Table 1.
Example 1 – HDR 192Ir BT source for vaginal cylinder applicator.
| Category | Typical level (%) | Assumptions |
|---|---|---|
| Source strength | 2 | PSDL traceable calibrations |
| Treatment planning | 3 | Reference data with the appropriate bin width |
| Medium dosimetric corrections | 1 | Valid for applicator without shielding and if CTV located inside pelvis; an advanced dose calculation formalism should be used if this assumption false |
| Dose delivery including registration of applicator geometry to anatomy | 5 | Accurate QA concept for commissioning and constancy checks, especially for source positioning and applicator/source path geometry, appropriate imaging techniques (either small slice thickness, 3D sequences or combination of different slice orientations), applicator libraries (either by using software solutions or manual) |
| Interfraction/Intrafraction changes between imaging and dose delivery | 5⁎ | For one treatment plan per applicator insertion and measures to detect major variations for subsequent fractions |
| Total dosimetric uncertainty (k = 1) | 8 | For treatment delivered with the same BT source |
⁎
Estimated value based on expert discussion.