New method that lights up tumors could help scientists detect and remove them
A team of researchers has found a way to light up malignant tumors during surgery so that doctors can differentiate between the cancerous areas and healthy tissues, as per a press release.
When cancer metastasizes, it spreads to the nearby areas or organs of the body. While doctors are able to remove these metastatic tumors, sometimes surgery can’t remove all of cancer.
The study, published in the peer-reviewed journal Cancer Research, was conducted on mice. The team used a technique called ‘molecular imaging’, where chemicals are injected into the bloodstream, and these chemicals get attracted to the cancer cells in the body. These chemicals then light up during a process called ‘fluorescence’, thus helping the doctors identify the parts of tumors that weren’t removed during surgery.
To improve the visual quality of the images, the researchers then used an HD camera to capture short-wave infrared light (SWIR) fluorescence, which is invisible to the naked eye.
This technique could help in the treatment of Neuroblastoma
Neuroblastoma is a type of cancer that mostly occurs in infants and children. It develops from immature nerve cells found in various parts of the body. Accounting for around ten percent of malignant tumors in children and resulting in 15 percent of cancer-related deaths in the pediatric population, Neuroblastoma is one of the most challenging diseases for pediatric doctors and surgeons.
The study recognizes that the treatment and results of high-risk Neuroblastoma patients remain poor because surgeries can be tricky. While a radical resection, meaning the removal of the entire tumor along with some healthy tissues around it, is known to be the gold standard among oncologists, it’s a challenging surgery because Neuroblastoma infiltrates the abdominal and thoracic cavities, major nerves and vessels, and is tightly connected to the surrounding organs.
Researchers believe that fluorescence-guided surgery can address this challenge by providing a visual map of tumors using fluorescent dyes. This map will help surgeons differentiate between tumor tissues and healthy tissues and therefore help in the preservation of surrounding structures.
The study notes that although many of these tumor-specific techniques have been developed and are under investigation in clinical trials in adult populations, none are yet available for use in pediatric oncology.
This technique was developed by engineers at the Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS) at UCL and surgeons at Great Ormond Street Hospital (GOSH).
Study Abstract:
Fluorescence-guided surgery is set to play a pivotal role in the intraoperative management of pediatric tumors. Short-wave infrared imaging (SWIR) has advantages over conventional near-infrared I (NIR-I) imaging with reduced tissue scattering and autofluorescence. Here, two NIR-I dyes (IRDye800CW and IR12), with long tails emitting in the SWIR range, were conjugated with a clinical-grade anti-GD2 monoclonal antibody (Dinutuximab-beta) to compare NIR-I and SWIR imaging for neuroblastoma surgery. A first-of-its-kind multispectral NIR-I/SWIR fluorescence imaging device was constructed to allow an objective comparison between the two imaging windows. Conjugates were first characterized in vitro. Tissue-mimicking phantoms, imaging specimens of known geometric and material composition, were used to assess the sensitivity and depth penetration of the NIR-I/SWIR device, showing a minimum detectable volume of ~0.9 mm3 and depth penetration up to 3 mm. In vivo, fluorescence imaging using the NIR-I/SWIR device showed a high tumor-to-background ratio (TBR) for both dyes, with anti-GD2-IR800 being significantly brighter than anti-GD2-IR12. Crucially, the system enabled higher TBR at SWIR wavelengths than at NIR-I wavelengths, verifying SWIR imaging enables high-contrast delineation of tumor margins. This work demonstrates that by combining the high-specificity of anti-GD2 antibodies with the availability and translatability of existing NIR-I dyes, along with the advantages of SWIR in terms of depth and tumor signal-to-background ratio, GD2-targeted NIR-I/SWIR-guided surgery could improve the treatment of neuroblastoma patients, warranting investigation in future clinical trials.