[Ablation of liver tumors : From pre-interventional imaging to post-interventional assessment]. / Ablation von Lebertumoren : Von der prä-interventionellen Bildgebung bis zur post-interventionellen Beurteilung.

The aim of this article is to provide an overview on the most frequently applied image-guided, percutaneous, local ablative techniques for treatment of primary and secondary liver tumors. The technical procedures of microwave ablation (MWA) and radiofrequency ablation (RFA) are presented. The pre-interventional diagnostics, indications and feasibility are also discussed, taking the current national guidelines into consideration. Finally, treatment outcomes and recommendations on post-interventional imaging following local tumor ablation are presented.

Personal mastery and quality of life in patients with atrial fibrillation after radiofrequency ablation: The mediating role of health promoting behavior.

BACKGROUND: Improving quality of life is vital for patients with atrial fibrillation (AF) after radiofrequency ablation. Quality of life can be affected not only by personal mastery but also by health promoting behavior as previously studied. However, it remains unclear whether health promoting behavior mediates the relationship between personal mastery and quality of life. OBJECTIVES: To explore whether health promoting behavior mediates the relationship between personal mastery and quality of life in patients with AF after radiofrequency ablation. METHODS: A cross-sectional design and convenience sampling were conducted at a tertiary hospital in China. Self-reported questionnaires were used to assess personal mastery, health promoting behavior and quality of life. SPSS and AMOS software were used for statistical analysis. RESULTS: A total of 202 patients with AF after radiofrequency ablation were enrolled (mean age 58.28 ± 12.70 years). The scores for personal mastery and quality of life were 22.52 ± 2.53 points and 62.58 ± 8.59 points, respectively, indicating a limited level. The health promoting behavior exhibited a moderate level, with scores averaging 103.82 ± 8.47 points. There was a positive correlation between the three variables (all P < 0.05). Health promoting behavior played a partial mediating role in the relationship between personal mastery and quality of life in patients with AF after radiofrequency ablation, accounting for 44.79 % of the total effect. CONCLUSIONS: In order to improve quality of life and prognosis, it is necessary to consider enhancing personal mastery and increasing patient compliance with health promoting behavior, which are important ways to improve their quality of life.

Comparison of safety, efficacy, and patient satisfaction with thermal ablation versus endoscopic thyroidectomy for benign thyroid nodules in a propensity-matched cohort.

BACKGROUND: Thyroid nodules (TNs) often require intervention due to symptomatic or cosmetic concerns. Radiofrequency ablation (RFA) has shown promise as a treatment option, offering potential advantages without neck scars. Recently, the scarless treatment alternative of transoral endoscopic thyroidectomy vestibular approach (TOETVA) has emerged. When surgery can be performed in a scarless manner, it remains unclear whether ablation is still the preferred treatment choice. This study aims to compare the safety, efficacy, and patient satisfaction of RFA and TOETVA. STUDY DESIGN: A retrospective data analysis was conducted on patients treated with RFA or TOETVA for unilateral benign TNs between December 2016 and September 2021. Propensity score matching was employed to create comparable groups. Various clinicopathologic parameters, treatment outcomes, and costs were assessed. RESULTS: Of the 2814 nonfunctional thyroid nodules treated during this period, 642 were benign and unilateral. A total of 121 and 100 patients underwent thermal ablation and transoral endoscopic thyroidectomy, respectively. After matching, 84 patients were selected for each group. Both RFA and TOETVA demonstrated low complication rates, with unique complications associated with each procedure. Treatment time (30.8±13.6 vs. 120.7±36.5 min, P <0.0001) was shorter in the RFA group. Patient satisfaction (significant improvement: 89.3% vs. 61.9%, P <0.0001) and cosmetic results (cosmetic score 1-2: 100.0% vs. 54.76%, P <0.0001) favored TOETVA. RFA was found to be less costly for a single treatment, but the cost of retreatment should be considered. The histological diagnoses post-TOETVA revealed malignancies in 9 out of 84 cases, underscoring the significance of follow-up assessments. CONCLUSION: Scarless procedures, RFA and TOETVA, are effective for treating unilateral benign TNs, each with unique advantages and drawbacks. While RFA is cheaper for a single treatment, TOETVA offers superior cosmetic results and patient satisfaction. Further research is needed to evaluate long-term safety and cost-effectiveness. It is crucial to remain vigilant about the possibility of malignancy despite benign cytology pre-treatment.

Time-Driven Activity-Based Cost Comparison of Thyroid Lobectomy and Radiofrequency Ablation.

OBJECTIVE: Radiofrequency ablation (RFA) of benign thyroid nodules has gained traction for its therapeutic effectiveness, thyroid function preservation, and minimally invasive nature. While a growing body of evidence reports positive outcomes from thyroid RFA, financial comparisons between both procedures remain limited. This analysis aims to more accurately measure the direct cost of thyroid RFA in comparison to thyroid lobectomy. STUDY DESIGN: Bottom-up financial cost analysis. SETTING: Tertiary endocrine head and neck surgery center. METHODS: Time-driven activity-based costing was utilized to obtain unit-based cost estimates. The care cycles for thyroid lobectomy and RFA were defined, and process maps were developed comprising all personnel and work in the care cycle. Time estimates were calculated for all personnel involved, and public government data were used to obtain capacity cost rates for each component of the care cycle. Consumable supply and overhead costs were obtained for both procedures, and overall costs were compared. RESULTS: For thyroid lobectomy, total personnel costs were $1087.97, consumable supplies were $942.68, and overhead costs $17,199.10. For thyroid nodule RFA performed in an office setting, the total personnel cost calculated was $379.90, consumable supplies $1315.28, and overhead $7031.20. Overall, the total cost for thyroid lobectomy was $19,229.75 compared to $8726.38 for RFA. CONCLUSION: In-office thyroid nodule RFA is associated with lower direct costs than thyroid lobectomy, and overhead is the greatest cost driver for both procedures. If clinical and patient-centered outcomes are comparable, then RFA may provide higher value for appropriately selected patients.

Cooled radiofrequency ablation of the genicular nerves for chronic pain due to osteoarthritis of the knee: a cost-effectiveness analysis compared with intra-articular hyaluronan injections based on trial data.

BACKGROUND: Effective symptom control in painful knee osteoarthritis (OA) may improve patient quality of life. In a randomised crossover trial (NCT03381248), COOLIEF* cooled radiofrequency ablation (CRFA) reduced pain and stiffness and improved physical function and quality of life compared with intra-articular hyaluronan (HA) injections. The present study aimed to establish the cost effectiveness of CRFA versus intra-articular HA injections for treating moderate-to-severe OA knee pain from a US Medicare perspective. METHODS: We conducted a cost-effectiveness analysis using utility data (EQ-5D) from the randomised crossover trial of CRFA versus intra-articular HA injections, which had follow-ups at 1, 3, 6, and 12 months. Patients in the HA group with unsatisfactory outcomes (e.g., continued pain) at 6 months could cross over to CRFA. Economic analysis outcomes included quality-adjusted life-years (QALYs), costs, and cost effectiveness (cost per QALY gained). Base-case analyses were modelled on a 6-month time horizon (to trial crossover). Due to limited trial data in the HA arm beyond 6 months, scenarios explored potential outcomes to 12 months if: 1) Utility with HA persisted for a further 6 months; 2) A second HA injection was received at 6 months and achieved the same utility change for the second 6 months. In both scenarios, the CRFA arm used trial data for patients who received CRFA from baseline to 12 months. Alternative costing scenarios were also explored. RESULTS: CRFA resulted in an incremental QALY gain of 0.020 at an incremental cost of US$1707, equating to an incremental cost-effectiveness ratio (ICER) of US$84,392 per QALY over 6 months, versus intra-articular HA injections. Extending the analysis to 12 months and assuming persistence in utility in the HA arm resulted in a larger utility gain for CRFA (0.056 QALYs) and a lower ICER of US$30,275 per QALY. If patients received a second HA injection, the incremental benefit of CRFA out to 12 months was reduced (QALY gain 0.043) but was offset by the costs of the second HA injection (incremental cost US$832). This resulted in an ICER of US$19,316 per QALY. CONCLUSIONS: CRFA is a cost-effective treatment option for patients with OA-related knee pain considering the typical US threshold of US$100,000/QALY.

Value of spectral detector computed tomography for the early assessment of technique efficacy after microwave ablation of hepatocellular carcinoma.

OBJECTIVES: To investigate whether virtual monoenergetic images (VMI) and iodine maps derived from spectral detector computed tomography (SDCT) improve early assessment of technique efficacy in patients who underwent microwave ablation (MWA) for hepatocellular carcinoma (HCC) in liver cirrhosis. METHODS: This retrospective study comprised 39 patients with 49 HCC lesions treated with MWA. Biphasic SDCT was performed 7.7±4.0 days after ablation. Conventional images (CI), VMI and IM were reconstructed. Signal- and contrast-to-noise ratio (SNR, CNR) in the ablation zone (AZ), hyperemic rim (HR) and liver parenchyma were calculated using regions-of-interest analysis and compared between CI and VMI between 40-100 keV. Iodine concentration and perfusion ratio of HR and residual tumor (RT) were measured. Two readers evaluated subjective contrast of AZ and HR, technique efficacy (complete vs. incomplete ablation) and diagnostic confidence at determining technique efficacy. RESULTS: Attenuation of liver parenchyma, HR and RT, SNR of liver parenchyma and HR, CNR of AZ and HR were significantly higher in low-keV VMI compared to CI (all p<0.05). Iodine concentration and perfusion ratio differed significantly between HR and RT (all p<0.05; e.g. iodine concentration, 1.6±0.5 vs. 2.7±1.3 mg/ml). VMI50keV improved subjective AZ-to-liver contrast, HR-to-liver contrast, visualization of AZ margin and vessels adjacent to AZ compared to CI (all p<0.05). Diagnostic accuracy for detection of incomplete ablation was slightly higher in VMI50keV compared to CI (0.92 vs. 0.89), while diagnostic confidence was significantly higher in VMI50keV (p<0.05). CONCLUSIONS: Spectral detector computed tomography derived low-keV virtual monoenergetic images and iodine maps provide superior early assessment of technique efficacy of MWA in HCC compared to CI.

The utility of a methylation panel in the assessment of clinical response to radiofrequency ablation for Barrett's esophagus.

BACKGROUND: Radiofrequency ablation (RFA) is an effective treatment for dysplastic Barrett's esophagus (BE), but recurrence can occur after initial response. Currently there is uncertainty about how to best define histological remission. A DNA methylation panel on esophageal samples was previously shown to have high diagnostic accuracy for BE. We aimed to investigate this biomarker panel in the assessment of response to RFA treatment. METHODS: We retrospectively analyzed esophageal and gastroesophageal junction (GEJ) biopsies from patients with BE before and after RFA treatment. We quantified the extent of intestinal metaplasia (IM) based on number of glands with goblet cells (IM-Score) and expression of the intestinal factor trefoil factor-3 (TFF3-Score). Promoter methylation of 3 genes (ZNF345, TFP12, ZNF569) was measured by methylight (Meth-Score) throughout the RFA treatment pathway. FINDINGS: We included 45 patients (11 non-dysplastic BE, 14 low-grade dysplasia, 20 high-grade dysplasia/intramucosal cancer). Meth-Scores were significantly higher in BE with and without dysplasia and GEJ with IM compared to GEJ without IM (P<·001). Meth-scores significantly correlated with the extent of IM at the GEJ measured both with IM-Scores (rho=66·0%, P<·001), and TFF3-Scores (rho=75·6%, P<·001). In patients with residual IM at the GEJ, RFA re-treatment brought about a 7·6-fold reduction in the methylation levels. The Meth-score had an area under the ROC curve of 95·1% (95%CI 91·1% - 99·1%) differentiating BE from normal GEJ. INTERPRETATION: A DNA methylation panel can discriminate between the extent of histological IM in esophageal and junctional biopsies and could be used to objectively quantify residual disease following RFA.

Risk assessment of neuromuscular stimulation by energy-based transurethral resection devices: an ex vivo test standard.

BACKGROUND: During transurethral resection of bladder tumours (TURB), radio-frequency (RF) currents can lead to adverse neuromuscular stimulation (NMS). Here we present a novel ex vivo method to determine the risk of RF generators and their bipolar TURB modes to cause NMS. We aimed to develop an experimental platform for safety evaluation of new RF generators and their modes with a newly established test standard, suitable for replacement or reduction of animal testing. METHODS: We tested four contemporary RF generators with their bipolar modes for TURB in saline. A two-stage ex vivo approach was pursued: First, we recorded voltages at possible positions of the obturator nerve behind a porcine bladder wall in a TURB model using 18 RF applications per generator. Second, these voltage records were used as stimuli to evoke nerve compound action potentials (CAPs) in isolated porcine axillary nerves. The NMS potential was defined as the ratio between the observed area under the CAPs and the theoretical CAP area at maximum response and a firing rate of 250 Hz, which would reliably induce tetanic muscle responses in most human subjects. The measurement protocol was tailored to optimise reproducibility of the obtained NMS potentials and longevity of the nerve specimens. RESULTS: As prerequisite for the clinical translation of our results, the robustness of our test method and reproducibility of the NMS potential are demonstrated with an excellent correlation (r = 0.93) between two sets of identical stimuli (n = 72 each) obtained from 16 nerve segments with similar diameters (4.2 ± 0.37 mm) in the nerve model. The RF generators differed significantly (p < 0.0001) regarding NMS potential (medians: 0-3%). CONCLUSIONS: Our test method is suitable for quantifying the NMS potential of different electrosurgical systems ex vivo with high selectivity at a reasonable degree of standardization and with justifiable effort. Our results suggest that the clinical incidence of NMS is considerably influenced by the type of RF generator. Future generations of RF generators take advantage from the proposed test standard through higher safety and less animal testing. Health professionals and treated patients will benefit most from improved RF surgery using generators with a low NMS risk.

The cost-effectiveness of radiofrequency ablation for treating patients with gastric antral vascular ectasia refractory to first line endoscopic therapy.

Objective: This economic evaluation aims to provide a preliminary assessment of the cost-effectiveness of radiofrequency ablation (RFA) compared with argon plasma coagulation (APC) when used to treat APC-refractory gastric antral vascular ectasia (GAVE) in symptomatic patients.Methods: A Markov model was constructed to undertake a cost-utility analysis for adults with persistent symptoms secondary to GAVE refractory to first line endoscopic therapy. The economic evaluation was conducted from a UK NHS and personal social services (PSS) perspective, with a 20-year time horizon, comparing RFA with APC. Patients transfer between health states defined by haemoglobin level. The clinical effectiveness data were sourced from expert opinion, resource use and costs were reflective of the UK NHS and benefits were quantified using Quality Adjusted Life Years (QALYs) with utility weights taken from the literature. The primary output was the Incremental Cost-Effectiveness Ratio (ICER), expressed as cost per QALY gained.Results: Over a lifetime time horizon, the base case ICER was £4840 per QALY gained with an 82.2% chance that RFA was cost-effective at a threshold of £20,000 per QALY gained. The model estimated that implementing RFA would result in reductions in the need for intravenous iron, endoscopic intervention and requirement for blood transfusions by 27.1%, 32.3% and 36.5% respectively. Compared to APC, RFA was associated with an estimated 36.7% fewer procedures.Conclusions: RFA treatment is likely to be cost-effective for patients with ongoing symptoms following failure of first line therapy with APC and could lead to substantive reductions in health care resource.

Long-Term Retrospective Assessment of Clinical Efficacy of Radiofrequency Ablation of the Knee Using a Cooled Radiofrequency System.

BACKGROUND: Cooled radiofrequency ablation (CRFA) in a randomized, prospective study demonstrated significantly greater improvements in pain, functional, and global outcome measures. OBJECTIVES: This large, real-life, retrospective study evaluated the long-term effectiveness of CRFA in the general chronic knee pain population. STUDY DESIGN: Retrospective electronic chart review. SETTING: Outpatient private practice. METHODS: After institutional review board approval, we reviewed data of 275 consecutive patients who had undergone a geniculate nerve block at a single-site pain practice between July 1, 2014 and July 1, 2017. A total of 44 patients had a negative response to the geniculate block, and 11 patients had long-term pain relief from the block and declined CRFA. Eight patients underwent knee surgery after the block, and 7 never followed up for further treatment. Finally, 205 patients had undergone CRFA, and 183 (89%) of them returned to provide data. RESULTS: The average age of the 183 patients was 61 (28-95) years, body mass index 34 (18.5-57), and there were 105 women and 78 men. A total of 137 patients had unilateral knee pain, whereas 46 patients had bilateral knee pain. Eighty percent (146/183) reported at least one or more additional sources of chronic pain (back, shoulder, and others). The average opioid use at baseline was 50 mg morphine sulfate equivalents (median 30 mg). The average baseline pain scores were 8.5, which decreased to 2.2 after the geniculate local anesthetic block, and to 4.2 after CRFA. A total of 65% of the patients claimed > 50% pain relief, whereas 77% had 2 or more Visual Analog Scale points decrease, and 26 (14%) patients reported no pain at all after CRFA. The mean duration of > 50% pain relief after CRFA was 12.5 months (range 0-35 months). There was no significant decrease of opioid use. Patients who underwent a repeated procedure (n = 43) achieved a similar pain relief (P = 0.402). We could not find a statistical difference in geniculate CRFA outcomes between the group who had total knee arthroplasty (TKA; n = 21) and maintained chronic knee pain and patients who had no prior surgery (P = 0.542). LIMITATIONS: Retrospective nature of the study. CONCLUSIONS: This study demonstrates the clinical effectiveness of CRFA in the treatment of chronic knee pain from osteoarthritis, and even in those patients who maintained chronic knee pain after TKA. Our real-life data seems to agree with data previously published in a randomized controlled trial, despite the fact that this was quite a heterogenous patient population with various sources of chronic pain. KEY WORDS: Radiofrequency ablation, chronic knee pain, knee osteoarthritis.

Budget Impact of Cryoablation Versus Radiofrequency Ablation of Atrial Fibrillation in the Brazilian Public Healthcare System.

BACKGROUND: Cryoablation is a new technology for ablation of atrial fibrillation (AF), effective and safe when compared with standard radiofrequency (RF) ablation. Nevertheless, the economic impact of its incorporation is unknown, especially considering the public health system of a developing country. This study analyzed the budget impact of cryoablation incorporation for treatment of paroxysmal AF in the Brazilian public health system. METHODS: The budget impact was calculated as the cost difference between the current scenario (RF ablation guided by electroanatomic mapping) and the new scenario (cryoablation). The cost of each intervention was obtained by multiplying the price of a single procedure by the number of candidates for it. Other technologies (RF ablation guided by intracardiac echocardiography or with a nonirrigated catheter) were considered in a sensitivity analysis. RESULTS: The budget impact showed savings of $43 097 096.84 with cryoablation. In the sensitivity analysis, cryoablation resulted in cost savings compared with RF ablation guided by intracardiac echocardiography, whereas in comparison to RF ablation with the nonirrigated catheter, cryoablation was more expensive. A market share assessment, performed using an incorporation rate of 3% per year, indicated savings of approximately $800 000 per 5 years. CONCLUSIONS: Cryoablation of AF resulted in cost savings compared with the current scenario (RF ablation guided by electroanatomic mapping). When alternative technologies were considered, cryoablation was more expensive than RF ablation with a nonirrigated catheter, but it also resulted in savings compared with RF ablation guided by intracardiac echocardiography. Overall, cryoablation of AF may reduce expenditures in the Brazilian public health system.

Value of monopolar and bipolar radiofrequency ablation for the treatment of benign thyroid nodules.

Only a few thyroid nodules are perceived as functional or optically disturbing. If there is a need for action, surgical intervention is the long-term standard by which thermoablative procedures (radiofrequency-, laser-, microwave ablation, high intensity focused ultrasound) must be measured against in terms of safety, effectiveness and patient satisfaction. Prior to intervention assessment of the dignity of the nodule by ultrasound-guided fine needle aspiration is essential for cold and warm nodules, as is the confirmation of an inconspicuous cervical lymph node status. The short-term treatment results of these newer interventions in terms of nodule volume reduction and symptomatic improvement are promising and the general complication rate of the procedures is low. Since functional thyroid parenchyma is preserved, maintaining normal thyroid status is the rule. The procedure is usually performed on an outpatient basis, under local anesthesia and monitoring. The subsequent convalescence is usually very short. Most studies are available on monopolar radiofrequency ablation. Several professional societies have defined indications for radiofrequency ablation (RFA), but these need to be further refined based on practical experience and literature. An acceptable long-term recurrence rate still has to be proven for practically all thermoablative methods, for monopolar RFA limited long-term data are encouraging so far. The recurrence rate as well as patient satisfaction will provide the basis for a meaningful overall cost-benefit analysis in the future.

Cooled radiofrequency ablation of the genicular nerves for chronic pain due to osteoarthritis of the knee: a cost-effectiveness analysis based on trial data.

BACKGROUND: For patients with painful knee osteoarthritis, long-term symptomatic relief may improve quality of life. Cooled radiofrequency ablation (CRFA) has demonstrated significant improvements in pain, physical function and health-related quality of life compared with conservative therapy with intra-articular steroid (IAS) injections. This study aimed to establish the cost-effectiveness of CRFA compared with IAS for managing moderate to severe osteoarthritis-related knee pain, from the US Medicare system perspective. METHODS: We conducted a cost-effectiveness analysis utilizing efficacy data (Oxford Knee Scores) from a randomized, crossover trial on CRFA (NCT02343003), which compared CRFA with IAS out to 6 and 12 months, and with IAS patients who subsequently crossed over to receive CRFA after 6 months. Outcomes included health benefits (quality-adjusted life-years [QALYs]), costs and cost-effectiveness (expressed as cost per QALY gained). QALYs were estimated by mapping Oxford Knee Scores to the EQ-5D generic utility measure using a validated algorithm. Secondary analyses explored differences in the settings of care and procedures used in-trial versus real-world clinical practice. RESULTS: CRFA resulted in an incremental QALY gain of 0.091 at an incremental cost of $1711, equating to a cost of US$18,773 per QALY gained over a 6-month time horizon versus IAS. Over a 12-month time horizon, the incremental QALY gain was 0.229 at the same incremental cost, equating to a cost of US$7462 per QALY gained versus IAS. Real-world cost assumptions resulted in modest increases in the cost per QALY gained to a maximum of US$21,166 and US$8296 at 6 and 12 months, respectively. Sensitivity analyses demonstrated that findings were robust to variations in efficacy and cost parameters. CONCLUSIONS: CRFA is a highly cost-effective treatment option for patients with osteoarthritis-related knee pain, compared with the US$100,000/QALY threshold typically used in the US.

Experimental assessment on feasibility of computed tomography-based thermometry for radiofrequency ablation on tissue equivalent polyacrylamide phantom.

Purpose: This study aimed to evaluate the effects of various computed tomography (CT) acquisition parameters and metal artifacts on CT number measurement for CT thermometry during CT-guided thermal ablation. Methods: The effects of tube voltage (100-140 kVp), tube current (20-250 mAs), pitch (0.6-1.5) and gantry rotation time (0.5, 1.0 s) as well as metal artifacts from a radiofrequency ablation (RFA) needle on CT number were evaluated using liver tissue equivalent polyacrylamide (PAA) phantom. The correlation between CT number and temperature from 37 to 80 °C was studied on PAA phantom using optimum CT acquisition parameters. Results: No statistical significant difference (p > 0.05) was found on CT numbers under the variation of different acquisition parameters for the same temperature setting. On the other hand, the RFA needle has induced metal artifacts on the CT images of up to 8 mm. The CT numbers decreased linearly when the phantom temperature increased from 37 to 80 °C. A linear regression analysis on the CT numbers and temperature suggested that the CT thermal sensitivity was -0.521 ± 0.061 HU/°C (R2 = 0.998). Conclusion: CT thermometry is feasible for temperature assessment during RFA with the current CT technology, which produced a high CT number reproducibility and stable measurement at different CT acquisition parameters. Despite being affected by metal artifacts, the CT-based thermometry could be further developed as a tissue temperature monitoring tool during CT-guided thermal ablation.

Combination of radiofrequency ablation and transcatheter arterial chemoembolization to treat hepatocellular carcinoma: measurement of distance from needle tip to nodule for assessment of local tumor progression.

OBJECTIVE: This study was performed to determine the relationship between the minimum distance from the radiofrequency ablation (RFA) needle tip to the tumor and local tumor progression (LTP) of hepatocellular carcinoma (HCC) nodules and identify prognostic factors for LTP. METHODS: We reviewed 197 patients (197 nodules) who underwent RFA after transcatheter arterial chemoembolization for HCC from January 2010 to January 2015. Three-dimensional registration of images was used to calculate the minimum distance from the tip to the tumor. We then divided the minimum distance into two groups: <2 and ≥2 mm. Contrast-enhanced computed tomography was performed after treatment. The LTP rate was calculated 1 and 3 years after RFA. We performed multivariate analysis to identify independent prognostic factors for LTP. RESULTS: The cumulative 1-year LTP rates in the <2- and ≥2-mm groups were 82.7% and 4.3%, respectively, and the cumulative 3-year LTP rates in the two groups were 94.8% and 10.8%, respectively. The minimum distance from the needle tip to the tumor was an independent prognostic factor for LTP. CONCLUSIONS: A minimum distance of 2 mm from the needle tip to the tumor should be completely ablated along with the tumor.

Comparative Effectiveness of Computed Tomography- Versus Ultrasound-Guided Percutaneous Radiofrequency Ablation Among Medicare Patients 65 Years of Age or Older With Hepatocellular Carcinoma.

BACKGROUND: For patients with hepatocellular carcinoma (HCC) not eligible for surgical resection, radiofrequency ablation (RFA) is a promising technique that reduces the risk of disease progression. OBJECTIVES: To evaluate whether the trend of image guidance for RFA is moving toward the more expensive computed tomography (CT) technology and to determine the clinical benefits of CT guidance over the ultrasound (US) guidance. METHODS: A cohort of 463 patients was identified from the Surveillance, Epidemiology, and End Results and Medicare-linked database. The temporal trends in use of image guidance were assessed using the Cochrane-Armitage test. The associations between modality of image guidance and survival, complications, and costs were assessed using the Cox regression model, the logistic regression model, and the generalized linear model, respectively. RESULTS: The use of CT-guided RFA increased sharply, from 20.7% in 2002 to 75.9% in 2011. Compared with CT-guided RFA, those who received US-guided RFA had comparable risk of periprocedural and delayed postprocedural complications. Stratified analyses by tumor size also showed no statistically significant difference. In adjusted survival analysis, no statistically significant difference was observed in overall and cancer-specific survival. Nevertheless, the cost of CT-guided RFA ($2847) was higher than that of US-guided RFA ($1862). CONCLUSIONS: Despite its rapid adoption over time, CT-guided RFA incurred higher procedural costs than US-guided RFA but did not significantly improve postprocedural complications and survival. Echoing the American Board of Internal Medicine's Choosing Wisely campaign and the American Society of Clinical Oncology's Value of Cancer Care initiative, findings from our study call for critical evaluation of whether CT-guided RFA provides high-value care for patients with HCC.

Economic impact of atrial fibrillation ablation with radiofrequency contact force catheter versus cryoballoon catheter.

AIM: To compare health utilization among atrial fibrillation (AF) patients undergoing ablation with a contact force-sensing (CF) catheter versus a cryoballoon (CB) catheter. METHODS: AF patients who underwent ablation using the CF catheter (THERMOCOOL SMARTTOUCH® catheter) or CB catheter (Arctic Front™/Arctic Front Advance™ catheter) were identified from the Premier Healthcare database. Propensity score analyses were used to evaluate cost, length of stay and readmissions. RESULTS: The CF catheter (n = 1409) was associated with significantly lower total (∼7%) and supply (∼13%) costs and a significantly lower likelihood of 4-12 month all-cause and CV-related readmission compared with the CB catheter (n = 2306). CONCLUSION: Differential health utilization outcomes are associated with the CF catheter versus the CB catheter in AF ablation.

Efficacy Assessment of Radiofrequency Ablation as a Palliative Pain Treatment in Patients with Painful Metastatic Spinal Lesions: A Systematic Review.

BACKGROUND: Metastatic spinal lesions are difficult-to-treat entities that are most commonly associated with pain and severely reduced health-related quality of life (HRQoL). Within the last 5 to 10 years, radiofrequency ablation (RFA) has emerged as an option in the palliative treatment of vertebral metastases. OBJECTIVES: Our review aims to evaluate the clinical effectiveness and safety of RFA, mostly in combination with vertebroplasty, in patients with painful vertebral metastases. STUDY DESIGN: The design of this study is a systematic review. METHODS: We conducted a systematic literature search and a manual search of 5 databases in December 2016. The review applied a methodological framework based on the HTA Core Model®. Data on each selected outcome category were synthesized according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) scheme. Risk of bias was assessed using the Institute of Health Economics (IHE) Risk of Bias checklist for case series. RESULTS: We identified 299 citations. After applying the inclusion criteria, a total of 9 studies (4 prospective and 5 retrospective studies) were determined to be eligible. These studies included a total of 583 patients with vertebral metastases who were treated with RFA and, in most cases, received an additional vertebroplasty treatment (n = 437). The studies were categorized as having a moderate to high risk of bias. The strength of evidence was found to be "very low" for safety outcomes and could not be assessed for efficacy outcomes. Current evidence suggests that RFA leads to significant pain reduction. Furthermore, no major complications occurred when using RFA. LIMITATIONS: A major concern is the low number of included patients and heterogeneity of study characteristics in most of the studies. The low number of patients also impeded comparison of the effectiveness of RFA alone to RFA in combination with vertebroplasty. CONCLUSION: According to the available evidence, RFA may be safe and effective, especially for patients with painful vertebral metastases who show contraindications or unresponsiveness to conventional therapies (e.g., radiation) or for those who are at risk of tumor progression. KEY WORDS: Radiofrequency ablation, vertebral metastases, metastatic spinal lesions, pain, clinical effectiveness, safety, palliative pain treatment.

Effectiveness and cost of radiofrequency ablation and stereotactic body radiotherapy for treatment of early-stage hepatocellular carcinoma: An analysis of SEER-medicare.

INTRODUCTION: For early-stage hepatocellular carcinoma (HCC) patients, ablative strategies are potentially curative treatment options. Stereotactic body radiotherapy (SBRT) has emerged as a promising ablative therapy, although its comparison with radiofrequency ablation (RFA) remains confined to a single institution retrospective review. We sought to characterize the comparative outcomes and cost between the two treatment strategies. METHODS: We conducted a secondary analysis of the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database (2004-2011) and identified adult patients with stage I or II HCC and treated with RFA or SBRT as the initial treatment within 6 months of diagnosis. Survival analysis was conducted using Kaplan-Meier curves and multivariate Cox proportional hazard analysis. Factors associated with overall survival and 90-day hospital admission post-treatment were identified using propensity score (PS) adjusted multivariate analysis. We performed costs analysis and calculated incremental cost-effectiveness ratios (ICER). RESULTS: Four hundred and forty patients were identified, 408 treated with RFA and 32 SBRT. In the overall cohort, 90-day hospitalization and 1-year mortality were similar between groups but RFA patients had better overall survival (P < 0.001). Multivariate analysis showed advanced age, higher stage, decompensated cirrhosis, and treatment with SBRT (HR 1.80; 95%CI: 1.15-2.82) was associated with worse survival, but in the PS adjusted analysis, survival and costs were similar between the two groups. CONCLUSION: In a national cohort of early stage HCC patients, treatment with RFA vs SBRT resulted in no significant difference in survival, 90-day hospitalization, or costs. These data highlight the need for a randomized clinical trial comparing these two modalities.