Laser procedure kills small liver tumors

Hepatocellular carcinoma is the most common type of liver cancer and often results from a hepatitis B or C infection. It usually is treated with surgical resection or liver transplantation. However, because most of these tumors are unsuitable for surgery at the time of diagnosis, ultrasound-guided percutaneous ablation with ethanol injection or with radio frequency are becoming increasingly popular alternative treatments. However, ethanol injection can take multiple sessions to completely kill the tumor, and radio frequency often is associated with complications

Dr. Vincenzo Arienti and Dr. Stefano Pretolani from Maggiore Hospital in Bologna, Italy, and their colleagues evaluated the efficacy and safety of using percutaneous laser ablation for treating hepatocellular carcinoma nodules. As reported in the March 2008 issue of Radiology, the researchers created a database of patients with liver tumors from nine treatment centers in Italy. It included 520 patients with an aggregate 647 nodules of various sizes who had been treated with percutaneous laser ablation over 1004 sessions.

The treatment involved delivering laser light to the tumor with multiple bare-tip 300-nm glass fibers inserted into four 21-gauge spinal needles during one session lasting approximately 6 min. Treatment effectiveness was evaluated with CT scans 30 to 45 days after the laser session.

The primary effectiveness rate — the percentage of cancer nodules killed in all the patients — was 60 percent for all such nodules and 81 percent in the nodules that were smaller than 3 cm. Fifteen patients had major complications, such as bile duct and hepatic vessel injury, which resulted mainly from technical or anatomical factors. Sixty-two patients experienced minor complications such as hemorrhage, inflammation and liver abscess, which were mainly associated with excess laser energy, a high bilirubin level and low prothrombin time.

Statistical analysis revealed that occurrences of major complications were about 22 times higher for patients who received laser ablation for deep nodules than for superficial ones and 32 times higher if the laser energy level exceeded 7200 J, regardless of size.

The researchers conclude that the complications experienced with laser ablation are primarily the result of technical problems rather than of tumor size or patient characteristics. They believe that it is a safe, minimally invasive treatment that can be used as an alternative to percutaneous ethanol injection and to radio frequency in some cases.