10.8\ Transoral Robotic Surgery

10.8.1  Discussion

Transoral robotic surgery (TORS) is a minimally invasive technique that involves the use of endoscopic visualization and dexterous robotic arms and has been mainly implemented for resecting T1 and T2 squamous cell carcinomas of the oropharynx, although various other applications have been explored. TORS offers a high rate of preserved postoperative swallowing function, but low incidence of complications. The postoperative imaging findings to TORS generally differ from those related to open surgery. Tongue base tumor TORS resection typically includes approximately the half of the tongue base on the side of the tumor, with dissection to the circumvallate papillae and glossotonsillar sulcus. Consequently,

a

during the first weeks to months after surgery, retraction of the tongue base bed is apparent on postoperative imaging (Fig. 10.55), without evidence of solid enhancement. A radical tonsillectomy using a TORS approach involves the tonsil, anterior and posterior tonsillar pillars, portions of the soft palate, tongue base, to encompass the superior constrictor muscle as the depth of resection and the posterior pharyngeal wall are resected. Imaging during the first several postoperative weeks typically demonstrates distortion of the fat planes around the medial pterygoid muscle and retropharyngeal edema (Fig. 10.56), which can result from retraction or thermal injury during the surgery. Over the ensuing months, scar tissue formation leads to gradual retraction of the lateral oropharyngeal wall, with “tilting” of the soft palate toward the surgical bed.

b

Fig. 10.55  TORS base of tongue tumor resection. Preoperative axial CT image (a) shows a right oropharyngeal tumor (encircled). Postoperative axial 18FDG-PET/ CT image (b) shows retraction of the right tongue base

surgical bed (arrow) without evidence of tumor, but residual normal hypermetabolic left lingual tissue, which should not be misinterpreted as tumor

Fig. 10.56  TORS lateral oropharyngectomy. Preoperative axial CT image (a) shows a right palatine tonsil squamous cell carcinoma (arrow). Postoperative

CT image (b) shows interval resection of the tumor and edema in the region of the surgical bed, with extension into the retropharyngeal space (encircled)