Diagnostic performance of PET-CT and technical efficacy of ultrasound-guided core needle biopsy of small and intermediate size malignant supraclavicular lymph nodes.

Aim: We aimed (1) to determine optimal PET-CT SUV and ultrasound (US) features associated for malignant smallintermediate size supraclavicular lymph nodes (SCN) and (2) to evaluate technical efficacy of core needle biopsy (CNB). Materials and methods: Between 2020 and 2023, CNB of SCN with short-axis less than 15 mm were included. PET-CT was evaluated for optimal SUV cut-off value. Multivariate logistic regression was performed for US features. Technical efficacy of CNB (success rate) was calculated, and US features were compared between satisfactory CNB specimen and unsatisfactory CNB specimen.

Results: Eighty-four SCN per 80 patients (age 64.0±17.2 years, 45.2% female) were included. The optimal SUV cut-off value was 1.1 with diagnostic accuracy of 89.8%. US features associated with malignancy were anteroposterior dimension ≥9 mm and absence of hilum. The overall CNB success rate was 94%, and unsatisfactory specimen demonstrated shorter transverse diameter (12 mm vs 5 mm, p<0.001), and non-parallel orientation (20.3% vs. 100%, p<0.001).

Conclusion:  CNB should be considered for small-intermediate size SCN with SUV exceeding 1.1, anteroposterior dimension ≥9 mm, and absence of hilum. SCN with shorter transverse diameter and non-parallel orientation may result in unsatisfactory CNB specimen.