1. What is the Phillip Cheng Prostate Calculator?

Definition: This calculator estimates prostate volume using the ellipsoid formula (Cheng method) based on length, width, and height measurements.

Purpose: It helps urologists and medical professionals assess prostate size, which is important for diagnosing and managing conditions like BPH.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( V \) — Prostate volume (cubic centimeters)
• \( L \) — Length (cm)
• \( W \) — Width (cm)
• \( H \) — Height (cm)

Explanation: The formula models the prostate as an ellipsoid and calculates its volume using the three orthogonal measurements.

3. Importance of Prostate Volume Calculation

Details: Accurate prostate volume measurement helps in assessing benign prostatic hyperplasia (BPH), planning surgical interventions, and evaluating prostate cancer risk.

4. Using the Calculator

Tips: Enter the prostate dimensions (length, width, height) in centimeters as measured by TRUS or MRI. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What imaging methods are used to measure prostate dimensions?
A: Transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) are most commonly used.

Q2: What's a normal prostate volume?
A: Typically 20-30 cm³ in young men, often increasing with age (may reach 40-60 cm³ in BPH).

Q3: How does this compare to other volume calculation methods?
A: The ellipsoid formula is most common, though planimetry (MRI) may be more accurate but more time-consuming.

Q4: Why is π/6 used in the formula?
A: This is the correction factor (≈0.52) for calculating volume of an ellipsoid based on its three axes.

Q5: How is prostate volume related to PSA levels?
A: Generally, larger prostates produce more PSA, though PSA density (PSA/volume) is often more clinically meaningful.