Comparison of ultrasonography-guided percutaneous microwave ablation for subcapsular and nonsubcapsular hepatocellular carcinoma

PurposeTo compare the prognosis of subcapsular and nonsubcapsular hepatocellular carcinoma (HCC) after ultrasonography (US)-guided percutaneous microwave ablation (MWA).Materials and methodsFrom January 2012 to December 2015, 463 enrollment patients (382 men, 81 women; age range, 24–95 years) with a single HCC underwent US-guided percutaneous MWA. The patients were divided into two groups according to tumor location: subcapsular (n = 224) and nonsubcapsular (n = 239). Therapeutic efficacy was assessed by contrast enhanced imaging after MWA. The technique effectiveness rate, the local tumor progression (LTP) rate, overall survival (OS) rate and complication were compared between two groups.ResultsThere were no significant differences in the mean treatment sessions (p = 0.105) and the mean number of antenna insertions (p = 0.065) between two groups. No significant difference in the technique effectiveness rate was found between subcapsular and nonsubcapsular tumors (95.5% vs 98.3%, p = 0.089). The respective 1-, 2-, 3-, and 4-year cumulative LTP rates were 5.0%, 5.5%, 5.5% and 5.5% in subcapsular group and 6.4%, 6.4%, 6.4% and 6.4% in nonsubcapsular group, respectively(p = 0.861). The 1-, 2-, 3-, and 4-year OS rates were estimated to be 95.7%, 90.1%, 82.9%, and 71.1% in subcapsular group and 98.5%, 92.8%, 83.2%, and 73.6% in nonsubcapsular group, respectively (p = 0.426). There was no significant difference in major complication rates between the subcapsular group (2.2%) and nonsubcapsular group (1.3%) (p = 0.653). There was higher postoperative pain rate in subcapsular group (13.4%) than nonsubcapsular group (7.1%) (p = 0.025).ConclusionsThere were no significant differences in the technique effectiveness rate, cumulative LTP rate, OS rate and major complication rate between subcapsular and nonsubcapsular group after MWA for HCC.     

Comparison of radiofrequency and microwave ablation and identification of risk factors for primary treatment failure and local progression

PurposeTo compare percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) for treatment of Hepatocellular carcinoma (HCC) and to identify risk factors for treatment failure and local progression.Methods145 unique HCC [87 (60%) RFA, 58 (40%) MWA] were retrospectively reviewed from a single tertiary medical center. Adverse events were classified as severe, moderate, or mild according to the Society of Interventional Radiology Adverse Event Classification system. Primary and secondary efficacy, as well as local progression, were determined using mRECIST. Predictors of treatment failure and time to local progression were analyzed using generalized estimating equations and Cox regression, respectively.ResultsTechnical success was achieved in 143/145 (99%) HCC. There were 1 (0.7%) severe and 2 (1.4%) moderate adverse events. Of the 143 technically successful initial treatments, 136 (95%) completed at least one follow-up exam. Primary efficacy was achieved in 114/136 (84%). 9/22 (41%) primary failures underwent successful repeat ablation, so secondary efficacy was achieved in 128/136 (90%) HCC. Local progression occurred in 24 (19%) HCC at a median of 25 months (95% CI = 19–32 months). There was no difference in technical success, primary efficacy, or time to local progression between RFA and MWA. In HCC treated with MWA, same-day biopsy was associated with primary failure (RR = 9.0, 95% CI: 1.7–47, P = 0.015), and proximity to the diaphragm or gastrointestinal tract was associated with local progression (HR = 2.40, 95% CI:1.5–80, P = 0.017).ConclusionThere was no significant difference in primary efficacy or time to local progression between percutaneous RFA and MWA.     

Efficacy and safety of percutaneous microwave ablation for hepatocellular carcinomas <4 cm in difficult location

Objective:Tumor location is a critical factor for determining technical success and local recurrence following percutaneous ablation of hepatocellular carcinomas (HCC). The purpose of this retrospective study was to evaluate the safety and outcome measures of percutaneous microwave ablation (pMWA) for HCCs <4 cm in difficult locations.Methods:Retrospective review included 81 patients who underwent pMWA for HCCs <4 cm. Fourty-three patients (30 males and 13 females; mean age, 61 years) with 53 HCCs located near the diaphragm, heart, gallbladder, kidney, gastrointestinal tract, large vessel and exophytic location were included under difficult location group. Thirty-eight patients (29 males and nine females; mean age, 60 years) with 48 HCCs in other locations were included under control group. Baseline demographics were recorded. Technical efficacy, local tumor progression (LTP), and complication rates were evaluated.Results:Mean follow-up period was 3.4 months (range 1–7). There was no major complication in both the groups; two patients had a mild perihepatic hemorrhage in the difficult location group which was managed conservatively. There was no difference between the groups in the overall technical efficacy rate (84.9% vs 91.7%, p = 0.294), LTP rate (4.4% vs 2.2%. p = 0.57) or complication rate (4.6% vs 0%, p = 0.177).Conclusion:Our data suggest that there is no significant difference in technical efficacy, LTP or complication rates for MWA in both difficult and normal locations.Advances in knowledge:With proper patient selection, pre-procedural planning and appropriate technique, pMWA is feasible, safe, and effective for small HCCs in difficult location with an acceptable range of complications.     

Efficacy and Safety of Percutaneous Argon-Helium Cryoablation for Hepatocellular Carcinoma Abutting the Diaphragm

PurposeTo evaluate the efficacy and safety of percutaneous argon-helium cryoablation (CA) for hepatocellular carcinoma (HCC) abutting the diaphragm (<5 mm).Materials and MethodsA total of 61 consecutive patients (50 men, 11 women; mean age, 56.3 ± 12.1 years old; range, 32–83 years) with 74 HCC tumors (mean size, 3.3 ± 1.7 cm; range, 0.8–7 cm) who were treated with percutaneous argon-helium CA were enrolled in this retrospective study. Adverse events were evaluated according to Common Terminology Criteria for Adverse Events, version 5.0. Local tumor progression (LTP) and overall survival (OS) were analyzed using the Kaplan-Meier method and the log-rank test. The risk factors associated with OS and LTP were evaluated using univariate and multivariate Cox regression analysis.ResultsNo periprocedural (30-day) deaths occurred. A total of 29 intrathoracic adverse events occurred in 24 of the 61 patients. Major adverse events were reported in 5 patients (pleural effusion requiring catheter drainage in 4 patients and pneumothorax requiring catheter placement in 1 patient). Median follow-up was 18.7 months (range, 2.3–60.0 months). Median time to LTP after CA was 20.9 months (interquartile range [IQR], 14.1–30.6 months). Median times of OS after CA and diagnosis were 27.3 months (IQR, 15.1–45.1 months) and 40.9 months (interquartile range, 24.8–68.6 months), respectively. Independent prognostic factors for OS included tumor location (left lobe vs right lobe; hazard ratio [HR], 2.031; 95% confidence interval [CI], 1.062–3.885; P = .032) and number of intrahepatic tumors (solitary vs multifocal; HR, 2.684; 95% CI, 1.322–5.447; P = .006). Independent prognostic factors for LTP included age (HR, 0.931; 95% CI, 0.900–0.963; P < .001), guidance modality (ultrasound vs computed tomography and US; HR, 6.156 95% CI, 1.862–20.348; P = .003) and origin of liver disease.ConclusionsPercutaneous argon-helium CA is safe for the treatment of HCC abutting the diaphragm, with acceptable LTP and OS.     

Thermal ablation alone vs thermal ablation combined with transarterial chemoembolization for patients with small (<3 cm) hepatocellular carcinoma

PurposeThermal ablation (TA) and transarterial chemoembolization (TACE) may be used alone or in combination (TACE+TA) for the treatment of hepatocellular carcinoma (HCC). The aim of our study was to compare the time to tumor progression (TTP) and overall survival (OS) for patients who received TA alone or TACE+TA for HCC tumors under 3 cm.Materials and methodsThis HIPAA-compliant IRB-approved retrospective analysis included 85 therapy-naïve patients from 2010 to 2018 (63 males, 22 females, mean age 62.4 ± 8.5 years) who underwent either TA alone (n = 64) or TA in combination with drug-eluting beads (DEB)-TACE (n = 18) or Lipiodol-TACE (n = 3) for locoregional therapy of early stage HCC with maximum tumor diameter under 3 cm. Kaplan-Meier analysis was performed using the log-rank test to assess TTP and OS.ResultsAll TA and TACE+TA treatments included were technically successful. TTP was 23.0 months in the TA group and 22.0 months in the TACE+TA group. There was no statistically significant difference in TTP (p = 0.64). Median OS was 69.7 months in the TA group and 64.6 months in the TACE+TA group. There was no statistically significant difference in OS (p = 0.14). The treatment cohorts had differences in AFP levels (p = 0.03) and BCLC stage (p = 0.047). Complication rates between patient groups were similar (p = 0.61).ConclusionFor patients with HCC under 3 cm, TA alone and TACE+TA have similar outcomes in terms of TTP and OS, suggesting that TACE+TA may not be needed for these tumors unless warranted by tumor location or other technical consideration.     

Hepatocellular carcinoma with type II–III portal vein tumour thrombosis: treatment using transarterial chemoembolisation and microwave ablation

Objective:To evaluate the use of transarterial chemoembolisation (TACE) combined with microwave ablation (MWA) to treat patients with hepatocellular carcinoma (HCC) and type Ⅱ–Ⅲ portal vein tumour thrombosis (PVTT) intolerant to targeted drug (TG) therapy.Methods:A total of 18 patients with HCC and type Ⅱ–Ⅲ PVTT intolerant to TG were enrolled between June 2015 and December 2019, who were treated with TACE + MWA (MWA group). 24 patients were treated with TACE + TG (TG group; control cohort). Time to progression and overall survival (OS) were analysed along with the incidence of adverse events.Results:The median follow-up time was 19.0 months (9.0–32.0 months). The median OS was 17.0 months (8.3–29.3 months; MWA group) and 13.5 months (5.5–22.5 months; TG group) and was not significantly different. The 1- and 2 year OS was also comparable (MWA group: 66.7%, 44.4% vs Target group: 41.7%, 29.2%). Time to progression showed no distinct differences (MWA group: 11.5 months; TG group: 9.0 months) between the two groups. Moreover, the incidence of major Grade 3–4 adverse events in the MWA group (5.6%) was similar to those in the TG group (8.3%).Conclusion:TACE + MWA and TACE + TG were comparable in their safety and efficacy in patients with HCC, type Ⅱ–Ⅲ PVTT, and intolerance to TG.Advances in knowledge:TACE + MWA can be used as a palliative treatment alternative for TACE + TG in patients with HCC, type Ⅱ–Ⅲ PVTT, and intolerance to TG.     

Microwave ablation of cT1a renal cell carcinoma: oncologic and functional outcomes at a single center

PurposePercutaneous ablation is an established alternative to surgical intervention for small renal masses. Radiofrequency and cryoablation have been studied extensively in the literature. To date, series assessing the efficacy and safety of microwave ablation (MWA) are limited. We present a cohort of 110 renal tumors treated with MWA.MethodsA review of the medical record between January 2015 and July 2019 was performed, retrospectively identifying 101 patients (110 tumors). All ablations were performed by a single board-certified urologist/interventional radiologist. Demographic information, intraoperative, postoperative, and follow-up surveillance data were recorded.ResultsMedian (IQR) age was 69.7 years (60.8–77.0); 27 (24%) were female. Median (IQR) BMI was 27.0 (25.1–30.2) and Charleston Comorbidity Index was 5.0 (4.0–6.0). 82 tumors were biopsy-confirmed renal cell carcinoma/oncocytic neoplasms. Median (IQR) tumor size was 2.0 cm (1.5–2.6). Median (IQR) RENAL nephrometry score was 6.0 (5.0–8.0). Technical success was achieved in all patients and all but one patient were discharged on the same day. Median (IQR) eGFR at baseline and 1 year were 71.9 mL/min/1.73 m² (56.5–82) and 63.0 mL/min/1.73 m² (54.0–78.2); the difference was −5.3 (p = 0.12). Two Clavien-Dindo type-I complications, one type-II complication, and one type-III complication were experienced in this cohort. Median radiographic follow-up was 376.5 days with 2 tumors (2.4% of RCC/oncocytic neoplasms) having recurred to date.ConclusionsMWA is a safe and efficacious treatment option for small renal masses with minimal adverse events and low rates of recurrence in this cohort of 101 patients. Continued follow-up is needed to assess long-term outcomes.     

Percutaneous microwave ablation for hepatocellular carcinoma adjacent to large vessels: A long-term follow-up

Purpose

To retrospectively evaluate the effectiveness and safety of ultrasound (US)-guided percutaneous microwave ablation (MWA) in the treatment of hepatocellular carcinoma (HCC) adjacent to large vessels.

Materials and methods

From February 2006 to February 2013, 452 patients with 605 HCC nodules were treated with US-guided percutaneous MWA. Into large vessels group (Group L), 139 patients with 163 lesions (diameter, 1.0–7.0 cm; mean, 2.5 ± 1.1 cm) located less than 5 mm away from large vessels were enrolled. And 313 patients with 442 lesions (diameter, 1.0–8.0 cm; mean, 2.5 ± 1.2 cm) located more than 5 mm away from hepatic surface, large vessels, gallbladder and gastrointestinal tract were included in control group (Group C). During the ablation, the temperature of marginal ablation tissues was monitored and controlled.

Results

The median follow-up time was 24.5 months (range 2.1–87.7 months) in Group L, and 25.7 months (range 1.6–93.9 months) in Group C. Technical effectiveness was achieved in 157 of 163 (96.3%) tumors in Group L and 429 of 442 (97.1%) tumors in Group C, respectively (p > 0.05). The 1-, 3- and 5-year local tumor progression rates and the 1-, 3- and 5-year accumulative survival rates in the two groups have no significantly statistical differences. In addition, no immediate or periprocedural major complications, no delayed complication of vessels or bile ducts injury were found in both of the two groups.

Conclusions

With strict temperature monitoring, US-guided percutaneous MWA is an efficient and safe technology in treating hepatocellular carcinoma adjacent to large vessels.     

Value of Nonrigid Registration of Pre-Procedure MR with Post-Procedure CT After Radiofrequency Ablation for Hepatocellular Carcinoma

Purpose

To evaluate the value of pre-radiofrequency ablation (RFA) MR and post-RFA CT registration for the assessment of the therapeutic response of hepatocellular carcinoma (HCC).

Materials and Methods

A total of 178 patients with single HCC who received RFA as an initial treatment and had available pre-RFA MR and post-RFA CT images were included in this retrospective study. Two independent readers (one experienced radiologist, one inexperienced radiologist) scored the ablative margin (AM) of treated tumors on a four-point scale (1, residual tumor; 2, incomplete AM; 3, borderline AM; 4, sufficient AM), in two separate sessions: (1) visual comparison between pre-and post-RFA images; (2) with addition of nonrigid registration for pre- and post-RFA images. Local tumor progression (LTP) rates between low-risk (response score, 3–4) and high-risk groups (1–2) were analyzed using the Kaplan–Meier method at each interpretation session.

Results

The patients’ reassignments after using the registered images were statistically significant for inexperienced reader (p < 0.001). In the inexperienced reader, LTP rates of low- and high-risk groups were significantly different with addition of registered images (session 2) (p < 0.001), but not significantly different in session 1 (p = 0.101). However, in the experienced reader, LTP rates of low- and high-risk groups were significantly different in both interpretation sessions (p < 0.001). Using the registered images, the cumulative incidence of LTP at 2 years was 3.0–6.6%, for the low-risk group, and 18.6–27.8% for the high-risk group.

Conclusion

Registration between pre-RFA MR and post-RFA CT images may allow better assessment of the therapeutic response of HCC after RFA, especially for inexperienced radiologists, helping in the risk stratification for LTP.

     

Preliminary Study of Microwave Ablation for Multifocal Papillary Thyroid Microcarcinoma in Nonoperative Candidates

PurposeTo study the feasibility, safety, and effectiveness of microwave ablation (MWA) in patients with multifocal papillary thyroid microcarcinoma (PTMC).Materials and MethodsThis retrospective study included patients who underwent MWA for multifocal PTMC (number of nodules ≤3). A total of 44 patients were included, and the mean age was 43 years (SD ± 11). After ablation, progression-free survival (PFS) at 6, 12, 24, 36, and 48 months; disease progression; change in tumor size and volume; tumor disappearance rate; and adverse events (AEs) were assessed, and the feasibility, safety, and effectiveness of MWA for PTMC were evaluated on the basis of statistical analysis.ResultsThe median follow-up period was 18 months (interquartile range, 12–33 months). The PFS rates at 6, 12, 24, 36, and 48 months were 100.0%, 96.4%, 96.4%, 70.3%, and 52.7%, respectively. The disease progression rate was 11.4% (5 of 44 patients). The maximum diameter (MD) and volume of the ablation zone were larger at the 3-month follow-up than before ablation (median MD, 13.0 vs 7.0 mm; P < .001; median volume, 503.8 vs 113.0 mm³; P < .001). Subsequently, the tumors exhibited a reduction in both size and volume after 18 months (median MD, 4.0 vs 7.0 mm; P = .04; median volume, 12.6 vs 113.0 mm³; P = .055). At the end of the follow-up period, the complete response rate was 59% (26 of 44 patients). The overall AE rate was 6.8%.ConclusionsMWA is a feasible treatment for PTMC (number of nodules ≤3), and this study preliminarily demonstrated the safety and effectiveness of this technique.     

Impact of the Ablative Margin on Local Tumor Progression after Radiofrequency Ablation for Lung Metastases from Colorectal Carcinoma: Supplementary Analysis of a Phase II Trial (MLCSG-0802)

PurposeTo explore what extent of ablative margin depicted by computed tomography (CT) immediately after radiofrequency (RF) ablation is required to reduce local tumor progression (LTP) for colorectal cancer (CRC) lung metastases.Materials and MethodsThis retrospective study was undertaken as a supplementary analysis of a previous prospective trial. Seventy patients (49 men and 21 women; mean age ± standard deviation, 64.9 years ± 10.6 years) underwent RF ablation for CRC lung metastases, and 95 tumors that were treated in the trial and followed up with CT at least 12 months after RF ablation were evaluated. The mean tumor size was 1.0 cm ± 0.5 cm. The ablative margin was estimated as the shortest distance between the outer edge of the tumor and the surrounding ground-glass opacity on CT obtained immediately after RF ablation. The impact of the ablative margin on LTP was evaluated using logistic regression analysis. Multivariate logistic regression analysis was also performed to identify the risk factors for LTP. The result was validated with multivariate logistic regression applying a bootstrap method (1,000 times resampling).ResultsThe mean ablative margin was 2.7 mm ± 1.3 (range, 0.4–7.3 mm). LTP developed in 6 tumors (6%, 6/95) 6–19 months after RF ablation. The LTP rate was significantly higher when the margin was less than 2 mm (P = .023). A margin of <2 mm was also found to be a significant factor for LTP (P = .048) on multivariate analysis and validated using the bootstrap method (P = .025).ConclusionsAn ablative margin of at least 2 mm is important to reduce LTP after RF ablation for CRC lung metastases.     

Long-term Outcomes of Patients with Hepatocellular Carcinoma Who Underwent Microwave Ablation after Downstaging with Transarterial Chemoembolization to Barcelona Clinic Liver Cancer Stage A

PurposeTo compare the clinical results of microwave ablation (MWA) between patients downstaged to Barcelona Clinic Liver Cancer (BCLC) Stage A with transarterial chemoembolization (TACE) and those initially classified as BCLC Stage A.Materials and MethodsFrom January 2012 to May 2017, 1,087 patients were reviewed retrospectively using propensity score matching (1:1): 86 patients underwent MWA as a curative treatment after downstaging to BCLC Stage A by TACE (downstaging group) and 86 patients initially classified as BCLC Stage A underwent MWA (control group). The overall survival (OS) and disease-free survival (DFS) between the 2 groups were compared.ResultsThe 1-, 3-, and 5-year OS rates were 95.3%, 79.1%, and 58.1%, respectively, in the downstaging group and 93.0%, 81.4%, and 61.6%, respectively, in the control group (hazard ratio [HR], 0.75; 95% CI, 0.50–1.13; P = .162). The 1-, 3-, and 5-year DFS rates were 80.2%, 50.0%, and 24.4%, respectively, in the downstaging group and 77.9%, 52.3%, and 27.9%, respectively, in the control group (HR, 1.08; 95% CI, 0.76–1.53; P = .678). No significant differences were found in OS and DFS.ConclusionsThe long-term prognosis in patients with HCC who underwent MWA after downstaging to BCLC Stage A using TACE was similar to that in patients with initial BCLC Stage A.     

Utility of the RENAL Nephrometry Scoring System in Predicting Adverse Events and Outcomes of Percutaneous Microwave Ablation of Renal Tumors

PurposeTo assess the utility of the radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry scoring system at predicting adverse events and outcomes in percutaneous microwave ablation (MWA) of renal tumors.Materials and MethodsA retrospective review of 116 patients who underwent MWA from 2004 to 2018 at 2 large university hospitals was conducted. Patient demographics and tumor characteristics were collected. The RENAL nephrometry scores were calculated, and procedure-related adverse events were stratified into minor and major (the Society of Interventional Radiology classification of class C or higher). Technical and oncologic outcomes were based on follow-up magnetic resonance imaging and computed tomography scans after ablation.ResultsThe mean RENAL score was 6.6 (range, 4–11), and the mean tumor size was 24 mm. Follow-up ranged between 16 and 161 weeks (median, 50 weeks; mean, 65 weeks). Oncologic control was achieved in 96% (n = 111) of patients. The major and minor adverse event rates were 8.6% (n = 10) and 17% (n = 19), respectively. The mean RENAL score for patients with recurrent and/or residual tumor (8.2 ± 2.7) was higher than that for patients without disease recurrence (6.5 ± 3.5, P = .05). However, in a multivariate analysis, the RENAL score was not found to be an independent predictor of oncologic outcomes (odds ratio, 1.548; P = .092).ConclusionsThe RENAL nephrometry score has minimal utility for predicting outcomes and adverse events in MWA of renal tumors. The inconsistent nature of RENAL nephrometry scoring in percutaneous ablation procedures underscores the need for an ablation-specific risk stratification system.     

Percutaneous Microwave versus Radiofrequency Ablation of Colorectal Liver Metastases: Ablation with Clear Margins (A0) Provides the Best Local Tumor Control

Purpose

To identify and compare predictors of local tumor progression (LTP)-free survival (LTPFS) after radiofrequency (RF) ablation and microwave (MW) ablation of colorectal liver metastases (CLMs).

Results of postoperative interstitial brachytherapy of resectable floor of mouth tumors

PurposeThe purpose of this study was to describe the results of postoperative sole interstitial brachytherapy (BT) in patients with resectable floor of mouth tumors.Methods and MaterialsBetween January 1998 and December 2017, 44 patients with squamous cell histology, stage T1-3N0-1M0 floor of mouth tumor were treated by excision of the primary lesion with or without neck dissection followed by sole high-dose-rate tumor bed BT with an average dose of 22.7 Gy (10–45 Gy) using rigid metal needles (n = 14; 32%) or flexible plastic catheters (n = 30; 68%).ResultsDuring a median followup time of 122 months for surviving patients, the probability of 5- and 10-year local and regional tumor control, overall survival (OS), and disease-specific survival (DSS) was 89% and 89%, 73% and 67%, 52% and 32%, 66% and 54%, respectively. In univariate analysis, lymphovascular invasion was a negative predictor of regional tumor control (p = 0.0062), DSS (p = 0.0056), and OS (p = 0.0325), whereas cervical recurrence was associated with worse DSS (p < 0.0001) and OS (p < 0.0001). The incidence of local Grade 1, 2, and 3 mucositis was 25%, 64%, and 11%, respectively. Grade 4 side effect, that is soft tissue necrosis occurred in four cases (9%).ConclusionsResults of postoperative sole high-dose-rate BT of floor of mouth tumors are comparable with those reported with low-dose-rate BT, and this method could improve local tumor control and DSS compared with exclusive surgical treatment.     

Comparison of two different thermal techniques for the treatment of hepatocellular carcinoma

Purpose

To compare the safety and efficacy of radiofrequency ablation (RFA) and microwave ablation (MWA) in treating hepatocellular carcinoma (HCC) while conforming to the Milan criteria.

Materials and methods

The study was approved by the Institutional Review Board, and informed consent was waived due to the retrospective study design. One hundred ninety-eight patients met the inclusion criteria and were included in the study. Eighty-five patients with 98 lesions received RFA, and 113 patients with 131 lesions underwent MWA. Complete ablation rates, local recurrence rates, disease-free survival rates, cumulative survival rates, and major complications were compared between the two treatment groups.

Results

Complete ablation rates were 99.0% for RFA and 98.5% for MWA (P = 1.000). Local recurrence rates were 5.2% for RFA and 10.9% for MWA (P = 0.127). Disease-free survival rates at 1, 2, 3, and 4 years were 80.3%, 61.8%, 39.5%, and 19.0% in the RFA group and 75.0%, 59.4%, 32.1%, and 16.1% in the MWA group, respectively (P = 0.376). Cumulative survival rates at 1, 2, 3, and 4 years were 98.7%, 92.3%, 82.7%, and 77.8% in the RFA group and 98.0%, 90.7%, 77.6%, and 77.6% in the MWA group, respectively (P = 0.729). Major complication rates were 2.4% and 2.7% in the RFA group and the MWA group, respectively (P = 1.000). There were no patient deaths due to treatment.

Conclusion

RFA and MWA have the same clinical value in treating HCC conforming to the Milan criteria. RFA and MWA are both safe and effective techniques for HCC as clinical application.     

Ultrasound-guided microwave ablation of hepatocellular carcinoma: Initial institutional experience

BackgroundMicrowave ablation (MWA) is a new treatment modality for hepatocellular carcinoma (HCC) at our institution. The aim of this study is to evaluate the safety, procedure time and rate of complete ablation of this new modality.Material and methodsHospital medical ethics committee approval and informed consent were obtained. A total of 98 nodules in 72 patients (59 male, 13 female; mean age 57 (±4.6) years, range 50–70 years) with HCC were treated with microwave ablation at our institution from June 2010 to February 2011. A 14 G cooled shaft Amica probe was introduced into the tumors under analgesic sedation and by US guidance. The patients were then followed up with contrast enhanced computed tomography (CT) and serum α-fetoprotein levels.ResultsOne month after therapy, complete ablation was obtained in 96% (94/98) nodules. The complete ablation rate in tumors ?3 cm and those >3 cm were 98%, and 94%, respectively. MW ablation success was higher with nodules ?3 cm (57/58, 98.3%) in comparison to nodules >3 cm (37/40, 92.5%): however, the difference was non-significant (P = 0.301). No complication occurred related to the ablation procedure, only minor complications post-ablation, as pain in (3/72) patients, mild fever in (48/72) patients, and discharge from wound in (2/72) patients. No local recurrence was detected, however, new lesions at other sites of the liver occurred in 11 (15%) patients.ConclusionSonographically guided percutaneous microwave ablation proved to be safe, fast, and effective for treatment of hepatocellular carcinoma.     

Margin Size is an Independent Predictor of Local Tumor Progression After Ablation of Colon Cancer Liver Metastases

Purpose

This study was designed to evaluate the relationship between the minimal margin size and local tumor progression (LTP) following CT-guided radiofrequency ablation (RFA) of colorectal cancer liver metastases (CLM).

Methods

An institutional review board-approved, HIPPA-compliant review identified 73 patients with 94 previously untreated CLM that underwent RFA between March 2003 and May 2010, resulting in an ablation zone completely covering the tumor 4–8 weeks after RFA dynamic CT. Comparing the pre- with the post-RFA CT, the minimal margin size was categorized to 0, 1–5, 6–10, and 11–15 mm. Follow-up included CT every 2–4 months. Kaplan–Meier methodology and Cox regression analysis were used to evaluate the effect of the minimal margin size, tumor location, size, and proximity to a vessel on LTP.

Results

Forty-five of 94 (47.9 %) CLM progressed locally. Median LTP-free survival (LPFS) was 16 months. Two-year LPFS rates for ablated CLM with minimal margin of 0, 1–5 mm, 6–10 mm, 11–15 mm were 26, 46, 74, and 80 % (p < 0.011). Minimal margin (p = 0.002) and tumor size (p = 0.028) were independent risk factors for LTP. The risk for LTP decreased by 46 % for each 5-mm increase in minimal margin size, whereas each additional 5-mm increase in tumor size increased the risk of LTP by 22 %.

Conclusions

An ablation zone with a minimal margin uniformly larger than 5 mm 4–8 weeks postablation CT is associated with the best local tumor control.     

Transarterial Chemoembolization Monotherapy Versus Combined Transarterial Chemoembolization–Microwave Ablation Therapy for Hepatocellular Carcinoma Tumors ≤5 cm: A Propensity Analysis at a Single Center

Purpose

To compare effectiveness of transarterial chemoembolization (TACE) combined with microwave ablation (MWA; TACE–MWA) with TACE alone for treating hepatocellular carcinoma (HCC) tumors ≤5 cm.

Materials and Methods

We reviewed data of 244 patients treated for HCC by TACE–MWA or TACE from June 2014 to December 2015. Median follow-up period was 505 days (TACE–MWA group: 485 days; TACE group: 542 days). Patients were propensity score matched (1:2 ratio); outcomes of TACE–MWA and TACE groups were compared. Primary endpoints were tumor responses, including tumor necrosis rates after initial treatment, tumor responses at 6 months [per modified Response Evaluation Criteria in Solid Tumors (mRECIST)], and time to tumor progression (TTP). Secondary endpoints were overall survival (OS) and re-intervention times.

Results

After initial treatments, tumor necrosis rates were higher in the TACE–MWA group (n = 48; 92.1% [58/63]) than the TACE group (n = 96; 46.3% [56/121]; P < 0.001). At 6 months’ follow-up, the TACE–MWA group had better tumor responses (CR + PR + SD [per mRECIST]: TACE–MWA, 95.8%; TACE, 64.5%; P < 0.001). The TACE–MWA group had better TTP (P < 0.001), but did not significantly differ in OS (P = 0.317). TACE–MWA decreased re-TACE times from 1.90 to 0.52; and re-MWA times from 0.22 to 0.17. In subgroup analysis, TACE–MWA also showed better TTP in patients with tumors ≤3 cm (P < 0.001) and 3–5 cm (P = 0.004).

Conclusions

Compared with TACE, TACE–MWA leads to better responses for HCC tumors ≤5 cm.

     

Safety and Efficacy of Percutaneous Cryoablation for Small Hepatocellular Carcinomas Adjacent to the Heart

PurposeThis study evaluated the safety and efficacy of percutaneous cryoablation for treatment of the left subdiaphragmatic small hepatocellular carcinomas (HCCs) adjacent to the heart.Materials and MethodsBetween September 2013 and March 2018, 189 consecutive patients underwent cryoablation for small HCCs (≤3 cm); 70 patients (mean: 61.3 ± 10.6 years of age; range: 40–82 years) with left hepatic tumors (22 juxtacardiac and 48 nonjuxtacardiac tumors) were retrospectively analyzed. Patients were divided into juxtacardiac and nonjuxtacardiac tumor groups (tumor margins: ≤10 mm and >10 mm, respectively, from the heart border). The rates of technical success, complete ablation, complications, and local tumor recurrence (LTR) were evaluated.ResultsNo significant intergroup differences were observed in the mean diameter of the tumor (17.9 ± 5.5 mm vs. 17.5 mm ± 5.2, respectively; P = 0.781) and of the ablation zone (41.3 ± 4.2 mm vs. 43.5 ± 5.8 mm, respectively; P = 0.115). Technical success was achieved in all patients. No procedure-related major complications occurred in either group. The median follow-up period was 15 months (range: 3.1–49.6 months). No statistically significant intergroup differences were observed in the rates of complete ablation (90.9% vs. 93.8%, respectively; P = 0.646) and LTR (20% vs. 15.6%, respectively; P = 0.725).ConclusionsCryoablation is a safe treatment modality for patients with juxtacardiac small HCCs, without an increased risk of cardiac complications compared to treatment of HCCs that are nonjuxtacardiac, and with comparable efficacy.