Sentinel node identification in laryngeal cancer: Feasible in primary cancer with previously untreated neck

With the current diagnostic techniques a considerable percentage of occult lymph node metastases are missed in the clinically negative (cN0) neck. Therefore, in patients with laryngeal cancer and cN0 neck a total laryngectomy is usually combined with elective neck dissection. Based on the risk of occult lymph node metastases the decision whether to perform a neck dissection or not is difficult. In recurrent laryngeal cancer or second primary tumors previous treatment possibly influences lymphatics and metastatic behavior. In this pilot study we investigated the feasibility of sentinel node (SN) identification and potential accuracy of sentinel node biopsy (SNB) in laryngeal cancer patients undergoing total laryngectomy with elective neck dissection.

Patients with cN0 laryngeal cancer were included. During surgery 40MBq (99m)Technetium labeled Nanocolloid was endoscopically injected around the tumor. Lymphoscintigraphy was not performed. We identified the sentinel node (SN) ex vivo in the neck dissection specimen with a gammaprobe. Histopathological examination of the neck dissection specimen served as reference test.

We included 19 patients, 13 patients with untreated necks and six with prior neck treatment. SN identification was successful in 68.4% (13/19) of patients, and significantly higher in patients with untreated necks (92.3% versus 16.7%, p<0.01). Four of 13 (30.7%) patients would potentially be upstaged by SNB. Sensitivity and negative predictive value would have been 80.0% and 87.5%, respectively.

With the current methodology, SN identification in laryngeal cancer patients undergoing total laryngectomy is feasible in patients with untreated necks. Further studies are needed to determine the exact accuracy of SNB in total laryngectomy patients.