Robotic-Assisted Surgery of the Base of the Tongue



Robotic-Assisted Surgery of the Base of the Tongue


Eric M. Genden



INTRODUCTION

Cancer of the base of the tongue can be managed surgically or nonsurgically. The decision regarding treatment depends on a variety of factors including the pathology and the stage of the cancer. Other factors such as the location of the cancer, patient considerations, and the surgeon’s bias also play a role in the treatment approach. Nonsurgical treatment of cancer of the base of the tongue typically consists of concomitant systemic chemotherapy and external beam radiotherapy.

Surgical approaches include open and endoscopic or endoscopic-assisted surgery. Until recently, transoral laser microsurgery was the only available endoscopic approach. Transoral robotic surgery (TORS) was recently introduced and has quickly gained popularity in the management of both squamous and nonsquamous cell cancer of the base of the tongue. Several studies have demonstrated the feasibility of TORS of the base of the tongue and suggested that primary surgery may confer an advantage by providing essential histologic information that can be used to determine the need for treatment escalation for aggressive cancers or treatment de-escalation for less aggressive cancers. Although randomized controlled trials evaluating these concepts are lacking, our experience and the experience of others strongly suggest that surgery may provide an advantage over combined chemoradiotherapy.

Choosing the appropriate patient for this procedure is arguably as challenging as the technical aspects of the surgery itself. The history, physical examination, and imaging are essential aspects of the preoperative evaluation. This evaluation will determine whether a patient is a suitable candidate for TORS of the base of the tongue.




PHYSICAL EXAMINATION

The physical examination should include palpation of the neck, nasopharyngoscopy, and bimanual palpation of the base of the tongue. Although the nasopharyngoscopy may suggest a well-lateralized tumor, digital palpation may reveal unsuspected invasion of the deep musculature. Submucosal extension that is identified on palpation
may impact the treatment approach and extent of resection. In addition to the information gleaned from the history and physical examination, axial imaging (CT, MRI, or PET/CT) can also provide important information that may not be appreciated by physical examination alone.




CONTRAINDICATIONS

The relative contraindications of TORS for resection of the base of the tongue include tumors that exhibit extensive lateral extension, extension across the midline, or deep invasion of the base of the tongue (Table 10.1). TORS for resection of the base of the tongue in cases with extension across the midline may result in irreparable functional disability, and therefore, these patients may be considered for nonsurgical therapy.

Additional considerations include the extent of metastasis to the neck. In those patients with extensive extracapsular spread (ECS), surgical therapy may not obviate the need for systemic chemotherapy. While the implications of ECS in the patient with human papillomavirus (HPV) associated disease is heavily debated, ECS portends a poor prognosis in patients with HPV-negative disease. As such, chemoradiotherapy is typically indicated and surgical management may not benefit the patient.


PREOPERATIVE PLANNING


Imaging Studies

Imaging is an important adjunct to the physical examination and is critical in determining whether a patient is a candidate for TORS of the base of the tongue. The PET/CT provides important information related to the presence of regional and distant metastasis, and the CT may provide information regarding invasion of the hyoid bone. The MRI can serve as an important adjunct to CT. An MRI is often more sensitive for evaluating deep soft tissue extension. The superior nature of the MRI to discern invasion into the soft tissue, perineural invasion, and diffuse poorly marginated cancer of the tongue is important in determining whether TORS is appropriate. The combination of the physical examination and the imaging is an important step in evaluating a patient for TORS.

Jun 15, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Robotic-Assisted Surgery of the Base of the Tongue

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