Calculation of PSA Doubling Time (PSADT) Post-operatively. The patient must have a PSA of ≥ 0.2 ng/mL and rising at least 6 weeks after prostatectomy. First item Rising means a PSA of < 0.2 and a PSA of ≥ 0.2 ng/mL, a PSA of 0.2 and a PSA > 0.2 ng/mL or a PSA > 0.2 and a further PSA increase.
A doubling time < 6 months is considered a negative predictor, with prolonged treatment likely to be needed. PSA doubling time = ln (2) / PSA Slope; PSA Slope = (ln (PSA level 2) – ln (PSA level 1)) / Time (no. of months) The PSA velocity is the rate of PSA rise, expressed in nanograms/mL/year:
Purpose: Prostate-specific antigen (PSA) doubling-time (PSA-DT) is an important indicator of progression and survival in men with prostate cancer. Three major limitations regarding PSA-DT determination may lead to inconsistent results: the variety of mathematical methods currently applied, the non-standardized handling of input variables and ...
Doubling Time. Serum PSA is measured using the Hybritech assay (San Diego, CA). The PSA doubling time (DT) is calculated assuming that PSA changes over time in an exponential fashion (Patel 1997): (1) where PSA(t) is the PSA level at time t after study enrolment, PSA(0) is the PSA level at baseline, λ and γ are linear and quadratic rates.
The doubling time is the amount of time that it takes for a quantity of something to double in size. Doubling time is more commonly known as the rule of 70. This formula is most helpful for populations or quantities that are experiencing exponential growth.
For those of you wondering how you can calculate PSA doubling time, here's a formula for doing it. You need a calculator with logarithms (I believe the Windows calculator accessory can do logs.) Please feel free to do this at home :) PSA1 = a PSA value taken some time ago. PSA2 = subsequent PSA, i.e., a later test M = months between PSA1 and PSA2.
According to a recent presentation by Mitchell C. Benson, MD*, at the 32nd Winter Urologic Forum – State-of-the-Art in Urology – January 25-29, 2008 – Vail, Colorado, USA most men who have failed a local, primary therapy and then experience a rising PSA will find that their follow-up therapy will most probably consist of anti-androgen […]
Morris: You can find a PSA doubling time calculator either here or on the web site of the Memorial Sloan-Kettering Cancer Center (open the calculator and then scroll down until you the link that says “PSA Doubling Time.”). The precise significance of your rising PSA needs to be discussed with your doctor because it depends on a variety of factors.
PSA doubling time (PSADT) among patients with castration-resistant prostate cancer (CRPC) strongly predicts their risk for metastatic disease and all-cause and cancer-specific mortality, according ...
PSA doubling time <12 months for PSA≥ 10 ng/mL PSA doubling time ≤ 6 months based on 3 consecutive measurements obtained ≥ 2 months apart We don’t have black and white rules on when to start ADT in this group of patients, so these points should be considered a starting point for a discussion with you and your physicians.