Detection of Recurrent Prostate Cancer Using Prostate-specific Membrane Antigen Positron Emission Tomography in Patients not Meeting the Phoenix Criteria for Biochemical Recurrence After Curative Radiotherapy

Abstract Biochemical recurrence of prostate cancer (PCa) after curative radiotherapy is defined as a prostate-specific antigen (PSA) rise of ≥2 ng/ml above the nadir ("Phoenix criteria", 2005). With the introduction of prostate-specific membrane antigen positron emission tomography (PSMA-PET), the ability to localise PCa recurrences has increased markedly. Here, we reviewed 315 patients scanned with PSMA-PET after curative radiotherapy in the Prostate Cancer Network Amsterdam (2015–2018). Sixty-three patients (20.3%) were scanned below the Phoenix threshold (PSA rise Patient summary This study reports on the unexpected detection of prostate cancer (PCa) recurrences with prostate-specific membrane antigen positron emission tomography in patients treated with radiotherapy. This calls for re-evaluation of the current criteria for recurrent PCa after radiotherapy.