Letter to the editor regarding residual vital ratio: predicting regrowth after radiofrequency ablation for benign thyroid nodules

Residual vital ratio predicts 5-year volume reduction and retreatment after radiofrequency ablation of benign thyroid nodules but not regrowth

“…The IAR is another semiquantitative index that was introduced by Sim et coauthors in 2018, which takes into account the amount of ablation rather than the viable volume left after an RFA. The IAR is calculated as follows: IAR¼ (ablated volume/total volume) Â 100, with a methodology that differs in terms of total volume assessment, as pointed out in a recent letter by Sim and Baek published in this Journal [5]. In our retrospective analysis of a cohort of 78 patients that were followed entirely for 5 consecutive years after the first RFA, we found that IAR was significantly associated with technique efficacy, 1-and 5-year volume reduction, and with the likelihood of a retreatment, but not with nodule regrowth [4].…”