ABSTRACT
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. © 2022, Zita Medical Managent. All rights reserved.
ABSTRACT
Introduction: Ultrasound guided sampling (USGS) of supraclavicular lymph nodes (SCLN) with fine needle aspiration (FNA) or core biopsy is a well established, minimally invasive method for obtaining cytological diagnosis in metastatic lung cancer. It is recommended in the National Lung Cancer Optimal Pathway 'Direct to Biopsy' option for cases where further staging is not required to guide treatment. Re-modelling of the pathway to incorporate 'direct to biopsy' (same day Radiology or Respiratory service) may help improve timeliness of investigations whilst minimising hospital visits and reducing invasive procedures particularly given COVID-19 precautions. Method: We performed a retrospective analysis of patients with SCLN amenable to FNA or biopsy detected on 2 week wait (2WW) CT, timeliness of subsequent SCLN sampling and (Figure presented) diagnostic yield. Data was extracted from InfoFlex from January 2017 to December 2019. Inclusion criteria was at least N2 mediastinal lymphadenopathy >0.5 cm at initial staging with adequate lower neck CT coverage, and where the node was amenable to biopsy (determined by a radiologist). Review of patient records identified those who underwent USGS, whether this was diagnostic and which other procedures were performed. Statistical analysis was performed using IBM SPSS. Results: From 186 patients with suspected N2 or N3 lymphadenopathy at initial staging, 49 (26%) had SCLN amenable to sampling, of whom 37 (75.5%) had sampling performed. Diagnostic yield was 81.2%. Average timeline from 2WW CT to USGS was variable (M = 18 days, 95% CI[14.5, 21.5]) but shorter, on average, compared to other diagnostic procedures (M=22.81 days, 95% CI[13.02, 35.6]). SCLNs with positive biopsy are larger than those without, with AUC of 0.814 (see figure 1). SCLN size of ≥0.65 cm was highly associated with a diagnostic result. Conclusion: 2WW CT with lower neck coverage provided an early opportunity to identify any amenable SCLN especially in the presence of enlarged mediastinal nodes, for ultrasound guided sampling even when SCLN measured <1 cm, and may apply in up to 25% of patients, A prospective study of ultrasound assessment of all patients with N2 mediastinal lymphadenopathy is now required to assess its clinical utility and effect on an accelerated diagnostic pathway.