Implementation of ultrasound surveillance following negative sentinel lymph node biopsy in early oral squamous cell carcinoma: a retrospective cohort study.

Abstract

Purpose: Management of the clinically node-negative neck in T1/T2 oral squamous cell carcinoma (OSCC) is controversial. While sentinel lymph node biopsy (SLNB) can highlight patients that require selective neck dissection (SND); its false-negative rate necessitates post-operative surveillance to detect missed cervical lymph node metastases (CLNM) and allow for salvage surgery. Ultrasound (US) in conjunction with clinical examination is commonly employed for this observation; however, the optimal regimen is unclear. This retrospective cohort study aimed to evaluate follow-up surveillance after negative SLNB in patients with T1/T2 OSCC at our centre.

Methods: Fifty-eight patients were identified over eight years. Nine (15.5%) had a positive SLNB and underwent further treatment. In the remaining 49 patients, data was collected on US utilisation, timing, and outcome events. The primary outcome was CLNM identified by US examination.

Results: A total of 51 US examinations were performed. The median time to first US was 7 months (range 2-48; n = 29), second 16.5 months (range 8-50; n = 14), third 26 months (range 14-65; n = 7) and fourth 26 months (n = 1), demonstrating considerable deviation from the local protocol. No CLNM was identified by US surveillance following negative SLNB. Three patients (3/49, 6.1%) had events during follow-up. Two developed metachronous primary tumours and one developed multiple synchronous tumours.

Conclusion: US surveillance following SLNB is variably implemented at our centre. These findings highlight the need for better defined and evidence-based protocols in this patient cohort.