Psa Rate of Rise Calculator

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PSA Rate of Rise (Velocity) Calculator

Monitor changes in Prostate-Specific Antigen levels over time. Enter two PSA readings and their respective dates to calculate the velocity and doubling time.

Calculation Results

PSA Velocity — ng/mL per year
PSA Doubling Time — months

Understanding PSA Rate of Rise (PSA Velocity)

PSA (Prostate-Specific Antigen) is a protein produced by both cancerous and noncancerous tissue in the prostate. While a single PSA reading provides a snapshot of prostate health, the PSA Rate of Rise (also known as PSA Velocity or PSAV) measures how fast those levels are changing over time.

Why is PSA Velocity Important?

Clinical research suggests that the speed at which PSA increases can be a significant indicator of prostate health. A rapid rise in PSA may sometimes be more indicative of aggressive prostate cancer than the absolute PSA number itself. It helps clinicians differentiate between benign conditions (like BPH or prostatitis) and potential malignancy.

The Calculation Formula

The PSA Velocity is typically calculated using the following mathematical approach:

PSAV = (PSA₂ – PSA₁) / Time (in years)

For PSA Doubling Time (PSADT), the formula utilizes natural logarithms to determine how long it would take for the current PSA level to double based on the current rate of growth.

Interpretation Guidelines

  • Low Velocity: An increase of less than 0.75 ng/mL per year is often considered a normal age-related change or benign growth.
  • High Velocity: An increase greater than 0.75 ng/mL per year may warrant further investigation (such as imaging or biopsy), especially if the absolute PSA is above 4.0 ng/mL.
  • PSA Doubling Time: A shorter doubling time (especially under 3 years) is generally associated with more aggressive biological activity.

Example Calculation

Suppose a patient has the following records:

  • Test 1: 2.0 ng/mL on January 1, 2022
  • Test 2: 3.1 ng/mL on January 1, 2023
  • Result: The PSA Velocity is exactly 1.1 ng/mL/year. Because this exceeds the 0.75 threshold, a physician might recommend closer monitoring or additional diagnostic tests.

Disclaimer:

This calculator is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified urologist or healthcare provider regarding PSA results.

function calculatePSAMetrics() { var p1 = parseFloat(document.getElementById('psaInitial').value); var p2 = parseFloat(document.getElementById('psaRecent').value); var d1Value = document.getElementById('dateInitial').value; var d2Value = document.getElementById('dateRecent').value; if (!p1 || !p2 || !d1Value || !d2Value) { alert("Please enter both PSA levels and both dates."); return; } var d1 = new Date(d1Value); var d2 = new Date(d2Value); // Difference in milliseconds var diffMs = d2 – d1; if (diffMs p1) { doublingTime = (Math.log(2) * diffMonths) / Math.log(p2 / p1); if (doublingTime > 24) { dtText = (doublingTime / 12).toFixed(2); dtUnit = "years"; } else { dtText = doublingTime.toFixed(1); dtUnit = "months"; } } else { dtText = "N/A"; dtUnit = "(Levels Stable or Decreasing)"; } // Display Results document.getElementById('psaResult').style.display = 'block'; document.getElementById('velocityOutput').innerText = velocity.toFixed(3); document.getElementById('doublingTimeOutput').innerText = dtText; document.getElementById('doublingTimeUnit').innerText = dtUnit; var interpretation = ""; if (velocity > 0.75) { interpretation = "Note: A PSA velocity higher than 0.75 ng/mL/year may be considered a significant increase in some clinical contexts."; } else if (velocity > 0 && velocity <= 0.75) { interpretation = "The PSA level is rising within a range often associated with normal age-related changes."; } else if (velocity <= 0) { interpretation = "The PSA level is stable or has decreased during this interval."; } document.getElementById('interpretation').innerText = interpretation; }

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