PSMA PET/CT imaging for biochemical recurrence of prostate cancer after radiotherapy: is it necessary to review the Phoenix criteria?

Purpose PSMA positron emission tomography (PET)/CT imaging and new systemic treatment strategies have been recently implemented in the routine care of patients with prostate cancer. In the new era of PSMA PET/CT imaging, the definition of recurrence as established by the Phoenix criteria may be questioned. Methods A search of the evidence published in the Medline, Scopus, and Embase databases has been carried out to identify the most relevant findings published in the literature in the last 10 years up to July 2022. QUADAS-2 analysis has been carried out. Results Published data show evidence for the diagnostic superiority of PSMA PET/CT for biochemical recurrence after radiotherapy compared to conventional imaging techniques. Several studies show that up to 80% of patients not meeting the Phoenix criteria for biochemical recurrence present disease progression by PSMA PET/CT. These patients may potentially benefit from metastasis-directed therapies (MDT), such as SBRT (stereotactic body radiotherapy) and surgery. SBRT shows a broad safety profile and potential clinical benefit in patients with oligo-metastatic prostate cancer after definitive RT (radiation therapy). Conclusions The development of PSMA PET/CT questions the need for a review of the Phoenix criteria. Solid studies are needed to evaluate new PSA thresholds to redefine these criteria considering the clinical benefit to the patient of changing the therapeutic approach at different stages of the disease.