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MDCalc

Online medical reference for healthcare professionals

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4 results
Jan 17, 2026
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How reliable are PSA doubling time calculations at very low PSA values and what standard methods reduce variability?

PSA doubling time (PSADT) at very low PSA levels is intrinsically noisy: measurement error, biological fluctuation and divergent calculation methods can change estimated PSADT enough to affect clinica...

Dec 17, 2025
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How is PSA doubling time calculated and how does it guide treatment after prostatectomy?

PSA doubling time (PSADT) measures how long it takes for prostate‑specific antigen (PSA) in the blood to double and is calculated by modeling PSA’s exponential rise over time; it is used after radical...

Dec 3, 2025
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How does PSA velocity differ from PSA doubling time in predicting recurrence?

PSA velocity (PSAV) measures the linear rate of PSA change in ng/mL per year, while PSA doubling time (PSADT) measures the time required for PSA to double assuming exponential growth; both are used as...

Nov 18, 2025

How is PSA doubling time calculated and what DT predicts metastatic progression after prostatectomy?

PSA doubling time (PSADT) is usually calculated from serial PSA measurements by fitting an exponential growth model — commonly by taking the natural log of PSA values, deriving a slope by linear regre...