Microwave coagulation therapy for hepatocellular carcinoma

Percutaneous ablative therapies for hepatocellular carcinoma in the caudate lobe of the liver: efficacy and outcome

OBJECTIVE

To assess the efficacy and outcomes of percutaneous ablative therapies for hepatocellular carcinoma (HCC) in the caudate lobe.

METHODS

Patients within Milan criteria, who underwent thermal ablation (RFA/MWA) for HCC were analyzed. Based on the inclusion-criteria, patients were categorized in two groups. Group-1 (caudate-lobe HCC) and Group-2 (non-caudate-lobe HCC). Both the groups were analyzed for technical success (TS), local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were compared between both the groups. Predictive factors for LTP, DFS, or OS in the study cohort were analyzed using appropriate statistical analyses.

RESULTS

Twenty-one patients qualified to be in Group-1 while 130 patients fulfilled the criteria for Group-2. TS of 90.5 and 97.7% was seen after the first session of ablation for Group-1 and group-2 respectively, while a TS of 95.2% (Group-1) and 100% (Group-2) was achieved after second session. The right-intercostal-approach was used in 66.7% (n = 14) and the anterior-epigastric-approach was used in 33.3% (n = 7) of patients having caudate-lobe HCC. Procedure-related complications in both the groups were comparable. Although, statistically insignificant, LTP in the Group-1 (19.5%, n = 4) was twice that of non-caudate lobe HCC (8.5%, n = 11). The cumulative DFS rate was better in Group-2 while OS in both groups were comparable. Multivariate analysis showed: tumor size and ablative margin of 5 mm being independent predictors of LTP after percutaneous-ablation of caudate-lobe HCC.

CONCLUSION

Ablative therapies for HCC in caudate lobe is feasible and safe with comparable LTP and OS to non-caudate lobe HCC. Tumor size >2 cm and lack of 5 mm ablative margin are independent predictors of LTP.

ADVANCES IN KNOWLEDGE

1. Percutaneous ablation of caudate lobe HCC is feasible using anterior epigastric approach or right intercostal approach. 2. These approaches may allow a safe and effective ablation of caudate lobe HCC with results comparable to non-caudate HCC ablation.

Study of ultrasound-guided percutaneous microwave ablation combined with portal vein embolization for rapid future liver remnant increase of planned hepatectomy

Purpose

To evaluate the efficacy of ultrasound-guided percutaneous microwave ablation (PMA) combined with portal vein embolization (PVE) for planned hepatectomy.

Methods

We retrospectively reviewed data of 18 patients with multiple right liver tumors or hilar tumor of liver invades the surrounding tissue and insufficient future liver remnant (FLR) for hepatectomy from July 2015 to March 2017. Ultrasound-guided PMA was performed by using PMCT cold circulation microwave treatment apparatus. PVE was performed after PMA. The increase of FLR was evaluated by computed tomography (CT) 6-22 days after PVE. The proportion of FLR, increase in the amplitude of FLR, procedure-related complications, perioperative morbidity and mortality, and overall survival (OS) rates, the median survival time were analyzed.

Results

The median volume of FLR before PMA and PVE was 369.7 ml (range: 239.4-493.1 ml). After a median waiting period of 11.5 days (range: 6-22 days), the median volume of FLR was increased to 523.4 ml (range: 355.4-833.3 ml). The changes in FLR before and after PMA and PVE were statistically significant (p<0.001). No serious perioperative complications or mortality were found. After a median follow-up time of 51.0 months (range: 2-54 months), the 6-month, 1-year, 2-year, 3-year and 4-year survival rates were 88.9%, 72.2%, 44.4%, 33.3%, 22.2%, respectively, and the median survival time was 15.0 ± 7.1 months.

Conclusion

PMA combined with PVE increases FLR rapidly, avoids touching malignant tumors, and produces fewer procedure-related complications. It appears safe and efficacious for planned hepatectomy.

Comparison of microwave ablation and hepatic resection for hepatocellular carcinoma: a meta-analysis

BACKGROUND AND AIMS

Hepatic resection (HRN) and microwave ablation (MWA) have significant advantages in treating hepatocellular carcinoma; however, it remains unclear which way produces better outcomes. This meta-analysis of cohort studies compared the treatments in terms of effectiveness and safety.

METHODS

Six electronic databases (PubMed, Medline, EMBASE, Web of Science, EBSCO, and The Cochrane Library) were retrieved for studies comparing MWA and HRN. The meta-analysis was conducted based on statement of preferred reporting items for systematic reviews and meta-analyses.

RESULTS

Nine studies met the inclusion criteria, with a total of 1,480 patients. The overall meta-analysis demonstrated no significant difference in overall survival between the MWA group and the HRN group (HR =0.98, 95% CI =0.76-1.26, P=0.878). There was no difference in disease-free survival between the MWA group and the HRN group (HR =1.16, 95% CI =0.79-1.71, P=0.442). Meanwhile, the meta-analysis demonstrated that MWA was associated with shorter operation time (standardized mean difference [SMD] =-1.37, 95% CI =-1.92 to -0.81, P=0.000), less amount of blood loss in operation (SWD =-1.19, 95% CI =-1.76 to -0.61, P=0.000), and less complications (OR =0.22, 95% CI =0.12-0.40, P=0.000) than HRN.

CONCLUSION

In conclusion, our meta-analysis suggests that MWA may be superior to HRN as it is as effective as HRN in terms of overall survival, disease-free survival, tumor recurrence, and is associated with shorter operation time, less amount of blood loss, and fewer complications.

Percutaneous thermal ablation for primary hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Percutaneous thermal ablation using radiofrequency ablation (RFA) and microwave ablation (MWA) are both widely available curative treatments for hepatocellular carcinoma. Despite significant advances, it remains unclear which modality results in better outcomes. This meta-analysis of randomized controlled trials (RCT) and observational studies was undertaken to compare the techniques in terms of effectiveness and safety.

METHODS

Electronic reference databases (Medline, EMBASE and Cochrane Central) were searched between January 1980 and May 2014 for human studies comparing RFA and MWA. The primary outcome was the risk of local tumor progression (LTP). Secondary outcomes were complete ablation (CA), overall survival, and major adverse events (AE). The ORs were combined across studies using the random-effects model.

RESULTS

Ten studies (two prospective and eight retrospective) were included, and the overall LTP rate was 13.6% (176/1298). There was no difference in LTP rates between RFA and MWA [OR (95% CI): 1.01(0.67-1.50), P = 0.9]. The CA rate, 1- and 3-year overall survival and major AE were similar between the two modalities (P > 0.05 for all). In subgroup analysis, there was no difference in LTP rates according to study quality, but LTP rates were lower with MWA for treatment of larger tumors [1.88(1.10-3.23), P = 0.02]. There was no significant publication bias or inter-study heterogeneity (I(2) < 50% and P > 0.1) observed in any of the measured outcomes.

CONCLUSION

Overall, both RFA and MWA are equally effective and safe, but MWA may be more effective compared to RFA in preventing LTP when treating larger tumors. Well-designed, larger, multicentre RCTs are required to confirm these findings.

Argon gas embolism in the application of laparoscopic microwave coagulation therapy

BACKGROUND

A major concern in the use of the argon beam coagulator system is the potential risk of argon gas embolism.

METHODS

Seven cases with argon gas embolism in the English literature were reviewed along with the current case. The latter case was a 77-year-old female having laparoscopic hepatectomy after application of the microwave coagulation system on the cutting planes.

RESULTS

Immediately following shots of an argon beam to control local bleeding at the needle hole in the liver caused by microwave coagulation, the end-tidal carbon disappeared, followed by cardiovascular collapse. After 18 min of cardiovascular resuscitation, the tumors were resected under laparotomy.

CONCLUSIONS

After reviewing the cases, pneumoperitoneum (57.1%), hepatic needle punctures (42.8%) and direct application of the argon beam to the liver (28.6%) can be considered as risky processes in such events. Caution is necessary in the use of an argon beam in liver surgery to avoid life-threatening gas embolism.

Prognostic factors and recurrence of small hepatocellular carcinoma after hepatic resection or microwave ablation: a retrospective study

PURPOSE

This study aims to analyze the long-term therapeutic results of small HCC less than 5 cm in diameter after microwave ablation (MA) or hepatic resection (HR) and choose factors that could predict metastasis and recurrence of small HCC.

MATERIALS AND METHODS

The metastasis and recurrence of 194 patients with one HCC less than 5 cm in diameter who underwent curative HR or MA between January 1995 and December 2004 were reviewed retrospectively; immunohistochemistry was used to analyze the expressions of VEGF, bFGF, and c-Met in HCC tissues. Posttreatment prognostic factors were evaluated by multivariate analysis using Cox's proportional hazards model. The variables included the expressions of these three proteins in HCC tissues, the clinical and pathologic characteristics of the patients.

RESULTS

The retrospective study showed that 1-, 3-, and 5-year disease-free survival rates of patients with single HCC of diameter <5 cm were 71.3, 57.0 and 32.5%, respectively. Furthermore, 1-, 3-, and 5-year disease-free survival rates of the patients in MA group and resection group were 72.8, 54.0 and 33.0%; 68.5, 60.0, and 25.6%, respectively. There was no significant difference in disease-free survival rates between these two groups. The result of multivariate analysis showed that differentiation degree of HCC and the expressions of VEGF and c-Met in HCC tissues could be as the independent prognostic factors affecting metastasis and recurrence in patients with small HCC, whereas the methods of therapy had no impact on prognosis.

CONCLUSIONS

The metastasis and recurrence rate after MA is similar to that after HR, and the methods of therapy do not affect the prognosis of small HCC. The metastasis and recurrence of patients with small HCC will differ depending on tumor differentiation, expressions of VEGF and c-Met in HCC tissues.

Microwave ablation of renal parenchymal tumors before nephrectomy: phase I study

OBJECTIVE

The purpose of this study was to determine, in renal neoplasms, the size of ablation zones induced in vivo with percutaneous microwave probes and whether skip areas remain within the ablation zones.

CONCLUSION

For a single 10-minute ablation, ablated volumes averaged 27 cm3 and 105 cm3 with a single-probe and a three-probe ablation array, respectively. There were no skip areas within the ablated zone. Microwave ablation can safely and quickly generate large ablation lesions and renal neoplasms.

Large-sized hepatocellular carcinoma (HCC): a neoadjuvant treatment protocol with repetitive transarterial chemoembolization (TACE) before percutaneous MR-guided laser-induced thermotherapy (LITT)

This study aims to evaluate the efficacy and safety of a neoadjuvant treatment protocol with repeated transarterial chemoembolization (TACE) before MR-guided laser-induced thermotherapy (LITT) for large-sized hepatocellular carcinomas (HCC). Repeated TACE (mean, 3.5 treatments per patient) was performed in 48 patients with neoadjuvant intention (the largest lesion was between 50 and 80 mm in diameter, and there were no more than five lesions). For the TACE treatment, we used 10 mg/m(2) mitomycin, 10 ml/m(2) Lipiodol and microspheres. The tumor volume was measured by MRI. Lipiodol retention of the tumors was evaluated with CT. After the diameter of the tumors had decreased to less than 50 mm, the patients were treated with MR-guided LITT 4 to 6 weeks after embolization. Repeated TACE reduced the tumor size in 32 patients (66.7%), forming the basis for performing MR-guided LITT procedures. These patients received one to four laser treatments (mean, 1.9 per patient) for tumor ablation, resulting in a median survival of 36.0 months after the first treatment. For the remaining patients, no reduction in tumor size was achieved in 12 patients and disease progression in 4 patients. Neoadjuvant TACE appears to be an effective treatment of large-sized HCC, which extends the indication for MR-guided LITT.

Interventional and intraoperative MRI at low field scanner--a review

Magnetic resonance imaging (MRI) is a cutting edge imaging modality in detecting diseases and pathologic tissue. The superior soft tissue contrast in MRI allows better definition of the pathology. MRI is increasingly used for guiding, monitoring and controlling percutaneous procedures and surgery. The rapid development of interventional techniques in radiology has led to integration of imaging with computers, new therapy devices and operating room like conditions. This has projected as faster and more accurate imaging and hence more demanding procedures have been applied to the repertoire of the interventional radiologist. In combining features of various other imaging modalities and adding some more into them, interventional MRI (IMRI) has potential to take further the interventional radiology techniques, minimally invasive therapies and surgery. The term "Interventional MRI" consists in short all those procedures, which are performed under MRI guidance. These procedures can be either percutaneous or open surgical of nature. One of the limiting factors in implementing MRI as guidance modality for interventional procedures has been the fact, that most widely used magnet design, a cylindrical magnet, is not ideal for guiding procedures as it does not allow direct access to the patient. Open, low field scanners usually operating around 0.2 T, offer this feature. Clumsy hardware, bad patient access, slow image update frequency and strong magnetic fields have been other limiting factors for interventional MRI. However, the advantages of MRI as an imaging modality have been so obvious that considerable development has taken place in the 20-year history of MRI. The image quality has become better, ever faster software, new innovative sequences, better MRI hardware and increased computing power have accelerated imaging speed and image quality to a totally new level. Perhaps the most important feature in the recent development has been the introduction of open configuration low field MRI devices in the early 1990s; this enabled direct patient access and utilization of the MRI as an interventional device. This article reviews the current status of interventional and intraoperative MRI with special emphasis in low field surrounding.

Percutaneous microwave and radiofrequency ablation for hepatocellular carcinoma: a retrospective comparative study

BACKGROUND

Percutaneous microwave ablation and radiofrequency ablation are two commonly used modalities for the treatment of hepatocellular carcinoma; however, comparisons of them have not been documented adequately.

METHODS

Of 102 patients with biopsy-proved hepatocellular carcinoma, 49 (98 nodules) were treated percutaneously with microwave ablation and 53 (72 nodules) with radiofrequency ablation. The local tumor control, complications related to treatment, and long-term results of the two modalities were compared retrospectively.

RESULTS

The complete ablation rates were 94.9% (93/98) using microwave ablation vs 93.1% (67/72) using radiofrequency ablation (P = 0.75), and no significant differences were found either in the ablation of tumors of 3.0 cm or less (P = 1.00) or in those of more than 3.0 cm (P = 1.00) between the two modalities. The local recurrence rates were 11.8% (11/93) using microwave ablation vs 20.9% (14/67) using radiofrequency ablation (P = 0.12), and there were no significant differences between the two modalities either in tumors of 3.0 cm or less (P = 0.36) or in those of more than 3.0 cm (P = 0.82). The rates of major complications associated with microwave ablation and radiofrequency ablation were 8.2% (4/49) vs 5.7% (3/53; P = 0.71). The disease-free survival rates in the microwave ablation group were 45.9%, 26.9%, 26.9%, and 13.4% at 1, 2, 3, and 4 years, respectively, and those in the radiofrequency ablation group were 37.2%, 20.7%, and 15.5% at 1, 2 and 3 years, respectively (P = 0.53). The 1-, 2-, 3-, and 4-year cumulative survival rates for patients who underwent microwave ablation were 81.6%, 61.2%, 50.5%, and 36.8%, respectively, and for patients who underwent radiofrequency ablation the rates were 71.7%, 47.2%, 37.6%, and 24.2%, respectively (P = 0.12).

CONCLUSIONS

Percutaneous microwave ablation and radiofrequency ablation are both effective methods in treating hepatocellular carcinomas. The local tumor control, complications related to treatment, and long-term survivals were equivalent for the two modalities.

Radiofrequency versus microwave ablation in a hepatic porcine model

PURPOSE

To compare microwave (MW) and radiofrequency (RF) ablation in a hepatic porcine model.

MATERIALS AND METHODS

Institutional animal research committee approval was obtained. Nineteen pigs were divided into groups based on time of sacrifice (group A, immediate; group B, 2 days; group C, 28 days; group D, 28 days). Groups A, B, and C each underwent a combination of RF and MW ablation. Group D underwent either four MW or four RF ablations. Ablation was performed with a prototype MW device (915 Mhz, 40 W, 10 minutes) and a commercial RF system (150 W, 10 minutes, 3-cm deployment). Computed tomography (CT) was performed in groups B and C at 2 days and in group C at 28 days. Group D underwent serial laboratory testing. Specimens were serially sectioned, and short-axis diameter and length of each were measured. The percentage deflection caused by local blood vessels (heat-sink effect) was also measured in group A. Likelihood ratio tests and unpaired t tests were used for statistical analyses as appropriate.

RESULTS

MW ablation zones were longer at days 0, 2, and 28 (P < .05), but short-axis diameter was not different from that with RF ablation at any time point (P > .05). Local blood vessels caused 3.5% +/- 5.3 (standard deviation) deflection at MW ablation compared with 26.2% +/- 27.9 at RF ablation (P < .05). MW and RF ablation zones were indistinguishable at CT or pathologic evaluation. Laboratory test results were similar between RF ablation-only animals and MW ablation-only animals, with the exception of a slightly higher alkaline phosphatase levels at day 2 in RF ablation-only animals (P < .02).

CONCLUSION

MW and RF ablation zones are similar in pathologic appearance and imaging characteristics. Increased length with MW ablation is likely caused by the length of the radiating segment of the antenna. MW ablation may be less affected by the heat-sink effect that is thought to contribute to local recurrence after RF ablation.

Multiple applicator approaches for radiofrequency and microwave ablation

Treatment of tumours greater than 2 cm by radiofrequency (RF) or microwave ablation typically use multiple sequential applications, since most currently available ablation devices are limited to use of a single applicator at a time. A major focus of current ablation research is on methodologies that allow increasing the coagulation zone to more rapidly treat large tumours. The ability to use multiple applicators simultaneously would satisfy this need. It would significantly reduce treatment time and may lead to a reduction in local tumour progression, especially in perivascular locations. Several methods have been suggested that potentially allow simultaneous use of multiple applicators, both with radiofrequency (RF) and microwave (MW) ablation. This review compares the different methods of multiple applicator use, investigating advantages and disadvantages of each modality.

Thermal ablative therapy for malignant liver tumors: a critical appraisal

The management of primary and secondary malignant liver tumors poses a great challenge to clinicians. Although surgical resection is the gold-standard treatment, most patients have unresectable malignant liver tumors. Over the past decade, various modalities of loco-regional therapy have gained much interest. Among them, thermal ablative therapy, including cryotherapy, microwave coagulation, interstitial laser therapy, and radiofrequency ablation (RFA), have been proven to be safe and effective. Despite the effective tumor eradication achieved within cryotherapy, the underlying freeze/thaw mechanism has resulted in serious complications that include bleeding from liver cracking and the 'cryoshock' phenomenon. Thermal ablation using microwave and laser therapy for malignant liver tumors is curative and is associated with minimal complications. However, this treatment modality is effective only for tumors <3 cm diameter. Radiofrequency ablation seems to be the most promising form of thermal ablative therapy in terms of a lower complication rate and a larger volume of ablation. However, its use is restricted by the difficulty encountered when using imaging studies to monitor the areas of ablation during and after the procedure. Moreover, the techniques of RFA need to be refined in order to achieve the same oncological radicality of malignant liver tumors as achieved by surgical resection. As each of the loco-regional therapies has its own advantages and limitations, a multidisciplinary approach using a combination of therapies will be the future trend for the management of malignant liver tumors.

Hepatic microwave ablation with multiple antennae results in synergistically larger zones of coagulation necrosis

BACKGROUND

Microwave ablation is a promising treatment for unresectable liver tumors. Unlike radiofrequency ablation, microwave ablation may be performed with multiple simultaneously active antennae.

METHODS

Microwave ablation was performed in an in vivo porcine liver model by using a single antenna (n = 11) or three antennae in a triangular array, activated either sequentially (n = 11) or simultaneously (n = 13). Lesions were measured and assigned a qualitative shape score.

RESULTS

Single-antenna microwave lesions had a mean volume of 7.4 +/- 3.9 cm(3), compared with 14.6 +/- 5.2 cm(3) and 43.1 +/- 4.3 cm(3) for sequential and simultaneous multiple-probe ablations, respectively (P <.001; analysis of variance). Simultaneous lesions were rounder than sequential ablations and were more effective near blood vessels. Simultaneous lesions created with probe separation of < or =1.7 cm were round and confluent, whereas clefts were present with distances >1.7 cm (P <.001).

CONCLUSIONS

Microwave ablation has several theoretical advantages over currently available radiofrequency devices. Simultaneous three-probe microwave ablation lesions were three times larger than sequential lesions and nearly six times greater in volume than single-probe lesions. Additionally, simultaneous multiple-probe ablation results in qualitatively better lesions, with more uniform coagulation and better performance near blood vessels. Simultaneous multiple-probe ablation may decrease inadequate treatment of large tumors and decrease recurrence rates after tumor ablation.

Effects of intraaterial chemoembolization combined with percutaneous microwave coagulation on hepatocellular carcinoma: a clinical and experimental study

AIM: To evaluate the role of microwave coagulation for liver cancer after occlusion of hepatic artery in animal experiment and clinical study.

METHODS: Total 24 suitable hepatic lobes of ten dogs were separated into two groups. Microwave coagulation alone (control group) or after hepatic artery occlusion (experiment group) was performed respectively. The power of irradiation was 50 W and the duration was 300 and 400 seconds. Clinically, 25 patients with hepatocellular carcinoma (30 nodules) were treated with PMCT after TACE. The TACE was performed 1-3 times and PMCT 1-2 times totally in every patients.

RESULTS: In animal experiment, the coagulated area was elliptic in control group and was elliptic or round in experimental group. The volume of coagulated tissue in experimental group was 3.8 times bigger than that in control. Clinically, all the lesions in contrast-enhanced CT showed slight enhancement or no enhancement after treatment. Intratumoral blood flow decreased significantly in 6 patients and disappeared in 20 patients. In 19 patients with elevated a-fetoprotein, the level decreased in all patients and was normalized in 14. There were no significant side- effects.

CONCLUSION: PMCT after TACE can significantly enlarge the necrosis volume of microwave coagulation, and promote the efficacy of treatment for hepatocellular carcinoma.

Microwave coagulation therapy accelerates growth of cancer in rat liver

BACKGROUND/AIMS

Although microwave coagulation therapy (MCT) has been performed for liver cancer, there has been no report examining the influence of this therapy on the growth of possible remnant cancer.

METHODS

A solid cube of AH-130 cells (ascites hepatoma cell line) was implanted into the left lateral lobe of the rat liver. Five days later, MCT was applied to the middle liver lobe of these rats. Tumor growth and cytokine levels in plasma and the liver were compared between rats that underwent MCT and rats that did not.

RESULTS

The mean tumor weight in the MCT group (222.6+/-51.5 mg, mean+/-SD) was significantly greater than that in the control group (126.7+/-19.7 mg, P<0.01) at postoperative day (POD) 5. Immunohistochemistry for anti-proliferating cell nuclear antigen showed the labeling index in the MCT group (90.4%) to be higher than that in the control group (76.7%, P<0.01). Liver basic fibroblast growth factor and transforming growth factor-beta 1 levels in the MCT group on POD 3 were significantly higher than levels in the control group.

CONCLUSIONS

The present study suggests the clinically important finding that MCT accelerates the growth of small residual tumors in the liver.

Locoregional therapies for hepatocellular carcinoma: a critical review from the surgeon's perspective

OBJECTIVE

This article reviews the current results of various locoregional therapies for hepatocellular carcinoma (HCC), with special reference to the implications for surgeons.

SUMMARY BACKGROUND DATA

Resection or transplantation is the treatment of choice for HCC, but most patients are not suitable candidates. The past decade has witnessed the development of a variety of locoregional therapies for HCC. Surgeons are faced with the challenge of adopting these therapies in the management of patients with resectable or unresectable HCC.

METHODS

A review of relevant English-language articles was undertaken based on a Medline search from January 1990 to August 2001.

RESULTS

Retrospective studies suggested that transarterial chemoembolization is an effective treatment for inoperable HCC, but its perceived benefit for survival has not been substantiated in randomized trials, presumably because its antitumor effect is offset by its adverse effect on liver function. Nonetheless, it remains a widely used palliative treatment for HCC not amenable to resection or ablative therapies, and it also plays an important role as a treatment of postresection recurrence and as a pretransplant therapy for transplantable HCC. Better patient selection, selective segmental chemoembolization, and treatment repetition tailored to tumor response and patient tolerance may improve its benefit-risk ratio. Transarterial radiotherapy is a less available alternative that produces results similar to those of chemoembolization. Percutaneous ethanol injection has gained wide acceptance as a safe and effective treatment for HCCs 3 cm or smaller. Uncertainty in tumor necrosis limits its potential as a curative treatment, but its repeatability allows treatment of recurrence after ablation or resection of HCC that is crucial to prolongation of survival. Cryotherapy affords a better chance of cure because of predictable necrosis even for HCCs larger than 3 cm, but its use is limited by a high complication rate. There has been recent enthusiasm for heat ablation by microwave, radiofrequency, or laser, which provides predictable necrosis with a low complication rate. Preliminary data indicated that radiofrequency ablation is superior to ethanol injection in the radicality of tumor ablation. The advent of more versatile radiofrequency probes has allowed ablation of HCCs larger than 5 cm. Recent studies have suggested that combined transarterial embolization and heat ablation is a promising strategy for large HCCs. Thus far, no randomized trials comparing various thermoablative therapies have been reported. It is also uncertain whether a percutaneous route, laparoscopy, or open surgery affords the best approach for these therapies. Thermoablative therapies have been combined with resection or used to treat postresection recurrence, and they have also been used as a pretransplant therapy. However, the value of such strategies requires further evaluation.

CONCLUSIONS

Advances in locoregional therapies have led to a major breakthrough in the management of unresectable HCC, but the exact role of the various modalities needs to be defined by randomized studies. Novel thermoablative techniques provide the surgeon with an exciting opportunity to participate actively in the management of unresectable HCC. Locoregional therapies are also useful adjuncts in the management of patients with resectable or transplantable disease. Hence, surgeons must be equipped with the latest knowledge and techniques of ablative therapy to provide the most appropriate treatment for the wide spectrum of patients with HCC.