Radiological and pathological assessment of hepatocellular carcinoma response to radiofrequency. A study on removed liver after transplantation

Radiofrequency ablation versus trans-arterial chemoembolization in patients with HCC awaiting liver transplant: an analysis of the Scientific Registry of Transplant Recipients

PURPOSE

To evaluate differences in waitlist mortality/dropout for liver transplant candidates with hepatocellular carcinoma (HCC) who undergo radiofrequency ablation (RFA) versus trans-arterial chemoembolization (TACE).

MATERIAL AND METHODS

From 2004-2013, 11,824 patients in the Scientific Registry of Transplant Recipients (SRTR) with HCC who underwent RFA or TACE. Patients were followed until December 31, 2019 or 5 years, whichever came first and stratified by Milan criteria. Competing risk and Cox regression analyses to compare waitlist mortality/dropout were performed with adjusted hazard ratios (asHR, reference group RFA). Regression models were adjusted for age, race, sex, calculated Model for End Stage Liver Disease (cMELD) score, tumor size, and number.

RESULTS

There was no difference in waitlist mortality/dropout for patients outside Milan criteria (N = 1,226) between TACE (19.2%) compared to RFA (19.0%) (asHR 0.91; 95% CI 0.79-1.03). There was also no difference for patients inside Milan criteria (N = 10,598) in waitlist mortality/dropout (TACE 13.4% vs. RFA 12.9%) (asHR 1.29; 95% CI 0.79-2.09). Subgroup analysis within Milan criteria demonstrated no evidence of difference in TACE compared to RFA in patients with single tumor ≤3 cm (asHR 0.92; 95% CI 0.77-1.10), single tumor > 3 cm (asHR 1.03; 95% CI 0.79-1.34), or with > 1 tumor (asHR 0.89; 95% CI 0.72-1.09).

CONCLUSION

Using national registry data, no difference was found in waitlist mortality/dropout for transplant candidates with HCC who received TACE vs. RFA.

Locoregional Treatments for Bridging and Downstaging HCC to Liver Transplantation

Liver transplantation (LT) is the first-line treatment for patients diagnosed with unresectable early-stage hepatocellular carcinoma (HCC) in the setting of cirrhosis. It is well known that HCC patients within the Milan criteria (solitary tumour ≤ 5 cm or ≤3 tumours, each <3 cm) could undergo LT with excellent results. However, there is a growing tendency to enlarge inclusion criteria since the Milan criteria are nowadays considered too restrictive and may exclude patients who would benefit from LT. On the other hand, there is a persistent shortage of donor organs. In this scenario, there is consensus about the role of loco-regional therapy (LRT) during the waiting list to select patients who would benefit more from LT, reducing the risk of drop off from the waiting list as well as decreasing tumour dimension to meet acceptable criteria for LT. In this review, current evidence on the safety, efficacy and utility of LRTs as neoadjuvant therapies before LT are summarized.

Histological Correlation for Radiofrequency and Microwave Ablation in the Local Control of Hepatocellular Carcinoma (HCC) before Liver Transplantation: A Comprehensive Review

Simple Summary

Liver cancer is a growing problem around the world. Drugs for liver cancer have limited effect, there are not enough donors for liver transplants and many patients are not candidates for surgery to remove the tumor. In many of these cases, hyperthermia can destroy the tumor in situ with minimally invasive methods such as radiofrequency or microwave ablation. In this paper we review the literature evaluating success rates for complete ablation as judged by actual examination of treated tumors that were removed when patients received a liver transplant. While notable successes can be achieved with ablation, the published studies indicate both that complete treatment is not as common as thought and that imaging methods such as computed tomography and magnetic resonance scans do not completely identify residual cancer. There is therefore an important opportunity for improvement in the treatment of this disease.

Abstract

Radiofrequency ablation (RFA) and microwave ablation (MWA) are the most widely studied and applied ablation techniques for treating primary and secondary liver tumors. These techniques are considered curative for small hepatic tumors, with post-ablation outcomes most commonly assessed by an imaging follow up. However, there is increasing evidence of a discrepancy between radiological and pathological findings when ablated lesions are evaluated following liver resection or liver transplantation. A comprehensive review of the available literature reporting the complete pathological response (cPR) following RFA and MWA was performed to estimate the success rate and identify the factors associated with treatment failure. Following RFA, cPR is reported in 26–96% of tumors compared to 57–95% with MWA. Larger tumor size and vessels larger than 3 mm adjacent to the treated tumor are the most important factors identified by previous studies associated with viable residual tumors after RFA. Correlating post-ablation radiological studies with pathological findings shows that computed tomography (CT) and magnetic resonance imaging (MRI) have low sensitivity but high specificity for detecting residual viable or recurrent hepatocellular carcinoma (HCC) tumors. There are promising recent reports combining multiprobe ablation techniques with three-dimensional treatment planning software and stereotactic-aiming instrumentation to achieve more than 90% cPR in both small and large HCC tumors. In conclusion, the reported success for achieving cPR in HCC following RFA and MWA is highly variable in different studies and decreases with increasing lesion size and unfavorable tumor characteristics. Very few studies have reported a high rate of cPR. As these studies are single-center and retrospective, they need to be further validated and reproduced in other clinical settings.

Stereotactic Radiofrequency Ablation of Hepatocellular Carcinoma: a Histopathological Study in Explanted Livers

This retrospective study was performed to evaluate the efficacy of three-dimensional (3D)-navigated multiprobe radiofrequency ablation (RFA) with intraprocedural image fusion for treatment of hepatocellular carcinoma (HCC) by histopathological examination. From 2009 to 2018, 97 patients (84 men, 13 women; median age, 60 years; range, 1-71) were transplanted after bridging therapy of 195 HCCs by stereotactic RFA (SRFA). The median interval between the first SRFA and transplantation was 6.8 months (range, 0-71). The rate of residual vital tissue (RVT) could be assessed in 188 of 195 lesions in 96 of 97 patients by histological examination of the explanted livers using hematoxylin and eosin (H&E) and Tdt-mediated UTP nick-end labeling (TUNEL) stains. Histopathological results were compared with the findings of the last computed tomography (CT) imaging before liver transplantation (LT). Median number and size of treated tumors were 1 (range, 1-8) and 2.5 cm (range, 1-8). Complete radiological response was achieved in 186 of 188 nodules (98.9%) and 94 of 96 patients (97.9%) and complete pathological response in the explanted liver specimen in 183 of 188 nodules (97.3%) and 91 of 96 patients (94.8%), respectively. In lesions ≥3 cm, complete tumor cell death was achieved in 50 of 52 nodules (96.2%). Residual tumor did not correlate with tumor size (P = 0.5). Conclusion: Multiprobe SRFA with intraprocedural image fusion represents an efficient, minimally invasive therapy for HCC, even with tumor sizes larger than 3 cm, and without the need of a combination with additional treatments. The results seem to justify the additional efforts related to the stereotactic approach.

Evaluation of the treatment of the hepatocarcinoma nodules in the patients in waiting list for liver transplant

OBJECTIVE

to compare the outcome of liver transplantation for hepatocarcinoma in submitted or not to locoregional treatment and downstaging regarding survival and risk of recurrence in transplant waiting list patients.

METHODS

retrospective study of patients with hepatocarcinoma undergoing liver transplantation in the metropolitan region of São Paulo, between January 2007 and December 2011, from a deceased donor. The sample consisted of 414 patients. Of these, 29 patients were included in the list by downstaging. The other 385 were submitted or not to locoregional treatment.

RESULTS

the analysis of 414 medical records showed a predominance of male patients (79.5%) with average age of 56 years. Treatment of the lesions was performed in 56.4% of patients on the waiting list for transplant. The most commonly used method was chemoembolization (79%). The locoregional patients undergoing treatment had a significant reduction in nodule size greater (p<0.001). There was no statistical difference between groups with and without locoregional treatment (p=0.744) and on mortality among patients enrolled in the Milan criteria or downstaging (p=0.494).

CONCLUSION

there was no difference in survival and recurrence rate associated with locoregional treatment. Patients included by downstaging process had comparable survival results to those previously classified as Milan/Brazil criteria.

Treatment Options in Patients Awaiting Liver Transplantation with Hepatocellular Carcinoma and Cholangiocarcinoma

Liver transplantation (LT) provides a good chance of cure for selected patients with hepatocellular carcinoma (HCC) and perihilar cholangiocarcinoma (pCCA). Patients with HCC on a waiting list for LT are at risk for tumor progression and dropout. Treatment of HCC with locoregional therapies may lessen dropout due to tumor progression. Strict selection and adherence to the LT criteria for patients with pCCA before and after neoadjuvant chemotherapy are critical for optimal outcome with LT. This article reviews the existing data for the various treatment strategies used for patients with HCC and pCCA awaiting LT.

When to consider liver transplantation in hepatocellular carcinoma patients?

Orthotopic liver transplantation (LT) has been regarded as the best cure among the three curative treatment modalities. However, when to consider LT in hepatocellular carcinoma (HCC) patients remains a complicated clinical question. In this article, we will look into the recent updates in the context of LT for HCC, including the timing of orthotopic LT (primary or salvage LT), patient selection criteria, newer prognostic markers and scoring systems, down-staging and bridging therapy, salvage LT and treatment option of post-LT HCC recurrence. Evolution of immunosuppressive therapy and future development of the LT for HCC will also be discussed.

Local ablative treatments for hepatocellular carcinoma: An updated review

Ablative treatments currently represent the first-line option for the treatment of early stage unresectable hepatocellular carcinoma (HCC). Furthermore, they are effective as bridging/downstaging therapies before orthotopic liver transplantation. Contraindications based on size, number, and location of nodules are quite variable in literature and strictly dependent on local expertise. Among ablative therapies, radiofrequency ablation (RFA) has gained a pivotal role due to its efficacy, with a reported 5-year survival rate of 40%-70%, and safety. Although survival outcomes are similar to percutaneous ethanol injection, the lower local recurrence rate stands for a wider application of RFA in hepato-oncology. Moreover, RFA seems to be even more cost-effective than liver resection for very early HCC (single nodule ≤ 2 cm) and in the presence of two or three nodules ≤ 3 cm. There is increasing evidence that combining RFA to transarterial chemoembolization may increase the therapeutic benefit in larger HCCs without increasing the major complication rate, but more robust prospective data is still needed to validate these pivotal findings. Among other thermal treatments, microwave ablation (MWA) uses high frequency electromagnetic energy to induce tissue death via coagulation necrosis. In comparison to RFA, MWA has several theoretical advantages such as a broader zone of active heating, higher temperatures within the targeted area in a shorter treatment time and the lack of heat-sink effect. The safety concerns raised on the risks of this procedure, due to the broader and less predictable necrosis areas, have been recently overcome. However, whether MWA ability to generate a larger ablation zone will translate into a survival gain remains unknown. Other treatments, such as high-intensity focused ultrasound ablation, laser ablation, and cryoablation, are less investigated but showed promising results in early HCC patients and could be a valuable therapeutic option in the next future.

Hepatocellular Carcinoma within Milan Criteria: No-Touch Multibipolar Radiofrequency Ablation for Treatment-Long-term Results

Purpose To assess the long-term outcome in 108 consecutive patients treated with no-touch multibipolar radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) that met the Milan criteria. Materials and Methods This retrospective study was approved by the ethical review board, and the need to obtain informed consent was waived. Between November 1, 2006, and December 31, 2011, 132 HCC tumors (diameter, 10-45 mm; 39 tumors ≥ 30 mm) in 108 consecutive patients (106 with cirrhosis) that met Milan criteria were treated with no-touch multibipolar RFA, which consisted of activating, in bipolar mode, three or four electrodes inserted just beyond the tumor margins. Follow-up was performed every 3 months for 2 years and every 6 months thereafter with computed tomographic or magnetic resonance imaging. Survival probabilities were computed by using the Kaplan-Meier method. Predictive factors of tumor progression and overall survival were assessed by using the Cox proportional hazard model. Results No technical failure occurred, and complete ablation was achieved for all the nodules. After a median of 40.5 months (range, 2-84 months) of follow-up, 3- and 5-year local and overall tumor progression-free survival were 96%, 94%, 52%, and 32%, respectively. Neither tumor diameter greater than 30 mm nor location abutting a large vessel were associated with local tumor progression. Tumor diameter greater than 30 mm was the only parameter predictive of overall tumor progression (P = .0036). Independent factors associated with shorter overall survival were Child-Pugh class B disease, age greater than 65 years, and platelet count of less than 150 g/L (P < .003). Three major complications occurred (2.7%): hemothorax in one patient and liver failure in two, with major portal-systemic shunts. One patient (0.9%) died, and one underwent transplantation. Conclusion No-touch multibipolar RFA for HCC tumors that meet Milan criteria provides a high local tumor progression-free survival rate. An ongoing randomized trial might help to clarify the role of this new approach for the treatment of early HCC. (©) RSNA, 2016 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on March 30, 2016.

Comparison of outcomes between SBRT, yttrium-90 radioembolization, transarterial chemoembolization, and radiofrequency ablation as bridge to transplant for hepatocellular carcinoma

PURPOSE

To evaluate and compare outcome of stereotactic body radiation therapy (SBRT), yttrium-90 radioembolization, radiofrequency ablation (RFA), or transarterial chemoembolization (TACE) as bridge to liver transplant (LT) in patients with hepatocellular carcinoma.

METHODS AND MATERIALS

We retrospectively reviewed patients treated at our institution with SBRT, TACE, RFA, or yttrium-90 as bridge to LT between 2006 and 2013. We analyzed radiologic and pathologic response and rate of failure after bridge therapy. Toxicities were reported using Common Terminology Criteria for Adverse Events, 4.0. Kaplan-Meier method was used to calculate disease-free survival (DFS) and overall survival after LT.

RESULTS

Sixty patients with a median age 57.5 years (range, 44-70) met inclusion criteria. Thirty-one patients (50.7%) had hepatitis C cirrhosis, 14 (23%) alcoholic cirrhosis, and 8 (13%) nonalcoholic steatohepatitis cirrhosis. Patients received a total of 79 bridge therapies: SBRT (n = 24), TACE (n = 37), RFA (n = 9), and Y90 (n = 9). Complete response (CR) was 25% for TACE, 8.6% for SBRT, 22% for RFA, and 33% for Y90. Grade 3 or 4 acute toxicity occurred following TACE (n = 4) and RFA (n = 2). Transplant occurred at a median of 7.4 months after bridge therapy. Pathological response among 57 patients was 100% necrosis (n = 23, 40%), >50% necrosis (n = 20, 35%), <50% necrosis (n = 9, 16%), and no necrosis (n = 5, 9%). Pathologic complete response was as follows: SBRT (28.5%), TACE (41%), RFA (60%), Y90 (75%), and multiple modalities (33%). At a median follow-up of 35 months, 7 patients had recurrence after LT. DFS was 85.8% and overall survival was 79% at 5 years.

CONCLUSION

All bridge therapies demonstrated good pathological response and DFS after LT. SBRT and Y90 demonstrated significantly less grade ≥3 acute toxicity. Choice of optimal modality depends on tumor size, pretreatment bilirubin level, Child-Pugh status, and patient preference. Such a decision is best made at a multidisciplinary tumor board as is done at our institution.

Surgical results for recurrent hepatocellular carcinoma after curative hepatectomy: Repeat hepatectomy versus salvage living donor liver transplantation

The aims of this study were to evaluate the efficacy of repeat hepatectomy (Hx) and salvage living donor liver transplantation (LDLT) for recurrent hepatocellular carcinoma (HCC). A retrospective cohort study was performed to analyze the surgical results of repeat Hx and salvage LDLT for patients with recurrent HCC within the Milan criteria from 1989 to 2012. A total of 159 patients were divided into 2 groups: a repeat Hx group (n = 146) and a salvage LDLT group (n = 13). Operative results and patient prognoses were compared between the 2 groups. The operative invasiveness, including the operation time (229.1 ± 97.7 versus 862.9 ± 194.4 minutes; P < 0.0001) and blood loss (596.3 ± 764.9 versus 24,690 ± 59,014.4 g; P < 0.0001), were significantly higher in the salvage LDLT group. The early surgical results, such as morbidity (31% versus 62%; P = 0.0111) and the duration of hospital stay (20 ± 22 versus 35 ± 21 days; P = 0.0180), were significantly worse in the salvage LDLT group. There was no significant difference in the overall survival (OS) rate, but the disease-free survival rate of the salvage LDLT group was significantly better (P = 0.0002). The OS rate of patients with grade B liver damage in the repeat Hx group was significantly worse (P < 0.0001), and the 5-year OS rate was quite low, that is, 20% (liver damage A, 77% for the repeat Hx group and 75% for the salvage LDLT group). The prognosis of patients with grade B liver damage after repeat Hx for recurrent HCC is poor, and salvage LDLT would be a potent option for such patients.

Histopathologic comparison of monopolar versus no-touch multipolar radiofrequency ablation to treat hepatocellular carcinoma within Milan criteria

PURPOSE

To compare histopathologically the completeness of radiofrequency (RF) ablation to treat hepatocellular carcinoma (HCC) with monopolar or multipolar technique.

MATERIALS AND METHODS

Thirty-five consecutive patients (mean age, 59 y) with cirrhosis and HCC (n = 59) within Milan criteria received RF ablation and subsequently underwent liver transplantation (LT) for tumor progression or liver failure. Data were extracted retrospectively from a prospective database. Thirty nodules were treated with a monopolar device with internally cooled (n = 17) or perfused (n = 13) electrodes, and 29 were treated with a multipolar technique with internally cooled electrodes based on the "no-touch" concept. This consisted of inserting two or three straight electrodes around the nodule to avoid intratumor puncture to the greatest extent possible. Effectiveness of the three devices was compared by histopathologic examination of explants. Fisher exact and χ(2) tests and multivariate logistic regression analysis were performed.

RESULTS

Mean sizes of nodules ablated (25, 22, and 21.6 mm) and median times from ablation to LT (11, 7.5, and 8.4 months) for patients treated with the monopolar internally cooled electrode device (MoICD), monopolar perfused electrode device (MoPED), and multipolar internally cooled electrode device (MuICD), respectively, were similar (P = .8 and P = .9, respectively). Pathologic examination showed complete necrosis for eight of 17 and six of 13 nodules treated with the MoICD and MoPED, respectively, versus 26 of 29 treated with the MuICD (P = .0019). In multivariate analysis, RF technique remained the predictive factor for complete necrosis (P = .005).

CONCLUSIONS

Ablation of small HCCs with multipolar RF ablation based on the no-touch concept improves the rate of complete necrosis during pathologic examination compared with monopolar techniques.

Bridging and downstaging treatments for hepatocellular carcinoma in patients on the waiting list for liver transplantation

Several therapeutic procedures have been proposed as bridging treatments for patients with hepatocellular carcinoma (HCC) awaiting liver transplantation (LT). The most used treatments include transarterial chemoembolization and radiofrequency ablation. Surgical resection has also been successfully used as a bridging procedure, and LT should be considered a rescue treatment in patients with previous HCC resection who experience tumor recurrence or post-treatment severe decompensation of liver function. The aims of bridging treatments include decreasing the waiting list dropout rate before transplantation, reducing HCC recurrence after transplantation, and improving post-transplant overall survival. To date, no data from prospective randomized studies are available; however, for HCC patients listed for LT within the Milan criteria, prolonging the waiting time over 6-12 mo is a risk factor for tumor spread. Bridging treatments are useful in containing tumor progression and decreasing dropout. Furthermore, the response to pre-LT treatments may represent a surrogate marker of tumor biological aggressiveness and could therefore be evaluated to prioritize HCC candidates for LT. Lastly, although a definitive conclusion can not be reached, the experiences reported to date suggest a positive impact of these treatments on both tumor recurrence and post-transplant patient survival. Advanced HCC may be downstaged to achieve and maintain the current conventional criteria for inclusion in the waiting list for LT. Recent studies have demonstrated that successfully downstaged patients can achieve a 5-year survival rate comparable to that of patients meeting the conventional criteria without requiring downstaging.

Third or more repeat hepatectomy for recurrent hepatocellular carcinoma

BACKGROUND

We sought to evaluate the surgical results of third or more repeat hepatectomy for recurrent hepatocellular carcinoma (HCC). The role of repeat hepatectomy for recurrent HCC, especially in cases with third or more repeat hepatectomy, is controversial.

METHODS

We performed A retrospective, cohort study to analyze the surgical results of repeat hepatectomy performed at a single medical center from 1989 to 2011. A total of 1,000 hepatectomies for HCC were divided into 3 groups: A first hepatectomy group (n = 791), second hepatectomy group (n = 163), and third or more hepatectomy group (n = 46). Operative results and patient prognoses were compared among the 3 groups.

RESULTS

There were no differences in early surgical results such as mortality and morbidity among the 3 groups. The 5-year survival rates after the first, second, and third or more hepatectomy were 67%, 60%, and 43%, respectively (P = .1913). There was a significant difference in disease-free survival among the 3 groups, and the 5-year disease-free survival rates after first, second, and third or more hepatectomy were 37%, 29%, and 18%, respectively (P = .0169).

CONCLUSION

Third or more repeat hepatectomy for recurrent HCC was performed safely and associated with relatively long-term survival. Third or more repeat hepatectomy for recurrent HCC seems justified, but high rate of HCC recurrence remains a problem.

Radiology estimates of viable tumor percentage in hepatocellular carcinoma ablation cavities correlate poorly with pathology assessment

CONTEXT

No study has evaluated radiology/pathology correlation of percentage viable tumor (PVT) estimates in ablated hepatocellular carcinoma (HCC) to examine the reliability of radiologic estimates.

OBJECTIVE

To determine how well interdisciplinary PVT estimates correlate and identify pathologic factors that influence this correlation.

DESIGN

Pathologists and radiologists established blinded PVT estimates in 22 HCC ablation cavities. Paired sample t tests examined the differences between the interdisciplinary estimates.

RESULTS

Fifteen cavities had pathologic viable tumor (VT) (68%) and 6 had radiographic VT (22%). Radiology's sensitivity for detecting VT was 40% and the specificity was 100%. Pathology detected significantly more VT than radiology (pathology mean = 22.3% versus radiology mean = 2.6%; P = .005). Five cavities had tumor growth in a discontinuous rim pattern, 7 in a nodular pattern, and 3 in a solid pattern. Radiology did not detect VT in cavities with a discontinuous rim pattern (sensitivity = 0%) but did detect VT in 3 cavities with a nodular pattern (sensitivity = 43%), and in all cavities with a solid pattern (sensitivity = 100%). There was no significant difference in PVT estimates in cavities 3.5 cm or larger (P = .07), but there was a significant difference in cavities smaller than 3.5 cm (P = .01).

CONCLUSION

This study clarifies that the risk of underestimation by imaging is greatest in small lesions (<3.5 cm), though the sensitivity of detection depends primarily on the tumor growth pattern within the cavity. This underestimation raises the question of whether basing treatment decisions on a radiologic impression of complete ablation is valid.

Radiofrequency ablation of liver tumors: Actual limitations and potential solutions in the future

Over the past decade, radiofrequency ablation (RFA) has evolved into an important therapeutical tool for the treatment of non resectable primary and secondary liver tumors. The clinical benefit of RFA is represented in several clinical studies. They underline the safety and feasibility of this new and modern concept in treating liver tumors. RFA has proven its clinical impact not only in hepatocellular carcinoma (HCC) but also in metastatic disease such as colorectal cancer (CRC). Due to the increasing number of HCC and CRC, RFA might play an even more important role in the future. Therefore, the refinement of RFA technology is as important as the evaluation of data of prospective randomized trials that will help define guidelines for good clinical practice in RFA application in the future. The combination of hepatic resection and RFA extends the feasibility of open surgical procedures in patients with extensive tumors. Adverse effects of RFA such as biliary tract damage, liver failure and local recurrence remain an important task today but overall the long term results of RFA application in treating liver tumors are promising. Incomplete ablation of liver tumors due to insufficient technology of ablation needles, tissue cooling by the neighbouring blood vessels, large tumor masses and ablation of tumors in close vicinity to heat sensitive organs remain difficult tasks for RFA. Future solutions to overcome these limitations of RFA will include refinement of ultrasonographic guidance (accuracy of probe placement), improvements in needle technology (e.g. needles preventing charring) and intraductal cooling techniques.

Pathomorphological changes after radiofrequency ablation in the liver

Radiofrequency ablation (RFA) has become a widespread treatment option for liver carcinoma. There is limited knowledge regarding the macroscopic and histomorphological changes of induced lesions. Twelve domestic pigs underwent RFA using a Starburst XL device with ablation diameter of 3 cm. One animal died within 24 h, two animals were killed after 2 weeks, and nine after 4 weeks. Their livers were used for macroscopic and histological investigation. Six human liver resection specimens after previous treatment with RFA were also investigated. In pig samples, acute RFA change showed a necrosis zone demarcated by resorption zone with granulocytes and hyperemia. In subchronic and chronic RFA change, the zone of thermofixation was followed by a fibrous capsule and a liver reaction zone. Small blood vessels in the lesions showed damage involving endothelial destruction and thrombosis. Larger vessels within the lesions were observed with intact vessel walls, surrounded by a rim of vital hepatocytes. In the human samples, tumor-infiltrating lymphocytes were reduced (CD3+ cells: 8.4 +/- 3.7/10 high-power fields (HPF); CD4+ cells: 4.2 +/- 1.9/10 HPF), whereas the number of histiocytes was found to be increased (CD68+ cells: 15.5 +/- 9.02/10 HPF). The recognition of thermofixation and the process of resorption of the RFA lesion is important for the interpretation of biopsies and surgical resection specimens.

Trends in the utilization and impact of radiofrequency ablation for hepatocellular carcinoma

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) is rising and radiofrequency ablation (RFA) appears to be increasingly used. The nationwide use and impact of RFA have not been well characterized.

STUDY DESIGN

We performed an historical cohort study of US patients 18 years old and older, with a diagnosis of HCC (n = 22,103) using the national Surveillance, Epidemiology, and End Results (SEER) limited-use database (1998 to 2005). Main outcomes measures were receipt of different therapeutic interventions (ablation, RFA, resection, or transplantation) and adjusted 1- and 2-year survivals.

RESULTS

A total of 4,924 (22%) patients underwent any intervention, with a 93% increase over the 8-year study period (trend test, p < 0.001). RFA accounted for 43% of this increase. Despite increased use of therapeutic interventions, 1- and 2-year survival rates did not improve over time for patients in the study cohort (48% and 34%, 52% and 37%, 50% and 36%; in 1998, 2002, and 2004, respectively; p = 0.31). Among patients with solitary lesions, adjusted 1- and 2-year survivals remained stable over time after transplantation (97% and 94%, 95% and 89%, 94% and 86% in 1998, 2002, and 2004, respectively; p = 0.99) and RFA (86% and 64%, 76% and 54%, in 2002 and 2004, respectively; p = 0.97), but improved after resection (83% and 71%, 91% and 84%, 97% and 94% in 1998, 2002, and 2004, respectively; p = 0.03).

CONCLUSIONS

Use of interventions for the treatment of HCC, and specifically RFA, have markedly increased over time. Because increased use of RFA among patients with potentially resectable disease is likely to occur, and because of a lack of high-level evidence supporting expanded indications, continued evaluation of the indications for RFA and subsequent outcomes among US patients is warranted.

Liver tumor ablation: percutaneous and open approaches

The global incidence of liver cancer is greater than a million cases a year. Surgical resection where applicable is still the standard of care for these patients. Various liver-directed regional therapies have been developed in an effort to treat the vast majority of unresectable liver tumors. This article reviews the principles behind various ablation therapies currently available for malignant liver tumors and their outcomes.

Second and third hepatectomies for recurrent hepatocellular carcinoma are justified

BACKGROUND

Liver resection is the main curative treatment for hepatocellular carcinoma (HCC), but recurrence rates are high. The remnant liver is the most common site of recurrence, but the role of repeat hepatectomy in the treatment of recurrent HCC is controversial.

METHODS

Patients who underwent curative hepatectomy for HCC and subsequent repeat hepatectomy for recurrent HCC between 1990 and 2007 were reviewed retrospectively. Clinicopathological characteristics, and early- and long-term outcomes of patients who had a first, second, third and fourth hepatectomy were compared.

RESULTS

Some 1177 patients underwent a first hepatectomy for HCC, and 149, 35 and eight patients respectively had a second, third and fourth hepatectomies for recurrence. There were no significant differences in early postoperative outcomes after first and repeat hepatectomies. Five-year disease-free and overall survival rates after first, second and third hepatectomies were 43.6, 31.8 and 33.8 per cent (P = 0.772), and 52.4, 56.4 and 59.4 per cent (P = 0.879), respectively. Patients undergoing second and third hepatectomies for recurrence had better survival rates than those who did not have a repeat hepatectomy, but not those after fourth hepatectomy.

CONCLUSION

Second and third hepatectomies seem justified for hepatic recurrence of HCC. The role of fourth hepatectomy needs further investigation.

Percutaneous laser ablation of hepatocellular carcinoma in patients with liver cirrhosis awaiting liver transplantation

OBJECTIVE

The aim of this study was to determine the effectiveness and safety of percutaneous laser ablation for the treatment of cirrhotic patients with hepatocellular carcinoma awaiting liver transplantation.

MATERIALS AND METHODS

The data of 9 male cirrhotic patients (mean age 50 years, range 45-60 years) with 12 biopsy proven nodules of hepatocellular carcinoma (mean diameter 2.0 cm, range 1.0-3.0 cm) treated by laser ablation before liver transplantation between June 2000 and January 2006 were retrospectively reviewed. Laser ablation was carried out by inserting 300 nm optical fibers through 21-Gauge needles (from two to four) positioned under ultrasound guidance into the target lesions. A continuous wave Neodymium:Yttrium Aluminium Garnet laser was used. Transarterial chemoembolization prior to liver transplantation was performed in two incompletely ablated tumors.

RESULTS

No procedure-related major complications were recorded. During the waiting time to liver transplantation local tumor progression after ablation occurred in 3 nodules (25%). At histological examination of the explanted livers complete necrosis was found in 8 nodules (66.7%, all treated exclusively with laser ablation), partial necrosis >50% in 3 nodules (25%), and partial necrosis <50% in 1 nodule.

CONCLUSION

In patients with cirrhotic livers awaiting liver transplantation, percutaneous laser ablation is safe and effective for the management of small hepatocellular carcinoma.

Is radiofrequency ablation the treatment of choice for patients with small hepatocellular carcinoma?

Liver resection is widely considered the mainstay of curative therapy for small hepatocellular carcinoma (HCC). Radiofrequency ablation (RFA) was initially developed as a treatment for small HCC in patients with considerable cirrhosis and inadequate liver function reserve for liver resection. However, in some centers, RFA is now used for small HCC, as an alternative to liver resection or even as the preferred treatment. This Practice Point commentary discusses the findings and limitations of a retrospective cohort study by Livraghi et al. that analyzed the outcomes of a group of patients with small, single HCC who underwent treatment with RFA. The authors reported a low major complication rate and a local complete response rate similar to that after resection. This commentary highlights the issues to consider when interpreting and generalizing these results, in particular that these findings need to be interpreted in the light of studies that suggest a high rate of local recurrence and incomplete histopathological response after RFA of small HCC.