Module 2

Why and when we biopsy

PSA, PSA density, DRE, risk tools, the MRI-first pathway, and who can safely avoid a biopsy.

We do not biopsy everyone with a raised PSA, and learning who not to biopsy is just as important as knowing who to. Let us make the decision logic feel obvious.

MRI slices live

The raw multi-parametric scan.

3D reconstruction live

Segmented gland, zones and lesion as a rotatable model.

Beside-patient spatial teaching future spatial workflow

Future spatial-computing workflows for placing the anatomy model in clinical space.

01 What PSA actually tells you 4 min

PSA is made by prostate tissue. The trap I fell into early was treating it as a cancer test. It is not. It is organ-specific, not cancer-specific.

Plenty of innocent things raise it: BPH, a urine infection, a recent catheter or instrumentation, vigorous cycling, and recent ejaculation.

Key point PSA is prostate-specific, not cancer-specific. Always read it in context, and treat reversible causes before acting.

You can explain to a worried patient why a raised PSA is not a cancer diagnosis.

A man has a mildly raised PSA and a UTI. The sensible first step?

02 Sharpening the signal: density and DRE 5 min

Two cheap things make a raised PSA far more useful.

PSA density

PSA divided by gland volume. A high PSA in a small gland is more worrying than the same PSA in a large one. A threshold around 0.15 is commonly quoted.

DRE

A hard, irregular or nodular prostate is significant regardless of the PSA number.

Worth holding Same PSA, small gland, higher density, more concern. Volume context changes everything.

You can turn a bare PSA number into a contextualised risk.

Two men have a PSA of 6. Whose result is more concerning?

03 MRI before biopsy, not after 4 min

The biggest shift in modern practice: we scan before biopsy now.

The PRECISION trial showed MRI-first, biopsy-only-if-target finds more significant cancers and spares some men a biopsy. In the UK, NG131 made mpMRI the first-line investigation for suspected localised prostate cancer.

Key point MRI-first is the standard. A negative MRI with low PSA density can sometimes justify avoiding biopsy after a shared discussion.

You understand why the pathway runs PSA, then MRI, then a targeted decision.

In the modern pathway, when is the mpMRI usually done?

04 Putting it together: who to biopsy 5 min

Now the decision feels logical. Combine the MRI score, PSA density and the clinical picture.

PI-RADS/Likert 4-5: biopsy.
3: let PSA density and shared decision-making tip the balance.
1-2 with low PSA density: a careful discussion may avoid biopsy.

Risk calculators support the conversation, but they support judgement, they do not replace it.

The shape of it High MRI score, biopsy. Low score, reassure. Middle score, the extra numbers decide.

You can reach an individualised biopsy decision. End of Module 2.

You have a PI-RADS 3 lesion. What most helps decide on biopsy?

That is Module 2. You can take a man from a raised PSA to a sensible, individualised decision.

Next: Consent and patient preparation →