Table 1.
Categories of IGRT-related variances reported by RTTs.
| Main Category | Sub-Category | Description |
|---|---|---|
| Tumor-related | Tumor motion | Target displacement, motion or deformation with stable volume |
| Tumor regression | Suspected decrease in target volume | |
| Tumor progression | Suspected increase in target volume | |
| Non tumor-related | Normal tissue motion | Normal tissue displacement, motion or deformation |
| Large shift/rotation | A translation/rotation exceeding the maximum action level | |
| Bone mismatch | Bony anatomy deformation or rotation | |
| Bladder/rectum filling | Increase or decrease in bladder/rectum volume | |
| Weight gain | Overall expansion of external body contour | |
| Weight loss | Overall decrease of external body contour | |
| Local swelling | Localized expansion of external body contour | |
| Abdominal gas | Substantial increase in gas (excluding rectum) | |
| Fluids | Increase of fluid in lungs or sinuses | |