Comparative Accuracy of 18-Gauge versus 20-Gauge Ultrasound-Guided Fine-Needle Aspiration in the Detection of Persistent Lymph Node Metastasis in Head and Neck Squamous Cell Carcinoma after Chemoradiation.

BACKGROUND AND PURPOSE: Viable malignant disease is uncommon in patients with persistent adenopathy after definitive chemoradiotherapy (CRT) for head and neck squamous cell carcinoma (HNSCC). Preoperative ultrasound-guided fine-needle aspiration (USFNA) can prevent unnecessary neck dissection. Postradiation fibrosis can complicate the approach, resulting in an inadequate aspirate volume when using standard 20- or 22-gauge needles. We assessed the comparative 18- and 20-gauge diagnostic accuracy of USFNA in detecting persistent viable nodal malignancy in patients with HNSCC with nodal metastasis treated with CRT. We hypothesized that 18-gauge USFNA would outperform 20-gauge USFNA in diagnostic accuracy and efficiency.

MATERIALS AND

METHODS

We identified a 239-patient cohort (210 men, 60.4 ± 9.8 years) presenting between 2002-2023 with HNSCC and biopsy-proved cervical nodal metastases. All patients were treated with CRT. After CRT, a suspicious nodal remnant underwent biopsy with an 18- or 20-gauge needle. A total of 101 patients received a biopsy with a 20-gauge and 138 received a biopsy with an 18-gauge needle. Biopsy results were compared with either postbiopsy surgical pathology results when available or at least 3 months of CT follow-up, referred to here as post-USFNA results.

RESULTS

Fine-needle aspiration (FNA) in 181 of 239 (75.7%) cases showed no evidence of viable metastatic disease on cytology evaluation. Twenty-gauge cases were performed with 1.36 ± 0.52 passes. Eighteen-gauge cases were performed with 1.26 ± 0.51 passes (P = .037). A neck dissection was performed within 90 days in 45 patients, while the other 194 patients had follow-up imaging. Forty/58 cases were positive concordant between FNA and post-USFNA results. Of 181 cases, 177 were negative concordant between FNA and post-USFNA results. Overall, USFNA showed a sensitivity of 90.9%, specificity of 90.8%, accuracy of 90.8%, positive predictive value (PPV) of 69.0%, and negative predictive value (NPV) of 97.8%. Twenty-gauge FNA showed positive concordant of 26 of 39 and negative concordant of 59 of 62 for a sensitivity of 89.7%, specificity of 81.9%, accuracy of 84.2%, PPV of 66.7%, and NPV of 95.2% Eighteen-gauge FNA showed a positive concordant of 14 of 19 and negative concordant of 118 of 119 for a sensitivity of 93.3%, specificity of 95.9%, accuracy of 95.7%, PPV of 73.7%, and NPV of 99.2%.

CONCLUSIONS

Residual cervical lymph node USFNA after CRT is an accurate procedure with excellent PPV and NPV. Eighteen-gauge USFNA is associated with statistically significant fewer biopsy passes and higher specificity compared with 20-gauge.