European Journal of Nuclear Medicine and Molecular Imaging

, Volume 37, Issue 6, pp 1106–1116

PSA doubling time for prediction of [11C]choline PET/CT findings in prostate cancer patients with biochemical failure after radical prostatectomy

Authors

  • Giampiero Giovacchini
    • Center for Molecular BioimagingUniversity of Milano-Bicocca
    • Department of Nuclear MedicineSan Raffaele Scientific Institute
  • Vincenzo Scattoni
    • Department of UrologySan Raffaele Scientific Institute
  • Rita Garcia Parra
    • Center for Molecular BioimagingUniversity of Milano-Bicocca
  • Alberto Briganti
    • Department of UrologySan Raffaele Scientific Institute
  • Luigi Gianolli
    • Department of Nuclear MedicineSan Raffaele Scientific Institute
  • Francesco Montorsi
    • Department of UrologySan Raffaele Scientific Institute
  • Cristina Messa
    • Center for Molecular BioimagingUniversity of Milano-Bicocca
    • Institute for Bioimaging and Molecular PhysiologyNational Research Council
    • Department of Nuclear MedicineSan Gerardo Hospital
Original Article

DOI: 10.1007/s00259-010-1403-7

Cite this article as:
Giovacchini, G., Picchio, M., Scattoni, V. et al. Eur J Nucl Med Mol Imaging (2010) 37: 1106. doi:10.1007/s00259-010-1403-7

Abstract

Purpose

Previous studies have shown that the positive detection rate of [11C]choline positron emission tomography/computed tomography (PET/CT) depends on prostate-specific antigen (PSA) plasma levels. This study compared PSA levels and PSA doubling time (PSADT) to predict [11C]choline PET/CT findings.

Methods

PSADT was retrospectively calculated in 170 prostate cancer (PCa) patients with biochemical failure after radical prostatectomy who underwent [11C]choline PET/CT. PSADT was calculated as PSADT = ln2/m, where m is the slope of the linear regression line of the natural log of PSA values. At least three PSA measurements were used (median: 4; range: 3–16), separated by at least 3 months, each with a minimum increase of 0.20 ng/ml. PET/CT findings were validated using criteria based on histological analysis and clinical and imaging data. Statistical analysis was performed using the t test, chi-square test, analysis of variance and binary logistic regression. Regression-based coefficients were used to develop a nomogram predicting the probability of positive [11C]choline PET/CT and 200 bootstrap resamples were used for internal validation.

Results

The median PSA was 1.25 ng/ml (range: 0.23–48.6 ng/ml), and the median PSADT was 7.0 months (range: 0.97–45.3 months). [11C]choline PET/CT was positive in 75 of 170 patients (44%). PET/CT findings were validated using histological criteria (11%) and clinical and imaging criteria (89%). The overall accuracy of [11C]choline PET/CT was 88%. Multivariate logistic regression showed that high PSA and short PSADT were significant (p < 0.05) predictors of positive [11C]choline PET/CT [PSA: odds ratio (OR) = 1.43; 95% confidence interval (CI): 1.15–1.78; PSADT: OR = 1.12; 95% CI: 1.04–1.21]. The percentage of patients with positive [11C]choline PET/CT was 27% for PSADT >6 months, 61% for PSADT between 3 and 6 months and 81% for PSADT <3 months. The percentage of patients who displayed pathological [11C]choline uptake in the skeleton significantly increased (p < 0.05) from 3% for PSADT >6 months to 52% for PSADT <3 months. Conversely, patients who displayed pathological [11C]choline uptake in the prostatectomy bed were 0% for PSADT <3 months and 17% for PSADT >6 months (p < 0.05). A nomogram based on age, PSA, PSADT, time to trigger PSA, Gleason score, pathological stage and androgen deprivation therapy demonstrated bootstrap-corrected predictive accuracy of 81%.

Conclusion

Like PSA, PSADT is an independent predictor of [11C]choline PET/CT. [11C]choline PET/CT is very sensitive to PCa tumour growth, as reflected by PSA kinetics. PSADT should be taken into account by physicians when referring PCa patients for [11C]choline PET/CT.

Keywords

[11C]choline PET/CTProstate cancerDoubling time

Supplementary material

259_2010_1403_MOESM1_ESM.doc (53 kb)
ESM 1(DOC 53 kb)

Copyright information

© Springer-Verlag 2010