Table 2 The creation method of auxiliary structures

ring0.5

Create ring of PTV with a 5 mm margin

ring1

Create ring of PTV between the 5 mm and 1cm margin

ring2

Create ring of PTV between the 1cm to 2 cm margin

ring3

Create ring of PTV between the 2 cm to 3 cm margin

nt

Subtract PTV and PTV rings from the body

PTV_new

Subtract the partial volume of the OARs from PTV

PTV_new-3mm

Create contraction of PTV_new with a 3 mm margin

bladder-ptv

Subtract PTV_new from bladder

rectum-ptv

Subtract PTV_new from rectum

bowel bag-ptv

Subtract PTV_new from bowel bag

bag

Create the overlap between bowel bag and PTV expanded outward by 2 cm

bowel bag_PTV

Create the overlap between bowel bag and PTV