H. Zhu, W. Chen, F. Wu, K. Li, H. Su, C. Jin, J. Bai, K. Zhou, L. Zhang, Z. Wang; Chongqing/CN

Purpose
The major complications of liver tumor treatment with radiofrequency ablation (RFA) are thermal damage to the organs surrounding the liver. For lesions that are adjacent to the cardiac cavities, a discussion of better therapeutic options remains necessary and has to take into account the effectiveness and complication rate of each technique. As a noninvasive extracorporeal therapy, high intensity focused ultrasound (HIFU) appears to be safe, effective, and feasible in the treatment of patients with malignancies. We employed to successfully perform HIFU therapy for the treatment of hepatocellular carcinoma near the diaphragm utilizing infusion of normal saline to push away the pulmonary tissue and to create a good acoustic pathway.

Material and methods
From January 2000 to December 2004, twenty five patients with HCC near the diaphragm were analyzed. All patients had HIFU treatment. The patients with a tumor size from 2.5 cm to 14.3 cm in diameter. The mean diameter of tumor was 5.5+/-2.5 cm. All 25 cases had 39 nodules including 15 cases with single nodule. According to TNM classification, 10 patients were diagnosed as stage II, 5 patients were stage III, and 10 patients were stage IV. The mean volume of infusion normal saline was 911+/-253 ml. MRI, CT, CDFI, and DSA image were used to evaluate the efficacy. The recurrence pattern was classified into local and distant recurrence. The recurrence rate was computed by Kaplan-Meier estimates and the Kaplan-Meier method.

Results
The 1-, 2-, 3- and 4-year cumulative local recurrence rate were 4%, 8%, 8%, and 8% and the 1-, 2-, 3- and 4-year cumulative distant recurrence rate were 22.1%, 37.7%, 37.7%, and 37.7%, respectively. The 1-, 2-, 3-, and 4-year overall cumulative survival rates were 82%, 53%, 35%, and 35%, respectively. No serious complications such as injury of diaphragm and bleeding occurred with this technique.

Conclusion
HIFU shows comparable results to other locoregional therapies for the treatment of HCC near diaphragm and the safety is better. Therefore, HIFU should be considered as the treatment of choice those patients with HCC near diaphragm.