Plan Scoring for RTOG Protocol 0321

Organs at Risk (OAR)

This protocol has specific dose constraints for critical structures that must be followed for patients entered on this protocol.� These dose constraints are the upper limit of dose to these normal structures and care should be taken to keep the doses to these structures as low as possible.

Urethra	The volume of the urethra receiving 125% of the prescription dose (23.75 Gy) must be kept less than 1 cc, i.e. V125 < 1 cc.
Rectum	The volume of the urethra receiving 75% of the prescription dose (14.25 Gy) must be kept less than 1 cc, i.e. V75 < 1 cc.
Bladder	The volume of the urethra receiving 125% of the prescription dose (14.25 Gy) must be kept less than 1 cc, i.e. V75 < 1 cc.

Failure to adhere to these constraints constitutes an unacceptable protocol deviation.

Target Volume

PTV Scoring (For this protocol PTV=CTV)
No Variation	Minor Variation	Major Variation
>90% of the PTV is at, or above 19 Gy.	> 80% to < 90% of PTV is at, or above 19 Gy.	Failure to achieve either No Variation or Minor Variation