The dilemma of localizing disease relapse after radical treatment for prostate cancer: which is the value of the actual imaging techniques?

Only few patients with PSA relapse after radical treatment will show clinically detectable disease. Although the natural history of recurrent prostate cancer is often one of the slowly progressing diseases, in some men it can be rapid and may need a salvage treatment. In general, time to PSA relapse, PSA velocity and PSA doubling time are useful in patient assesment. In patients with PCa disease relapse after primary therapy, salvage treatment for a local recurrence should only be offered to patients with little risk of already having metastases. In these patients a systemic imaging negative for metastases is mandatory, a positive biopsy is not always necessary before radiotherapy, but is mandatory before salvage prostatectomy. In patients with a high risk of distant metastases and suitable for systemic salvage therapy, a positive lesion must be obviously visualized with one of the currently available imaging techniques. Transrectal ultrasound has low accuracy in the detection of the recurrence. Multiparametric Magnetic Resonance Imaging may have a role in the early phase of PSA relapse. Conventional imaging, such as bone scan and CT, are not suggested in the initial phase of BCR. Today, it has been reported that PET/CT allows changing the therapeutic strategy (from palliative to curative treatment and vice-versa) in about 20% of cases. In recent years, the new radiotracer 18F-FACBC has been proposed as a possible alternative radiopharmaceutical to detect PCa relapse. The aim of the present paper is to evaluate the management of patients with BCR after radical treatment of PCa from the urologist point of view.