Influence of Trigger PSA and PSA Kinetics on 11C-Choline PET/CT Detection Rate in Patients with Biochemical Relapse After Radical Prostatectomy

P. Castellucci, C. Fuccio, C. Nanni, I. Santi, A. Rizzello, F. Lodi, A. Franceschelli, G. Martorana, F. Manferrari, S. Fanti
2009 Journal of Nuclear Medicine  
The purpose of this study was to investigate the effect of total prostate-specific antigen (PSA) at the time of 11 C-choline PET/ CT (trigger PSA), PSA velocity (PSAvel), and PSA doubling time (PSAdt) on 11 C-choline PET/CT detection rate in patients treated with radical prostatectomy for prostate cancer, who showed biochemical failure during follow-up. Methods: A total of 190 patients treated with radical prostatectomy for prostate cancer who showed an increase in PSA (mean, 4.2; median, 2.1;
more » ... 4.2; median, 2.1; range, 0.2-25.4 ng/mL) were retrospectively enrolled. All patients were studied with 11 C-choline PET/CT. Patients were grouped according to trigger PSA (PSA # 1 ng/mL, 1 , PSA # 2 ng/mL, 2 , PSA # 5 ng/mL, and PSA . 5 ng/mL). In 106 patients, data were available for calculation of PSAvel and PSAdt. Logistic regression analysis was used to determine whether there was a relationship between PSA levels and PSA kinetics and the rate of detection of relapse using PET. Results: 11 C-choline PET/CT detected disease relapse in 74 of 190 patients (38.9%). The detection rate of 11 C-choline PET/CT was 19%, 25%, 41%, and 67% in the 4 subgroups-PSA # 1 ng/mL (51 patients), 1 , PSA # 2 ng/mL (39 patients), 2 , PSA # 5 ng/mL (51 patients), and PSA . 5 ng/mL (49 patients)-respectively. Trigger PSA values were statistically different between PET-positive patients (median PSA, 4.0 ng/mL) and PET-negative patients (median PSA, 1.4 ng/mL) (P 5 0.0001). Receiver-operating-characteristic analysis showed an optimal cutoff point for trigger PSA of 2.43 ng/mL (area under the curve, 0.76). In 106 patients, PSAdt and PSAvel values were statistically different between patients with PET-positive and -negative scan findings (P 5 0.04 and P 5 0.03). The 11 C-choline PET/CT detection rate was 12%, 34%, 42%, and 70%, respectively, in patients with PSAvel , 1 ng/mL/y (33 patients), 1 , PSAvel # 2 ng/mL/y (26 patients), 2 , PSAvel # 5 ng/mL/y (19 patients), and PSAvel . 5 ng/mL/y (28 patients). The 11 C-choline PET/CT detection rate was 20%, 40%, 48%, and 60%, respectively, in patients with PSAdt . 6 mo (45 patients), 4 , PSAdt # 6 mo (20 patients), 2 , PSAdt # 4 mo (31 patients), and PSAdt # 2 mo (10 patients). There was no statistical difference between PET-positive and -negative scan detection rates according to the Gleason score, pT and N status, patient age, or duration between surgery and biochemical relapse. Trigger PSA and PSAvel were found to be independent predictive factors for a PET-positive result (P 5 0.002; P 5 0.04) and PSAdt was found to be an independent factor only in patients with trigger PSA less than 2 ng/mL (P 5 0.05) using multivariate analysis. Conclusion: The 11 C-choline PET/CT detection rate is influenced by trigger PSA, PSAdt, and PSAvel. This finding could be used to improve the selection of patients for scanning by reducing the number of false-negative scans and increasing the detection rate of disease in patients with early relapse and potentially curative disease.
doi:10.2967/jnumed.108.061507 pmid:19690023 fatcat:wt4nndz5nnc73mfz26bd4xhuyi