Lymph-node relapsed prostate cancer management and PET-driven external beam radiotherapy: salvage or palliative treatment?

New imaging modalities such as choline- positron emission tomography (PET) or PET/computed tomography (CT) may be useful to identify prostate cancer patients with small volume, limited nodal relapse ("oligo-recurrent"), potentially amenable to metastasis directed treatment (e.g. radiotherapy,) with the aim of long-term control of the disease, even in a setting traditionally considered prognostically unfavorable, so usually gone to palliative treatment. This report reviews the diagnostic tools and the main published data about the role of PET or PET/CT driven radiation therapy, (not only for the diagnosis, but also for the planning) in relapsed node prostate carcinoma, as an alternative therapeutic strategy than surgery or androgen deprivation therapy.