Interstitial laser photocoagulation under ultrasound guidance of liver tumors: results in 104 treated patients

The latest research progress on minimally invasive treatments for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide. Due to the high prevalence of hepatitis B virus (HBV) infection in China, the incidence of HCC in China is high, and liver cirrhosis caused by chronic hepatitis also brings great challenges to treatment. This paper reviewed the latest research progress on minimally invasive treatments for HCC, including percutaneous thermal ablation and new nonthermal ablation techniques, and introduced the principles, advantages, and clinical applications of various therapeutic methods in detail.

DATA SOURCES

The data of treatments for HCC were systematically collected from the PubMed, ScienceDirect, American Chemical Society and Web of Science databases published in English, using "minimally invasive" and "hepatocellular carcinoma" or "liver cancer" as the keywords.

RESULTS

Percutaneous thermal ablation is still a first-line strategy for the minimally invasive treatment of HCC. The effect of microwave ablation (MWA) on downgrading treatment before liver transplantation is better than that of radiofrequency ablation (RFA), while RFA is more widely used in the clinical practice. High-intensity focused ultrasound (HIFU) is mainly used for the palliative treatment of advanced liver cancer. Electrochemotherapy (ECT) delivers chemotherapeutic drugs to the target cells while reducing the blood supply around HCC. Irreversible electroporation (IRE) uses a microsecond-pulsed electric field that induces apoptosis and necrosis and triggers a systemic immune response. The nanosecond pulsed electric field (nsPEF) has achieved a good response in the ablation of mice with HCC, but it has not been reported in China for the treatment of human HCC.

CONCLUSIONS

A variety of minimally invasive treatments provide a sufficient survival advantage for HCC patients. Nonthermal ablation will lead to a new wave with its unique advantage of antitumor recurrence and metastasis.

Update on Percutaneous Local Ablative Procedures for the Treatment of Hepatocellular Carcinoma

BACKGROUND

 Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide. Because many hepatocellular carcinomas are already unresectable at the time of initial diagnosis, percutaneous tumor ablation has become established in recent decades as a curative therapeutic approach for very early (BCLC 0) and early (BCLC A) HCC. The aim of this paper is to provide a concise overview of the percutaneous local ablative procedures currently in use, based on their technical characteristics as well as clinical relevance, taking into account the current body of studies.

MATERIALS AND METHODS

 The literature search included all original papers, reviews, and meta-analyses available via MEDLINE and Pubmed on the respective percutaneous ablation procedures; the primary focus was on randomized controlled trials and publications from the last 10 years.

RESULTS AND CONCLUSIONS

 Radiofrequency ablation (RFA) and microwave ablation (MWA) are well-established procedures that are considered equal to surgical resection in the treatment of stage BCLC 0 and A HCC with a diameter up to 3 cm due to their strong evidence in international and national guidelines. For tumors with a diameter between 3 and 5 cm, the current S3 guidelines recommend a combination of transarterial chemoembolization (TACE) and thermal ablation using RFA or MWA as combination therapy is superior to thermal ablation alone in tumors of this size and shows comparable results to surgical resection in terms of overall survival. Alternative, less frequently employed thermal procedures include cryotherapy (CT) and laser ablation (LA). Non-thermal procedures include irreversible electroporation (IRE), interstitial brachytherapy (IBT), and most recently, electrochemotherapy (ECT). Due to insufficient evidence, these have only been used in individual cases and within the framework of studies. However, the nonthermal methods are a reasonable alternative for ablation of tumors adjacent to large blood vessels and bile ducts because they cause significantly less damage to these structures than thermal ablation methods. With advances in the technology of the respective procedures, increasingly good evidence, and advancements in supportive techniques such as navigation devices and fusion imaging, percutaneous ablation procedures may expand their indications for the treatment of larger and more advanced tumors in the coming years.

KEY POINTS

· RFA and MWA are considered equal to surgical resection as a first-line therapy for the curative treatment of stage BCLC 0 and A HCCs with a diameter of up to 3 cm.. · For HCCs with a diameter between 3 and 5 cm, a combination of TACE and RFA or MWA is recommended. This combination therapy yields results comparable to those of surgical resection in terms of overall survival.. · Due to insufficient evidence, alternative ablation methods have only been used in individual cases and within the framework of studies. However, nonthermal methods, such as IRE, IBT, and, most recently, ECT, are a reasonable alternative for ablation of HCCs adjacent to large blood vessels and bile ducts because they cause significantly less damage to these structures than thermal ablation methods..

CITATION FORMAT

· Luerken L, Haimerl M, Doppler M et al. Update on Percutaneous Local Ablative Procedures for the Treatment of Hepatocellular Carcinoma. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1768-0954.

Prediction of In Vivo Laser-Induced Thermal Damage with Hyperspectral Imaging Using Deep Learning

Thermal ablation is an acceptable alternative treatment for primary liver cancer, of which laser ablation (LA) is one of the least invasive approaches, especially for tumors in high-risk locations. Precise control of the LA effect is required to safely destroy the tumor. Although temperature imaging techniques provide an indirect measurement of the thermal damage, a degree of uncertainty remains about the treatment effect. Optical techniques are currently emerging as tools to directly assess tissue thermal damage. Among them, hyperspectral imaging (HSI) has shown promising results in image-guided surgery and in the thermal ablation field. The highly informative data provided by HSI, associated with deep learning, enable the implementation of non-invasive prediction models to be used intraoperatively. Here we show a novel paradigm “peak temperature prediction model” (PTPM), convolutional neural network (CNN)-based, trained with HSI and infrared imaging to predict LA-induced damage in the liver. The PTPM demonstrated an optimal agreement with tissue damage classification providing a consistent threshold (50.6 ± 1.5 °C) for the damage margins with high accuracy (~0.90). The high correlation with the histology score (r = 0.9085) and the comparison with the measured peak temperature confirmed that PTPM preserves temperature information accordingly with the histopathological assessment.

US-guided laser treatment of parathyroid adenomas

Objective: To determine the clinical efficacy of laser ablation for the tredatment of primary hyperparathyroidism (pHPT).Materials and methods: Twelve patients with pHPT were treated with laser ablation. Energy was administered by means of 1.5 m optical fibers percutaneously placed into the target via 21 G needles. A laser ablation unit (EchoLaser X4, Esaote) applied 3 W power for 400-600 s/fiber/insertion to a total 3600-9000 Joules of energy. Patient serum parathyroid hormone (PTH) and calcium levels were checked at baseline and thereafter every 6 months. Patients were followed-up for 2 years with serologic and contrast-enhanced ultrasound. Therapeutic success was defined as normal PTH and calcium levels together with disappearance of nodule-related symptoms.Results: All procedures were performed in single session. Immediately following ablation, contrast enhanced ultrasound confirmed that all but one target had become avascular (technical success rate 11/12; 92%), remaining avascular at all follow-up ultrasound examinations, thereafter. The mean volume of parathyroid nodules decreased from 0.54 cc to 0.36 cc (72.0%). Serum PTH and calcium levels were significantly lower at 1, 12 and 24 m compared to baseline (p < 0.01). By 6 m, PTH and calcium returned to normal and were stable until 24 m in all successfully treated patients. All cases of hyperparathyroid-related symptoms resolved by 6 m (ostealgia [n = 5], repeated renal colic [n = 5], vomiting [n = 3]). Only one patient (8%) reported transient dysphonia as a minor complication.Conclusion: Laser ablation of enlarged, symptomatic parathyroid glands is safe and well-tolerated and can produce long-term, sustained reduction of serum PTH and calcium levels.

Safety and Local Efficacy of Laser Ablation for the Extrahepatic Metastasis of Hepatocellular Carcinoma: An Available Treatment Strategy

Thermal ablation plays an important role in the treatment of extrahepatic metastasis of hepatocellular carcinoma (HCC). Yet laser ablation (LA), as a safe thermal ablative modality, is less investigated in this field. In this study, the safety and local effectiveness of LA in the treatment for the extrahepatic metastasis of HCC were evaluated. From May 2012 to May 2019, 17 patients (13 males and 4 females; mean age, 54.1 ± 14.6 years; age range, 34–80 years), who underwent LA for treatment of extrahepatic metastasis of HCC at the First Affiliated Hospital of Sun Yat-sen University, were retrospectively enrolled in this study. Local effectiveness, complications, local tumor progression (LTP), and overall survival (OS) were evaluated. Finally, a total of 28 LA treated extrahepatic metastatic lesions of HCC were reviewed. Neither LA-related mortality nor major complication occurred. Complete ablation (CA) was achieved in 20 out of 28 lesions (71.4%). During the follow-up (mean, 19.5 ± 12.8 months; range, 5–42.7 months), LTP developed in 4 out of 20 lesions with CA (20%). Four patients died of tumor progression or multiple organ dysfunction syndrome. The accumulative one- and three-year OS rates were 79.0% and 65.8%, respectively. In conclusion, LA is a safe and effective therapeutic option in the treatment of extrahepatic metastasis of HCC. Further studies are necessary to evaluate the benefit of LA.

Innovative approaches for cancer treatment: current perspectives and new challenges

Every year, cancer is responsible for millions of deaths worldwide and, even though much progress has been achieved in medicine, there are still many issues that must be addressed in order to improve cancer therapy. For this reason, oncological research is putting a lot of effort towards finding new and efficient therapies which can alleviate critical side effects caused by conventional treatments. Different technologies are currently under evaluation in clinical trials or have been already introduced into clinical practice. While nanomedicine is contributing to the development of biocompatible materials both for diagnostic and therapeutic purposes, bioengineering of extracellular vesicles and cells derived from patients has allowed designing ad hoc systems and univocal targeting strategies. In this review, we will provide an in-depth analysis of the most innovative advances in basic and applied cancer research.

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.

Radiofrequency ablation versus laser ablation for the treatment of small hepatocellular carcinoma in cirrhosis: a randomized trial

BACKGROUND AND AIM

In patients with cirrhosis and small hepatocellular carcinoma (HCC), thermal ablation is currently recognized as an effective local treatment. Among thermal procedures, radiofrequency ablation (RFA) is the most diffusely used and is the standard against which any new treatment should be compared. In retrospective studies, laser ablation (LA) resulted as safe and effective as RFA. Therefore, we performed a non-inferiority randomized trial comparing RFA with LA in patients with cirrhosis and HCC within Milan criteria.

METHODS

Overall, 140 patients with 157 HCC nodules were randomly assigned to receive RFA or LA. The primary end-point was the proportion of complete tumor ablation (CTA). Secondary end-points were time to local progression (TTLP) and overall survival (OS).

RESULTS

Per patient CTA rates after RFA and LA were 97.4% (95% CI, 91.0-99.3) and 95.7% (88.1-98.5), respectively (difference = 1.4%, 95% CI from -6.0% to + 9.0%). Per nodule CTA rates for RFA and LA were 97.4% (91.0-99.3) and 96.3% (89.6-98.7), respectively (difference = 1.1%, from -5.7% to + 8.1%). The mean TTLP was comparable between RFA group (42.0 months; 95% CI, 36.83-47.3) and LA group (46.7 months; 95% CI, 41.5-51.9) (P = .591). The mean OS was 42 months in both groups and survival probability at 1 and 3 years was 94% and 89% in RFA group, and 94% and 80% in LA group.

CONCLUSION

LA resulted not inferior to RFA in inducing the CTA of HCC nodules and therefore it should be considered as an evaluable alternative for thermal ablation of small HCC in cirrhotic patients.

Laser ablation for small hepatocellular carcinoma: State of the art and future perspectives

During the last two decades, various local thermal ablative techniques for the treatment of unresectable hepatocellular carcinoma (HCC) have been developed. According to internationally endorsed guidelines, percutaneous thermal ablation is the mainstay of treatment in patients with small HCC who are not candidates for surgical resection or transplantation. Laser ablation (LA) represents one of currently available loco-ablative techniques. In this article, the general principles, technique, image guidance, and patient selection are reported. Primary effectiveness, long-term outcome, and complications are also discussed. A review of published data suggests that LA is equivalent to the more popular and widespread radiofrequency ablation in both local tumor control and long-term outcome in the percutaneous treatment of early HCC. In addition, the LA technique using multiple thin laser fibres allows improved ablative effectiveness in HCCs greater than 3 cm. Reference centres should be equipped with all the available techniques so as to be able to use the best and the most suitable procedure for each type of lesion for each patient.

A novel needle guide system to perform percutaneous laser ablation of liver tumors using the multifiber technique

BACKGROUND

Previous studies have shown that laser ablation with the multifiber technique is effective in the treatment of liver tumors. However, the correct positioning of multiple needles may be challenging.

PURPOSE

To investigate the use of a novel needle guide system that was developed to perform percutaneous laser ablation of liver tumors with the multifiber technique under ultrasonographic guidance.

MATERIAL AND METHODS

Between February 2009 and June 2011, 116 patients (104 hepatocellular carcinomas and 12 metastases) with 127 liver nodules (median diameter, 3.0 cm; range, 1.5-6.0) were treated. Nineteen nodules were in high-risk locations. A needle guide with separate channels to insert two needles in a parallel position and at a prefixed distance was used.

RESULTS

Needles were positioned inside the target nodule easily and quickly, and correct spacing (1.5-1.8 cm) between light sources was immediately achieved. Complete tumor ablation was achieved in a single session in 112 (88.2%) lesions. In nodules ≤3.0 cm and >3.0 cm in size, ablation was complete in 93.6% and 79.6% of cases, respectively. Of note, complete ablation was achieved in 91.7% of nodules up to 5.0 cm.

CONCLUSION

With the new guidance system, needles could be inserted in parallel fashion, which facilitated positioning the needles in geometrical configurations to maximize the ablative effect. Worthy of note, the complete ablation rate in nodules >3.0 cm using the new guide system was higher than what has been reported in the literature so far.

Laser ablation for small hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and is increasingly detected at small size (<5 cm) owing to surveillance programmes in high-risk patients. For these cases, curative therapies such as resection, liver transplantation, or percutaneous ablation have been proposed. When surgical options are precluded, image-guided tumor ablation is recommended as the most appropriate therapeutic choice in terms of tumor local control, safety, and improvement in survival. Laser ablation (LA) represents one of currently available loco-ablative techniques: light is delivered via flexible quartz fibers of diameter from 300 to 600 μm inserted into tumor lesion through either fine needles (21g Chiba needles) or large-bore catheters. The thermal destruction of tissue is achieved through conversion of absorbed light (usually infrared) into heat. A range of different imaging modalities have been used to guide percutaneous laser ablation, but ultrasound and magnetic resonance imaging are most widely employed, according to local experience and resource availability. Available clinical data suggest that LA is highly effective in terms of tumoricidal capability with an excellent safety profile; the best results in terms of long-term survival are obtained in early HCC so that LA can be proposed not only in unresectable cases but, not differently from radiofrequency ablation, also as the first-line treatment.

Hepatic tumor ablation

Ablation of liver tumors is part of a multimodality liver-directed strategy in the treatment of various tumors. The goal of ablation is complete tumor destruction, and ultimately improvement of quality and quantity of life for the patient. Technology is evolving rapidly, with important improvements in efficacy. The current state of ablation technology and indications for ablation are described in this review.

Long-term outcome of cirrhotic patients with early hepatocellular carcinoma treated with ultrasound-guided percutaneous laser ablation: a retrospective analysis

PURPOSE

Percutaneous laser ablation (PLA) has been proposed as an active treatment in patients with hepatocellular carcinoma (HCC). However, large multicenter studies using this technique have not been reported.

PATIENTS AND METHODS

We retrospectively analyzed treatment and survival parameters of 432 cirrhotic patients with nonsurgical early HCC (single nodule < or = 4 cm or three nodules < or = 3 cm each) who had received PLA in nine Italian centers.

RESULTS

Single tumors were seen in 344 (80%) of 432 patients, and two to three nodules were seen in 88 patients (20%), for a total of 548 tumors. An initial complete response after PLA was observed in 338 patients (78%). Median overall survival time was 47 months (95% CI, 41 to 53 months). The 3- and 5-year cumulative survival rates were 61% and 34%, respectively. In multivariate analysis, independent predictors of survival were serum albumin levels more than 3.5 g/dL (P = .002; risk ratio [RR] = 0.580; 95% CI, 0.409 to 0.821), the achievement of a complete tumor ablation (P = .001; RR = 0.517; 95% CI, 0.346 to 0.771), and age less than 73 years (P < .001; RR = 0.466; 95% CI, 0.320 to 0.681). Child-Turcotte-Pugh class A patients had a 5-year cumulative survival rate of 41%; this figure increased up to 60% with a median survival time of 63 months (95% CI, 48 to 78 months) in patients with tumors < or = 2.0 cm.

CONCLUSION

This analysis confirms that a complete tumor ablation results in improved survival in patients with nonsurgical HCC. Ideal candidates for PLA are younger patients with normal serum albumin levels and tumor size < or = 2 cm.

Inoperable colorectal liver metastases: a declining entity?

BACKGROUND

Untreated colorectal liver metastases (CLMs) have a dismal prognosis. Surgery remains the gold standard of treatment, but many patients will have inoperable disease at presentation. Until recently, the outlook for such patients was bleak. The purpose of this review was to report on available options in the treatment CLMs, which would be considered unresectable by conventional evaluation.

METHODS

Inclusion criteria were articles published in English-language journals reporting on either retrospective or prospective cohorts of patients undergoing treatment for conventionally inoperable CLM. Main outcome measures were survival, resectability rates, morbidity and mortality following treatment of the patients' disease.

RESULTS

Improved chemotherapy regimes and other innovative treatments have opened up new options for such patients and may even render conventionally inoperable disease resectable. The aim of treatment should be down-staging of metastases to achieve resectability, however, other treatments such as ablation may be also be used (either alone or in conjunction with resection).

CONCLUSION

A nihilistic attitude to the patient with seemingly inoperable liver metastases should be discouraged. Discussion of such patients at multi-disciplinary meetings is essential in order to plan and monitor treatments.

Long acting octreotide in the treatment of advanced hepatocellular cancer and overexpression of somatostatin receptors: randomized placebo-controlled trial

AIM

To estimate if and to what extent long acting octreotide (LAR) improves survival and quality of life in patients with advanced hepatocellular carcinoma (HCC).

METHODS

A total of 127 cirrhotics, stages A-B, due to chronic viral infections and with advanced HCC, were enrolled in the study. Scintigraphy with 111Indium labeled octreotide was performed in all cases. The patients with increased accumulation of radionuclear compound were randomized to receive either oral placebo only or octreotide/octreotide LAR only as follows: octreotide 0.5 mg s.c. every 8 h for 6 wk, at the end of wk 4-8 octreotide LAR 20 mg i.m. and at the end of wk 12 and every 4 wk octreotide LAR 30 mg i.m.. Follow-up was worked out monthly as well as the estimation of quality of life (QLQ-C30 questionnaire). Patients with negative somatostatin receptors (SSTR) detection were followed up in the same manner.

RESULTS

Scintigraphy demonstrated SSTR in 61 patients. Thirty were randomized to receive only placebo and 31 only octreotide. A significantly higher survival time was observed for the octreotide group (49+/-6 wk) as compared to the control group (28+/-1 wk) and to the SSTR negative group (28+/-2 wk), LR=20.39, df=2, P<0.01. The octreotide group presented 68.5% lower hazard ratio [95% CI (47.4%-81.2%)]. During the first year, a 22%, 39% and 43% decrease in the QLQ-C30 score was observed in each group, respectively.

CONCLUSION

The proposed therapeutic approach has shown to improve the survival and quality of life in SSTR positive patients with advanced HCC.

Long acting octreotide in the treatment of advanced hepatocellular cancer and overexpression of somatostatin receptors: Randomized placebo-controlled trial

AIM: To estimate if and to what extent long acting octreotide (LAR) improves survival and quality of life in patients with advanced hepatocellular carcinoma (HCC).

METHODS: A total of 127 cirrhotics, stages A-B, due to chronic viral infections and with advanced HCC, were enrolled in the study. Scintigraphy with ¹¹¹Indium labeled octreotide was performed in all cases. The patients with increased accumulation of radionuclear compound were randomized to receive either oral placebo only or octreotide/octreotide LAR only as follows: octreotide 0.5mg s.c. every 8 h for 6 wk, at the end of wk 4-8 octreotide LAR 20 mg i.m. and at the end of wk 12 and every 4 wk octreotide LAR 30mg i.m.. Follow-up was worked out monthly as well as the estimation of quality of life (QLQ-C30 questionnaire). Patients with negative somatostatin receptors (SSTR) detection were followed up in the same manner.

RESULTS: Scintigraphy demonstrated SSTR in 61 patients. Thirty were randomized to receive only placebo and 31 only octreotide. A significantly higher survival time was observed for the octreotide group (49 ± 6 wk) as compared to the control group (28 ± 1 wk) and to the SSTR negative group (28 ± 2 wk), LR = 20.39, df = 2, P < 0.01. The octreotide group presented 68.5% lower hazard ratio [95% CI (47.4%-81.2%)]. During the first year, a 22%, 39% and 43% decrease in the QLQ-C30 score was observed in each group respectively.

CONCLUSION: The proposed therapeutic approach has shown to improve the survival and quality of life in SSTR positive patients with advanced HCC.

Technology insight: Image-guided therapies for hepatocellular carcinoma--intra-arterial and ablative techniques

Locoregional techniques have become the mainstay of therapy for patients with unresectable hepatocellular carcinoma (HCC). Such image-guided interventions include catheter-based approaches (transarterial chemoembolization and yttrium-90 radiotherapy) and locoregional ablative techniques, either chemical (percutaneous ethanol injection), or thermal (radiofrequency ablation, laser ablation, microwave ablation and cryoablation). These therapies are mainly utilized for palliation, but have also been used with curative intent. In selected cases, percutaneous interventional treatments have shown good results (5-year survival 40-50%), but, even when chosen as first-line treatment, have not been able to achieve the response rates and outcomes achieved by surgical options (resection or transplantation). New promising image-guided therapies are continuously emerging, as we attempt to improve tumor targeting, minimize hepatic toxicity and ultimately improve quality of life and survival of patients with HCC. With new technologies in imaging and drug delivery becoming available, it is likely that, in the future, patients with HCC will be best treated by a multidisciplinary team approach, utilizing a combination of techniques to improve patient survival. This review outlines the current status of the most commonly used image-guided locoregional interventions in the treatment of patients with HCC, and describes recent research and advances related to image-guided interventions for liver cancer.

Multiple fiber laser-induced thermotherapy for ablation of large intrahepatic tumors

OBJECTIVE

The aim of this study was to test three techniques used simultaneously to increase lesion size.

BACKGROUND DATA

Laser-induced thermotherapy (LITT) is a method of local tumor ablation, which may prolong survival in patients with unresectable liver metastases. The main limitation has been the production of lesions with sufficient tumor-free margin.

METHODS

LITT treatment was performed with water-cooled, multiple fiber application and hepatic blood flow occlusion in six patients with unresectable intrahepatic metastases. Response was measured by computed tomography scan.

RESULTS

In all patients, tumors were effectively ablated. In two patients with colorectal metastases, lesions up to 8.6 cm could be created.

CONCLUSION

The use of watercooled multiple fiber application and hepatic inflow occlusion makes LITT an effective ablative method, expanding the treatment options for patients with large intrahepatic masses.

Treatment of small hepatocellular carcinoma: a comparison of techniques and long-term results

OBJECTIVE

The aim of this study was to compare the results over time of transcatheter arterial chemoembolization (TACE), percutaneous ethanol injection (PEI), laser thermal ablation (LTA) and combined therapy in the treatment of small hepatocellular carcinoma.

METHODS

Between 1998 and 2004, 131 cirrhosis patients (99 Child-Pugh class A, 32 Child-Pugh class B) with a small hepatocellular carcinoma were included in the study; 34 were treated with PEI, 46 with LTA, 18 with TACE and 33 with combined therapy.

RESULTS

No major complication occurred during any procedure. Computed tomography scan showed that complete necrosis was achieved in 81% of treated nodules (120 out of 148); as a whole, the disease relapsed in 42 (32.0%) patients (with a disease-free interval of 17.0+/-13.7 months). The cumulative survival rates were 81.9, 35.7 and 20.8% at 12, 36 and 60 months respectively. A univariate analysis of survival showed statistically significant differences in the comparison between Child-Pugh class A with respect to Child-Pugh class B (P<0.0001) and between nodules with a diameter of 20 mm or less as opposed to larger than 20 mm (P=0.001). Patients subjected to LTA showed a statistically significant longer survival than those treated with TACE and PEI.

CONCLUSIONS

LTA proves to be the most effective treatment, affording reduced invasiveness, a limited number of sessions, complete necrosis in almost all cases and better total survival in the treated patients.

Analysis of factors predicting survival in patients with hepatocellular carcinoma treated with percutaneous laser ablation

BACKGROUND/AIMS

The factors which predict the long-term outcome in patients with hepatocellular carcinoma who are treated with percutaneous laser ablation (PLA) are not well established.

METHODS

We prospectively analyzed treatment and survival parameters of 148 cirrhotic patients with nonsurgical hepatocellular carcinoma who had undergone PLA at a single institution during an 11-year period.

RESULTS

Single tumors were seen in 129 of 148 (87%) patients, and 2-3 nodules were seen in 19 (13%) patients, for a total of 169 tumors. The median overall time survival was 39 months (95% confidence interval [CI], 30-47 months). The 1-, 2-, 3-, 4-, and 5-year cumulative survival rates were 89, 75, 52, 43, and 27%, respectively. From multiple regression analysis, the independent predictors of survival were found to be tumor grading (P=0.002; risk ratio [RR] 0.37, 95% CI 0.20-0.70), bilirubin levels < or =2.5mg/dl (P=0.014; RR 1.58, 95% CI 1.09-2.28), and the achievement of complete tumor ablation (P=0.020; RR 0.53, 95% CI 0.31-0.90). An initial complete tumor ablation was the only factor associated with longer survival in patients with Child-Turcotte-Pugh class A cirrhosis (P=0.012; hazard ratio [HR] 0.48, 95% CI 0.23-1.03).

CONCLUSIONS

A complete tumor ablation results in improved survival in all patients with nonsurgical hepatocellular carcinoma. Ideal candidates for PLA are those with a well-differentiated histology, and normal bilirubin levels.

Synergistic effect of interstitial laser coagulation and doxorubicin in a murine tumor recurrence model of solitary colorectal liver metastasis

BACKGROUND

Interstitial laser coagulation (ILC) is gaining acceptance for treatment of unresectable colorectal liver metastases. However, local recurrence rates are still high. To overcome this problem, we investigated the potential of additional systemic therapy after ILC in a murine model.

METHODS

Single C26 colon carcinoma nodules (approximately 1 mm3) expressing firefly luciferase were implanted in the left liver lobe of 32 BALB/c mice. Seven days after implantation, tumors were treated with either ILC alone (neodymium-yttrium aluminum garnet; 6 W/cm; 800 J/cm) or ILC followed by 1 mg/kg of doxorubicin intravenously. Controls received either doxorubicin alone or sham treatment. Tumor load was measured by in vivo bioluminescent imaging.

RESULTS

Solitary colorectal liver metastases developed over 7 days after tumor implantation in the liver. Extrahepatic disease was not observed. The ILC dose was set to ablate the liver metastases with recurrent tumor growth in 9 of 16 mice after 7 days. After ILC plus doxorubicin, complete tumor destruction occurred without recurrence (0 of 14). Sham treatment or treatment with doxorubicin alone showed an exponential increase in tumor load.

CONCLUSIONS

A murine tumor recurrence model after local ablative treatment of solitary liver metastasis was developed. The combination of ILC and doxorubicin had a strong synergistic effect that led to complete tumor remission in all animals treated.

Outcome of regional and local ablative therapies for hepatocellular carcinoma: a collective review

BACKGROUND

Transcatheter arterial (chemo) embolization (TACE), cryoablation (CA) and percutaneous ethanol injection (PEI) were the first regional and local ablative techniques that came into use for irresectable HCC. Radiofrequency ablation (RFA) and interstitial laser coagulation (ILC) followed and have now evolved rapidly. It would not be ethical to compare resection with ablation in patients well enough to undergo major surgery. Therefore, hepatic resection and hepatic transplantation remain the only curative treatment options for HCC.

METHODS

On the basis of a Medline literature search and the authors' experiences, the principles, current status and prospects of TACE and local ablative techniques in HCC are reviewed.

RESULTS

Complete tumour necrosis can be achieved in 60-100% of patients treated with PEI (70-100%), cryoablation (60-85%), RFA (80-90%) or ILC (70-97%). After TACE significant tumour response is achieved in 17-61.9% but complete tumour response is rare (0-4.8%) as viable tumour cells remain after TACE. Five-year survival rates are available for TACE (1-8%), PEI (0-70%) and cryoablation (40%). Only PEI and RFA were compared in one RCT. RFA was associated with fewer treatment sessions and a higher complete necrosis rate. Furthermore, all techniques are associated with low morbidity and mortality, but cryoablation seems to be associated with a higher morbidity rate.

CONCLUSION

TACE has shown to be a valuable therapy with survival benefits in strictly selected patients with unresectable HCC. RFA and PEI are now considered as the local ablative techniques of choice for the treatment of, preferably small, HCC. When tumours are located close to bile ducts or large vessels, PEI remains a valuable therapy. Completeness of ablation can be more easily monitored during cryoablation and another advantage of cryoablation is the possibility of edge freezing. The results of ILC are comparable to RFA with only few side effects and high tumour response rates.

Thermal ablation for hepatocellular carcinoma

Thermal ablation, as a form of minimally invasive therapy for hepatocellular carcinoma (HCC), has become an important treatment modality. Because of the limitations of surgery, the techniques of thermal ablation have become standard therapies for HCC in some situations. This article reviews 4 thermal ablation techniques-radiofrequency (RF) ablation, microwave ablation, laser ablation, and cryoablation. Each of these techniques may have a role in treating HCC, and the mechanisms, equipment, patient selection, results, and complications of each are considered. Furthermore, combined therapies consisting of thermal ablation and adjuvant chemotherapy also show promise for enhancing these techniques. Important areas of research into thermal ablation remain, including improving the ability of ablation to treat larger tumors, determining the indications for each thermal ablation modality, optimizing image guidance, and obtaining good outcome data on the efficacy of these techniques.

Percutaneous ablation of liver tumours

The goal of local ablation treatment of hepatic disease is to prolong survival for patients with unresectable tumours. Presently, influence on survival is difficult to estimate because of the heterogeneity of indications and treatments and short follow-up. This chapter therefore focuses on potential benefits and limitations, complications and solutions for improvement. The main problems with in situ ablation are the lack of good imaging techniques to determine the extent of disease and the lack of a method for real-time monitoring of irreversible tissue effect. With one exception, there are no prospective, randomized studies comparing local destruction methods. It appears that percutaneous ethanol injection and cryotherapy should be replaced by radiofrequency ablation (RFA) or interstitial laser thermotherapy (ILT) and that there is little difference in outcome between RFA and ILT. Intraoperative RFA or ILT is valuable as an adjunct to hepatic resection in order to increase the rate of resectability. The percutaneous approach needs further development. It might be valuable in a few truly unresectable or inoperable patients or in selected patients with neuroendocrine liver metastases. In the large majority of unresectable patients it should, however, presently be used and evaluated only in prospective, randomized studies.

The emergent role of focal liver ablation techniques in the treatment of primary and secondary liver tumours

Only 20% of patients with primary or secondary liver tumours are suitable for resection because of extrahepatic disease or the anatomical distribution of their disease. These patients could be treated by ablation of the tumour, thus preserving functioning liver. This study presents a detailed review of established and experimental ablation procedures. The relative merits of each technique will be discussed and clinical data regarding the efficacy of the techniques evaluated. A literature search from 1966 to 2003 was undertaken using Medline, Pubmed and Web of Science databases. Keywords were Hepatocellular carcinoma, liver metastases, percutaneous ethanol injection, cryotherapy, microwave coagulation therapy, radiofrequency ablation, interstitial laser photocoagulation, focused high-intensity ultrasound, hot saline injection, electrolysis and acetic acid injection. Ablative techniques offer a promising therapeutic modality to treat unresectable tumours. Large-scale randomised controlled trials are required before widespread acceptance of these techniques can occur.

Interstitial laser thermotherapy for liver tumours

BACKGROUND

Primary hepatocellular carcinoma (HCC) and metastases from colorectal cancer are the most common malignant liver tumours. Surgical resection is the optimum treatment in suitable patients. Interstitial laser thermotherapy (ILT) is gaining acceptance for the treatment of irresectable liver tumours and as a potential alternative to surgery. An understanding of the principles of therapy and review of clinical outcomes may allow better use of this technology.

METHOD

An electronic search using the Medline database was performed for studies on the treatment of hepatic malignancy published between January 1983 and February 2003.

RESULTS

Current information on the efficacy of ILT is based on prospective studies. ILT appears to be a safe and minimally invasive technique that consistently achieves tumour destruction. The extent of destruction depends on the fibre design, delivery system, tumour size and tumour biology. Real-time magnetic resonance imaging provides the most accurate assessment of laser-induced tumour necrosis. In selected patients with HCC and colorectal cancer liver metastases, ILT achieves complete tumour necrosis, provides long-term local control, and improves survival, compared with the natural history of the disease. In addition, ILT has survival benefits for patients with other tumour types, especially those with isolated liver metastases from a breast cancer primary.

CONCLUSION

ILT improves overall survival in specific patients with liver tumours. Advances in laser technology and refinements in technique, and a better understanding of the processes involved in laser-induced tissue injury, may allow ILT to replace surgery as the procedure of choice in selected patients with liver malignancies.

Percutaneous sonographically guided saline-enhanced radiofrequency ablation of hepatocellular carcinoma

OBJECTIVE

The purpose of our study was to analyze the efficacy, side effects, and short-term complications of saline-enhanced percutaneous radiofrequency ablation performed under sonographic guidance in a series of cirrhotic patients with hepatocellular carcinoma. SUBJECTS AND METHODS. Between September 2000 and June 2002, 84 patients (55 men and 29 women) with cirrhosis who ranged in age from 48 to 74 years (mean age, 64 years) and who had 95 hepatocellular carcinomas (seven patients had two tumors and two patients had three tumors) were treated with high frequency-induced thermotherapy. The diameters of the tumors ranged from 1.5 to 8.5 cm (mean, 3.6 cm). The efficacy of radiofrequency ablation was evaluated with triphasic contrast-enhanced CT performed 4 weeks after the procedure.

RESULTS

Posttreatment CT showed complete necrosis in 73 (77%) of 95 hepatocellular carcinomas in 62 patients. Complete necrosis based on tumor size was seen in 40 (95%) of 42 tumors with diameters equal to or smaller than 3 cm, 32 (71%) of 45 tumors with diameters between 3.1 and 5.0 cm, and one (12%) of eight tumors with diameters larger than 5.0 cm. Twenty-two hepatocellular carcinomas showed incomplete necrosis. None of the patients experienced major complications. Four patients were lost to follow-up. The length of the follow-up period ranged from 4 to 22 months (mean, 10 months). One patient died 8 months after the radiofrequency ablation treatment. All the remaining patients are still alive. During the follow-up period, eight (10%) of 80 patients showed a local recurrence on sonography and CT.

CONCLUSION

Our experience suggests that percutaneous radiofrequency ablation of hepatocellular carcinoma with high frequency-induced thermotherapy is safe and effective in the treatment of hepatocellular carcinomas equal to or smaller than 3 cm, fairly effective for hepatocellular carcinomas between 3 and 5 cm, and ineffective for tumors larger than 5 cm.

Interstitial laser coagulation with temporary hepatic artery occlusion for patients with cirrhosis and irresectable hepatoma

BACKGROUND

The aim was to determine the degree of local control of hepatocellular carcinoma (HCC) in patients with cirrhotic liver disease when treated with ultrasonographically guided interstitial laser coagulation (ILC) with temporary hepatic artery occlusion.

METHODS

Sixteen patients with 24 HCC tumours were treated. Follow-up was by computed tomography or magnetic resonance imaging every 3 months.

RESULTS

Nineteen of 24 tumours showed complete necrosis immediately after treatment, and there was no tumour recurrence during follow-up (mean 14 months, median 12 months). No effect on liver function was observed after 1 week and there was no death. In 13 of the 16 patients, new HCC foci developed at other sites.

CONCLUSION

Percutaneous ILC combined with temporary hepatic artery occlusion during a single session is an effective local treatment for HCC nodules smaller than 5 cm. However, new HCC lesions develop in the majority of patients, which underscores the need for adjuvant therapy or repeated treatment in these patients.

Review article: percutaneous treatment of hepatocellular carcinoma

In early stage hepatocellular carcinoma (HCC), liver transplantation, surgical resection and percutaneous techniques are classified as radical treatments, and may be offered to about 25% of all patients with HCC evaluated in referral centres. The restricted inclusion criteria for surgical resection and the shortage of liver donors for transplantation have stimulated an increasing demand for minimally invasive treatments able to achieve effective and reproducible percutaneous tumour ablation, with less associated morbidity and lower cost than other interventions. Among percutaneous techniques, ethanol injection has proven to be highly effective in single HCC up to 3 cm, with a rate of complete response of 80%, being well tolerated and with a limited risk of minor complication. In larger and/or multinodular HCC the efficacy is reduced to 50% of complete response in nodules between 3 and 5 cm, and to lower rate in larger tumours. Alternative options to ethanol injection have been recently proposed, including radiofrequency, microwave and laser thermal ablation, aimed to extend the necrotic area thus improving the rate of complete response. To date, radiofrequency is the most used technique, with a reported rate of complete response of 90-98% in nodules smaller than 3 cm, and with the advantage of fewer sessions, otherwise counteracted by a higher rate of side-effects. Microwave and laser are promising technologies, but only few clinical data are available. Randomized controlled trials are needed in order to assess treatment response, long-term survival, rate of complication and cost-efficacy of newer technologies in comparison to ethanol injection.

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.

Other thermal ablation techniques: microwave and interstitial laser ablation of liver tumors

BACKGROUND

Thermal ablation of hepatic malignancies is becoming a widespread treatment approach. In addition to radiofrequency ablation, microwave coagulation (MCT) and laser-induced interstitial thermotherapy (LITT) are being used clinically to treat patients with liver cancers.

METHODS

The principles and clinical indications for MCT and LITT are described. Treatment approaches and results from published clinical studies are reviewed. The evolution of these thermal treatment modalities and limitations of currently available equipment is provided.

RESULTS

The interstitial probes and equipment used for MCT and LITT for liver tumors are undergoing changes to improve treatment efficacy. Both MCT and LITT have been limited by the relatively small zone of coagulation produced with a single probe placement. Both techniques can be performed safely, and local recurrence and long-term survival rates are being established.

CONCLUSIONS

MCT and LITT are two alternative thermal ablation techniques being used to treat patients with primary and metastatic hepatic malignancies. The utility of these two treatments has been limited by the relatively small area of thermal necrosis produced around the interstitial probes, but design modifications and new equipment may improve these limitations.

Complications after interventional sonography of focal liver lesions: a 22-year single-center experience

OBJECTIVE

To analyze the complications of diagnostic and therapeutic sonographically guided interventional procedures of focal liver lesions observed during a 22-year period in a single center.

METHODS

Complications of sonographically guided diagnostic and therapeutic procedures on focal liver lesions, observed during a 22-year period in a single center, were reviewed. From 1979 to 2001, 13,222 patients (age range, 7-89 years; mean, 59 years; 8,688 male and 4,534 female) with 13,777 focal liver lesions underwent 16,648 sonographically guided biopsies and 3,035 therapeutic procedures: pyogenic and amebic abscess aspiration, ethanol injection of hydatid liver cysts, and percutaneous ablative treatments (ethanol injection in either multiple or one-shot sessions, radio frequency ablation, and interstitial laser photocoagulation) of primary and secondary liver tumors.

RESULTS

The overall mortality was 0.06%. No death or major complication occurred after diagnostic procedures and liver abscess drainage. In the therapeutic group mortality was 0.6%: 1 patient died of anaphylactic shock during treatment of a hydatid cyst; 7 patients died after liver tumor ablation with ethanol injection (6 after one-shot treatments and 1 after multisession treatments). Major complications after liver tumor ablative procedures included 10 cases of acute liver failure, 2 cases of acute tubular necrosis, 2 cases of self-limiting hemoperitoneum, 2 cases of paralytic ileum, 2 abscesses, and 1 case of cholangitis. One case of a biliary cyst fistula and 1 case of intracystic hemorrhage occurred after treatment of hydatid liver cysts.

CONCLUSIONS

Sonographically guided diagnostic biopsy of focal liver lesions and liver abscess drainage are safe procedures. In contrast, liver tumor ablation procedures have a low but definite risk of mortality and major complications. Puncture of hydatid cysts must be performed only in institutions that can treat anaphylactic shock.

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.

Non-surgical treatment of hepatocellular carcinoma

Primary hepatocellular cancer is a disease with a poor prognosis for which there is little consensus on treatment and a paucity of comparative trials. The coexistence of cancer with cirrhosis complicates treatment, and also confers a high risk for the development of further tumours. Surgery, either by hepatic resection or orthotopic liver transplantation, is only a feasible option in a minority of patients. This article surveys the non-surgical approaches to the treatment of hepatocellular cancers-local ablation techniques, arterial embolization with and without chemotherapy, conventional chemotherapy and hormonal modulation, and targeted and external irradiation.

New nonsurgical therapies in the treatment of hepatocellular carcinoma

The last decade has seen a rapid increase in the incidence of hepatocellular carcinoma in the United States, mostly because of the increased incidence of hepatitis C. Surgical therapy remains limited to the few patients who are surgical candidates at presentation. In addition, surgery has been plagued by high recurrence rates, which can reach 80% at 3 years. Systemic chemotherapy has been found to be ineffective, with response rates approaching 10% to 20%. Nonsurgical percutaneous therapies, including percutaneous locoregional ablative procedures (ethanol or acetic acid injection, radiofrequency ablation, microwave coagulation therapy, chemotherapy infusion, laser photocoagulation, and high-intensity ultrasound) and intra-arterial procedures (radioembolization with yttrium-90 microspheres or transcatheter intra-arterial chemoembolization) are gaining popularity because they are less invasive than surgery and can be nearly as effective in prolonging survival. Multiple studies have shown good response rates with high technical success rates, as well as significant survival advantages for nonresectable disease. Furthermore, they can be performed repeatedly without compromising liver function and at a considerably lower morbidity and cost than surgery.