Vital volume increase versus clinical evaluation as the indication of additional radiofrequency ablation for benign thyroid nodule: a single center retrospective study.

To compare results in patients treated with additional radiofrequency ablation (RFA) after clinical evaluation or vital volume (Va) increase. Forty patients with 42 benign thyroid nodules who underwent additional RFA were evaluated in this retrospective study. According to the different indication for additional RFA, 18 patients were divided into Vv increase group (V group) and 22 into clinical evaluation group (C group). Patients were followed up at 1, 3, 6, 12 months and every 12 months thereafter by conventional ultrasound (US), contrast-enhancement ultrasound (CEUS) and clinical evaluation. Volume, volume reduction rate (VRR), symptom score and cosmetic score were evaluated before treatment and each ablation. After the first RFA, there were no statistically differences between two groups in volume, VRR, cosmetic and symptom scores. Compared with the first RFA, volume of all the patients after additional RFA decreased significantly ( < 0.001). In additional RFA, during a mean follow-up time of 10.15 ± 9.17 months, volume in V group was significantly smaller than in C group (2.84 ± 5.43 ml Vs 7.39 ± 13.01 ml,  = 0.046). VRR in V group was significantly larger than in C group (90.18 ± 12.74% Vs 75.66 ± 26.47%,  = 0.007) with significant improvement of cosmetic and symptom scores ( = 0.047;  = 0.030). No complications occurred after each session ablation. Vv increase was a more reliable indicator for additional RFA than clinical evaluation. Additional RFA performed after Vv increase was more effective with respect to volume reduction and improvement of clinical outcomes. Therefore, Vv increase should be set as an indication for additional RFA.