A Systematic Review on the Role of Imaging in Early Recurrent Prostate Cancer

CONTEXT: In patients treated for prostate cancer, a rising serum prostate-specific antigen (PSA) level is a first sign of relapse, but imaging is needed to determine the localization of the recurrence, which may be local, in lymph nodes, and/or metastatic. With the increasing success rate of earlier salvage therapy, the diagnosis has become pertinent when the recurrent PSA level is still very low. OBJECTIVE: To systematically review the literature on the role of the existing imaging techniques in patients with early recurrent prostate cancer. EVIDENCE ACQUISITION: A systematic literature search across the MEDLINE and EMBASE databases was conducted in February 2018, searching for original studies reporting on imaging in a (sub)group of patients with recurrent PSA levels not higher than 5ng/ml. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The methodological quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. EVIDENCE SYNTHESIS: A total of 98 studies were included in this systematic review, reporting on the role of transrectal ultrasonography (TRUS), computed tomography (CT), bone scintigraphy (BS), single-photon emission CT, multiparametric magnetic resonance imaging (mpMRI), whole-body MRI (wbMRI), and positron emission tomography (PET)-CT/MRI using 18F fluoro-deoxy-glucose, 11C choline, 18F (fluoro)(methyl)choline, 11C acetate, 18F FACBC (fluciclovine) and prostate-specific membrane antigen (PSMA)-based tracers. CT and BS were not sufficiently sensitive in the early recurrence setting. For the detection of local recurrence, TRUS or mpMRI can be used; however, at the lowest PSA levels, few data were available, only after radical prostatectomy, showing a wide range of positivity. TRUS or mpMRI need to be combined with (PET)-CT to assess distant disease, but new techniques such as wbMRI, PET-MRI, or PET-CT allow for an all-in-one approach. At recurrent PSA levels <0.5ng/ml, detection rates up to 31.3% were reported using (11)C choline PET-CT and up to 65.0% using (68)Ga PSMA-11 PET-CT. At recurrent PSA levels