Safety of radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: a systematic review and meta-analysis

Abstract

Objective: We performed a systematic review and meta-analysis to evaluate the safety of radiofrequency ablation (RFA) for the treatment of benign thyroid nodules and recurrent thyroid cancers.

Materials and methods: Ovid-MEDLINE, EMBASE, and Library of Cochrane databases were searched up to 12 July 2016 for studies on the safety of RFA for treating benign thyroid nodules or recurrent thyroid cancers. Pooled proportions of overall and major complications were assessed using random-effects modelling. Heterogeneity among studies was determined using the χ² statistic for the pooled estimates and the inconsistency index I².

Results: A total of 24 eligible studies were included, giving a sample size of 2421 patients and 2786 thyroid nodules. 41 major complications and 48 minor complications of RFA were reported, giving a pooled proportion of 2.38% for overall RFA complications [95% confidence interval (CI): 1.42%–3.34%] and 1.35% for major RFA complications (95% CI: 0.89%–1.81%). There were no heterogeneities in either overall or major complications (I²?=?1.24%–21.79%). On subgroup analysis, the overall and major complication rates were significantly higher for malignant thyroid nodules than for benign thyroid nodules (p?=?0.0011 and 0.0038, respectively).

Conclusions: RFA was found to be safe for the treatment of benign thyroid nodules and recurrent thyroid cancers.     

Benign thyroid nodules treatment using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA)

Purpose: To evaluate the reduction over time of benign thyroid nodules treated using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA) by the same equipe.

Materials and methods: Ninety patients (age 55.6?±?14.1 years) underwent ablation for benign thyroid nodule causing compression/aesthetic dissatisfaction from 2011. Fifty-nine (age 55.8?±?14.1 years) underwent RFA and 31 (age 55.2?±?14.2 years) PLA, ultrasound guided. Technical success, complications, duration of ablation and treatment, energy deployed, volumetric percentage reduction at 1, 6 and 12 months were derived. A regression model for longitudinal measurements was used with random intercept and random slope. Values are expressed as mean?±?standard deviation or N (%).

Results: Technical success was always obtained. No major complications occurred. Mean ablation time was 30.1?±?13.8 vs. 13.9?±?5.9?min (p?Conclusions: RFA and PLA are similarly feasible, safe and effective in treating benign thyroid nodules when performed by the same equipe. RFA is faster than PLA but require significantly higher energy.     

Nodule size as predictive factor of efficacy of radiofrequency ablation in treating autonomously functioning thyroid nodules

Context: No defined pre-treatment factors are able to predict the response to radiofrequency ablation (RFA) of an autonomously functioning thyroid nodule (AFTN).

Objective: Primary endpoint was to evaluate the success rate of RFA to restore euthyroidism in a cohort of adult patients with small solitary AFTN compared with medium-sized nodules. Secondary endpoints included nodule volume reduction and rate of conversion from hot nodules to cold using scintiscan.

Methods: This was a 24-month prospective monocentric open parallel-group trial. Twenty-nine patients with AFTN were divided into two groups based on thyroid volume: 15 patients with small nodules (<12?mL) in group A and 14 patients with medium nodules (>12?mL) in group B. All patients underwent a single session of RFA and were clinically, biochemically, and morphologically evaluated at baseline and at 1, 6, 12 and 24 months after treatment.

Results: After RFA, there was greater nodule volume reduction in group A compared with group B (p?p?=?0.01), 12 (p?=?0.005), and 24?months (p?p?p?Conclusions: A single session of RFA was effective in restoring euthyroidism in patients with small AFTNs. Nodule volume seems to be a significant predictive factor of the efficacy of RFA in treating AFTN.     

Microwave ablation compared to thyroidectomy to treat benign thyroid nodules

Objective: Benign thyroid nodules occur commonly but only require treatment when symptomatic. Surgical treatment, once routine, has been replaced by newer technologies, such as microwave ablation (MWA). The aim of this study was to assess the efficacy, tolerability and cost of MWA compared to surgery to treat benign thyroid nodules.

Methods: After obtaining ethical approval and informed consent, a prospective trial was conducted with 52 patients who had symptomatic benign thyroid nodules. Patients were randomly assigned to receive MWA or surgical treatment. The volume reduction ratio (VRR), thyroid function, complications, HRQoL, costs and some parameters were compared.

Results: MWA reduced mean nodule volume by 72.3% at 3 months, 84.5% at 6 months and 92.4% at 12 months as effective as surgery in inactivating nodules, and thyroid dysfunction did not occur during 12-month follow-up for those receiving MWA. Although both MWA and surgery were safe, patients undergoing MWA had fewer cases of complications and rarely reported pain. The MWA group was superior to the surgery group in length of stay, postoperative scar length and the operation time. Compared to patients who underwent surgery, those who underwent MWA had better general health and mental health scores at 6 months and 12 months. The mean total cost of the MWA group was lower than that of the surgery group.

Conclusion: MWA can significantly reduce nodule volume and nodule-related symptoms with more rapid recovery, more pleasing esthetic outcomes, less physiologic disruption and less expense compared to the surgery.     

Comparison of efficacy and complications between radiofrequency ablation and repeat surgery in the treatment of locally recurrent thyroid cancers: a single-center propensity score matching study

Purpose: To compare the efficacy and complication rates of radiofrequency ablation (RFA) and repeat surgery in the treatment of locally recurrent thyroid cancers.

Materials and methods: A total of 221 patients with locally recurrent thyroid cancers who underwent either RFA (n?=?96) or repeat surgery (n?=?125) between March 2008 and March 2017 were retrospectively enrolled (range of follow-up, 1–10?years). Each cohort consisted of 70 patients after propensity score adjustment. Patients with more than three recurrent lesions were excluded. The primary and secondary end points were recurrence-free survival and complication rates, respectively. Recurrence-free survival curves were compared via the log-rank test. The complications—voice changes, hypocalcemia, and immediate procedural complications—were compared between the groups. In addition, pretreatment serum thyroglobulin (T_g) levels and those at the last follow-up were also compared between the two groups to examine therapeutic efficacy.

Results: After propensity score matching, both groups showed no significant differences in baseline characteristics. The recurrence-free survival rates were comparable between the RFA and surgery groups (p?=?.2). There were no significant differences in mean serum T_g levels and their mean decrease after treatment between the groups (p?=?.891 and p?=?.963, respectively). Immediate procedural complications and voice changes also showed no significant between-group differences (p?=?.316, p?=?.084, respectively). Hypocalcemia occurred only in the repeat surgery group (n?=?18). Overall complications were significantly more frequent in the repeat surgery group (RFA, n?=?7; surgery, n?=?27; p?<?.001).

Conclusion: RFA may be an effective and safe alternative to repeat surgery in the treatment of a small number of locally recurrent thyroid cancers.     

A comparison of laser with radiofrequency ablation for the treatment of benign thyroid nodules: a propensity score matching analysis

Abstract

Purpose: To compare technique efficacy and safety of laser ablation (LA) and radiofrequency ablation (RFA) in treatment of benign thyroid nodules.

Materials and methods: Institutional review board approval was obtained, and patients’ consent was waived. 601 nodules were treated from May 2009 to December 2014 at eight centres, 449 (309 females, age 57?±?14?years) with LA and 152 (107 females, age 57?±?14?years) with RFA. A matched cohort composed of 138 patients from each group was selected after adjustment with propensity score matching. Factors influencing volume reduction at 6 and 12?months and complications were evaluated.

Results: No significant differences were observed in the baseline characteristics between groups after propensity score matching adjustment. Mean nodule reduction at 6 and 12?months was ?67?±?19% vs. ?57?±?21% (p?<?0.001)???70?±?19% vs. ?62?±?22% (p =?0.001) in LA group and in RFA group, respectively. Nodules with volume?>30?mL had significantly higher percentage volume reduction at 6 and 12?months (?69?±?19 vs. ?50?±?21, p?=?0.001) and (?73?±?18 vs. ?54?±?23 8, p?=?0.001) in the LA group than in the RFA group, respectively. In both groups, operator’s skills affected the results. Major complications occurred in 4 cases in each group (p?=?0.116)

Conclusions: LA and RFA showed nearly similar outcome but LA was slightly more effective than RFA in large nodules. Operator’s skills could be crucial in determining the extent of nodule volume reduction regardless of the used technique.     

超声诊断甲状腺结节钙化的临床意义

目的：探讨超声诊断甲状腺钙化结节在临床诊治中的意义。方法：回顾分析2009年本院进行手术的227例甲状腺结节患者的临床,彩色多谱勒超声和病理资料。结果：227例甲状腺结节中,43例有钙化,占18．94％（43／227）。甲状腺钙化结节存在于各种病理类型,但恶性甲状腺结节钙化率41．38％（12／29）,明显高于良性甲状腺结节钙化率15．66％（31／198）,差异有显著性（P〈0．005）。在43例存在钙化的甲状腺结节中,微钙化17例,粗钙化26例,微钙化常发生在恶性肿瘤,粗钙化多发生在甲状腺良性病变。结论：彩色多谱勒超声发现甲状腺钙化结节需引起注意,若为微钙化提示甲状腺恶性肿瘤可能性大,应尽早手术治疗,粗钙化提示甲状腺良陆疾病可能性大,需密切随诊观察。     

Ethanol and thermal ablation for malignant thyroid tumours

Abstract

Papillary thyroid carcinoma (PTC) is the most common subtype of thyroid malignancy and has a good prognosis and low mortality rate. Surgery is the standard treatment for patients with primary and recurrent thyroid cancer. Although patients with PTC usually exhibit excellent treatment outcome, the incidence of recurrence in the neck ranges from 20% to 59%. When a patient with thyroid cancer is contraindicated for surgery, ultrasound (US)-guided ablation techniques, including ethanol ablation (EA) and thermal ablations, are suggested alternatives. In this review, we evaluated the indications, devices, techniques, clinical outcomes, and complications associated with US-guided EA and thermal ablations based on available scientific evidence and expert opinions regarding the use of ablation for primary and recurrent thyroid cancers.     

超声诊断甲状腺结节钙化的临床意义

目的:探讨超声诊断甲状腺钙化结节在临床诊治中的意义。方法:回顾分析2009年本院进行手术的227例甲状腺结节患者的临床,彩色多谱勒超声和病理资料。结果:227例甲状腺结节中,43例有钙化,占18.94%(43/227)。甲状腺钙化结节存在于各种病理类型,但恶性甲状腺结节钙化率41.38%(12/29),明显高于良性甲状腺结节钙化率15.66%(31/198),差异有显著性(P<0.005)。在43例存在钙化的甲状腺结节中,微钙化17例,粗钙化26例,微钙化常发生在恶性肿瘤,粗钙化多发生在甲状腺良性病变。结论:彩色多谱勒超声发现甲状腺钙化结节需引起注意,若为微钙化提示甲状腺恶性肿瘤可能性大,应尽早手术治疗,粗钙化提示甲状腺良性疾病可能性大,需密切随诊观察。     

Radiofrequency ablation of primary thyroid carcinoma: efficacy according to the types of thyroid carcinoma

Objective: To evaluate the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) according to the types of thyroid carcinoma, particularly in patients with a high-surgical risk.

Materials and methods: Eight patients with nine tumours of pathologically proven papillary and anaplastic carcinoma were treated by US-guided RFA. Patients with primary thyroid carcinoma were divided into three groups; group (1) Anaplastic carcinoma, group (2) papillary macrocarcinoma, and group (3) papillary microcarcinoma. We evaluated changes in clinical symptoms, tumour volume and local tumour recurrence/metastasis after RFA. Patients were followed up at 1, 6 and 12 months and annually thereafter.

Results: Among nine tumours, one anaplastic carcinoma was treated three times and the other anaplastic carcinoma and one papillary macrocarcinoma were treated twice. Group 3 were treated once. The initial mean tumour volume was 107.9?±?78.6 (with neck bulging), 126.9 (with neck bulging) and 0.16?±?0.08?mL (without cosmetic or symptomatic problems) in groups 1–3, respectively. Group 1 showed no improvement in clinical symptoms or neck bulging after RFA, whereas group 2 demonstrated a decreased tumour volume measuring 0.7?mL with improved neck bulging. In group 3, mean volume decreased measuring 0.07?±?0.12?mL. No local tumour recurrence or metastatic lesion was detected during the mean follow-up of 19.3 months in papillary carcinomas. No major complications were encountered.

Conclusions: In patients with primary thyroid carcinoma, RFA achieved excellent local tumour control for papillary macro- and microcarcinoma; however, its clinical effect on anaplastic carcinoma was questionable.     

Microwave ablation induces a lower systemic stress response in patients than open surgery for treatment of benign thyroid nodules

Objective: In this study, we compared the systemic stress response induced by microwave ablation with that induced by conventional open surgery for treatment of benign thyroid nodules.

Methods: A total of 108 patients with benign thyroid nodules were randomly assigned to receive ultrasound-guided thyroid microwave ablation (microwave group, n?=?57) and conventional open thyroid surgery (open group, n?=?51). Body temperature, white blood cell (WBC) counts, visual analogue scale (VAS) scores for pain, and serum levels of high sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6) and cortisol were measured at 24?h before operation and at 8?h, 24?h and 48?h after operation.

Results: No significant between-group differences were observed with respect to preoperative body temperature, VAS scores, WBC counts, serum hs-CRP, IL-6 and cortisol levels. Patients in the open group exhibited higher body temperature at 24?h after operation and higher WBC counts at both 24?h and 48?h after operation, as compared to those in the microwave group. As compared with microwave ablation, open surgery was associated with significantly higher VAS scores, and significantly higher serum levels of hs-CRP, IL-6 and cortisol at all postoperative time-points (8?h, 24?h and 48?h).

Conclusion: Microwave ablation induces a lower systemic stress response than open surgery for treatment of benign thyroid nodules.     

Laser ablation is more effective for spongiform than solid thyroid nodules. A 4-year retrospective follow-up study

Purpose: Laser ablation (LA) is used as therapeutic modality for reducing the volume of large benign thyroid nodules. The aim of this retrospective study was to assess the efficacy of LA therapy in patients with benign non-functioning thyroid nodules in a 4-year follow-up and evaluate whether different compactness of nodules may influence the final shrinkage.

Patients and methods: Fifty-six euthyroid patients (42 females; mean age 54.7?±?11.7 years) with benign cold thyroid solitary nodules or a dominant nodule within a multinodular goitre underwent LA between July 2009 and March 2012. Nodule volume, thyroid function test and ultrasound were monitored at baseline, and at 3, 6 and 12 months after the procedure, then annually.

Results: With a mean baseline volume of 15.7?±?11.7?mL, nodule volume decreased by 55.5% (6.5?±?5.7?mL) 4 years after LA (p?p?=?.04) and became even more significant up to 48 months (p?=?.001).

Conclusions: The LA technique succeeded in reducing thyroid nodules by about 50% at 4 years, but was more effective for spongiform than solid nodules.     

Percutaneous microwave ablation of thyroid nodules: effects on thyroid function and antibodies

Abstract

Purpose: Microwave ablation (MWA) is a new minimally invasive method for thermal ablation of benign thyroid nodules with promising results. The aim of this study was to investigate whether MWA has an impact on thyroid function. Materials and methods: Thirty patients with a total of 34 benign thyroid nodules underwent MWA between January 2013 and July 2014. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobuline (Tg) and additionally antibodies against Tg (anti-Tg), thyrotropin receptors (TRAb) and thyroid peroxidase (anti-TPO) were measured at enrolment, 24?h after MWA, as well as at the 3-month and 6-month follow-up. Moreover, the nodule volume was evaluated to determine effectiveness. Results: Serum TSH, T4, T3 and Tg levels did not change significantly at the 3-month or 6-month follow-up (p?>?0.05); thyroid function was not affected by MWA. Antibody levels did not change significantly either; however, two patients developed antibodies after treatment. A volume reduction of 51.4% or 7.85?mL could be demonstrated after 3 months and a reduction of 55.8% or 14.0?mL after 6 months. Slight complications such as mild pain during the ablation or superficial haematomas emerged. The development of Graves’ disease and mild Horner’s syndrome were observed as more severe side effects. Conclusions: The data suggest MWA as an alternative for the treatment of benign thyroid nodules. While first results for preservation of thyroid function are positive, further measurements of laboratory data and especially antibodies are necessary.     

Minimally-invasive treatments for benign thyroid nodules: a Delphi-based consensus statement from the Italian minimally-invasive treatments of the thyroid (MITT) group

Benign thyroid nodules are a common clinical occurrence and usually do not require treatment unless symptomatic. During the last years, ultrasound-guided minimally invasive treatments (MIT) gained an increasing role in the management of nodules causing local symptoms. In February 2018, the Italian MIT Thyroid Group was founded to create a permanent cooperation between Italian and international physicians dedicated to clinical research and assistance on MIT for thyroid nodules. The group drafted this list of statements based on literature review and consensus opinion of interdisciplinary experts to facilitate the diffusion and the appropriate use of MIT of thyroid nodules in clinical practice. (#1) Predominantly cystic/cystic symptomatic nodules should first undergo US-guided aspiration; ethanol injection should be performed if relapsing (level of evidence [LoE]: ethanol is superior to simple aspiration = 2); (#2) In symptomatic cystic nodules, thermal ablation is an option when symptoms persist after ethanol ablation (LoE = 4); (#3) Double cytological benignity confirmation is needed before thermal ablation (LoE = 2); (#4) Single cytological sample is adequate in ultrasound low risk (EU-TIRADS ≤3) and in autonomously functioning nodules (LoE = 2); (#5) Thermal ablation may be proposed as first-line treatment for solid, symptomatic, nonfunctioning, benign nodules (LoE = 2); (#6) Thermal ablation may be used for dominant lesions in nonfunctioning multinodular goiter in patients refusing/not eligible for surgery (LoE = 5); (#7) Clinical and ultrasound follow-up is appropriate after thermal ablation (LoE = 2); (#8) Nodule re-treatment can be considered when symptoms relapse or partially resolve (LoE = 2); (#9) In case of nodule regrowth, a new cytological assessment is suggested before second ablation (LoE = 5); (#10) Thermal ablation is an option for autonomously functioning nodules in patients refusing/not eligible for radioiodine or surgery (LoE = 2); (#11) Small autonomously functioning nodules can be treated with thermal ablation when thyroid tissue sparing is a priority and ≥80% nodule volume ablation is expected (LoE = 3).     

Local thyroid tissue ablation by high-intensity focused ultrasound: Effects on thyroid function and first human feasibility study with hot and cold thyroid nodules

Objective: The aim of this study was to assess whether high-intensity focused ultrasound (HIFU), a new and promising method for the treatment of benign hot and cold thyroid nodules using thermal ablation, has an impact on thyroid function, and to evaluate its feasibility in outpatient settings. Additionally, a possible difference in the treatment of solid and complex thyroid nodules was evaluated. Method: Ten patients with one thyroid nodule each (six cold and four hot nodules) underwent HIFU in January 2014. Four nodules were solid and six nodules were complex. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobulin (hTg) and additionally antibodies against hTg (TAK), TSH receptors (TRAK) and thyroid peroxidase (TPO) were measured at enrolment and 24?h after the HIFU treatment. The pre- and post-thyroglobulin reduction was measured to evaluate the scale of ablation. In addition, patients’ pain was recorded on a numeric rating scale from 0 to 10. Results: The HIFU treatment did not affect thyroid function, since hormone levels stayed stable (p?p?p?Conclusion: HIFU is a safe and effective method to treat benign, solid, complex, hot and cold thyroid nodules preserving thyroid function. Further developments of the system are needed to gain suitability for daily use.     

Vocal cord paresis following single-session high intensity focused ablation (HIFU) treatment of benign thyroid nodules: incidence and risk factors

Abstract

Background: Vocal cord paresis (VCP) may occur following high intensity focused ultrasound (HIFU) of thyroid nodules. We hypothesised its occurrence relates to the distance of the focus point (FP) of the HIFU beams from the recurrent laryngeal nerve (RLN) and the thermal power that this point received. Their relationships were examined.

Methods: One hundred and three patients who underwent HIFU for symptomatic benign thyroid nodule from October 2015 to March 2017 were analysed. All treatment images were captured and were later watched by 2 reviewers to identify three FPs closest to the tracheoesophageal groove (TEG) on transverse sonographic view. TEG was taken as the RLN position. After identifying these FPs, their distance (mm) from the TEG, thermal power (W) used and depth from skin (mm) were recorded. These parameters were compared between those with and without VCP. VCP was defined as a cord with reduced or no movement.

Results: Four (3.9%) patients suffered from a unilateral VCP afterwards but they all recovered fully within 6?weeks. There were no significant differences in baseline characteristics and treatment efficacy between the two groups. The distance from TEG (OR?=?1.706, 95%CI?=?1.001 to 2.915, p?=?0.050) was the only significant factor for VCP. None of the other variables including thermal power were significant.

Conclusions: The incidence of VCP was 3.9% (4/103) and they completely recovered within 6?weeks. The distance between the FP and the TEG was the only related factor for VCP. The safe distance between FP and TEG should be ≥1.1?cm.     

Radiofrequency ablation of benign thyroid nodules: depicting early sign of regrowth by calculating vital volume

Abstract

Objective: We evaluated long-term follow-up results of radiofrequency ablation of benign thyroid nodules to analyse the role of marginal vital tissue on nodule regrowth.

Materials and methods: We reviewed the medical records of 54 patients who underwent radiofrequency ablation between June 2008 and November 2013 with pressure symptoms, and/or cosmetic problems. All patients were followed up at least 12?months on three occasions. To evaluate an early sign of regrowth, three types of nodule volumes (total volume, ablated volume and vital volume) were measured and calculated using ultrasonography. Regrowth was defined as a more than a 50% increase in the total volume and vital volume increase was defined as a more than 50% increase compared to the previously reported smallest volume on ultrasonography.

Results: The mean follow-up period was 39.4?±?21.7 (range, 13–87) months. Vital volume increases occurred in 31 nodules (57.4%) and there was regrowth in 13 nodules (24.1%). The mean timing of the vital volume increase was 27.5?±?18.5?months, and for regrowth it was 39.9?±?17.5?months. Vital volume increase tended to precede regrowth.

Conclusion: Vital volume increase tended to occur earlier than regrowth and might be an early sign of regrowth in following-up after the radiofrequency ablation of benign thyroid nodules.     

超声引导下微波消融治疗甲状腺良性结节的临床效果及安全性评估北大核心

目的:评价超声(ultrasound,US)引导下微波消融(microwave ablation,MWA)治疗甲状腺良性结节的临床效果及安全性。方法:回顾性分析2016年08月至2020年12月共152例(210枚结节)接受MWA治疗的甲状腺良性结节患者,其中男42例,女110例,年龄20~76岁,平均(51.39±13.89)岁。以术后12个月为随访终点,以结节最大直径(maximum diameter,MD)进行分组评价治疗效果,评估结节体积的变化、颈部症状评分、美容评分以及体积缩小率和并发症。结果:本研究中所有肿瘤均正确定位,并1次进针成功,均按照术前计划使用MWA成功消融。术后12个月时总有效率为100.0%。术前及术后3、6、12个月结节体积呈持续减小趋势,术后3、6、12个月体积缩小率(volume reduction ratio,VRR)呈逐渐增加趋势,MD>30 mm的结节的VVR低于MD<15 mm与15~30 mm两组。术后的美容评分与颈部症状评分均与术前比较差异具有统计学意义(P<0.05)。并发症发生率为17.8%(27/152),所有症状均在1个月内缓解,无任何特殊治疗。结论:超声引导下的MWA治疗甲状腺良性结节具有明显成效,疗效与结节大小有关,并且具有较高的安全性,不仅能够提高美观程度,更有利于患者术后康复。     

术中超声在冷循环射频治疗肝脏肿瘤中的作用

Objective:To explore the feasibility and efficiency of intraoperative ultrasonography (IOUS) in the cool-tip radiofrequency ablation (RFA) of hepatic carcinoma.Methods:Thirty-one patients of hepatic carcinoma were enrolled in this study.In the process of open-surgical cool-tip radiofrequency ablations,tOUS was applied to assess the hepatic lesions,guide and monitor the process of RFA in real-time.Results:Under the guidance of intraoperative ultresonography,the open surgical RFA in all patients proceed smoothly.Seven additional hepatic lesions were found that were not detected in preoperative imaging.A false positive focal lesion reported by preoperative MRI was accurately ruled out by IOUS.Conclusion:Intraoperative ultrasonography is superior to ordinary imaging techniques in finding missed lesions,avoiding complications such as injuries of bile ducts and vessels.Monitoring the real-time RFA process thereby obviously optimizing the treatment of hepatic carcinoma.