PSADT_guideline v.1

PSA Doubling Time (PSADT) Calculator

Maryam Razavi

maryam.razavi@cambio.se

Cambio CDS

To calculate rate of PSA doubling in prostate cancer (correlates with survival).

Used in patients with prostate cancer who have undergone radical prostatectomy or definitive radiation therapy and have biochemical recurrence, defined as confirmed PSA ≥0.2 ng/mL if radical prostatectomy or confirmed PSA rise of ≥2 ng/mL above the nadir PSA level if radiation therapy. Variables: PSA1 (First (earliest) available PSA result) ng/mL PSA2 (Second available PSA result) ng/mL Time between PSA1 and PSA2 measurement month Formula: PSA doubling time = ln (2) / PSA Slope PSA Slope = (ln (PSA level 2) – ln (PSA level 1)) / Time (no. of months)

1. Pound CR, Partin AW, Eisenberger MA, Chan DW, Pearson JD, Walsh PC. Natural history of progression after PSA elevation following radical prostatectomy. JAMA. 1999 May 5;281(17):1591-7. doi: 10.1001/jama.281.17.1591. PMID: 10235151. 2. Patel A, Dorey F, Franklin J, deKernion JB. Recurrence patterns after radical retropubic prostatectomy: clinical usefulness of prostate specific antigen doubling times and log slope prostate specific antigen. J Urol. 1997 Oct;158(4):1441-5. doi: 10.1016/s0022-5347(01)64238-1. PMID: 9302139.

OBSERVATION.lab_test_psa.v1, OBSERVATION.psa_doubling_time.v0