Table 2.
The most common dose–volume parameters used for reporting partial-breast irradiation. (Adapted according [84])
| Parameter | Definition/calculation |
|---|---|
| Reference dose related | |
| VPD | Absolute volume irradiated by the prescribed dose |
| V1.5xPD | Absolute volume irradiated by 1.5 x the prescribed dose |
| DNR—dose non-uniformity ratio (only for brachytherapy) | V1.5xPD/VPD |
| DHI—dose homogeneity index (only for brachytherapy) | (VPD − V1.5xPD)/VPD |
| Target related | |
| VPTV | Volume of the PTV |
| Vxx | Percentage of PTV receiving xx% of the PD |
| CI—coverage index (V100) | V100/100 |
| COIN—conformal index | PTVPD/VPTV PTVPD/VPD |
| Dxx | Percentage dose that covers xx% of the PTV |
| OAR related | |
| Dmean | Mean dose in organ |
| VxGy | Relative volume x receiving Gy |
| Vxx | Percentage of organ receiving xx% of the PD |
| Dxcm3 | Relative dose given to most exposed x cm3 of organ |
PD prescribed dose, PTVPD volume in planning target volume receiving at least the PD