Briganti Nomogram (Educational Estimate)
Use this tool to estimate the probability of lymph node involvement (LNI) before radical prostatectomy.
What is the Briganti nomogram?
The Briganti nomogram is a preoperative risk-prediction model used in prostate cancer care. Its main purpose is to estimate the likelihood of lymph node invasion (LNI) before surgery. Clinicians often use this estimate to decide whether an extended pelvic lymph node dissection (ePLND) should be considered during radical prostatectomy.
In simple terms, the nomogram combines several known risk factors into one probability. Rather than using a single data point (such as PSA alone), it blends multiple findings from your biopsy and clinical staging.
Inputs used in this calculator
1) PSA (ng/mL)
Prostate-specific antigen is one indicator of disease burden. Higher values tend to increase estimated risk, although PSA by itself is never the full story.
2) Clinical T stage
Clinical stage reflects how far the tumor appears to extend on exam and imaging.
- cT1c: non-palpable, found by biopsy
- cT2a/b/c: tumor confined to prostate, with increasing extent
- cT3: likely extension beyond the prostate capsule
3) Biopsy Grade Group
Grade Group summarizes Gleason architecture and aggressiveness. Higher Grade Groups are associated with greater nodal risk.
4) Percentage of positive biopsy cores
This is calculated as positive cores divided by total cores sampled. A higher proportion generally indicates larger volume or more extensive disease.
How to use this page
- Enter your PSA value.
- Select your clinical stage and Grade Group.
- Enter positive and total core counts.
- Choose a decision threshold (5% or 7%).
- Click Calculate Risk to view the estimated LNI probability and interpretation.
How to interpret the result
The output is shown as a percentage risk of lymph node invasion. A threshold-based message then indicates whether the estimate is below or above your selected cutoff.
- Below threshold: ePLND may be omitted in some treatment pathways.
- At/above threshold: ePLND may be considered, depending on surgeon and guideline context.
Different institutions and guidelines may use different cutoffs. Common values are 5% and 7%, balancing missed nodal disease against overtreatment risk.
Important limitations
- Nomograms estimate probability; they do not confirm pathology.
- Input quality matters: staging accuracy, biopsy sampling method, and pathology review can change risk estimates.
- MRI findings, genomic assays, comorbidity profile, and patient goals are not fully captured in simple calculators.
- Model versions differ (historical Briganti variants are not identical).
Clinical context matters
Risk tools are best used as part of shared decision-making. For a real care decision, discuss your full chart with a prostate cancer specialist who can integrate MRI, pathology details, surgical candidacy, and long-term quality-of-life goals.