Liver tumours treated effectively by MR-guided laser ablation
20 December 2005
Destruction of cancerous liver tissue by laser light guided by magnetic
resonance (MR) imaging was found to be as effective as traditional surgery
for some patients, in a large-scale, 12-year study in Germany.
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 (LITT) for the treatment of liver tumours resulting from
colorectal cancer. Between 1993 and 2005, the researchers treated 2,506
liver tumours and tracked survival rates to evaluate the long-term results
of the procedure. The average survival rate from the date of diagnosis was
3.8 years, which compares favourably to survival rates after traditional
surgery (approximately 1.5 to 5.0 years). The study was presented at the
annual meeting of the Radiological Society of North America (RSNA).
In LITT, also known as laser ablation, laser light is used to destroy
tumour tissue. According to the study's lead author, Martin Mack, M.D.,
laser ablation has many advantages over other treatment methods.
"Traditional surgical resection has higher morbidity and mortality rates
than laser ablation," said Dr. Mack, an associate professor in the
department of diagnostic and interventional radiology at the University of
Frankfurt. "Laser treatment can be done on an outpatient basis under local
anaesthesia. Typically, the patient stays only a couple of hours, instead of
a couple of weeks in the hospital after surgical liver resection," he said.
Laser ablation can be used to treat tumours that occur in both halves of
the liver — often during the same treatment — which is practically
impossible in a traditional surgery where typically only the left or right
lobe is resected. If new tumours are found during follow-up exams, it is
much easier to repeat laser treatment than to subject the patient to another
Laser ablation also holds advantages over radiofrequency ablation,
another minimally invasive method of treating liver tumours, because it can
be applied to different parts of the liver simultaneously and can be used
with MR guidance to provide the radiologist with an accurate image of the
tumour for precise targeting throughout the procedure. Radiofrequency
ablation can only treat one tumour at a time and cannot be used with
continuous MR monitoring.
Dr. Mack believes that laser combined with MR guidance will have
wide-ranging impact on the treatment of tumours 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 tumour ablation
together with chemotherapy will play the most important role in the
treatment of tumours in the years to come."