A large-scale, 12-year study has found that laser ablation with magnetic resonance (MR) guidance is as effective as traditional surgery as treatment of liver tumors in selected patients, according to a presentation at the annual meeting of the Radiological Society of North America.

In the largest study of its type with the longest follow-up, 839 patients at the University of Frankfurt in Germany received MR-guided laser-induced thermotherapy for liver tumors resulting from colorectal cancer.

Between 1993 and 2005, the researchers treated 2,506 liver tumors and tracked survival rates to evaluate long-term results. The average survival rate from date of diagnosis was 3.8 years, which compares favorably with survival rates after traditional surgery (approximately 1.5 to 5.0 years).

In laser-induced thermotherapy, also known as laser ablation, laser energy is used to destroy tumor tissue. According to the study's lead author, Martin Mack, MD, laser ablation has many advantages over other treatment methods.

"Traditional surgical resection has higher morbidity and mortality rates than laser ablation," said Mack. "Laser treatment can be done on an outpatient basis under local anesthesia. Typically, the patient stays only a couple of hours, instead of a couple of weeks in the hospital after surgical liver resection."

Laser ablation can be used to treat tumors that occur in both halves of the liver?often during the same treatment?which is practically impossible in traditional surgery where typically only the left or right lobe is resected. If new tumors are found during follow-up exams, it is much easier to repeat laser treatment than to subject the patient to another open surgical procedure.

Mack believes that laser combined with magnetic resonance guidance will have wide-ranging impact on the treatment of tumors throughout the body, and may one day replace traditional surgery as the gold standard of treatment.

"Many surgeons are already performing local ablation instead of resection because they have already recognized the positive effect of local ablation," he said. "I believe that minimally invasive tumor ablation together with chemotherapy will play the most important role in the treatment of tumors in the years to come."