Efficacy of Percutaneous Laser Ablation in the Treatment of Cervical Metastatic Lymph Nodes after the Surgery of Papillary Thyroid Carcinoma: A Prospective Cohort Study

  Objective  The aim of this study was to evaluate the therapeutic efficacy of ultrasound-guided percutaneous laser ablation (PLA) in the treatment of cervical metastatic lymph nodes (MLNs) after the surgery of papillary thyroid carcinoma (PTC).

  Methods  Clinical data of patients with recurrent PTC after surgery undergoing PLA treatment and regular follow-up from January 2014 to September 2016 were prospectively collected in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. Two-dimensional ultrasound was used to monitor the intraoperative process of PLA, and to evaluate the complications and lesion changes after ablation. Contrast-enhanced ultrasound(CEUS) was performed before treatment and at 1 h and 2-7 d after PLA to evaluate perfusion defects. All patients were followed up(As of May 2019), and the maximum diameter and volume of lesions after ablation were recorded during follow-up.

  Results  A total of 35 patients (46 cervical MLNs) meeting the inclusive and exclusive criteria were enrolled in this study. Preoperative CEUS showed that 20 MLNs were heterogeneously perfused (including 1 liquefied lymph node), while 26 MLNs were homogeneously perfused. During 2-7 d after PLA, CEUS showed that the boundary of the perfusion-defect area was clearer than that of 1 h after the operation, and the volume of the perfusion-defect area was significantly larger than that of 1 h after the operation230.40(78.03, 361.17)mm³ vs. 130.62(43.06, 253.66)mm³, P < 0.05. All patients tolerated well to PLA without neck hematoma, active bleeding, infection, tracheal esophageal injury, or other complications. The mean follow-up was (56.7±8.9)months, and there was no case of lymph node recurrence in situ. The maximum diameter 0.00(0.00, 0.00)mm vs. 7.35(5.70, 9.63)mm, P < 0.05 and the lesion volume 0.00(0.00, 0.00)mm³ vs. 95.59(32.82, 169.01)mm³, P < 0.05 at the last follow-up after ablation were significantly reduced compared with preoperation.

  Conclusions  PLA guided by ultrasound guidance may have a certain therapeutic effect on the neck MLNs after PTC surgery.