Ultrasound-Guided Cryoablation, Laser or Radiofrequency Ablation of Cervical Metastases From Thyroid Carcinoma: a Prospective Clinical Trial

Sunday, March 30, 2025

4:21 PM – 4:30 PM CT

Location: Music City Center, 201 AB

Presenting Author(s)

Ricardo M C Freitas, MD, PhD, MBA (he/him/his)

Professor of Radiology
Instituto de Radiologia - INRAD HCFMUSP, Brazil

Author/Co-author(s)

PA

Pedro N B Araujo, MD

Radiology Assistant
Ultrasound Unit, Instituto do Cancer do Estado de Sao Paulo FMUSP, Brazil
ES

Erick F. Santos, MD

Radiology Assistant
Ultrasound Unit, Instituto do Cancer do Estado de Sao Paulo FMUSP, Brazil
LC

Luciana A. Castro-Neves, MD, PhD

Endocrinology Assistant
Endocrinology Department, Instituto do Cancer do Estado de Sao Paulo, Brazil
DD

Debora L S Danilovic, MD, PhD

Professor of Endocrinology
Endocrinology Department HCFMUSP, Brazil
LK

Luiz Kowalski, MD, PhD

Full Professor
Head and Neck Surgery Department HCFMUSP, Brazil
MK

Marco A V Kulcsar, MD, PhD

Professor of Head and Neck Surgery
Head and Neck Department HCFMUSP, Brazil
MC

Maria Cristina Chammas, MD, PhD

Professor of Radiology
Instituto de Radiologia - INRAD HCFMUSP, Brazil
AH

Ana O. Hoff, MD, PhD

Head of Thyroid Cancer Unit - ICESP FMUSP
Endocrinology Department of HCFMUSP, Brazil

Purpose: To assess the efficacy and safety of cervical lymph node metastases (LNMs) from differentiated or medullary thyroid carcinoma (DTC or MTC) thermal ablation under ultrasound (US) guidance; the best response, defined as LNM volume reduction or stability post-ablation; tumor marker response; and to compare complications, side effects, and tolerability among laser (LA), radiofrequency (RF), or cryoablation (CA).

Materials and Methods:

This prospective clinical trial obtained IRB approval. All subjects provided informed consent. Eligible subjects presented with up to six concurrent LNMs between 0.8-4.0 cm diameter. US examinations were conducted at baseline, 6, 12, and 24-months. Changes in tumor volume, technical success, complications, tumor markers and need for additional surgery were evaluated. Data was collected in a web-based electronic data tool. Statistical analyses used 0.05 significance levels Shapiro-Wilk, Kruskall-Wallis, Friedman and Qui-Square tests.

Results:

Eighty-four patients (n=165 tumors) were treated, 71 with DTC (84.5%) and 13 with MTC (15.5%). The median age was 55.5-year-old, 63 (75%) being women. Twenty-eight patients (131 LNMs) were randomly assigned for each ablation group. Fifteen patients (17.9%) who developed 34 new LNMs underwent ablation (CA) overtime (total treated LNMs: 165). Two LNMs were not amenable to treatment after hydrodissection attempt. Technical success was 98.8%. General baseline, 6-, 12- and 24-month LNM volume (cc) were: 1.20±3.14 (n=84); 0.33±1.60 (n=74); 0.15±0.73 (n=60); and 0.10±0.36 (n=45). LNMs VRR at 6-, 12-, and 24-months increased in all groups (P< 0.05). Two LNMs (1.2%) showed volume regrowth. Baseline and 24-month mean serum Tg (n=22) were 5.3±9.8 ng/mL, and 1.9±3.6 ng/mL. One severe AE (1.2%) (1/84) - a vague nerve lesion leading to vocal cord palsy, prolonged hospitalization, pulmonary infection and death occurred in a patient with widely metastatic disease. No moderate AE was observed. Mild AE were transient hoarseness 9.5% (8/84), cutaneous fistula with spontaneous resolution 1.2% (1/84), and persistent hoarseness due to unilateral vocal cord palsy 1.2% (1/84). No subsequent therapies were required to the treated LNMs.

Conclusion:

Thermal ablation modalities (LA, RF, CA) were both feasible, effective, and safe for well-selected patients, providing adequate local control of LNMs. No significant differences among the three ablation methods regarding complications, side effects, and tolerability were observed. Thermal ablation is an alternative therapy for treating cervical LNMs from thyroid carcinoma.