08 Apr 2013
MRI-guided laser interstitial thermal therapy system appears to improve survival in patients with otherwise inoperable tumors.
Results from a Phase I clinical trial suggest that laser ablation of deep-seated brain tumors may increase the survival time of patients with an otherwise inoperable form of the disease.
In the trial, which used an MRI-guided laser interstitial thermal therapy (LITT) system developed by Canada-based Monteris Medical, ten patients suffering from recurrent gliobastoma (rGBM) were treated.
rGBM is an invasive cancer of the brain that leaves sufferers with what specialists describe as a “dismal” prognosis, and a typical survival time of less than six months. Although conventional open surgery and re-section of the tumors does improve patient survival figures, fewer than half of those diagnosed with the condition can be operated on safely, mostly because of the location and size of their tumors.
Using Monteris’ “NeuroBlate” system, which features a 12 W, 1064 nm pulsed laser that heats and destroys the GBM tissue in a minimally invasive fashion, surgical teams at the University Hospitals Case Medical Center and elsewhere reported a median survival of 316 days.
Having initially performed the procedures in 2008 and 2009, they have just published the results of their study in the Journal of Neurosurgery. They say that the treatment appears to be safe and well-tolerated – although a much larger study is required to fully assess its effectiveness.
“NeuroBlate holds the promise of enabling the delivery of thermal ablation in real time with surgical precision in some patients with brain tumors in whom safe, conventional surgery is impractical or impossible,” concluded the team in their paper.
Commenting on the study in the same issue of the journal, two specialists from the Ohio State University Medical Center added: “Patients previously thought to have inoperable tumors may benefit most, not only by having their tumor removed, but by maximizing their adjuvant therapy options.”
Hyperthermia Treatment for Inoperable Brain Tumors at Barnes-Jewish Hospital:
LITT is in fact a relatively old surgical laser technique, having been used in cancer treatment for more than 20 years. However, the approach has mostly been used to treat cancer of the liver and prostate, where damage to tissue surrounding tumors is much more tolerable than in the brain – because of the proximity of critical neurological functions.
In a press release highlighting the study results, lead author Andrew Sloan – also a paid consultant for Monteris Medical and a member of the company’s medical advisory board – said:
“This technology is unique, in that it allows the surgeon not only to precisely control where the treatment is delivered, but the ability to visualize the actual effect on the tissue as it is happening.”
Sloan pointed out that, after their treatment, all ten patients were alert and responsive within two hours, and all but one were able to walk shortly afterwards. “Response and survival was also nearly ten and a half months, better than expected for patients with such advanced disease,” he said.
Gene Barnett, another of the paper authors and director of the Brain Tumor and Neuro-Oncology Center at Cleveland Clinic and Case Comprehensive Cancer Center, added that other minimally invasive treatments had proved to be ineffective following larger-scale follow-up and analysis, saying:
“Unlike therapies using ionizing radiation, NeuroBlate therapy results in tumor death at the time of the procedure. A larger national study will be developed, as a result of this initial success.” Like Sloan, Barnett is a paid consultant for Monteris.
Founded in 1999 to develop research at the St Boniface General Hospital in Winnipeg, venture-backed Monteris gained US Food & Drug Administration clearance for what is now known as the NeuroBlate system in 2009. It is also used to treat symptoms of epilepsy at two US hospitals.
Last year saw work begin on a larger US clinical trial aimed at treating brain cancers with the NeuroBlate. The “Laser Ablation After Stereotactic Radiosurgery (LAASR)” is expected to enrol 40 patients with metastatic (secondary) brain tumors who have been treated with conventional methods but suffered further progression of the cancer.
Participants for that study are currently being recruited, and the study should be completed in around a year’s time.