A new imaging technique designed to help surgeons identify the location of malignant brain tumors during surgery is showing promising early clinical trial results. The technique combines a new high-sensitivity near-infrared camera with a special imaging agent synthesized from an amino acid found in scorpion venom.
Treating gliomas, a lethal kind of brain tumor, can be incredibly difficult. These tumors don't respond well to conventional chemo or radiotherapy, and they tend to spread across a wide spectrum of brain tissue, making it difficult for surgeons to easily detect and remove all of the cancerous tissue.
The new imaging technique is based around a novel compound called tozuleristide (BLZ-100, which is an optimized synthetic version of a peptide found in scorpion venom. The compound naturally binds to brain cancer cells, and researchers added a fluorescent dye so under near-infrared light the tumor cells become easily distinguishable from normal tissue.
"With this fluorescence, you see the tumor so much clearer because it lights up like a Christmas tree," explains Adam Mamelak, senior author on the new research.
This early clinical trial established BLZ-100 is safe, non-toxic, and effective in binding with brain tumors. Seventeen adult brain cancer patients were tested and the imaging compound was found to generate no adverse side effects, while effectively illuminating a majority of tumors.
Alongside the new imaging agent, the clinical trial was testing an experimental camera system that can simultaneously take both near-infrared and white-light images. Previously, to achieve this kind of dual imaging in a surgical environment, multiple bulky cameras would be needed. This new technology allows real-time switching between two imaging views, helping surgeons home in on brain tumors and effectively remove the cancerous tissue.
"For a surgeon, this seamless integration of fluorescence imaging into the surgical microscope is very appealing," adds Mamelak.
The entire imaging technique is currently undergoing broader clinical trialing, including a study involving pediatric brain cancer, ahead of a hopeful FDA approval in the near future. It is suggested the BLZ-100 compound may also be effective in targeting other cancer types.
"The technique in this study holds great promise not only for brain tumors but for many other cancer types in which we need to identify the margins of cancers," says Keith Black, from Cedars-Sinai. "The ultimate goal is to bring greater precision to the surgical care we provide to our patients."
Thew new research was published in the journal Neurosurgery.
Source: Cedars-Sinai Medical Center
