PSA Density
Enter total PSA (ng/mL) and prostate volume (cm³) from ultrasound or MRI to calculate PSA density, a useful marker for clinically significant prostate cancer.
Volume can be estimated via transrectal ultrasound or MRI (length × width × height × 0.52).
How to Use This Calculator
Measure total PSA
Use the most recent serum PSA (ng/mL). Avoid testing within 24–48 hours of ejaculation, instrumentation, or infection.
Obtain prostate volume
Calculate prostate volume from imaging (TRUS or MRI) using the ellipsoid formula or reported measurement.
Interpret risk thresholds
PSA density ≥0.15 raises suspicion for significant cancer and often prompts MRI-targeted biopsy.
Formula
PSA density = Total PSA (ng/mL) ÷ Prostate volume (cm³)
Volume may be derived from imaging using: Volume = Length × Width × Height × 0.52.
Full Description
PSA density refines prostate cancer risk assessment by normalising PSA to gland volume. Values ≥0.15 ng/mL/cm³ correlate with higher likelihood of clinically significant (Grade Group ≥2) cancer. PSAD aids biopsy decisions, especially with indeterminate MRI (PI-RADS 3) or when discerning benign prostatic hyperplasia from malignancy. Use alongside MRI findings, family history, genetic risk, and prior biopsy results.
Frequently Asked Questions
How accurate is PSA density?
PSAD improves specificity compared to PSA alone but should be interpreted with MRI and clinical findings. It is not a standalone diagnostic.
Does inflammation affect PSAD?
Prostatitis elevates PSA without much volume change, increasing PSAD. Repeat measurements after treating inflammation if suspected.
Can PSAD guide active surveillance?
Yes, PSAD <0.15 supports surveillance eligibility in many protocols. Rising PSAD may prompt repeat biopsy or treatment escalation.
What about very large prostates?
Extremely large glands may yield low PSAD despite elevated PSA. Combine PSAD with MRI and risk calculators (e.g., PCPT, ERSPC) for comprehensive assessment.