Utility of ultrasound-guided supraclavicular lymph node sampling in lung cancer diagnosis – remodelling the pathway in the era of COVID-19

Introduction: Ultrasound guided sampling (USGS) of supraclavicular lymph nodes (SCLN) is a minimally invasive method for obtaining cytological diagnosis in metastatic lung cancer. Same day USGS service may improve timeliness of investigations, minimise hospital visits and reduce invasive procedures. Methods: We performed a 3-year retrospective analysis of patients with SCLN amenable to biopsy detect-ed on 2 week-wait (2WW) CT. We identified those who underwent USGS or other procedures, diagnostic yield and their timeliness were determined. Results: 49 patients (26%) had amenable SCLN, of whom 37 (75.5%) had USGS. USGS alone sufficient for 27 (73%) patients. Diagnostic yield is better for larger nodes (<1cm 62.5% positive; ≥1cm 86.2% positive, 95% CI 0.13-0.93, p=0.011). The overall diagnostic yield of USGS SCLN was 81% (30/37, 95% CI 65% to 92%). Al-though faster to obtain USGS, no statistically significant difference was reached between USGS and other methods (USGS median 15.5 days (IQR 11.2), other procedures median 17.5 days (IQR 26.5), Mann-Whitney U p=0.42). Conclusion: USGS SCLN has potential utility in early lung cancer diagnosis, even in lymph nodes <1cm, and is an underutilized diagnostic investigation. A prospective study of same day 2WW outpatient clinic and USGS procedure is now required to assess its effect on an accelerated diagnostic pathway.