Adverse events during radiofrequency treatment of 582 hepatic tumors

Case study of hepatic radiofrequency ablation causing a systemic inflammatory response under total intravenous anesthesia

Objective

To investigate the effects of hepatic radiofrequency ablation (RFA) in patients with malignant liver disease with respect to inflammation activation and stress response.

Materials and Methods

In an observational trial, we investigated the physiologic parameters of 17 patients (20 interventions) who underwent percutaneous RFA under general anesthesia after applying total intravenous anesthesia. TNFα, IL-6, IL-8, IL-10, adrenaline and noradrenaline, liver enzymes, lactate and creatine kinase were determined pre-interventionally after induction of anesthesia (T1), 90 minutes after initiation of RFA (T2), immediately after the conclusion of the procedure (T3), and 24 hours after the procedure (T4).

Results

A significant increase in body temperature (p < 0.001), and mean arterial pressure (p = 0.001) were measured intraoperatively (T2) and the day after the procedure (T4). Increased levels of IL-6 were measured at T3 and T4 (p = 0.001). IL-10 increased immediately after the procedure (T3; p = 0.007). IL-6 levels correlated well with the total energy applied (r = 0.837). Significant increases in the levels of adrenaline and noradrenaline were present at T3 and T4 (p < 0.001). The RFA-induced destruction of hepatic tissue was associated with increased levels of AST, ALT, GLDH and LDH.

Conclusion

Percutaneous RFA of hepatic malignancies causes an inflammatory and endocrine activation, similar to the systemic inflammatory response syndrome. These effects have to be taken in account when dealing with patients susceptible to sepsis or multi-organ failure.

Survival and cost-effectiveness analysis of competing strategies in the management of small hepatocellular carcinoma

The aim of the present study is to compare the survival rates and cost-effectiveness of different treatment strategies for small (<2 cm) hepatocellular carcinoma (HCC). Markov chains are developed to model different management strategies for patients with compensated cirrhosis and small HCC. Probabilities of progression and survival and the likelihood of orthotopic liver transplantation are taken from the literature and incorporated into the models. As a starting population, 1000 patients are followed over a period of 10 years. Patients treated immediately with transarterial chemoembolization (TACE) or radiofrequency ablation (RFA) live as long as or longer than patients who are monitored expectantly with the intention of liver transplantation once the HCC has grown larger than 2 cm and a higher transplant priority score becomes available. With TACE, immediate treatment results in an average survival time of 4.269 years versus 4.324 years with the monitoring strategy. With RFA, immediate treatment results in an average survival time of 5.273 years versus 5.236 years with the monitoring strategy. In addition, the cost analysis shows that immediate treatment with either TACE or RFA is less expensive than monitoring. The better cost-effectiveness of immediate therapy versus the monitoring strategy remains robust and unaffected by variations of the assumptions built into the model. In conclusion, in patients with compensated cirrhosis and small HCC, a strategy of immediate treatment with either TACE or RFA prevails over a strategy of expectant monitoring with the intention of transplantation.

Early three-dimensional conformal radiotherapy for patients with unresectable hepatocellular carcinoma after incomplete transcatheter arterial chemoembolization: a prospective evaluation of efficacy and toxicity

PURPOSE

We prospectively evaluated the efficacy and toxicity of early 3-dimensional conformal radiotherapy (3D-CRT) for patients with unresectable hepatocellular carcinoma (HCC) after incomplete transcatheter arterial chemoembolization (TACE).

METHODS

Patients with unresectable HCC who failed 1 or 2 courses of TACE were eligible for this study. Three dimensional-CRT was added for HCC with incomplete uptake of iodized oil. Between January 2006 and February 2007, 40 patients (43 lesions) were enrolled. TACE was performed by using Lipiodol and adriamycin, followed by Gelfoam embolization. Two cycles of TACE were performed in 24 patients (60%), whereas 16 patients (40%) underwent one cycle. The median dose of 54 Gy (3 Gy daily) was delivered with 3D-CRT. Tumor response was evaluated by changes in tumor size on serial computed tomography scans and toxicity was evaluated by the Common Terminology Criteria for Adverse Events v3.0.

RESULTS

An objective response was achieved in 27 of 43 lesions (62.8%), with a complete response in 9 lesions (20.9%) and partial response in 18 lesions (41.9%). The overall survival rate was 72.0% at 1 year and 45.6% at 2 years. There was no grade 3 or greater acute toxicity. Nine patients (22.5%) showed progression of the disease within the irradiated field during the follow-up and intrahepatic metastases developed in 16 patients (40.0%).

CONCLUSION

Early 3D-CRT for HCC unresponsive to 1 or 2 cycles of TACE resulted in a 62.8% tumor response rate and relatively high complete response rates (20.9%) with acceptable toxicity. This study shows that the application of 3D-CRT could be considered for patients with incomplete TACE.

Radiofrequency ablation of hepatocellular carcinoma: pros and cons

Among locoregional treatments for hepatocellular carcinoma (HCC), radiofrequency ablation (RFA) has been accepted as the most popular alternative to curative transplantation or resection, and it shows an excellent local tumor control rate and acceptable morbidity. The benefits of RFA have been universally validated by the practice guidelines of international societies of hepatology. The main advantages of RFA include 1) it is minimally invasive with acceptable morbidity, 2) it enables excellent local tumor control, 3) it has promising long-term survival, and 4) it is a multimodal approach. Based on these pros, RFA will play an important role in managing the patient with early HCC (smaller than 3 cm with fewer than four tumors). The main limitations of current RFA technology in hepatic ablation include 1) limitation of ablation volume, 2) technically infeasible in some tumors due to conspicuity and dangerous location, and 3) the heat-sink effect. Many technical approaches have been introduced to overcome those limitations, including a novel guiding modality, use of artificial fluid or air, and combined treatment strategies. RFA will continue to play a role as a representative ablative modality in the management of HCC, even in the era of targeted agents.

Radiofrequency ablation for hepatocellular carcinoma: a survival analysis of 117 patients

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world especially in Asia. Radiofrequency ablation is now commonly use as either first line or in combination with other treatment modality for patients with HCC. It is the objective of this article to report our experience in a tertiary referral hospital.

METHODS

Patients who diagnosed with HCC and underwent RFA in Queen Elizabeth Hospital during the period from May 2002 to February 2009 were included and analyzed.

RESULTS

During this period, 138 sessions of RFA were performed in 117 consecutive patients with HCC. The calculated rate of primary (single attempt) successful ablation during this entire period was 89.2%. The in-hospital/30-day mortality rate was zero, and morbidity was 24.1%. Hospital stays were significantly longer in the open group (4.4 days versus 8.9 days, P = 0.000). Median follow-up in this study was 21 months. 11 (9.4%), 10 (8.5%) and 49 (41.0%) patients developed local tumor progression (LTP), systemic recurrence and Intrahepatic distant recurrence (IDR), respectively. The mean and median times to recurrence were 15.4 and 11 months, respectively. Most patients (91%) with LTP developed in the first 24 months. Disease-free survival was 65% at 1 year, 40% at 3 years and 25% at 5 years. Overall survival at 1, 3 and 5 years was 85, 66 and 40%, respectively. Alpha fetoprotein, aFP > 1,000 ng/ml and multiple tumor ablation predicted increased risk of recurrence.

CONCLUSION

Radiofrequecy ablation is useful tool in treating patients with HCC with high successful rate. However, intrahepatic recurrence is common and a well designed post ablation follow up protocol based on a sound knowledge of recurrence pattern is vital.

Increased ablation zones using a cryo-based internally cooled bipolar RF applicator in ex vivo bovine liver

PURPOSE

To evaluate the feasibility of ex vivo ablation implementing a cryo-based internally cooled bipolar radiofrequency (RF) applicator and to determine the influence of power and gas pressure on the size and shape of the resulting ablation zones.

MATERIALS AND METHODS

Two hundred twenty-five ablations were performed using a custom-built internally CO2-cooled bipolar cryo RF applicator in ex vivo bovine livers. The active tip of the applicator was 55 mm long. RF power (32-50 watts) and gas pressure of cooling medium (500-600 psi) were varied independently. Power was applied in continuous mode. Control group experiments were carried out solely using the RF function at 32, 40, and 50 watts. Ablation duration was 15 minutes for all applications. Experiments were repeated 5 times for all parameter combinations. Short and long axes of the induced white ablation zone were macroscopically assessed. The ablation zone was referred to as homogeneous if complete ablation was observed without spots of untreated tissue. The short axis diameters for the simultaneous application of cryo and RF function were analyzed using a multiple linear regression analysis. An unpaired Mann-Whitney U test was used to analyze the differences between the short axes with RF alone and RF using cryo cooling.

RESULTS

All ablation zones were homogeneous. Using simultaneous RF ablation function and gas cooling with a single applicator, the long axes of the ablation zones ranged between 42 +/- 2 mm (mean +/- SD) and 59 +/- 5 mm, the short axes between 24 +/- 1 and 44 +/- 1 mm, depending on the parameter combination. At a stable gas pressure level, short axes increased with rising power levels and decreased after reaching a maximum. The maxima of the short axis increased with higher gas pressure levels and were shifted to higher power values. Optimal parameter settings were 46 to 50 watts and 600 psi gas pressure, resulting in a short axis of 44 +/- 1 mm. Short axis weakly correlated with gas pressure (r2 = 0.10) and power (r2 = 0.34) alone, whereas the correlation was r2 = 0.76 for the combined factors. Without cooling, short axis diameters were significantly shorter (P < 0.05), ranging between 13 +/- 2 mm at 50 watts and 15 +/- 2 mm at 32 watts.

CONCLUSION

The results of this initial ex vivo study show that the combined cryo RF ablation device allows for large ablation volumes using a single needle, which is superior to RF ablation alone.

Quality improvement guidelines for radiofrequency ablation of liver tumours

The development of image-guided percutaneous techniques for local tumour ablation has been one of the major advances in the treatment of liver malignancies. Among these methods, radiofrequency ablation (RFA) is currently established as the primary ablative modality at most institutions. RFA is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma (HCC) when liver transplantation or surgical resection are not suitable options [1, 2]. In addition, RFA is considered a viable alternate to surgery (1) for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer, and (2) for patients deemed ineligible for surgical resection because of extent and location of the disease or concurrent medical conditions [3]. These guidelines were written to be used in quality-improvement programs to assess RFA of HCC and liver metastases. The most important processes of care are (1) patient selection, (2) performing the procedure, and (3) monitoring the patient. The outcome measures or indicators for these processes are indications, success rates, and complication rates.

Thermoablation of colorectal liver metastasis

Thermoablation is a local therapy that is effective in in situ destruction of colorectal liver metastasis while preserving surrounding normal liver tissue. It is less invasive compared to surgery, easy to use, and can be repeated. The therapy provides local control of unresectable disease and is an alternative therapy for small resectable lesions in patients with insufficient hepatic reserve after resection or coexistent comorbid conditions. It can artificially increase the resection margin thus increasing the number of patient candidate for resection. When used in conjunction with liver resection it clears the liver of multiple lesions that are surgically inaccessible or unresectable. Main limitations of the treatment are local recurrence of the disease, treatment-related complications, and questionable impact on patient. Outcome of therapy can be improved when used as part of multimodality treatment.

Hemorrhagic complications of percutaneous radiofrequency ablation for liver tumors

BACKGROUND

Although radiofrequency ablation (RFA) is widely accepted as a percutaneous treatment for liver tumors; serious complications may occur resulting in 0.1% to 0.5% mortality. This study analyzed the risk factors and management of hemorrhagic complications, such as hemoperitoneum, hemothorax, and hemobilia.

METHODS

We performed 4133 RFA treatments in 2154 patients with primary and metastatic liver tumors from February 1999 to December 2007. Of these, we enrolled patients with hemorrhagic complications and reviewed their medical records thoroughly. The risk factors for each hemorrhagic complication were analyzed using unconditional logistic regression.

RESULTS

Hemorrhagic complications occurred in 63 out of 4133 treatments (1.5%), including hemoperitoneum in 29 (0.7%), hemothorax in 14 (0.3%), and hemobilia in 20 (0.5%). Eleven, 8, and 4 of these patients, respectively, were categorized as major complications requiring blood transfusion or drainage. Two patients died after hemoperitoneum. Logistic regression analysis revealed large tumor size [odds ratio (OR) 1.06 per 1 mm increase in diameter] and low platelet count (OR 0.88 per 10,000/microL increase) were significant risk factors for hemoperitoneum. The location of tumor nodules was a significant risk factor for hemothorax (segment 7, OR 2.31) and hemobilia (segment 1, OR 3.30). Other factors, including the number of needle insertions or the duration of ablation, were not significant.

CONCLUSIONS

Although hemorrhagic complications were relatively rare with percutaneous RFA, specific treatments, such as blood transfusion and drainage, were required in some cases. Care must be taken, especially in high-risk patients.

Current status of radiofrequency ablation of hepatocellular carcinoma

Loco-regional treatments for hepatocellular carcinoma (HCC) are important alternatives to curative transplantation or resection. Among them, radiofrequency ablation (RFA) is accepted as the most popular technique showing excellent local tumor control and acceptable morbidity. The current role of RFA is well documented in the evidence-based practice guidelines of European Association of Study of Liver, American Association of Study of the Liver Disease and Japanese academic societies. Several randomized controlled trials have confirmed that RFA is superior to percutaneous ethanol injections in terms of local tumor control and survival. The overall survival after RFA is comparable to after surgical resection in a selected group of patients with smaller (< 3 cm) tumors. Currently, the clinical benefits of combined RFA with transarterial chemoembolization for intermediate stage HCC are increasingly being explored. Here we review the ongoing technical advancements of RFA and future potential.

[Practice guidelines for management of hepatocellular carcinoma 2009]

Hepatocellular carcinoma (HCC) is a major cancer in Korea, typically has a poor prognosis, and constitutes the majority of primary hepatic malignancies. It is the number one cause of death among people in their 50s in Korea. The five-year survival rate of liver cancer is poor; at 18.9%. Efforts to increase the survival rate through early diagnosis of HCC and optimal treatments are keenly needed. Western guideline for the management of HCC were developed, but these guidelines are somewhat unsuitable for Korean patients. Thus, the Korean Liver Cancer Study Group (KLCSG) and the National Cancer Center (NCC), Korea jointly produced the Clinical Practice Guidelines for HCC for the first time in Korea in 2003. Owing to medical advances over the following six years, diagnosis and treatment of HCC has changed considerably. As more national and foreign data are accumulated, KLCSG and NCC, Korea recently revised the Clinical Practice Guidelines for HCC. Forty or more specialists in the field of hepatology, general surgery, radiology and radiation oncology participated, and meticulously reviewed national and foreign papers, and collected opinions through advisory committee conferences. These multidisciplinary, evidence-based guidelines summarized diagnosis, surgical resection, liver transplantation, local treatments, transarterial chemoembolization, radiation therapy, chemotherapy, preemptive antiviral treatments, and response evaluation of HCC. These Korean guidelines are expected to be useful for clinical management of and research on HCC.

Evidence for a synchronous operative approach in the treatment of colorectal cancer with hepatic metastases: a case matched study

BACKGROUND

Traditionally, a staged operative approach has been used for patients with synchronous colorectal cancer and liver metastases in the U.K. With improved outcomes from hepatic resection the role of a synchronous operative approach needs re-evaluated.

METHODS

32 consecutive patients with colorectal cancer and hepatic metastases that underwent a synchronous operative approach were individually case matched (according to: age; sex; ASA grade; type of hepatic and colonic resection) with patients that had undergone a staged approach. The following variables were analysed: operative blood loss; in hospital morbidity and mortality; duration of hospital stay; disease free and overall survival.

RESULTS

Operative blood losses were: synchronous group, median 475mL (range 150-850mL) vs median 425mL (range 50-1700mL), (p>0.050). There were no significant differences in morbidity: (34% synchronous group vs 59%, p=0.690) with no recorded mortality. Synchronous group had a shorter hospital stay (median 12 days [range 8-21] vs 20 [range 7-51], p=0.008). There were no statistical differences between synchronous and staged patients for disease free and overall survival: 10 months (95% CI 5.8-13.7) versus 14 (95% CI 12.2-16.3; p=0.487) and 21% versus 24% at 5 years (p=0.838).

CONCLUSION

This present study provides supporting evidence for synchronous operative procedures in patients with colorectal liver metastases.

Extension of hepatic necrosis secondary to current arcing to surgical clips: a potential complication of radiofrequency ablation

The authors present a case report of a 67-year-old woman who underwent radiofrequency ablation of recurrent hepatic metastases. She was managed 2 years previously with a right hemi-hepatectomy. Subsequent to RF ablation she developed hepatic necrosis extending in a linear fashion to two of the metallic surgical clips at the free edge of the liver, consistent with current arcing.

American Society of Clinical Oncology 2009 clinical evidence review on radiofrequency ablation of hepatic metastases from colorectal cancer

PURPOSE

To review the evidence about the efficacy and utility of radiofrequency ablation (RFA) for hepatic metastases from colorectal cancer (CRHM).

METHODS

The American Society of Clinical Oncology (ASCO) convened a panel to conduct and analyze a comprehensive systematic review of the RFA literature from Medline and the Cochrane Collaboration Library.

RESULTS

Because data were considered insufficient to form the basis of a practice guideline, ASCO has instead published a clinical evidence review. The evidence is from single-arm, retrospective, and prospective trials. No randomized controlled trials have been included. The following three clinical issues were considered by the panel: the efficacy of surgical hepatic resection versus RFA for resectable tumors; the utility of RFA for unresectable tumors; and RFA approaches (open, laparoscopic, or percutaneous). Evidence suggests that hepatic resection improves overall survival (OS), particularly for patients with resectable tumors without extrahepatic disease. Careful patient and tumor selection is discussed at length in the literature. RFA investigators report a wide variability in the 5-year survival rate (14% to 55%) and local tumor recurrence rate (3.6% to 60%). The reported mortality rate was low (0% to 2%), and the major complications rate was commonly reported to be between 6% and 9%. RFA is currently performed with all three approaches.

CONCLUSION

There is a compelling need for more research to determine the efficacy and utility of RFA to increase local recurrence-free, progression-free, and disease-free survival as well as OS for patients with CRHM. Clinical trials have established that hepatic resection can improve OS for patients with resectable CRHM.

Stereotactic body radiation therapy for liver metastases

Although resection is the standard of care for liver metastasis, 80-90% of patients are not resectable at diagnosis. Advances in combination chemotherapy, particularly with targeted agents, have increased tumour response and survival in patients with unresectable metastatic colorectal cancer, but these techniques have limitations and may be associated with high recurrence rates. Some autopsy series have shown that as many as 40% of patients with metastatic colorectal cancer have disease confined to the liver; aggressive local therapy may improve overall survival in such patients. Local control of liver metastases can also ease hepatic capsular pain to improve quality of life. Stereotactic body radiation therapy (SBRT) offers an alternative, non-invasive approach to the treatment of liver metastasis through precisely targeted delivery of radiation to the tumours while minimising normal tissue toxicity. Early applications of SBRT to liver metastases have been promising with the reports of 2-year local control rates of 71-86% and other studies reporting 18-month local control rates of 71-93%. While these data establish the safety of SBRT for liver metastases, more rigorous phase II clinical studies are needed to fully evaluate long-term efficacy and toxicity results. In the interim, this review stresses that SBRT of liver must be performed cautiously given the challenges of organ motion and the low toxicity tolerance of the surrounding hepatic parenchyma.

Preoperative prediction of poorly differentiated components in small-sized hepatocellular carcinoma for safe local ablation therapy

BACKGROUND

Poorly differentiated hepatocellular carcinoma (HCC) has a malignant potential such as frequent microvascular invasion even if the tumor is smaller than 3 cm in diameter. The aim of this study was to clarify the preoperative predictors of poorly differentiated HCC for safe local ablation therapy.

METHODS

Sixty-six patients underwent a hepatic resection for solitary small-sized HCC (<or=3 cm) were included in this study. According to the postoperative histological examination, the patients were divided into a "poorly differentiated group" (n = 17) and a "well/moderately differentiated group" (n = 49). This study investigated the clinicopathological factors and imaging findings, and elucidated the predictive factors of the poorly differentiated type.

RESULTS

In a univariate analysis, serum hepatitis B surface antigen positive, hepatitis C virus antibody negative, alpha-fetoprotein level, des-gamma-carboxy prothrombin level, and a high contrast-to-noise ratio (CNR) in T2-weighted MR imaging were significantly associated with the poorly differentiate type. In a multivariate analysis, a high CNR in T2-weighted MR imaging was the only independent predictor of the poorly differentiated type. In the postoperative pathological findings, portal vein invasion and intrahepatic metastasis were significantly frequent in the poorly differentiated group.

CONCLUSIONS

The CNR in T2-weighted MR imaging is a useful tool to predict poorly differentiated HCC preoperatively.

Percutaneous laser ablation in patients with isolated unresectable liver metastases from colorectal cancer: Results of a phase II study

We prospectively evaluated the safety, local tumor control, and impact on survival parameters of percutaneous laser ablation (PLA) in patients with colorectal liver metastases not amenable to surgical resection. The study included 44 individuals with 75 unresectable liver metastases and no known extrahepatic disease. The median number of metastases treated for each patient was one, with a range of 1-4. Metastases had a median diameter of 3.4 cm (range 0.5-9 cm), and a median volume of 16.8 cm(3) (range 0.4-176.4 cm(3)). All patients also received systemic chemotherapy with modalities that differed according to the type of response to PLA. After treatment, 61% (46/75) of the tumors were ablated completely. The likelihood of achieving a complete ablation was significantly higher when metastases had a diameter <3.0 cm (p = 0.004). Overall survival was 30.0+/-12.7 months in patients with a complete ablation, and 20.2+/-10.2 months in those with a partial ablation (p = 0.002). There were no major complications during or after PLA, the most frequent side effect being abdominal pain that required analgesics. These findings indicate that PLA can be safely used as an adjunct to chemotherapy in unresectable colorectal liver metastases, and may have a positive impact on survival.

Liver ablation techniques: a review

BACKGROUND

Ablation techniques for unresectable liver carcinomas have evolved immensely since their introduction. Results of studies involving these techniques are restricted to reports of patient case series, which are often not presented in a standardised manner. This review aims to summarise the major studies in ablation technologies and present them in a way that may make comparison between the major modalities easier.

METHODS

All major databases (Medline, Cochrane, Embase and Pubmed) were searched for studies using microwave, radiofrequency or cryoablation to treat unresectable liver tumours. Only studies with at least 30 patients and 3-year follow-up were included. Complication, recurrence and survival rates of all studies are summarised and presented.

RESULTS AND CONCLUSION

It is difficult to compare ablation modalities, as probe design and energy sources have evolved rapidly over the last decade. Ablation offers an invaluable palliative option and in some cases it may offer rates of cure approaching that of surgical resection with lower morbidity and mortality. Perhaps the time has come, therefore, for prospective large-scale randomised control trials to take place comparing ablation modalities to each other and surgical resection.

Imaging after radiofrequency ablation of hepatic tumors

Radiofrequency ablation (RFA) is now increasingly used as a first-line therapeutic modality for small malignant hepatic tumors in many parts of the world. The importance of radiological imaging at follow-up to assess therapeutic effectiveness, presence of complications, and recurrences cannot be overemphasized, as RFA treatment is minimally invasive and locally applied. A broad spectrum of imaging findings obtained by the use of various modalities has been reported by many investigators. In this review, we describe findings, including chronologic changes of the ablation zones, both local and remote recurrences, and complications that occur after RFA of the liver as well as the advantages and disadvantages of the use of each imaging modality for a specific situation.

Percutaneous radiofrequency ablation for the hepatocellular carcinoma abutting the diaphragm: assessment of safety and therapeutic efficacy

Objective

To assess the safety and therapeutic efficacy of a percutaneous radiofrequency (RF) ablation for the hepatocellular carcinoma (HCC) abutting the diaphragm.

Materials and Methods

We retrospectively assessed 80 patients who underwent a percutaneous RF ablation for a single nodular (< 4 cm) HCC over the last four years. Each patient underwent an ultrasound-guided RF ablation using internally cooled electrodes for the first-line treatment. We divided patients into two subgroups based on whether the index tumor was abutting (less than 5 mm) the diaphragm or not: group A (abutting; n = 31) versus group B (non-abutting; n = 49). We compared the two subgroups for complications and therapeutic efficacy using image and the review of medical records. The statistical assessment included an independent t-test, Fisher's exact test, and chi-square test.

Results

The assessment of the diaphragmatic swelling at CT immediately following the procedure was more severe in group A than group B (mean thickness change:1.44 vs. 0.46 mm, p = 0.00). Further, right shoulder pain was more common in group A than B (p = 0.01). Although minor complications (hemothorax 1 case, pleural effusion 1 case) were noted only in group A, no major thoracic complication occurred in either group. The technical success rate was lower in group A than group B (84% vs. 98%, p = 0.03). As well, the primary and secondary technique effectiveness rates in group A and group B were 90% versus 98% (p = 0.29) and 79% versus 91% (p = 0.25), respectively. The local tumor progression rate was higher in group A than in group B (29% vs. 6%, p = 0.02).

Conclusion

We found that the percutaneous RF ablation for the HCC abutting the diaphragm is a safe procedure without major complications. However, it is less effective with regard to technical success and local tumor control.

Percutaneous ablation for small hepatocellular carcinoma

Hepatocellular carcinoma is increasingly detected at small size, usually 5 cm or smaller in diameter. For small hepatocellular carcinoma, percutaneous ablation is a potentially curative treatment. Ethanol injection is able to achieve a complete response of 70-80% and a 5-year survival of 40-60% in the treatment of hepatocellular carcinoma of 3 cm or less. Radiofrequency ablation has emerged as the more powerful alternative method. Randomized controlled trials show that radiofrequency ablation offers a higher complete response at fewer treatment sessions and better survival compared with ethanol injection. Microwave ablation has been demonstrated to be equivalent to radiofrequency ablation in both local efficacy and long-term outcome. Laser ablation is mainly applied in clinical settings in Europe. Nowadays, percutaneous ablation is commonly accepted as the best option for patients with small hepatocellular carcinoma who are not candidates for surgical resection or liver transplantation. However, whether it can compete with surgery as the first-line treatment has long been debated. There are some retrospective studies and only a few randomized controlled trials to compare the two modalities. The currently available data are not robust enough to draw a solid conclusion. This review article provides an overview of the current status of percutaneous ablation in management of small hepatocellular carcinoma and also focuses on comparison with surgical resection.

Laser ablation of metastatic lesions of the lung: long-term outcome

OBJECTIVE

Pulmonary metastatic lesions are present in 20-54% of all patients who die of cancer. Surgical studies have shown that local management of distant tumor metastasis as part of multimodal cancer therapy improves survival. Minimally invasive procedures such as thermal ablation are still to prove their clinical relevance. The aim of this study was to monitor therapeutic outcome and long-term results after percutaneous laser-induced thermal ablation.

SUBJECTS AND METHODS

Sixty-four patients with metastasis to the lung underwent laser-induced thermal ablation in an ongoing prospective study. A total of 129 percutaneous procedures were performed to manage a total of 108 lung lesions. The median tumor size was 2.0 cm (range, 0.4-8.5 cm). Adequate management of all known individual tumor correlates was critical for definitive patient therapy. The Kaplan-Meier method was used to calculate survival and recurrence rates.

RESULTS

Definitive management of initial pulmonary disease was achieved in 31 of 64 patients. The 1-, 2-, 3-, 4-, and 5-year survival rates after ablative therapy were 81%, 59%, 44%, 44%, and 27%. The median progression-free interval was 7.4 months. There were no therapy-related deaths. Pneumothorax occurred in 38% of the patients, necessitating periprocedural drainage in 5% of all cases. Parenchymal bleeding (13% of cases) always was self-limited.

CONCLUSION

Laser ablative therapy for pulmonary metastasis is a promising option in multimodal cancer therapy. The procedure is safe and effective. The initial clinical outcome data strongly suggest that this technique has the potential to improve survival among selected patients.

Radiofrequency thermal ablation vs. percutaneous ethanol injection for small hepatocellular carcinoma in cirrhosis: meta-analysis of randomized controlled trials

OBJECTIVES

Radiofrequency thermal ablation (RF) and percutaneous ethanol injection (PEI) have been employed in the treatment of small hepatocellular carcinoma (HCC) as curative treatments. The aim of the study was to review the available evidence comparing RF to PEI for small HCC.

SEARCH STRATEGY

Cochrane, MEDLINE, CANCERLIT, and ENBASE databases were used.

SELECTION CRITERIA

randomized clinical trials evaluating RF vs. PEI. Data were extracted from each randomized controlled trial (RCT). Primary outcomes were overall survival and local recurrence. Meta-analysis software was used and risk differences (RDs) and their 95% confidence intervals and Q-test for heterogeneity were calculated.

RESULTS

Five RCTs were identified including 701 patients. The overall survival was significantly higher in patients treated with RF than in those treated with PEI (RD 0.116, 95% CI 0.173/0.060; heterogeneity not present). Local recurrence rate is significantly higher in patients treated with PEI than in those treated with RF. In the RF group the 1, 2, and 3 years cancer-free survival rates were significantly better than in the PEI-treated patients (respectively: RD 0.098-95% CI 0.006/0.189; heterogeneity P=0.57; RD 0.187, 95% CI 0.082/0.293; heterogeneity P=0.98; RD 0.210, 95% CI 0.095/0.325; heterogeneity P = 0.78). A small number of adverse events were reported in the two treatments.

CONCLUSIONS

RF ablation is superior to PEI in the treatment of small HCC with respect to overall survival, 1, 2, and 3 years survival rates, 1, 2, and 3 cancer-free survival rates, and tumor response. RF shows a significantly smaller risk of local recurrence.

Comparison of therapeutic effects between radiofrequency ablation and percutaneous microwave coagulation therapy for small hepatocellular carcinomas

BACKGROUND

Although thermal ablation therapies have gained fairly wide acceptance as an effective treatment for small hepatocellular carcinoma (HCC), there have been only a few clinical studies comparing the response to radiofrequency ablation (RFA) and percutaneous microwave coagulation therapy (PMCT). We evaluated the therapeutic efficacy and safety of these two procedures for the treatment of small HCC measuring < or = 2 cm in diameter.

METHODS

Thirty-four patients who had 37 nodules were treated by RFA and were compared with 49 patients (56 nodules) who underwent PMCT. Treatment was repeated until complete tumor necrosis was confirmed by contrast computed tomography (CT) scanning. The therapeutic efficacy and complications were retrospectively compared between the two procedures.

RESULTS

(i) There were significantly fewer treatment sessions (P < 0.001) in the RFA group than in the PMCT group, but the necrotic area was significantly larger (P < 0.001) in the former group. (ii) The local recurrence rate was significantly lower (P = 0.031) after RFA than after PMCT, although the ectopic recurrence rate showed no significant difference. (iii) The cumulative survival rate was significantly higher (P = 0.018) after RFA than after PMCT. (iv) The incidence of pain and fever after treatment was significantly higher in the PMCT group. Bile duct injury, pleural effusion, and ascites were also significantly more common in the PMCT group.

CONCLUSIONS

RFA is more useful than PMCT for the treatment of small HCC because it is minimally invasive and achieves a low local recurrence rate, high survival rate, and extensive necrosis after only a few treatment sessions.

Prophylactic administration of antibiotics unnecessary following ultrasound-guided biopsy and ablation therapy for liver tumors: Open-labeled randomized prospective study

AIM

To determine the prophylactic effect of antibiotics administration in the prevention of infection following an ultrasound-guided percutaneous liver biopsy or treatment of liver tumors, we performed an open-labeled randomized prospective study of patients who received prophylactic antibiotics after undergoing those procedures.

METHODS

We studied 101 patients, with ultrasound-guided percutaneous aspiration biopsies of the liver performed in 48 to diagnose diffuse liver diseases or liver tumors, while percutaneous ethanol-injection therapy was performed in two patients with malignant liver tumors and percutaneous radiofrequency ablation was performed in 51 patients. An oral administration of levofloxacin at 400 mg/day was given to 50 of the enrolled patients from the morning of the treatment day for three days. Preventive antibiotics were not administered to the remaining 51 patients. Body temperature, peripheral blood leukocyte number, c-reactive protein, alanine aminotransferase, and lactic dehydrogenase were measured daily for three days after treatment.

RESULTS

Most parameters changed following percutaneous treatments of liver tumors, though no significant differences were seen between the patients treated with antibiotics and those untreated. Most significantly, there was no difference in the frequency of post-procedure infection between the groups.

CONCLUSION

Our results suggest that prophylactic administration of antibiotics following a percutaneous liver biopsy and treatment of liver tumors does not have a significant impact on the post-procedure results or incidence of infection.

Laser ablation of liver metastases from colorectal cancer with MR thermometry: 5-year survival

PURPOSE

To determine technical success, technique effectiveness, complications, and survival after laser ablation of liver metastases from colorectal cancer.

MATERIALS AND METHODS

Eighty-seven consecutive patients (65 men and 22 women; mean age, 62.8 years) with 180 liver metastases from colorectal carcinoma were included between 1998 and 2005. They underwent laser ablation with magnetic resonance (MR) thermometry in 170 sessions. Indications for laser ablation were locally unresectable tumors (16.1%), metastases in both liver lobes (34.5%), and refusal of surgery and/or general contraindications to surgery (49.4%). Technical success, technique effectiveness, and complication and survival rates were evaluated retrospectively.

RESULTS

Technical success was achieved in 178 of 180 sessions (99%). Follow-up after 24-48 hours demonstrated an effectiveness rate of 85.6%. Local tumor progression rate was 10% after 6 months. Major complications included large pleural effusion, large subcapsular hematoma, abscess, large pneumothorax, pleuritis with fever, intrahepatic hemorrhage, and biloma. Mean survival from the time of diagnosis of the primary tumor was 50.6 months for all patients treated (95% CI, 44.9-56.3 months). Median survival time was 54 months and survival rates were 95.7% at 1 year, 86.2% at 2 years, 72.4% at 3 years, 50.1% at 4 years, and 33.4% at 5 years. The mean survival time after the first treatment was 31.1 months (95% CI, 26.9-35.3 months).

CONCLUSIONS

Laser ablation of liver metastases of colorectal cancer with MR thermometry appears safe and efficacious. Although the results are encouraging, direct comparison with other ablative modalities in a prospective clinical trial would be necessary to definitely show one modality is superior.

Neoplastic seeding after radiofrequency ablation for hepatocellular carcinoma

BACKGROUND

Neoplastic seeding reportedly occurs in up to 12.5% of patients treated with radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). The aim of this study is to assess the incidence, risk factors, and prognosis of neoplastic seeding after RFA among a large number of patients with a long-term follow-up.

METHOD

From February 1999 to December 2004, 1,031 patients underwent a total of 1,845 treatments with RFA for a total of 3,837 HCC nodules. The following variables were assessed to elucidate the risk factors of neoplastic seeding: age, sex, positivity for viral markers, tumor size, number of tumor nodules, number of RFA sessions, tumor location, percutaneous biopsy prior to RFA, alpha-fetoprotein (AFP), des-gamma-carboxy prothrombin (DCP) and lens culinaris agglutinin-reactive fraction of AFP (AFP-L3) levels, and the degree of tumor differentiation.

RESULTS

Neoplastic seeding was detected in 33 patients (3.2% per patient) at intervals of 4.8-63.8 (median, 15.2) months after RFA. On multivariate logistic regression analysis, only the poor differentiation degree was associated with the risk of neoplastic seeding (P= 0.012). Of tumor factors, tumor size, and AFP, DCP, and AFP-L3 levels were significantly associated with the poor differentiation degree. The cumulative survival rates 1 and 2 yr after the detection of neoplastic seeding were 86% and 47%, respectively.

CONCLUSION

Poor differentiation degree was the risk factor of neoplastic seeding after RFA for HCC. The surrogate markers for poor differentiation degree were larger tumor size and elevated tumor marker levels. Indication for RFA should be carefully considered for HCC patients under these conditions.

Intrahepatic dissemination of hepatocellular carcinoma after local ablation therapy

BACKGROUND/PURPOSE

We aimed to clarify the histological features of and risk factors for intrahepatic dissemination after local ablation therapy (LAT) for hepatocellular carcinoma (HCC).

METHODS

Between April 1992 and December 2005, 192 HCC patients underwent hepatic resection at our department, among whom were 17 patients who had local recurrences after LAT. Eight of these 17 patients had intrahepatic dissemination. The clinical and histological characteristics of these 8 surgically treated patients with intrahepatic dissemination were investigated.

RESULTS

Histologically, numerous intrahepatic metastases were observed, mainly in the same section as the treated tumor, together with main or sectional portal vein tumor thrombi. Before the ablation therapy, the average tumor diameter was 2.1 cm, and 62.5% of the tumors were adjacent to the main or sectional portal vein. In terms of therapeutic factors, 25% of the patients had a prior needle biopsy and 62.5% had insufficient safety margins.

CONCLUSIONS

LAT for HCCs (even those less than 3 cm in diameter) adjacent less than 5 mm to the main or sectional portal vein possibly promotes intrahepatic dissemination.

Techniques of interventional tumor therapy

INTRODUCTION

The last few years have seen the rapid development of new image-guided interventions for the local treatment of malignant tumors. The goal of this article is to provide an overview of the techniques that are most commonly used today in interventional oncology.

METHODS

Selective literature review on the current state of image-guided interventional techniques for local tumor therapy.

RESULTS

While surgery, radiation oncology, and systemic chemotherapy are still the three main pillars of tumor therapy, a broad range of minimally invasive, image-guided techniques for local tumor treatment is now available. These may be categorized as percutaneous injection of a toxic substance, transarterial embolization, thermal ablation, and internal radiotherapy. The choice of treatment depends on the type, location, and size of tumor. The greatest amount of clinical experience to date has been gathered in the treatment of primary and secondary hepatic malignancy, but there are interventional treatment options for virtually all regions of the body. At present, the utility of this form of treatment is limited for very large or multiple tumors; novel therapeutic options for these situations are now being studied.

DISCUSSION

The outcome of treatment depends on a judicious determination of the indication for it. The indication should be established by interdisciplinary consensus after all treatment options have been considered.

Radiofrequency ablation versus ethanol injection for early hepatocellular carcinoma: A randomized controlled trial

OBJECTIVE

To compare percutaneous ethanol injection (PEI), the standard approach which has been used for many years to treat early non-surgical hepatocellular carcinoma (HCC) in cirrhotic patients, and radiofrequency ablation (RFA), which has become an interesting alternative.

MATERIAL AND METHODS

A randomized trial was carried out on 139 cirrhotic patients in Child-Pugh classes A/B with 1-3 nodes of HCC (diameter 15-30 mm), for a total of 177 lesions. Patients were randomized to receive RFA (n=70) or PEI (n=69). The primary end-point was complete response (CR) 1 year after the percutaneous ablation of all HCC nodes identified at baseline. Secondary end-points were: early (30-50 days) CR, complications, survival and costs.

RESULTS

In an intention-to-treat analysis, 1-year CR was achieved in 46/70 (65.7%) and in 25/69 (36.2%) patients treated by RFA and PEI, respectively (p=0.0005). For lesions >20 mm in diameter, there was a larger CR rate in the RFA group (68.1% versus 26.3%). An early CR was obtained in 67/70 (95.7%) patients treated by RFA compared with 42/64 (65.6%) patients treated by PEI (p=0.0001). Complications occurred in 10 and 12 patients treated by RFA and PEI, respectively. The overall survival rate was not significantly different in the RFA versus PEI arm (adjusted hazard ratio=0.88, 95% CI: 0.50-1.53). There was an incremental health-care cost of 8286 euro for each additional patient successfully treated by RFA.

CONCLUSIONS

The 1-year CR rate after percutaneous treatment of early HCC was significantly better with RFA than with PEI but did not provide a clear survival advantage in cirrhotic patients.

Radiofrequency thermal ablation of breast cancer local recurrence: a phase II clinical trial

BACKGROUND

The role of radiofrequency (RF) ablation to treat local recurrence of breast cancer is unknown.

METHODS

We conducted a two-stage phase II clinical trial. Eligible patients had a histologically confirmed noninflammatory and < or =3 cm ipsilateral breast tumor recurrence. The tumor site was identified by intraoperative sonography. A LeVeen needle electrode (RadioTherapeutics Corp, Mountain View, Calif) was inserted into a single site within the tumor and radiofrequency ablation was performed using a RF-2000 generator (RadioTherapeutics Corp). After completion of radiofrequency, a mastectomy was performed. Conventional staining and nicotinamide adenine dinucleotide-diaphorase (NADH-diaphorase) cell viability staining were performed.

RESULTS

During the first stage, procedures were uneventful. Conventional, cytokeratin, and NADH-diaphorase staining identified persistent viable tumor cells in the RF-ablated region in three patients. This phase II trial was stopped after completion of the first stage because of insufficient efficacy.

CONCLUSION

We demonstrate in this study that RF ablation is a potential technique to destroy local recurrence of breast tumors but the technique we tested in this phase II clinical trial had insufficient efficacy to recommend its use in routine.

Radiofrequency ablation of the liver abutting stomach: in vivo comparison of gastric injury before and after intragastric saline administration in a porcine model

PURPOSE

To compare the in vivo gastric injury observed during radiofrequency (RF) ablation of the liver abutting the stomach before and after the intragastric administration of chilled saline.

MATERIALS AND METHODS

Twenty RF ablation zones were created in the livers of 10 pigs with a 1-cm-exposed active tip of an internally cooled electrode under ultrasound guidance for 10 min. Ten RF ablation zones were created before (non-saline group) and after (saline group) the intragastric administration of approximately 1000 mL of chilled saline, and 20 RF ablation zones were made in the posterior part of the left lobe abutting the stomach. The frequency and severity of the thermal injury observed in the stomach of the two groups were compared histologically.

RESULTS

All the resected gastric specimens showed thermal injuries of varying degrees of severity. The largest diameter of the gastric injury was significantly smaller in the saline group (mean 1.5 cm; range 1.3-1.8 cm) than in the non-saline group (mean 2.1cm; range 1.8-2.4 cm) (p=0.000). The saline group showed significantly less thermal injury to the muscular layer of the gastric wall by the histopathology (p=0.033).

CONCLUSIONS

The intragastric administration of chilled saline might be a useful technique for reducing the severity of gastric injury during RF ablation of the liver abutting the stomach.

Perineural air injection as a means of prevention of thermal injury of the sciatic nerve during radio frequency ablation: a preliminary experimental study in rabbits

OBJECTIVE

The purpose of this study was to determine whether perineural air injection before radio frequency (RF) ablation of thigh muscles can minimize thermal injury to the sciatic nerve.

METHODS

Eighteen percutaneous RF ablation procedures were performed in the thighs of 9 rabbits (control, n = 9, right thigh; experimental, n = 9, left thigh) with an internally cooled electrode (1-cm active tip). In the control group, the tip of the electrode was located in posterior muscles 5 mm away from the sciatic nerve before ablation. In the experimental group, sonographically guided air injection into the perineural space was performed just before ablation. Animals were killed 7 days after ablation, and the presence or absence of pathologic changes of the sciatic nerves (axonal necrosis, myelin digestion, endoneurial fibrosis, perineurial fibrosis, and dystrophic calcification) in both groups were compared under an optical microscope.

RESULTS

Perineural air injection was achieved successfully with a single puncture in all rabbits in the experimental group. All of the pathologic findings were observed much more frequently in the control group, and the differences in the frequencies of axonal necrosis and myelin digestion of the sciatic nerve between the groups were clinically significant (P < .05).

CONCLUSIONS

Perineural air injection may be useful for reducing the frequency of thermal injury during RF ablation of lesions adjacent to nerves.

Major complications of ultrasound-guided percutaneous radiofrequency ablations for liver malignancies: single center experience

BACKGROUND AND AIM

Despite radiofrequency ablation (RFA) for malignant liver nodular lesions having promising therapeutic effects, the trade-off between the risks and benefits must be acceptable. This study analyzed the major complications of ultrasound (US)-guided percutaneous RFA procedures encountered at a single center, by a single physician.

METHODS

A total of 104 patients (total 183 tumors) underwent 172 US-guided percutaneous RFA sessions between May 2003 and March 2006. The definition of major complications was according to the standardized Society of Interventional Radiology grading system (classification C-E).

RESULTS

Eighty-six patients had hepatocellular carcinoma (HCC) and 18 patients had hepatic metastatic tumors. Nine major complications occurred from 172 RFA sessions (9/172, incidence of 5.2% per session); namely, two cases of transient liver function impairment, two cases of infection (liver abscess and septicemia), two cases of tumor seeding along the ablated track, one case of colon perforation, one case of acalculous cholecystitis and, lastly, a case of hemocholecyst. We further analyzed the possible risk factors precipitating these complications, and found that only tumor size (Pearson's correlation coefficient, 0.324; P < 0.05) and baseline liver function reserve (compensated 0%, 0/148 vs decompensated 8.3%, 2/24; P = 0.019) were significant factors for the complication of transient liver function impairment.

CONCLUSION

Radiofrequency ablation for liver malignancy is a safe procedure with acceptable incidence of complications. Decompensated baseline liver function reserve and large tumor size are precipitating factors for transient liver function impairment after RFA and warrant a close follow up.