153 Background: To identify sites and patterns of prostate cancer (PCa) recurrence following primary PCa treatment with 18F-choline PET/CT and estimate the number of patients potentially eligible for metastasis-directed therapy (MDT, defined as patients with up to 3 metastatic lesions). Methods: Between 7/7/2011 and 7/6/2016, 229 patients underwent a 18F-choline PET/CT for a biochemical PCa recurrence for potential inclusion in a randomized phase II-trial (STOMP). The trial randomizes patients with oligorecurrent (Orec) PCa between active surveillance (AS) and MDT. Patients were eligible for the trial in case of biochemical recurrence following primary prostate cancer treatment, up to 3 extracranial metastases and testosterone > 50 ng/ml. Patterns of recurrence were classified as local (prostate or prostate bed), distant (N1, M1a/b/c) or a combination of both. The number of lesions were counted per scan and patients with up to 3 distant lesions with or without a local recurrence were considered as ORec vs > 3 lesions as polyrecurrent (PRec). Results: A total number of 229 patients underwent 277 choline PET-CTs, resulting in 208 patients (91%) with a recurrence and 21 patients (9%) without any detectable recurrence. Twenty-two men (10%) had a local recurrence and 186 men (81%) had a distant recurrence, which was combined with a local recurrence in 17 men. Of the 186 patients, 131 (57%) were considered as ORec and 55 (24%) as PRec at median PSA values of 3.4 and 5.4 ng/ml, respectively (p < 0.003). ORec were categorized as N1: 16%, M1a: 8%, M1b: 13%, M1c: 2% or a combination of sites: 17% (Figure 1). Fifty-eight patients had 1 lesion (25%), 39 2 lesions (17%) and 34 3 lesions (15%). Men with ORec PCa were treated with AS, MDT or palliative ADT in respectively 27%, 27% and 1% of the cases. Sixty-two of ORec men (27%) agreed to be randomized in the STOMP-trial. PRec were categorized as N1: 2%, M1a: 1%, M1b: 3%, M1c: 1% or a combination: 17% (Figure 1). Thirteen patients had 4 lesion (6%), 9 5 lesions (4%) and 33 > 5 lesions (18%) Conclusions: Two out of three PCa recurrences on 18F-choline PET-CT are potentially salvageable with local therapy and/or metastasis-directed therapy. Clinical trial information: NCT01558427.
Direct comparison of choline PET/CT and MRI in the diagnosis of lymph node metastases in patients with prostate cancer