Molecular imaging biomarker able to detect high-grade prostate cancer

A recent study has highlighted the ability of prostate-specific membrane antigen (PSMA) PET imaging to detect fast-growing primary prostate cancer and could prove significant in the care of patients with suspected prostate cancer that had not been confirmed by biopsy.

"We were able to demonstrate in our research that PSMA PET imaging was more specific than MR imaging for detection of clinically significant high-grade prostate cancer lesions, and importantly was able to distinguish benign prostate lesions from primary prostate cancer, currently a difficult diagnostic imaging task," said co-author Steven P. Rowe, MD, PhD, resident at Johns Hopkins Medical Institutions in Baltimore, in a statement.

Rowe added that the study also found a direct correlation between PSMA PET radiotracer activity in prostate cancer and the cancer’s Gleason score.

The study was published in the Journal of Nuclear Medicine.

Thirteen patients with primary prostate cancer were enrolled in the study. All were imaged with F-18 DCFBC PET prior to prostatectomy, and 12 of the patients also underwent pelvic prostate MRI.

While the results showed MRI was more sensitive than 18F-DCFBC PET for detection of primary prostate cancer in a per-segment and per-dominant lesion analysis, PET imaging offered a boost to specificity.

The authors found a per-segment specificity of 0.96 for PET imaging and 0.89 specificity for MRI in a non-stringent analysis, and a 1.00 versus 0.91 specificity, respectively, for stringent analysis. PET imaging was also highly specific for detection of high-grade lesions at least 1.1 mL in size, according to the authors.

A statement from the senior corresponding author, Steve Y. Cho, MD, associate professor at the University of Wisconsin School of Medicine and Public Health, noted the importance of the findings, while keeping an eye on the future.

"There are a number of PSMA-based PET agents currently being introduced into prostate cancer imaging, many with improved signal to background uptake and sensitivity from this earlier first-generation PSMA 18F-DCFBC PET radiotracer, which should further improve the detection of prostate cancer,” said Cho.

"While it is difficult to predict which of the numerous prostate cancer molecular imaging agents being developed will ultimately become clinically adopted, this work, in aggregate with that of other groups, suggests there are important advantages to the PSMA ligands for prostate cancer molecular imaging."