Using Lasers to Destroy Liver Tumours
Laser energy can destroy liver tumours in patients who are ineligible for surgery, resulting in survival outcomes similar to patients who undergo traditional surgery.
A New Treatment Option
The laser is directly applied to the tumour through optical fibres.
Photo courtesy of Dr. M. Mack.
The standard treatment for patients with metastatic liver cancer is surgical resection to remove part of the liver; however, 70% to 90% of patients are ineligible for resection due to the number, size or position of the tumours.[1] A new option for these patients is to destroy the liver tumour(s) using magnetic resonance-guided laser-induced interstitial thermotherapy (MR-guided LITT).
The Technology
MR-guided LITT is performed with the Medilas™ Fibertom 5100 laser (Dornier, Germany) and a laser application kit (Somatex, Germany). The laser applicator is compatible with MR imaging, which provides the visualization necessary to precisely position the laser probe in the tumour.
The Procedure
An interventional radiologist performs MR-guided LITT in an outpatient setting where patients receive local anesthesia.[2] The laser procedure takes approximately 20 minutes.[3] Larger or multiple tumours can be treated simultaneously using multiple laser applicators.
Patient Group
Unlike liver resection, MR-guided LITT is a suitable treatment for multiple liver tumours, tumours in both lobes of the liver and tumour recurrence.[3] However, the treatment is generally limited to patients with five or fewer tumours that each measure less than 5 cm.[2–4]
Regulatory Status
The Medilas Fibertom 5100 laser is not licensed in Canada. It received US Food and Drug Administration approval in February 1997.
Evidence
In a 12-year prospective case series, 646 patients with five or fewer liver metastases who underwent MR-guided LITT demonstrated an average survival time of 48 months from the first treatment.[4] This compares with an average survival time of 25 to 35 months for patients who undergo liver resection.[5]
Low rates of major complications following 2,132 MR-guided LITT procedures were reported in one study, including pleural effusion requiring thoracentesis (0.8%), liver abscess (0.7%), bile duct injury (0.2%), segmental infarction (0.1%) and hemorrhage requiring blood transfusion (0.05%). The death rate was 0.1%.[2] By comparison, the mortality rate following surgical resection of liver tumours is approximately 5.0%.[3]
MR-guided LITT has not been used in randomized studies. Dr. Martin Mack, a LITT researcher (Institute of Diagnostics and Interventional Radiology, Frankfurt) said that efforts to conduct a randomized study have been unsuccessful because most patients refused open surgery over the less invasive MR-guided LITT.
Cost
According to the manufacturer, the Medilas Fibertom 5100 laser costs approximately US$65,000. Dr. Mack estimates that MR-guided LITT costs approximately C$7,000 per patient procedure depending on the size of tumours. This cost includes all required materials and diagnostics.
References
[1] Gannon CJ, et al. Semin Radiat Oncol 2005;15(4):265-72.
[2] Vogl TJ, et al. Radiology 2002;225(2):367-77.
[3] Vogl TJ, et al. Med Laser Appl 2005;20(2):115-8.
[4] Mack MG, et al. Presentation at RSNA 2005; 2005 Nov 27-Dec 2; Chicago.