Our journal round-up this month includes articles on combined RFA and surgical approaches, RFA effectiveness, new microwave ablation equipment, and possible complications of RFA.

Combination therapies

Disease course after liver transplantation for hepatocellular carcinoma in patients with complete tumor necrosis in liver explants after performance of bridging treatments

Eur J Med Res. 2005;10(12):539-42

The German group studied the disease course of patients with hepatocellular carcinoma (HCC) showing complete tumor necrosis in their liver explants after undergoing bridging treatments followed by liver transplantation (LTx). The authors evaluated data from 10 patients with liver cirrhosis who experienced complete tumor necrosis after undergoing bridging treatments for HCC prior to LTx. Four patients underwent RFA and six patients were treated with transarterial chemoembolization. All patients were alive without recurrence after a median follow-up of 19 months. The authors concluded that achievement of 100% tumor necrosis by means of bridging treatments followed by LTx for HCC is characterized by a very low recurrence rate and should receive further consideration and study.

Radiofrequency assisted liver resection—a novel technique

Hepatogastroenterology 2005 Nov-Dec;52(66):1685-7.

The authors describe a novel technique of combining liver resection with RFA in a patient with colorectal liver metastases. They indicate RFA with standard surgical resection of liver cancers provides a quick, relatively bloodless operation that may reduce morbidity and mortality that is easy to learn. Following laparotomy, the physicians used a cooled-tip RFA probe to ablate liver parenchyma 2 cm away from the edge of a tumor identified with intraoperative ultrasound. To achieve full thickness of RFA, several insertions were applied. The length of the resection was 45 minutes with a blood loss of 30 mL. The patient was discharged on the sixth postoperative day without complications.

Kidney

Renal tumor radiofrequency ablation

Minerva Urol Nefrol. 2005 Dec;57(4):261-9

The authors review literature on renal RFA from 1990 to the present. They find that RFA is an effective minimally invasive alternative for small renal masses in patients with significant comorbidities that preclude extirpative surgery. Limited follow up from a number of series demonstrate a success rate of 92%. The authors determine that the short-term efficacy and minimum morbidity of RFA is encouraging, and conclude that RFA provides a versatile tool in the minimally invasive treatment of renal cancer.

New equipment for microwave ablation

Hepatocellular carcinoma: Microwave ablation with multiple straight and loop antenna clusters—pilot comparison with pathologic findings

Radiology 2006, 10.1148/radiol.2383041592

The authors evaluate the clinical implementation of triangular and spherical designs for simultaneous multiple-antenna ablation of human hepatocellular carcinoma (HCC) with a recently engineered microwave coagulation system. They studied nine patients with resectable HCC who underwent intraoperative ultrasonography-guided tumor ablation followed by resection and pathologic examination. Standard single-straight (n = 2), triangular triple-straight (n = 4), and spherical triple-loop (n = 3) antenna configurations produced mean estimated coagulation volumes of 16.7, 51.7, and 54.3 cm, respectively, during a single concurrent five to 10-minute ablation cycle. The authors conclude that the triple-loop configuration yielded the most uniformly round ablation shape, and determine that simultaneous activation of multiple straight or loop antennae is a potentially promising technique for rapid and effective treatment of large HCCs.

Complications

Liver abscess formation after radiofrequency ablation in patients with hepatocellular carcinoma

AJR 2006; 186:582-583

Drs. Antonio Giorgio and Giovanna Ferraioli respond to an earlier article written by Dr. Choi and colleagues that concluded that treatment with an internally cooled electrode system is a significant risk factor for liver abscess formation. Giorgio and Ferraioli contend that the abscess rate observed seemed high compared with their experience, and posit that the complication of liver abscess may occur after RFA of tumors near the intestine, probably because of contamination of the area of radiofrequency-induced necrosis by pathogens from the digestive tract.

Drs. Dongil Choi and Hyo K. Lim reply that the abscess rate they reported was consistent with a recent French study, and posit that the differences among the abscess rates reported by researchers at many different institutions might result from differences in the aggressiveness with which researchers perform radiofrequency ablation for treatment of difficult cases. They further report that the tumors developing abscesses were located throughout the right hepatic lobe, and of 14 ablation zones developing abscesses, only two abutted the colon.

Choi and Lim suggest that most abscesses in the study were associated with retrograde enteric bacterial contamination of the bile ducts. RFA could have connected the biliary tract and ablation zone by severe thermal injury to the bile ducts and the ablation zones could have been contaminated by enteric bacteria.