A new technique under Phase 1 clinical trial gave surgeons the ability to see a brain tumor glow like they’ve never seen before. And because of this powerful visual ability, they were able to successfully remove a golf-ball size brain tumor from a 2-year-old boy, giving him and his family a new lease on life.
Among cancer’s most insidious traits is its ability to camouflage itself alongside normal healthy tissues. This makes tumor removal even more complicated, as surgeons have to sometime resort to guessing. In some cases, a surgeon may err on the side of caution and opt to remove the tissue, even if they aren’t 100 percent sure is cancerous. However, this radical approach is not appropriate for delicate organs, such as the brain – here, excising any more than necessary could lead to a multitude of cognitive deficits.
But with cancer’s cunning ability to blend in, how can surgeons know for sure which tissue is healthy and which tissue is tumor? The naked eye can only be so good.
To extend a surgeon’s ability to differentiate cancer tissues in live operations, researchers developed a chemical called BLZ-100 Tumor Paint. This compound is described as a tumor ligand chlorotoxin conjugated to a fluorescent dye, indocyanine green. When injected intravenously prior to the surgery, a brain tumor that would otherwise be masked now glows bright green under a laser light and imaged with a near-infrared camera system.
This technique was recently conducted on a 2-year-old boy, named Hunter, diagnosed with a golf-sized brain tumor. "What I thought was probably just Hunter being a wobbly toddler with a virus turned out to be a brain tumor," said Coffman. "I will never forget that day. It was the most traumatic six hours of our lives."
With the help of BLZ-100 Tumor Paint, doctors were able to remove the majority of Hunter’s tumor. They intentionally left a small piece behind, as the position of the tumor on the brain stem compromised surgical benefits. This tumor was successfully treated with radiation and chemotherapy following the surgery. Hunter has been confirmed to be in full remission.
As the Phase 1 trial for this technique continues, Hunter’s doctors reflect on this powerful tool in cancer therapy.
"Cure is not just about successful treatment of a tumor, but successful treatment of a child," said Dr. Sarah Leary, principal investigator for the trial, and Hunter's oncologist at Seattle Children's. "Much of cancer treatment for children is a trade-off where curative therapy comes with serious long-term side effects. By lighting the way for expert surgeons, we're hopeful that BLZ-100 Tumor Paint could help improve the quality of life for children by reducing treatment-related damage to the healthy brain."
Additional sources: Seattle Children's Hospital, Blaze Bioscience