title: Target Definition in Salvage Radiotherapy for Recurrent Prostate Cancer: The Role of Advanced Molecular Imaging.
abstract: Salvage radiotherapy (SRT) represents the main treatment option for relapsing prostate cancer in patients after radical prostatectomy. Several open questions remain unanswered in terms of target volumes definition and delivered doses for SRT: the effective dose necessary to achieve biochemical control in the SRT setting may be different if the tumor recurrence is micro- or macroscopic. At the same time, irradiation of only the prostatic bed or of the whole pelvis will depend on the localization of the recurrence, local or locoregional. In the "theragnostic imaging" era, molecular imaging using positron emission tomography (PET) constitutes a useful tool for clinicians to define the site of the recurrence, the extent of disease, and individualize salvage treatments. The best option currently available in clinical routine is the combination of radiolabeled choline PET imaging and multiparametric magnetic resonance imaging (MRI), associating the nodal and distant metastases identification based on PET with the local assessment by MRI. A new generation of targeted tracers, namely, prostate-specific membrane antigen, show promising results, with a contrast superior to choline imaging and a higher detection rate even for low prostate-specific antigen levels; validation studies are ongoing. Finally, imaging targeting bone remodeling, using whole-body SPECT-CT, is a relevant complement to molecular/metabolic PET imaging when bone involvement is suspected.
authors.affiliation: Division of Nuclear Medicine, Hospital of Neuchâtel, Neuchâtel, Switzerland; Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Gaël
authors.initials: G
authors.lastname: Amzalag
authors.affiliation: Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital , Geneva , Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Rager
authors.affiliation: Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital , Geneva , Switzerland.
authors.forename: Claire
authors.initials: C
authors.lastname: Tabouret-Viaud
authors.affiliation: Division of Nuclear Medicine, Hospital of Neuchâtel, Neuchâtel, Switzerland; Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Wissmeyer
authors.affiliation: Division of Radiology, Geneva University Hospital , Geneva , Switzerland.
authors.forename: Electra
authors.initials: E
authors.lastname: Sfakianaki
authors.affiliation: Division of Radiology, Geneva University Hospital , Geneva , Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: de Perrot
authors.affiliation: Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland; Faculty of Medicine, Geneva University, Geneva, Switzerland.
authors.forename: Osman
authors.initials: O
authors.lastname: Ratib
authors.affiliation: Faculty of Medicine, Geneva University, Geneva, Switzerland; Division of Radiation-Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Raymond
authors.initials: R
authors.lastname: Miralbell
authors.affiliation: Department of Radiology and Nuclear Medicine, Stadtspital Triemli , Zurich , Switzerland.
authors.forename: Giampiero
authors.initials: G
authors.lastname: Giovacchini
authors.affiliation: Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland; Faculty of Medicine, Geneva University, Geneva, Switzerland.
authors.forename: Valentina
authors.initials: V
authors.lastname: Garibotto
authors.affiliation: Faculty of Medicine, Geneva University, Geneva, Switzerland; Division of Radiation-Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zilli
keywords: MRI; PET; PSMA; choline; prostate cancer; salvage radiotherapy