Table 2.
Five highest scoring failure modes in terms of RPN and SOD
| Failure mode | Failure pathway | S | O | D | RPN | SOD |
|---|---|---|---|---|---|---|
| Wrong data set used for contouring | Inadequate training/MR images | 6 | 5 | 8 | 240 | 658 |
| Organ location inaccurate | Patient-induced distortions near interfaces present | 6 | 7 | 5 | 210 | 675 |
| Inaccurate dose calculation | Bone volume overestimated | 6 | 8 | 4 | 192 | 684 |
| Organ location inaccurate | System-level geometric distortion not taken into account | 6 | 7 | 4 | 168 | 674 |
| Treatment volume not properly identified | Physician interpretation of images | 5 | 4 | 8 | 160 | 548 |
| Organ location inaccurate | Changed target location because of state | 8 | 2 | 2 | 32 | 822 |
| Inaccurate dose calculation | Bone volume underestimated | 7 | 5 | 4 | 140 | 754 |
| Organ location inaccurate | Patient anatomy is not standard for patient—unable to reproduce anatomy | 7 | 3 | 3 | 63 | 733 |
| Wrong treatment volume delineated | Wrong image set used | 7 | 2 | 6 | 84 | 726 |
| Inaccurate dose calculation | Bone volume overestimated | 6 | 8 | 4 | 192 | 684 |
Abbreviations: RPN = risk priority number; SOD = severity-occurrence-detectability.