How do you effectively spare the medial RP nodes and superior constrictors when you contour the bilateral RP nodes and place a 3-5 mm CTV to PTV expansion?  

If you use PTV margins of 3 mm (allowed if you check set-up imaging before each treatment and adjust for set-up deviations), and you mark the lateral RPN CTV in the triangular space between the carotid artery and the longus muscle, You will be able to spare the part of the constrictor which is betwe...