Abstract
431 patients who underwent ultrasound-guided RFA for unifocal T1aN0M0 papillary thyroid carcinoma (PTC) were divided by location of the lesion into the PTCI group (52 females, 7 males, mean age 43.79 ± 12.04 years, range 22–74 years) and the PTCL group ((291 females, 81 males, mean age 43.42 ± 10.87 years, range 18–75 years) for comparative analysis. The efficacy of ultrasound-guided RFA was evaluated by volume reduction rate (VRR), complete disappearance rate (CDR), and disease progression, and the safety was evaluated by incidence of complications. The two groups exhibited a consistent trend of change, with the PTCI group performing slightly better in volume, VRR, and CDR at all follow-up time points expect 1 month. The mean initial volume of the PTCI group vs the PTCL group decreased significantly from 65.4 ± 69.79 vs 86.38 ± 87.09mm³ (range 10.92-427.58 vs 3.05-471.6mm³) to 0 vs 0 mm³ at a mean follow-up time of 31.12 ± 12.5 months (range 12–60 months); their VRR increased significantly from − 618.62 ± 655.61% vs -789.85 ± 1135.07%, at 1 month to 100% vs 100% at 48 months. No disease progression was found in the two groups. The PTCI group had no complications, whereas the PTCL group had 7 complications (1.88%). Ultrasound-guided RFA is reliable for unifocal T1aN0M0 PTCI in the isthmus.