Reuters Health Information (2011-04-08): High-intensity ultrasound gets high marks for HCC ablation
Drug & Device Development
High-intensity ultrasound gets high marks for HCC ablation
Last Updated: 2011-04-08 18:57:01 -0400 (Reuters Health)
NEW YORK (Reuters Health) - High-intensity focused ultrasound (HIFU) might hold some promise for patients with unresectable hepatocellular carcinoma (HCC), according to a small uncontrolled study from Hong Kong.
The use of HIFU to treat liver cancer is still in its infancy, the authors note. Known to be effective against liver cancer since the early 1990s, the practice never caught on, primarily because it was difficult to target tumors accurately and to monitor the ablation process.
The accuracy of HIFU has improved significantly, but Dr. Kelvin Ng, who led the study, and his colleagues say there's still a great need to identify factors that influence its success in patients with HCC or that predict survival afterward.
In a March 9th online paper in Annals of Surgery, the researchers contribute their own experience in 49 patients treated at Queen Mary Hospital in Hong Kong from 2006 to 2008.
In 28 patients, HIFU was the primary treatment. Liver tumors in the others had been treated with surgery, radiofrequency ablation, chemoembolization, or some combination of those methods.
Each patient had a single session of HIFU for unresectable HCC (median tumor size, 2.2 cm). Just over 83% had a single tumor. To prevent injury to the lung and diaphragm, doctors induced an artificial right pleural effusion in 63% of the patients.
Two patients developed first-degree skin burns around the treatment site, and another had second-degree burns. All three burn cases were due to errors in the degree of acoustic power.
Another patient had bruising over the right chest wall, which was attributed to a bleeding complication associated with a pleural effusion procedure.
One patient died of a heart attack the day after the procedure; this patient's underlying ischemic heart disease had not been recognized beforehand.
The authors deemed the technique effective in 39 patients; the other 10 had residual tumors detected a month after the treatment.
Out of the overall total of 57 nodules, HIFU eradicated 47, for a primary technique effectiveness rate of 82%.
One- and three-year overall survival rates were 87.7% and 62.4%, respectively. One- and three-year disease-free survival rates were 40.7% and 0%, respectively.
Child-Pugh tumor grade was the only clinical or pathological factor to significantly predict survival.
The most significant factor associated with complete ablation was tumor size. The primary technique effectiveness was 91% for tumors <3.0 cm, vs 59% for larger tumors.
Previous chemoembolization with Lipiodol (ethiodized oil) was also linked with a greater rate of success, but not to a statistically significant extent.
Despite the study's drawbacks - it was not controlled, it had a relatively short follow-up, and a small patient cohort - the authors say it "has provided an insight into a new direction for ablation treatment for hepatocellular carcinoma."
Ann Surg 2011.