Comparison of dual- and triple-freeze protocols for hepatic cryoablation in a Tibet pig model

Percutaneous cryoablation for hepatocellular carcinoma

Local ablation therapy is considered as a conventional treatment option for patients with early stage hepatocellular carcinoma (HCC). Although radiofrequency (RF) ablation is widely used for HCC, the use of cryoablation has been increasing as newer and safer cryoablation systems have developed. The thermodynamic mechanism of freezing and thawing used in cryoablation is the Joule-Thomson effect. Cryoablation destroys tissue via direct tissue destruction and vascular-related injury. A few recent comparative studies have shown that percutaneous cryoablation for HCCs is comparable to percutaneous RF ablation in terms of long term therapeutic outcomes and complications. Cryoablation has several advantages over RF ablation such as well visualization of iceball, no causation of severe pain, and lack of severe damage to great vessels and gallbladder. It is important to know the advantages and disadvantages of cryoablation compared with RF ablation for improvement of therapeutic efficacy and safety.

Safety and efficacy of a China-made cryoablation device in treatment of hepatocellular carcinoma smaller than 5 cm

AIM

To assess the safety and efficacy of a China-made cryoablation device in the treatment of hepatocellular carcinoma (HCC) smaller than 5 cm.

METHODS

A total of 33 patients with HCC smaller than 5 cm were treated by cryoablation using a China-made cryoablation device under the guidance of computed tomography. Operation-associated complications within and after procedures were evaluated. The efficacy of target lesions within procedures and local recurrence rate after procedures were evaluated with imaging modalities.

RESULTS

All 37 lesions of the 33 patients were successfully treated with a China-made cryablation device. Upon the finish of procedures, complete ablation was achieved in 83.78% (31/37) of lesions, and partial ablation was achieved in 16.22% (6/37). In a median follow-up period of 10.8 mo, 32 patients remained alive and 1 was lost to follow-up. The rate of local recurrence for target lesions was 30.3% (10/33), which is equal to that achieved with imported devices.

CONCLUSION

Our findings suggest that the China-made cryoablation device is safe and effective for HCC smaller than 5 cm with the capability of destroying the whole tumor lesion.

Percutaneous Cryoablation for Liver Cancer

Based on the primary tumor site, liver cancer can be divided into two categories: (1) primary liver cancer and (2) metastatic cancer to the liver from a distant primary site. Guided cryoablation via many imaging methods induces iceball formation and tumor necrosisand is an attractive option for treating unresectable hepatocellular carcinoma (HCC) and metastatic liver cancer. There are several advantages to using cryoablation for the treatment of liver cancer: it can be performed percutaneously, intraoperatively, and laparoscopically; iceball formation can be monitored; it has little impact on nearby large blood vessels; and it induces a cryo-immunological response in situ. Clinically, primary research has shown that percutaneous cryoablation of liver cancer is relatively safe and efficient, and it can be combined with other methods, such as radiation therapy, chemotherapy, and immunology, to control disease. Although research is preliminary, cryosurgery is fast becoming an alternative treatment method for HCC or liver tumors. Here, we review the mechanisms of liver tumor cryoablation, cryoablation program selection, clinical efficiency, and complications following treatment.

Cryotherapy for local recurrent dermatofibrosarcoma protuberans: experience in 19 patients

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive, cutaneous, malignant tumor characterized by a high propensity for local relapse. Wide and deep local excision with reconstructive surgery is the current standard therapy for DFSP, with a local recurrence rate (LRR) of nearly 40%. In this study, we cured 19 patients with local recurrence of DFSP with 39 sessions of percutaneous cryoablation performed between July 2004 and August 2008. The LRRs after one, two and three cryosurgery sessions per patient were 68%, 54% and 0%, respectively. Moreover, the LRR did not differ with tumor location or size. Furthermore, all patients had a progression-free survival of >5 years. Only minor complications such as fever, local edema, mild nerve injury and local pain occurred, and were resolved within 1 week with symptomatic treatment. In our experience, percutaneous cryoablation is a relatively safe and efficient technique for the treatment of local recurrence of DFSPs.

Percutaneous cryotherapy for metastatic bladder cancer: experience with 23 patients

Bladder cancer is the most common malignancy of the urinary tract and in many patients is metastatic at diagnosis. Chemotherapy is the standard treatment for these patients but has serious side effects and in many patients is not tolerated. To avoid the side effects of systemic chemotherapy, patients with late stage bladder cancer have sought cryotherapy in our hospital. We reviewed data for the past 4 years to evaluate the safety and efficiency of percutaneous cryotherapy in 23 patients. Within 3 days after cryosurgery, all complications of bladder cancer (e.g. hematuria, urinary irritation, hypogastralgia, lumbago) had decreased to some degree. No new complications (e.g. bladder perforation) occurred and all complications had disappeared completely after 2 weeks. The progression-free survival (PFS) of these patients was 14 ± 8 months. There was no effect on PFS of tumor location or histopathology; however, differentiation status and tumor size influenced the therapeutic effect of percutaneous cryoablation. In conclusion, percutaneous cryotherapy may be a safe and efficacious therapeutic option in the treatment of metastatic bladder cancer.