PURPOSE: To highlight a new imaging acquisition protocol during 18F-fluorocholine PET/CT in patients with biochemical recurrence after RP.
METHODS: A total of 146 patients with PSA levels between 0.2 and 1 ng/ml with negative conventional imaging who did not receive salvage treatment were prospectively enrolled. Imaging acquisition protocol included an early dynamic phase (1-8 min), a conventional whole body (10-20 min), and a late phase (30-40 min). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were measured. Univariable and multivariable analyses were performed to identify independent predictors of positive PET/CT.
RESULTS: The median trigger PSA was 0.6 ng/ml (IQR 0.43-0.76). Median PSA doubling time (PSA DT) was 7.91 months (IQR 4.42-11.3); median PSA velocity (PSAV) was 0.02 ng/ml per month (IQR 0.02-0.04). Overall, 18F-fluorocholine PET/CT was positive in 111 of 146 patients (76 %). Out of 111 positive examinations, 80 (72.1 %) were positive only in the early dynamic phase. Sensitivity, specificity, PPV, NPV, and accuracy were 78.9, 76.9, 97.2, 26.3, and 78.7 %, respectively. At multivariable logistic regression, trigger PSA ≥ 0.6 ng/ml [odds ratio (OR) 3.13; p = 0.001] and PSAV ≥ 0.04 ng/ml per month (OR 4.95; p = 0.004) were independent predictors of positive PET/CT. The low NPV remains the main limitation of PET/CT in this setting of patients.
CONCLUSIONS: The increased sensitivity, thanks to the early imaging acquisition protocol, makes 18F-fluorocholine PET/CT an attractive tool to detect prostate cancer recurrences in patients with a PSA level < 1 ng/ml.
Simone G, Di Pierro GB, Papalia R, Sciuto R, Rea S, Ferriero M, Guaglianone S, Maini CL, Gallucci M. Are you the author?
Department of Urology, "Regina Elena" National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy.
Reference: World J Urol. 2015 Jan 11. Epub ahead of print.