Thermal field management improves patient-reported outcomes during ablation for papillary thyroid carcinoma: A retrospective cohort study

Figure 1 Patient flowchart. PTC: Papillary thyroid carcinoma; TFM: Thermal field management; PSM: Propensity score matching.

Figure 2 Thermal field management during radiofrequency ablation in a 31-year-old woman with papillary thyroid carcinoma in the right thyroid lobe. A and B: Longitudinal and transverse pre- radiofrequency ablation ultrasound images show a hypoechoic solid nodule (1.2 cm × 1.1 cm × 1.0 cm) abutting the thyroid capsule; C: Tissue adhesions from tumor invasion impeded formation of an effective fluid barrier between the capsule and surrounding tissue (orange dashed circle); D: The active needle tip extended ≥ 2 mm beyond the original tumor margin (upper boundary on the image) without penetrating the capsule (thick arrow); E: The hydrodissection needle tip (thin arrow) was placed flush against the capsule at the site of heat leakage along the ablation needle shaft (thick arrow), with continuous injection of isolating fluid; F: Heat generated by the active tip was completely confined within the thyroid lobe, and the patient had no discomfort or hoarseness after the procedure.

Figure 3 Microwave ablation without thermal field management in a 27-year-old woman with papillary thyroid carcinoma in the left thyroid lobe. A and B: Longitudinal and transverse pre-microwave ablation ultrasound (US) images show a hypoechoic solid nodule measuring 11 cm × 0.9 cm × 0.8 cm; C: Pre-ablation contrast-enhanced US demonstrates hypoenhancement in the arterial phase; D: No effective fluid isolation zone was formed between the thyroid capsule and surrounding tissue (dashed circle); E: The active needle tip penetrated the thyroid capsule, and heat leakage (yellow dashed circle) was observed outside the capsule (dashed line); F: Immediately after treatment, the patient developed hoarseness; US revealed paralysis of the left vocal cord, fixed at the median position (dashed arrow).