A novel imaging technique using prostate-specific membrane antigen (PSMA) is superior to conventional imaging for staging men with high-risk prostate cancer, according to a phase 3 trial conducted in Australia and published in the Lancet.
PSMA is overexpressed on prostate cancer cells; positron emission tomography–computed tomography (PET-CT) using PSMA allows tumour-specific imaging of the entire body.
Some 300 men with high-risk prostate cancer who were being considered for either radical prostatectomy or radiotherapy with curative intent were randomised to undergo PSMA PET-CT or standard CT with bone scanning. The primary outcome — accuracy for identifying pelvic nodal or distant metastatic disease — favoured PSMA PET-CT. In particular, such imaging had higher sensitivity than conventional imaging (85% vs. 38%) and higher specificity (98% vs. 91%).
The researchers say their study shows "unequivocal superiority" of PSMA PET-CT. They note that the effects on patient survival are unknown, but "improving accuracy is desirable because the detection of metastatic disease can prevent futile attempts at cure or better direct locoregional therapies."