Table 1 Sensitivity test cases and modified parameters for introducing errors into prediction model
Error Class | Simulated Errors | Plan modification methods |
|---|---|---|
Patient position misalignment | Patient setup errors = 5, 7, 10 mm | Horizontal spatial shift of CT images data set, then recalculate predicted EPID data; only gantry angle at zero is tested. |
MU errors | Increasing 5, 7, 10 % | Decrease MU in treatment plan then calculate predicted EPID data; this simulates overdose delivery to patient. |
Wrong Patient or Plan | Incorrect patient same treatment site | Apply different patient CT data for predicted EPID data. This simulates wrong patient being treated. |
Wrong gantry angle | Correct plan (patient) incorrect field or wrong gantry angle | Re-ordered gantry angle in treatment plan (exchanged gantry angle between treatment fields) then re-calculated predicted EPID data. This simulates wrong gantry angle in IMRT. |