AROI-ESTRO GYN Teaching Course

Inter application variation- spatial location

• Flange as the ref point (polar co cordinates)

r(bladder) = distance b/w centre of Flange and ICRU bladder point

r(rectum) = distance b/w centre of Flange and ICRU rectum point

Flange as origin

r(rectum)

ø

r(rectum)

r(bladder)

Ɵ(bladder) =270 ° - Sin -1 ø where, Sin ø =(a/r) & a= perpendicular distance b/w ICRU bladder point and vertical axis

r(bladder)

a