Table 1: Evaluation criteria used for the optimisation, selected from QUANTEC [25]. Due to different PTV margins and the possibility to retract the rectal wall, the limits were lower in this study.

PriorityStructurePresent study
criteria
QUANTEC
criteria

1PTV ≥ 95%
2Rectal wall ≤ 0 cm3 < 8 
2Rectal wall ≤ 1 cm3 < 10 
2Rectal wall ≤ 1 cm3 < 14 
2Rectal wall ≤ 1 cm3 < 20 
3Bladder ≤ 50%

The volumes are expressed in relative volume in QUANTEC. It is translated to absolute dose for a rectal wall volume of 40 cm3.