How does 68Ga‐prostate‐specific membrane antigen positron emission tomography/computed tomography impact the management of patients with prostate cancer recurrence after surgery?
Authors: Bianchi Lorenzo , Schiavina Riccardo , Borghesi Marco , Ceci Francesco , Angiolini Andrea , Chessa Francesco , Droghetti Matteo , Bertaccini Alessandro , Manferrari Fabio , Marcelli Emanuela , Cochetti Giovanni , Porreca Angelo , Castellucci Paolo , Fanti Stefano , Brunocilla Eugenio 
Published: May 2019

Objective

To evaluate the clinical impact of 68Ga‐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 68Ga‐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 68Ga‐prostate‐specific membrane antigen positron emission tomography/computed tomography was assessed according to different prostate‐specific antigen levels. Second, the independent predictors of 68Ga‐prostate‐specific membrane antigen positron emission tomography/computed tomography positive results were assessed. Finally, the intended treatment before revision of 68Ga‐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 68Ga‐prostate‐specific membrane antigen positron emission tomography/computed tomography. The effective clinical impact of 68Ga‐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 68Ga‐prostate‐specific membrane antigen positron emission tomography/computed tomography was 47.5%. Prostate‐specific antigen at 68Ga‐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 68Ga‐prostate‐specific membrane antigen positron emission tomography/computed tomography results (all P ≤ 0.03). 68Ga‐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 68Ga‐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 68Ga‐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

68Ga‐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.