Sentinel Node in Larynx and Pharynx Cancers

The presence of lymph node metastases has a large impact on prognosis and treatment in head-and neck cancer (HNC) patients and necessitates treatment intensification. However, despite increased spatial resolution of current imaging techniques, around 20% of patients with a pre-operative clinically negative neck will have occult metastases in the neck dissection specimen. It is therefore that, when patients are treated with radiotherapy, the neck is almost always included in the target volume, also when the tumor is clinically staged N0 (elective neck treatment). As a consequence, large tissue volumes must be treated resulting in significant morbidity such as mucositis, dysphagia, xerostomia and on the long term also hypothyroidism and vascular damage.

If the detection of small lymph node metastases can be improved elective neck treatment may be avoided in at least part of the patients resulting in less toxicity and improved quality of life. One promising approach is the sentinel node procedure. Thus far, the sentinel node procedure is not employed in patients with larynx and pharynx cancers that are treated with primary radiotherapy. One reason is that these tumors are not easily accessible for tracer injection and this needs to be done under general anesthesia. However, in the past few years there has been progress with instrumentation via flexible endoscopy. The ENT-department of Radboudumc has developed expertise with endoscopic biopsy taking and even laser surgery of pharynx and larynx cancers.

The purpose of this study is to explore the feasibility of sentinel lymph node identification in pharynx and larynx cancers using flexible endoscopy-guided tracer injection.

Inclusion criteria

• Male or female aged >18 years.
• Mucosal tumor of the oropharynx, hypopharynx or larynx.
• Patients planned to undergo biopsy via flexible endoscopy.
• Patients planned to undergo curative radiotherapy with or without concurrent chemotherapy.
• Patient provided written informed consent.

Exclusion criteria

• Patients who underwent previous surgery or radiotherapy to the neck.
• Patients with airway obstruction causing stridor.
• Prior allergic reaction to Tc-99m-nanocolloïd.
• Pregnancy.
• Unable to provide informed consent.