Fig 4.

Patient with a 4.5-mL cancer of the right pyriform sinus with minimal involvement of its apex. The patient was cured with RT alone.

A, Pretreatment enhanced CT scan through the lower third of the sinus shows a large mass (arrow) predominantly along the anterior and lateral walls of the sinus on the right.

B, Axial image at the level of the true vocal cords shows minimal involvement of the apex of the sinus on the involved side. Compare the mildly enhancing fullness of the apex on the right with normally enhancing mucosa on the left (arrows). Note subtle obliteration of the submucosal fat plane on the right compared with the left (arrowheads).