Radiofrequency ablation of liver tumors: a novel needle perfusion technique enhances efficiency

Laparoscopic microwave ablation of human liver tumours using a novel three-dimensional magnetic guidance system

BACKGROUND

Accurate antenna placement is essential for effective microwave ablation (MWA) of lesions. Laparoscopic targeting is made particularly challenging in liver tumours by the needle's trajectory as it passes through the abdominal wall into the liver. Previous optical three-dimensional guidance systems employing infrared technology have been limited by interference with the line of sight during procedures.

OBJECTIVE

The aim of this study was to evaluate a newly developed magnetic guidance system for laparoscopic MWA of liver tumours in a pilot study.

METHODS

Thirteen patients undergoing laparoscopic MWA of liver tumours gave consent to their participation in the study and were enrolled. Lesion targeting was performed using the InnerOptic AIM™ 3-D guidance system to track the real-time position and orientation of the antenna and ultrasound probe.

RESULTS

A total of 45 ablations were performed on 34 lesions. The median number of lesions per patient was two. The mean ± standard deviation lesion diameter was 18.0 ± 9.2 mm and the mean time to target acquisition was 3.5 min. The first-attempt success rate was 93%. There were no intraoperative or immediate postoperative complications. Over an average follow-up of 7.8 months, one patient was noted to have had an incomplete ablation, seven suffered regional recurrences, and five patients remained disease-free.

CONCLUSIONS

The AIM™ guidance system is an effective adjunct for laparoscopic ablation. It facilitates a high degree of accuracy and a good first-attempt success rate, and avoids the line of site interference associated with infrared systems.

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes.

DC-CIK cell therapy combined with transcatheter arterial chemoembolization and radiofrequency ablation for treatment of small hepatocellular carcinoma

AIM: To evaluate the efficacy of dendritic and cytokine-induced killer cell therapy (DC-CIK) after transcatheter arterial chemoembolization combined with radiofrequency ablation in patients with small hepatocellular carcinoma (SHCC) and to investigate the changes in immunologic indexes in patients with SHCC.

METHODS: Eighty-five patients with SHCC treated at our hospital from April 2008 to April 2012 were recruited and divided into two groups after transcatheter arterial chemoembolization (TACE) and radiofrequency ablation (RFA): a study group and a control group. The study group (n = 41) received DC-CIK therapy 6 times 7 days after TACE and RFA, and the number of DC-CIK cells was above 1.0×10¹⁰. The control group (n = 44) only received TACE and RFA.

RESULTS: AFP differed significantly between before and after treatment in both the control group (494.5 mg/L ± 51.3 mg/L vs 226.5 mg/L ± 39.4 mg/L, P < 0.05) and the study group (486.4 mg/L ± 54.8 mg/L vs 168.7 mg/L ± 49.5 mg/L, P < 0.01). ALT and AST differed significantly between before and after treatment in the study group (66 U/L ± 6.3 U/L vs 31 U/L ± 5.9 U/L, 68 U/L ± 7.7 U/L vs 45 U/L ± 3.7 U/L, P < 0.05 for both), but showed no significant differences in the control group (67 U/L ± 7.4 U/L vs 65 U/L ± 6.2 U/L, 63 U/L ± 4.5 U/L vs 61 U/L ± 5.2 U/L, P > 0.05 for both). The efficacy evaluated by imaging examination in the study group was better than that in the control group (87.80% vs 79.54%, P < 0.05). The 1-, 2- and 3-year survival rates were significantly better in the study group than in the control group (95.1% vs 90.9%, 71.6% vs 65.9%, 68.3% vs 59.1%, P < 0.05 for all). The percentages of CD3⁺ and CD16⁺CD56⁺ cells and the ratio of CD4⁺/CD8⁺ cells were significantly increased after DC-CIK therapy (P < 0.05 for all), while the percentage of CD8⁺ cells was decreased in the study group (P < 0.05).

CONCLUSION: Sequential DC-CIK therapy after TACE and RFA can improve hepatic function and immune function of patients with SHCC, and may play an important role in reducing recurrence of SHCC and prolonging the survival time.

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

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

Radiofrequency ablation of colorectal hepatic metastases

Radiofrequency ablation (RFA) may be performed intraoperatively, laparoscopically, or percutaneously. The percutaneous approach is associated with the least procedural risk and may be performed under local anesthesia. Percutaneous RFA should be considered a primary treatment option for patients with unresectable hepatic tumors or conditions that prohibit general anesthesia or abdominal surgery. Continually improving thermal ablation and imaging technologies are likely to further increase tumor ablation efficacy and expand its role in treatment of hepatic metastases.