From the Guidelines
Prostatomegaly is primarily graded in radiology using prostate volume measurements, with the most common method involving the ellipsoid formula: length × width × height × 0.52, as supported by recent guidelines 1.
Grading of Prostatomegaly
The grading of prostatomegaly is crucial for determining the severity of prostate enlargement and guiding treatment decisions.
- Normal prostate volume is generally considered to be less than 30cc,
- 30-50cc indicates mild enlargement,
- 50-80cc moderate enlargement, and
- greater than 80cc severe enlargement, as suggested by various studies 1.
Methods of Measurement
The measurement of prostate volume can be performed using various imaging modalities, including:
- Transrectal ultrasound (TRUS),
- MRI, and
- CT scans, with TRUS being the most commonly used method 1.
Clinical Significance
The degree of prostate enlargement is clinically significant as it correlates with symptom severity in benign prostatic hyperplasia (BPH) and influences treatment decisions, as highlighted in recent guidelines 1.
- Additionally, prostate-specific antigen (PSA) density, calculated by dividing PSA by prostate volume, can help differentiate between benign enlargement and potential malignancy, with higher ratios raising suspicion for cancer.
Morphological Patterns
Beyond volume measurements, radiologists may also assess for specific morphological patterns, such as:
- Median lobe hypertrophy,
- Intravesical protrusion, or
- The presence of a "middle lobe," which can provide additional information on the severity of prostate enlargement and guide treatment decisions 1.
From the Research
Prostatomegaly Grading in Radiology
- Prostatomegaly, also known as benign prostatic hyperplasia (BPH), is a condition where the prostate gland is enlarged, which can cause urinary symptoms 2, 3.
- In radiology, the size of the prostate gland can be assessed using ultrasound examination, which is helpful in making the choice between transurethral electroresection and adenomectomy 4.
- The standards of an ultrasound examination of the prostate gland include the assessment of the size of the prostate gland, its configuration, the echostructure in classical ultrasonography, the vascularization in an ultrasound examination performed with power doppler, and the differences in the gland tissue firmness (consistency) in elastography 4.
- Multiparametric MRI can be used to detect clinically significant prostate cancer in men with prostatomegaly, with a positive predictive value of 26.5% for PIRADS 4 and 73.5% for PIRADS 5 5.
- The Prostate Imaging-Reporting and Data System (PIRADS) is a scoring system used to evaluate the likelihood of prostate cancer based on MRI findings, with higher scores indicating a higher likelihood of cancer 5.
- PSA density can be used to inform biopsy decisions for PIRADS 4 and 5 lesions, with a negative predictive value of 78.9% for PIRADS 4 lesions at PSA density <0.05 and a positive predictive value of 90.5% for PIRADS 5 lesions at PSA density ≥0.15 5.
- Targeted biopsy, specifically in-bore, may have a pronounced role in prostatomegaly, reducing the likelihood of missing clinically significant prostate cancer by >50% 5.