Localizing sites of disease in patients with rising serum prostate-specific antigen up to 1 ng/ml following prostatectomy: How much information can conventional imaging provide?

Purpose Accurate identification of the source of a detectable serum prostate-specific antigen (PSA) in the postprostatectomy setting is a major challenge among the urologic community. The aim of this study was to assess positivity rates of imaging examinations performed in patients with early PSA rise after prostatectomy and to summarize the management strategies adopted in this clinical scenario. Methods Institutional Review Board-approved retrospective study of 142 postprostatectomy patients with PSA rise up to 1 ng/ml who underwent evaluation with combination of multiparametric pelvic magnetic resonance imaging (MRI)±whole-body or bone MRI, bone scintigraphy, computed tomography (CT) chest-abdomen-pelvis, ¹⁸F-fludeoxyglucose-positron emission tomography (PET)/CT or ¹⁸F-sodium fluoride-PET/CT at a single tertiary cancer center. Imaging results were summarized per modality and compared with pathology findings. Results Pelvic MRI was positive in 15/142 (11%) patients (14 patients with local recurrence in the surgical bed and 1 patient with pelvic osseous metastases). Of these 15, 10 patients underwent additional imaging examinations; none revealed positive findings. Of the 127 patients with negative pelvic MRI, 54 (43%) underwent additional imaging examinations; only 1/54 had positive findings (false-positive T8 lesion on bone scintigraphy and FDG-PET/CT; biopsy was negative for cancer). Overall, 12/16 patients with positive imaging findings and 75/126 (60%) patients with negative imaging received treatment (radiation, hormones or chemotherapy). Conclusion The conventional imaging identified sites of disease, almost always in the form of local recurrence, in a minority of patients with early PSA rise postprostatectomy.