Table 1.
Measurements of the positive lymph nodes
| Variable (unit) | Description |
|---|---|
| Diameter positive lymph node (mm) | The largest diameter of the complete positive lymph node |
| Diameter LNM (mm) | The largest diameter of the metastatic lesion within the positive lymph node |
| Area positive lymph node (mm2) | The area of the complete positive lymph node, including the capsule and all directly adjacent lymphoid tissue and vessels within the contour of the lymph node |
| Area LNM (mm2) | The area of the largest continuous metastatic lesion in the positive lymph node, or, in case of multiple smaller lesions, including the adjacent metastatic lesions (i.e. lesions for which the distance between two lesions is less than the size of the lesion themselves) |
| Ratio area LNM: lymph node (%) | The ratio of the area of the metastatic lesion and the complete positive lymph node, portraying the percentage that the metastasis occupies of the lymph node |
| TSR-c (%) | The ratio of the stromal percentage in comparison to the tumour epithelial percentage within the metastatic lesion, scored in a 3.1 mm2 annotation, and meeting the requirements of van Pelt et al. |
| TSR-t (%) | The absolute amount of stroma in the metastatic lesion, taking in account all tissue types within the metastasis, e.g. necrosis or mucin, and categorized in percentages starting at 0–1%, 1–5% and then per tenfold (i.e. 10%, 20%, etc.) |
| TSR-c category (no.–perc.) | |
|
-Stroma-low -Stroma-high -Not applicable |
≤ 50% stroma > 50% stroma In the case the official 3.1 mm2 annotation area could not meet the requirements and an adjusted annotation size is used |
| Area adjusted TSR-c annotation (mm2) | The area of the annotation used for scoring the TSR-c in the case the official 3.1 mm2 annotation area could not meet the requirements |
| Area of stroma in LNM (mm2) | A feature portraying the area of the stromal compartment in the metastasis, calculated through the formula: area stroma in metastasis = (Percentage stroma/100) × Area metastasis) |
LNM lymph node metastasis; TSR-c tumour-stroma ratio—conventional scoring method; TSR-t tumour-stroma ratio—total percentage of stroma