Background: The prognostic value of positive surgical margins after transoral laser microsurgery (TOLM) is still under debate. In case of positive superficial margins, some experts recommend a second-look surgery (SL) and some recommend wait and watch approach with close observation. Narrow band imaging (NBI) is an advanced imaging system used to enhance visualization of mucosal vascular pattern. In laryngology, NBI is used to improve the detection of premalignant, dysplastic and malignant lesions.
Aim: To assess the usefulness of NBI imaging in guiding clinical decision making regarding follow-up plan and SL after TOLM.
Materials and methods: A prospective cohort of 127 patients was divided into three groups based on the histology results and NBI vascular pattern of the mucosa. Group A (24/127, 18.90%) consisted of patients with suspicious vascular pattern in NBI or/and with positive deep margin. Group B (52/127, 40.94%) consisted of patients with positive or uncertain superficial margins and non-suspicious vascular pattern in NBI. Group C (51/127, 40.15%) had non-suspicious vascular NBI pattern and all negative margins.
Results: After the first TOLM procedure, 9/24 (37.5%) patients had positive deep margins, 1/24 (4.2%) had uncertain deep margin and 1/24 patient (4.2%) had both positive deep margin and suspicious vascular pattern in NBI. The remaining 13 cases in Group A had a suspicious NBI finding only during the first follow-up. All of the 24 patients (Group A) underwent a second look surgery. The final histology after SL showed squamous cell carcinoma in 10/24 (41.7%) patients. All 10 patients had suspicious vascular pattern in NBI and one patient had both a positive deep margins after the first TOLM and positive NBI finding. None of Group B and C subjects developed an early recurrence.
Conclusions: Our study provides evidence that NBI imaging will be a useful adjunct to margin status after TOLM and will facilitate clinical decision-making regarding performing the SL in patients with positive or uncertain superficial surgical margins in the first TOLM procedure. However, additional investigation with more subjects is required at this time to further validate this technique and change the standard of care.