Pre-treatment 18F-choline PET/CT is prognostic for biochemical recurrence, development of bone metastasis, and cancer specific mortality following radical local therapy of high-risk prostate cancer

Abstract

Background: The aim of this study was to determine whether lymph node metastasis on pre-treatment 18F-choline PET/CT is an independent prognostic factor for biochemical recurrence (BCR), skeletal metastasis, and cancer specific mortality (CSM), after radical local treatment (radical prostatectomy and/or radiotherapy) in men with high-risk prostate cancer. Medical records were reviewed for men with newly diagnosed high-risk prostate cancer who had pre-treatment 18F-choline positron emission tomography fused with computed tomography (PET/CT) scan for primary metastasis staging. Results: Of 174 eligible men, 124 met the criteria for inclusion. The PET/CT scan was negative for metastasis in 97 (78%) men, inconclusive in 15 (12%), and positive in 12 (10%). The men with a positive PET/CT scan had significantly shorter time to BCR (p = 0.02), time to skeletal metastasis (p = 0.002), and time to prostate cancer specific death (p < 0.001). On multivariable Cox regression analysis, including also tumour stage, Gleason score, and PSA, a non-negative PET/CT scan was the only significant covariate for time to BCR (HR 2.6, 95% CI 1.3–5.5) and time to skeletal metastasis (HR 2.7, 95% CI 1.3–5.9). Conclusions: In men with a newly diagnosed high-risk prostate cancer and a negative or inconclusive bone scan, 18F-choline uptake on PET/CT suggestive metastasis was associated with recurrence, progression to distant metastasis, and prostate cancer death. This strongly indicates that the choline uptakes represented metastasis and not false positive findings.