Contours
bladder—4 mm isotropic constriction, prostate
PROSTATE, URETHRA

The prostate ± seminal vesicles will be contoured as the clinical target volume (CTV). The PTV expansion for the CTV will be 2–3 mm at the physician’s discretion.The optional boost volume will be at the discretion of the treating physician, but the addition of a boost should not exceed dose constraints compared to a non-boost plan.The rectum will be drawn from the bottom of the ischial tuberosities to the sigmoid flexure.The bladder, bladder wall (bladder—4 mm isotropic constriction), urethra (method of urethral delineation is at the treating physician’s discretion), femoral heads, and penile bulb will also be contoured as normal structures. Delineation of the urethra can be performed using the T2 sequence, contouring and interpolating on axial slices where the urethra is visible, and/or contouring on the sagittal plane from the bladder to the penile urethra.