Table A1.
List of abbreviations with definitions.
| Abbreviation | Definition |
|---|---|
| cDGI | Cumulative dose gradient index |
| CIRTOG | RTOG conformity index |
| D99% | 99% of PTV volume covered by 100% of prescription dose |
| DDS | Dose‐dropping speed |
| GI | Gradient index |
| GM | Gradient measure |
| HIRTOG | RTOG homogeneity index |
| IDC | Isodose cloud |
| IDC50% | 50% (of prescription dose) isodose cloud |
| IDC50%shell | Distance from the edge of the planning target volume to the edge of the 50% isodose cloud |
| IDC100% | 100% (of prescription dose) isodose cloud |
| NTO | Normal tissue objective; Instructs the optimizer to limit dose to non‐target volumes |
| OAR | Organs at risk |
| PIDL | Prescription isodose line |
| PTV | Planning target volume |
| Δr | Distance of dose drop‐off from the edge of the planning target volume to 50% dose |
| rIDC50% | Radius of the 50% isodose cloud |
| rPTV | Radius of the planning target volume |
| r50%eq | Equivalent sphere radius of the volume of the 50% isodose cloud |
| r100%eq | Equivalent sphere radius of the volume of the 100% isodose cloud |
| R50% | Ratio of the volume of the 50% isodose cloud to the volume of the planning target volume |
| R50%Analytic | Value of R50% generated from our analytical expression |
| R50%Clinical | Value of R50% calculated from clinical data |
| RTPS | Radiation treatment planning system |
| SAPTV | Surface area of the planning target volume |
| SRS | Stereotactic radiosurgery |
| SRT | Stereotactic radiotherapy |
| VIDC50% | Volume of the 50% isodose cloud |
| VIDC50%shell | Volume of the 50% isodose cloud minus the volume of the planning target volume |
| VIDC100% | Volume of the 100% isodose cloud |
| VPTV | Volume of the planning target volume |
| VMAT | Volumetric modulated arc therapy |