The GENPET Study - An Imaging Study of FCH-PET-CT in Men With Prostate Cancer and a DNA Repair Gene Mutation.

Inclusion Criteria: * Confirmed pathogenic germline mutation in any of the following genes BRCA1, BRCA2, MSH2, MSH6, MLH1, PMS2, CHEK2, PALB2 or ATM. * Over the age of 18 * Diagnosed with prostate cancer and at a time when staging imaging is clinically indicated; either: * At a new diagnosis * Biochemically progressing patients who were treated radically with surgery or radiotherapy (more than 6 months ago) and are currently not receiving hormonal treatment or chemotherapy * Patients on active surveillance with a PSA doubling time of 6 months or less Exclusion Criteria: * Diagnosis of other malignancy (excluding basal cell cancer/squamous cell cancer of the skin) within five years of diagnosis * Known metastatic prostate cancer, both local and distant * Patients who have received any oncological treatment within the last six months * Patients on any investigational drug treatment * Patients on steroids * Known history of inflammatory/infective diseases (e.g. sarcoidosis, tuberculosis, inflammatory bowel disease) * Contraindications to having an MRI using the standard MRI checklist (e.g. pacemakers, aneurysm clips, claustrophobia)