Table 2.

Organ at risk constraints for prostate IMRT.

Organ at risk	Ideal constraint	Minor violation
Rectum, sigmoid	V40Gy < 35% V65Gy < 17% V75Gy < 10% Max Dose 2cc < 102.5%	V40Gy < 45% V65Gy < 21% V75Gy < 15%
Small bowel	Single phase max dose 70 Gy 100cc < 45 Gy	Refer to RO
Bladder	V40Gy < 60% V50Gy < 50% V60Gy < 40%	V50 Gy between 50–60%
Femoral heads	V35Gy < 100% V45Gy < 60% V60Gy < 30%
Penile bulb	V50Gy < 95%

Minor violations were acceptable when all reasonable efforts to achieve ideal constraints had been made. PD: prescribed dose. Gy: Grey. Vx refers to the percentage volume of a structure receiving XGy.