How does Ga-prostate-specific membrane antigen positron emission tomography/computed tomography impact the management of patients with prostate cancer recurrence after surgery?

Objective: To evaluate the clinical impact of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography on the planned management of prostate cancer patients with biochemical recurrence after surgery.

Methods: We enrolled 276 prostate cancer patients referred to Ga-prostate-specific membrane antigen positron emission tomography/computed tomography due to biochemical recurrence after surgery (two consecutive prostate-specific antigen assays ≥0.2 ng/mL). First, the detection rate of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography was assessed according to different prostate-specific antigen levels. Second, the independent predictors of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography positive results were assessed. Finally, the intended treatment before revision of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography was assessed by a multidisciplinary team based on the European Association of Urology guidelines, patient clinical condition and clinical parameters. Then, re-assessment of the treatment plan was prospectively recorded by the same board after revision of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography. The effective clinical impact of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography was rated as major (change in therapeutic approach), minor (same treatment, but modified therapeutic strategy) or none.

Results: The overall detection rate of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography was 47.5%. Prostate-specific antigen at Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (odds ratio 3.52) and prostate-specific antigen doubling time <3 months (odds ratio 3.98) were independent predictors of positive Ga-prostate-specific membrane antigen positron emission tomography/computed tomography results (all P ≤ 0.03). Ga-prostate-specific membrane antigen positron emission tomography/computed tomography led to a major treatment change in 177 cases (64.1%), with a minor clinical impact of 2.5%. The overall clinical impact of Ga-prostate-specific membrane antigen positron emission tomography/computed tomography was 42.4%, 27.7%, 21.2% and 8.7% in men with prostate-specific antigen at Ga-prostate-specific membrane antigen positron emission tomography/computed tomography of 0.2-0.4, 0.5-1, 1.1-2 and >2 ng/mL, respectively.

Conclusions: Ga-prostate-specific membrane antigen positron emission tomography/computed tomography allows clinicians to radically change the intended treatment approach before imaging evaluation, in roughly two out three individuals.