Prostate cancer is the second most common cancer in men in the USA, according to the CDC, and is one of the leading causes of cancer death among men of all races. Treatment following recurrence is variable, but early detection of recurrence is key for both treatment and survival prospects.
A recent study published in The Journal of Nuclear Medicine reported that the novel Ga-68-prostate-specific membrane antigen (PSMA)-ligand PET/CT imaging method has substantially higher detection rates of PSMA in individuals with biochemical recurrence following radical prostatectomy compared with other imaging methods. Of particular note, the hybrid PSMA-ligand identified a large number of positive findings in the clinically important range of low prostate-specific antigen (PSA) values (<0.5 ng/ml).
The study evaluated 248 individuals with biochemical recurrence following radical prostatectomy. All patients were given contrast-enhanced PET/CT following injection of Ga-68-PSMA ligand, and the detection rates were correlated with PSA level and PSA kinetics. Influencing factors assessed included primary Gleason score and antihormonal treatment, as well as contribution of PET and morphological findings to the final diagnosis.
In 89.5% of patients, the test detected above-average levels of PSMA. Matthias Eiber, corresponding author of the study, noted, “The study is the first to examine this highly promising PET tracer in the use of a homogeneous patient collective consisting of only those with biochemical recurrence after radical prostatectomy. It found superb detection rates compared to other tracers, like choline, or imaging modalities, like MRI. For patients, this means that the referring urologist can receive earlier and more precise information about the site and extent of metastatic disease. Physicians will also be better able to estimate whether a PSMA-PET scan might be useful in a specific setting.”
Of note, compared with CT, Ga-68-PSMA-ligand PET/CT imaging exclusively provided pathological findings in 32.7% of patients; in 24.6% of patients it exclusively identified involved regions; and for those with a higher Gleason score detection, efficacy was significantly increased.
Eiber commented, “These findings will certainly enhance the use of PET in the diagnostic workup of patients with recurrent prostate cancer. When regulatory hurdles and reimbursement issues are overcome, this tracer might gain significant acceptance beyond Europe.”