Influence of PSA, PSA velocity and PSA doubling time on contrast-enhanced (18)F-choline PET/CT detection rate in patients with rising PSA after radical prostatectomy - Abstract

PURPOSE: To evaluate the accuracy of contrast-enhanced 18F-choline PET/CT in restaging patients with prostate cancer after radical prostatectomy in relation to PSA, PSA velocity (PSAve) and PSA doubling time (PSAdt).

METHODS:PET/CT was performed in 49 patients (age range 58-87 years) with rising PSA (mean 4.13 ng/ml) who were divided in four groups according to PSA level: ≤ 1 ng/ml, 1 to ≤2 ng/ml, 2 to ≤ 4 ng/ml, and >4 ng/ml. PSAve and PSAdt were measured. PET and CT scans were interpreted separately and then together.

RESULTS:PET/CT diagnosed relapse in 33 of the 49 patients (67%). The detection rates were 20%, 55%, 80% and 87% in the PSA groups ≤ 1, 1 to ≤ 2, 2 to ≤ 4 and >4 ng/ml, respectively. PET/CT was positive in 7 of 18 patients (38.9%) with a PSA ≤ 2 ng/ml, and in 26 of 31 (83.9%) with a PSA >2 ng/ml. PET/CT was positive in 7 of 25 patients (84%) with PSAdt ≤ 6 months, and in 12 of 24 patients (50%) with PSAdt >6 months, and was positive in 26 of 30 patients (86%) with a PSAve >2 ng/ml per year, and in 7 of 19 patients (36.8%) with PSAve ≤ 2 ng/ml per year. PET alone was positive in 31 of 49 patients (63.3%), and of these 31 patients, CT was negative in 14 but diagnosed bone lesions in 2 patients in whom PET alone was negative. CT with the administration of intravenous contrast medium did not provide any further information.

CONCLUSION:Detection rate of 18F-choline imaging is closely related to PSA and PSA kinetics. In particular, 18F-choline PET/CT is recommended in patients with PSA >2 ng/ml, PSAdt ≤ 6 months and PSAve >2 ng/ml per year. CT is useful for detecting bone metastases that are not 18F-choline-avid. The use of intravenous contrast agent seems unnecessary.

Written by:
Schillaci O, Calabria F, Tavolozza M, Caracciolo CR, Agrò EF, Miano R, Orlacchio A, Danieli R, Simonetti G.   Are you the author?
Department of Biopathology and Diagnostic Imaging, Interventional, University "Tor Vergata", Rome, Italy.

Reference: Eur J Nucl Med Mol Imaging. 2012 Jan 10. Epub ahead of print.
doi: 10.1007/s00259-011-2030-7

PubMed Abstract
PMID: 22231016 Prostate Cancer Section