‘Dual-mode’ tracer enables visual and audio guidance in prostate procedures
The fluorine-18–based tracer, enhanced by Geiger counter feedback, could offer surgeons high resolution PET images to identify ‘hidden’ cancer.
A new tracer, labelled with fluorine-18, has demonstrated promise in providing consistent and targeted guidance for surgeons conducting prostate procedures in a preclinical evaluation. The tracer offers high optical brightness for PET imaging as well as the option for auditory guidance via a Geiger counter.
The American Cancer Society projects 313,780 new prostate cancer cases will be diagnosed in 2025. Current treatment options include chemotherapy and radiotherapy, and, in severe cases, surgery to remove the prostate gland. However, this brings a high risk of long–term bladder and bowel problems due to the complex, intertwined system of nerves in that area.
A new way of visualizing prostate cancer
In research from University of British Columbia (UBC; BC, Canada), a team has developed this new tracer, which binds to prostate–specific membrane antigen (PSMA), and tested it on mice with human tumors implanted in them.
“Our tracer provides high-resolution visual guidance, but would also allow a surgeon to use a hand-held Geiger counter probes to ‘hear’ areas of high radiation density that would accumulate in cancerous tissue not immediately visible – whether it’s a lymph node, or distant metastasis, or local invasion in the like the bowel or the gut,” explained David M Perrin, UBC chemist and paper senior author.
“There’s a real lack of good clinical options when it comes to dual-mode PSMA tracers. So, we feel this could fill an incredibly useful function in the treatment spectrum for prostate cancer, and potentially other diseases like larynx and ovarian cancer if the same approach can be applied to these.”
The team developed an organotrifluoroborate for one-step radiofluorination at Curie levels of [18F] fluoride, two fluorescein moieties (FAM and FITC) for fluorescent visualization and two pharmacophores based on clinically validated scaffolds PSMA-617 and PSMA-1007. The tracers were evaluated in xenografts.
Improving outcomes, bringing hope
“The implementation of dual–mode fluorescent-PET tracers in the surgical field is an exciting new approach to maximize benefit and minimize harm associated with more extended lymph node removal as well as to decrease the rate of positive surgical margins of a radical prostatectomy,” commented Larry Goldenberg, UBC, who was not involved in the study. “This novel approach has the potential to maximize local disease control and theoretically improve oncologic outcomes.”
Perrin’s team hope to continue progressing the tracer, with Good Manufacturing Practices assessments, toxicity testing and validation runs.