Artistic rendering of Ki-67 IHC staining showing nuclear positivity proliferation index pattern

Ki-67 Scoring

Ki-67 Proliferation Index with Hotspot Detection

Global percentage positive, H-score, Allred score — plus spatial hotspot localization identifying the highest-density proliferative region.

EXAMPLE OUTPUT

Ki67_result = {
  "global_pct": 42.1,
  "hotspot_pct": 61.7,
  "h_score": 168,
  "allred_score": 6,
  "nuclei_counted": 4821,
  "hotspot_coords": [x:18240, y:9420]
}

Scoring Systems

Ki-67: Global Score vs. Hotspot — Why Both Matter

Ki-67 scoring is not simply counting brown nuclei across the whole slide. Clinical guidelines specify hotspot regions, and the choice of global vs. hotspot score changes the prognostic interpretation.

Scoring Formats Synthia Provides

Global Percentage Positive

Ki-67 positive nuclei ÷ total nuclei counted across the entire tissue area × 100. International Ki67 in Breast Cancer (IKiBC) working group recommended method for consistency.

Hotspot Percentage (Peak Region)

The highest Ki-67 proliferation index within a 400× HPF equivalent. Spatial attention maps identify the hotspot automatically — no manual high-power field selection required.

H-Score and Allred Score

Allred score (proportion + intensity, 0–8) and H-score (intensity-weighted proportion, 0–300) for centers using those historical scoring frameworks for breast cancer grading.

Clinical Context

In breast cancer, Ki-67 ≥ 20–25% is commonly used as a threshold for high proliferative activity (luminal B vs. luminal A distinction). In mantle cell lymphoma, Ki-67 > 30% defines high-risk disease. These thresholds vary by institution and guideline version.

Synthia provides the score; the pathologist interprets it in clinical context. The system deliberately outputs all three formats — global, hotspot, and H-score — so the pathologist can apply whichever framework their institution uses.

Ki-67 Score Detail
Global PI (%) 42.1%
Hotspot PI (%) 61.7%
H-score (0–300) 168
Allred score (0–8) 6
Total nuclei counted 4,821
Pos nuclei counted 2,028
Hotspot location [x:18240, y:9420]
Proliferation class High (>20%)

Performance Metrics

Ki-67 Internal Validation Results

Internal study, data on file. For investigational use only.

Ki-67
Concordance vs. 3-Pathologist Consensus
Internal validation · n=265 WSI · breast carcinoma + lymphoma biopsies
Metric Value 95% CI Reference Standard
ICC (global % positive vs. pathologist estimate) 0.91 0.88–0.94 Mean of 3 pathologist manual counts
ICC (H-score) 0.93 0.91–0.95 Pathologist H-score
Categorical concordance (<14% / 14–20% / >20%) 89.4% 85.4–92.6% 3-reader majority vote
Hotspot localization concordance 86.8% 82.0–90.8% Pathologist-identified hotspot HPF region
Nucleus detection recall 94.2% 92.5–95.7% Manual nucleus annotation (n=5,000 cells)
Test-retest ICC (n=50) 0.996 0.994–0.998 Same slide, 7-day interval
Disclaimer: Internal validation studies. Data on file. For research and investigational use only. Ki-67 thresholds for clinical management decisions vary by tumor type and institutional protocol; clinical application requires pathologist interpretation.

Evaluate Ki-67 Hotspot Detection on Your Cases

Request a pilot with breast carcinoma or lymphoma WSI sets. Receive global + hotspot scores with spatial heatmap overlays.

Request Pilot Access Full Validation Data