New Imaging Method Accurately Identifies Surgical Margin Status in Radical Prostatectomy

Radical prostatectomy, the removal of the prostate gland and surrounding tissues, is a primary treatment option for localized prostate cancer. Incomplete removal of the cancer tissue during this procedure is associated with poorer clinical outcomes, including tumor recurrence and prostate cancer-related mortality. Prostate-specific membrane antigen (PSMA) ligand positron emission tomography (PET) is utilized to detect prostate cancer in both primary staging and during biochemical recurrence. Cerenkov luminescence is a phenomenon that occurs when PET imaging agents emit optical photons.

In this feasibility study, the researchers sought to evaluate diagnostic accuracy of CLI in detecting prostate cancer, particularly cancer tissue that remains at the resection margin during radical prostatectomy.

The single-center study enrolled 10 patients with high-risk primary prostate cancer. ⁶⁸Ga-PSMA PET scans were performed prior to radical prostatectomy and intraoperative CLI of the excised prostate. Margin assessment was performed postoperatively by analyzing elevated signals present in CLI images, and tumor-to-background ratios were calculated. Results were confirmed with postoperative histopathology to determine tumor margin status.

Investigators were able to successfully detect tumor cells on the incised prostate CLI images, which were confirmed via histopathology. Two of three patients who had positive surgical margins, or remaining cancer cells at the resection site, were correctly identified using CLI images. Overall, 25 of 35 CLI regions of interest successfully visualized tumor signaling in line with standard histopathology.

“Intraoperative radioguidance with CLI may help surgeons in the detection of extracapsular extension, positive surgical margins, and lymph node metastases with the aim of increasing surgical precision,” coauthor Christopher Darr, PhD, of the University Medical Center Essen in Essen in Germany, said in a press release. “The intraoperative use of CLI would allow the examination of the entire prostate surface and provide the surgeon with real-time feedback on the resection margins.”