Histologic Response Grading Systems
| System | Grade | Description |
|---|---|---|
| Rosen et al. (20) | ||
| IV | No viable tumor cells | |
| III | >90% tumor necrosis | |
| II | 50% ≤ 90% tumor necrosis | |
| I | 0% < 50% tumor necrosis | |
| Picci et al. (21) | ||
| Total response | No viable tumor | |
| Good response | 90%∼99% necrosis | |
| Fair response | 60%∼89% necrosis | |
| Poor response | <60% necrosis | |
| Salzer-Kuntschik et al. (22) | ||
| I | No viable tumor cell | |
| II | Single tumor cell or 1 vital cell cluster < 0.5 cm | |
| III | Vital tumor < 10% | |
| IV | Vital tumor 10%–50% | |
| V | Vital tumor > 50% | |
| VI | No effect of chemotherapy |