3-6.3) at the last recorded follow-up (range 20-24 weeks in 4/5 studies). For OO, at 1-month follow-up, effective pain relief was noted in 92.3-100% of patients.

CONCLUSION

MWA is effective in achieving pain relief at short- (1 month) and mid-term (4-6 months) for painful OO and malignant bone tumors, respectively. Although MWA seems safe, further prospective studies are warranted to further assess this aspect, and to standardize MWA protocols.

KEY POINTS

• Large heterogeneity exists across literature about ablation protocols used with microwave ablation applied for the treatment of benign and malignant bone tumors. • Although microwave ablation of bone tumors appears safe, further studies are needed to assess this aspect, as current literature does not allow definitive conclusions. • Nevertheless, microwave ablation is effective in achieving pain relief at short- (1 month) and mid-term (4-6 months) for painful osteoid osteomas and malignant bone tumors, respectively.

Outcomes of Radiofrequency Ablation Therapy for Large Benign Thyroid Nodules: A Mayo Clinic Case Series

OBJECTIVE

To assess the effectiveness, tolerability, and complications of radiofrequency ablation (RFA) in patients with benign large thyroid nodules (TNs).

PATIENTS AND METHODS

This is a retrospective review of 14 patients with predominantly solid TNs treated with RFA at Mayo Clinic in Rochester, Minnesota, from December 1, 2013, through October 30, 2016. All the patients declined surgery or were poor surgical candidates. The TNs were benign on fine-needle aspiration, enlarging or causing compressive symptoms, and 3 cm or larger in largest diameter. We evaluated TN volume, compressive symptoms, cosmetic concerns, and thyroid function.

RESULTS

Median TN volume reduction induced by RFA was 44.6% (interquartile range [IQR], 42.1%-59.3%), from 24.2 mL (IQR, 17.7-42.5 mL) to 14.4 mL (IQR, 7.1-19.2 mL) (P<.001). Median follow-up was 8.6 months (IQR, 3.9-13.9 months). Maximum results were achieved by 6 months. Radiofrequency ablation did not affect thyroid function. In 1 patient with subclinical hyperthyroidism due to toxic adenoma, thyroid function normalized 4 months after ablation of the toxic nodule. Compressive symptoms resolved in 8 of 12 patients (67%) and improved in the other 4 (33%). Cosmetic concerns improved in all 8 patients. The procedure had no sustained complications.

CONCLUSION

In this population, RFA of benign large TNs performed similarly to the reports from Europe and Asia. It induces a substantial volume reduction of predominantly solid TNs, improves compressive symptoms and cosmetic concerns, and does not affect normal thyroid function. Radiofrequency ablation has an acceptable safety profile and should be considered as a low-risk alternative to conventional treatment of symptomatic benign TNs.

Radiofrequency ablation and thyroid nodules: updated systematic review

PURPOSE

In the thyroid gland, radiofrequency ablation (RFA) is being applied to both benign nodules and cancers internationally, while interest is also growing in the West. Benign thyroid nodules (BTNs) may be candidates for intervention when symptoms develop. For differentiated thyroid cancers (DTC), surgery is currently the first-line treatment. However, for candidates with high surgical risk or those who refuse to undergo repeated surgery, newer techniques such as RFA are an option. Surgery is associated with complications including hypothyroidism, voice change, hypocalcemia, and a scar. RFA has been used in Asian and European institutions as an alternative to surgery, but is relatively new in North America. Although RFA is not associated with significant complications, few randomized control trials have assessed its efficacy. The studies to date suggest a low rate of severe complications and a small need for thyroid hormone replacement following RFA. Further large-scale studies focusing on a Western population are needed. The aim of this review is to evaluate the evidence with respect to the current studies and data about the safety and efficacy of radiofrequency ablation for the management of BTNs and DTC.

METHODS

We systematically searched the PubMed/MEDLINE, EMBASE, Clinical Queries, and Web of Science databases, for articles published up to April 30th, 2020.

RESULTS

Total of 75 studies that met the inclusion criteria were included in the review. Thirty-five studies focused on RFA use for solid nodules, 12 studies on predominantly cystic nodules, 10 for autonomously functioning thyroid nodules, and 18 studied were published on differentiated thyroid cancer.

CONCLUSIONS

RFA seems to be an effective and safe alternative to surgery in high-risk surgical patients with thyroid cancers and for selected BTNs. Additional trials with longer follow-up in North American patients are needed to validate its full role in the armamentarium of thyroid ologists.

Radiofrequency ablation for low-grade dysplasia in Barrett's esophagus: long-term outcome of a randomized trial

BACKGROUND AND AIMS

A prior randomized study (Surveillance versus Radiofrequency Ablation study [SURF study]) demonstrated that radiofrequency ablation (RFA) of Barrett's esophagus (BE) with confirmed low-grade dysplasia (LGD) significantly reduces the risk of esophageal adenocarcinoma. Our aim was to report the long-term outcomes of this study.

METHODS

The SURF study randomized BE patients with confirmed LGD to RFA or surveillance. For this retrospective cohort study, all endoscopic and histologic data acquired at the end of the SURF study in May 2013 until December 2017 were collected. The primary outcome was rate of progression to high-grade dysplasia (HGD)/cancer. All 136 patients randomized to RFA (n = 68) or surveillance (n = 68) in the SURF study were included. After closure of the SURF study, 15 surveillance patients underwent RFA based on patient preference and study outcomes.

RESULTS

With 40 additional months (interquartile range, 12-51), the total median follow-up from randomization to last endoscopy was 73 months (interquartile range, 46-85). HGD/cancer was diagnosed in 1 patient in the RFA group (1.5%) and in 23 in the surveillance group (33.8%) (P = .000), resulting in an absolute risk reduction of 32.4% (95% confidence interval [CI], 22.4%-44.2%) with a number needed to treat of 3.1 (95% CI, 2.3-4.5). Seventy-five of 83 patients (90%; 95% CI, 82.1%-95.0%) treated with RFA for BE reached complete clearance of BE and dysplasia. BE recurred in 7 of 75 patients (9%; 95% CI, 4.6%-18.0%), mostly minute islands or tongues, and LGD in 3 of 75 (4%; 95% CI, 1.4%-11.1%).

CONCLUSIONS

RFA of BE with confirmed LGD significantly reduces the risk of malignant progression, with sustained clearance of BE in 91% and LGD in 96% of patients, after a median follow-up of 73 months. (Clinical trial registration number: NTR1198.).

Laser Ablation Versus Radiofrequency Ablation for Benign Non-Functioning Thyroid Nodules: Six-Month Results of a Randomized, Parallel, Open-Label, Trial (LARA Trial)

Background: No direct prospective studies comparing laser ablation (LA) and radiofrequency ablation (RFA) for debulking benign non-functioning thyroid nodules (BNTNs) exist. We aimed at comparing the efficacy and safety of both techniques in patients with solid or predominantly solid BNTN. Methods: This six-month, single-use, randomized, open-label, parallel trial compared the following primary endpoints between the RFA and LA groups six months after treatment: (i) nodule volume reduction expressed as a percentage of nodule volume at baseline; (ii) proportion of nodules with more than 50% reduction (successful rate). We enrolled subjects with a solitary BNTN or dominant nodule characterized by pressure symptoms/cosmetic problems or patients without symptoms who experienced a volume increase >20% in one year. Nodules underwent core needle biopsy for diagnosis. Patients were randomly assigned (1:1) to receive LA or RFA. Safety was assessed in all randomly assigned participants. Results: Sixty patients were randomly assigned to receive either RFA or LA (1:1) between January 2016 and November 2018. Both groups were similar in basal nodule volume, thyroid function, histology, symptoms/cosmetic score, and procedure time. At six months, the nodule volume reduction was 64.3% (95% confidence interval, CI 57.5-71.2) in the RFA group and 53.2% ([CI 47.2-95.2]; p = 0.02) in the LA group. This effect was also confirmed in the linear regression model adjusted for age, baseline volume, and proportion of cellular component (LA vs. RFA percent change Delta = -12.8, p = 0.02). No significant difference was observed in success rate six months after treatment (RFA vs. LA: 86.7% vs. 66.7%, p = 0.13) or in thyrotropin level between the groups. Although improved, no significant difference was observed between RFA and LA for compressive symptoms (RFA: 2.13 vs. 3.9, p < 0 · 001; LA: 2.4 vs. 3.87, p < 0.001) and cosmetic score (RFA: 1.65 vs. 2.2, p < 0.001; LA: 1.85 vs. 2.2, p < 0.001). The adverse event rates (local pain, dysphonia, thyrotoxicosis, fever, hematoma) were 37% (n = 11) and 43% (n = 13) for RFA and LA, respectively, with no requirement for hospitalization. Conclusion: Although the success rate was similar in the RFA and LA groups, RFA achieved a significantly larger nodule volume reduction at six months.

Postoperative adjuvant transcatheter arterial chemoembolization should be considered selectively in patients who have hepatocellular carcinoma with microvascular invasion

BACKGROUND

Microvascular invasion (MVI) is a powerful predictor of recurrence in patients who undergo liver resection for hepatocellular carcinoma (HCC). This study aimed to evaluate the efficacy of postoperative adjuvant transarterial chemoembolization (PA-TACE) in HCC patients with MVI, and further select potential patients benefitting from PA-TACE.

METHODS

Patients who had HCC with MVI and underwent liver resection between September 2004 and December 2015 were identified for further analysis. Overall survival (OS) and disease-free survival (DFS) were compared between patients treated with and without PA-TACE. Propensity score matching analysis was used to minimize inter-group differences.

RESULTS

A total of 176 patients with HCC and MVI were included. In both the entire and propensity-matched cohorts, OS and DFS were higher in PA-TACE group than non-TACE group (all P < 0.05). In subgroup analyses, PA-TACE showed efficacy in improving OS and DFS in HCC patients at early stage beyond Milan criteria and intermediate stage, but not in patients within Milan criteria. Multivariable analysis identified PA-TACE as a significantly favorable factor of OS and DFS for patients beyond Milan criteria, but not for those within Milan criteria.

CONCLUSION

PA-TACE could be beneficial for patients who have HCC with MVI beyond Milan criteria, but not for those within Milan criteria.

Efficacy and Safety of Microwave Ablation for Malignant Renal Tumors: An Updated Systematic Review and Meta-Analysis of the Literature Since 2012

OBJECTIVE

To systematically determine the treatment outcomes of percutaneous microwave ablation (MWA) in patients with malignant renal tumor.

MATERIALS AND METHODS

Original studies that reported the clinical outcomes of MWA in patients with malignant renal tumors were identified in MEDLINE and EMBASE from 2012 to June 30, 2017. Inverse variance and random-effects models were used to evaluate and acquire meta-analytic summary estimates of various clinical outcomes, including technical outcomes (technical success rate [TSR] and technical efficacy rate [TER]), oncologic outcomes (local tumor recurrence rate [LRR], cancer-specific survival rate [CSSR], and overall survival rate [OSR]), and complications.

RESULTS

Among the 145 articles screened, 13 articles including 567 patients carrying 616 malignant renal tumors were included in the meta-analysis. The meta-analytic pooled TSR and TER were 97.3% (95% confidence interval, 94.3-99.4%; I2 = 0.0%) and 97.6% (95.0-99.4%, I2 = 48.5%), respectively. The meta-analytic pooled LRR was 2.1% (0.3-4.7%, I2 = 54.1%). At 1-, 2-, 3-, and 5-year follow-up time points, the meta-analytic pooled CSSRs were 99.1% (97.2-100.0%; I2 = 0.0%), 98.4% (95.1-100.0%; I2 = 31.2%), 97.6% (93.4-99.9%; I2 = 52.3%), and 96.9% (93.3-99.2%; I2 = 0.0%) respectively, while the OSRs were 98.3% (96.1-99.8%; I2 = 0.0%), 94.9% (91.7-97.5%; I2 = 0.0%), 86.8% (81.9-91.1%; I2 = 22.1%), and 81.9% (75.4-87.6%; I2 = 0.0%). In terms of major complications, a 1.8% (0.6-3.3%; I2 = 0.0%) rate of meta-analytic pooled incidence was found.

CONCLUSION

Microwave ablation showed favorable technical and oncologic outcomes with a low incidence of major complications. Hence, image-guided percutaneous MWA can be considered as a safe and effective treatment for malignant renal tumors.

Overall survival and local recurrence following RFA, MWA, and cryoablation of very early and early HCC: a systematic review and Bayesian network meta-analysis

OBJECTIVE

To compare overall survival (OS) and local recurrence (LR) following radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) for very early and early hepatocellular carcinoma (HCC).

METHODS

This systematic review was performed according to the PRISMA guidelines. MEDLINE, Embase, and Cochrane databases were searched. Randomized controlled trials (RCTs) and observational studies were included. OS and LR at 1 year and 3 years were assessed. OS was reported as hazard ratio (HR) with 95% credible intervals (CrI) and LR as relative risk (RR) with 95% CrI, to summarize effect of each comparison.

RESULTS

Nineteen studies (3043 patients), including six RCTs and 13 observational studies, met inclusion criteria. For OS at 1 year, as compared to RFA, CA had HR of 0.81 (95% CrI: 0.43-1.51), and MWA had HR of 1.01 (95% CrI: 0.71-1.43). For OS at 3 years, as compared to RFA, CA had HR of 0.90 (95% CrI: 0.48-1.64) and MWA had HR of 1.07 (95% CrI: 0.73-1.50). For LR at 1 year, CA and MWA had RR of 0.75 (95% CrI: 0.45-1.24) and 0.93 (95% CrI: 0.78-1.14), respectively, as compared to RFA. For LR at 3 years, CA and MWA had RR of 0.96 (0.74-1.23) and 0.98 (0.87-1.09), respectively, as compared to RFA. Overall, none of the comparisons was statistically significant. Age of patients and tumor size did not influence treatment effect.

CONCLUSIONS

RFA, MWA, and CA are equally effective for locoregional treatment of very early and early HCC.

KEY POINTS

• There is no significant difference in the OS and LR (at 1 year and 3 years) following ablation of very early and early HCC with RFA, MWA, and CA. • There was no effect of tumor size on the treatment efficacy. • More RCTs comparing CA with RFA and MWA should be performed.