1. What is PSA Density?

Definition: PSA Density (PSAD) is a calculated value that relates the prostate-specific antigen (PSA) level to the volume of the prostate gland.

Purpose: It helps urologists evaluate prostate cancer risk more accurately than PSA alone, especially in men with enlarged prostates.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( PSAD \) — PSA density (ng/mL/cm³)
• \( PSA \) — Prostate-specific antigen level (ng/mL)
• \( V_{prostate} \) — Prostate volume (cm³)

Explanation: Dividing the PSA value by prostate volume normalizes the PSA for gland size, providing a more meaningful cancer risk indicator.

3. Importance of PSA Density

Details: PSAD helps distinguish between elevated PSA due to benign prostatic hyperplasia (BPH) versus potential prostate cancer. Higher PSAD values (>0.15) may indicate increased cancer risk.

4. Using the Calculator

Tips: Enter the PSA level in ng/mL and prostate volume in cm³ (typically measured by TRUS or MRI). Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal PSAD value?
A: Generally, PSAD <0.15 ng/mL/cm³ is considered normal, while >0.15 may warrant further investigation.

Q2: How is prostate volume measured?
A: Typically via transrectal ultrasound (TRUS) or MRI, using the ellipsoid formula (length × width × height × π/6).

Q3: Why use PSAD instead of just PSA?
A: PSAD accounts for prostate size, as larger glands naturally produce more PSA. This reduces false positives in men with BPH.

Q4: When is PSAD most useful?
A: Particularly valuable for PSA values in the "gray zone" (4-10 ng/mL) to help decide about biopsy.

Q5: Are there limitations to PSAD?
A: Yes, it depends on accurate volume measurement and doesn't replace other diagnostic tools like digital rectal exam or imaging.