LAUSR

We would like to thank Shen et al. for their interest and comments on our study. They question the consistency of the results between our two studies comparing microwave ablation (MWA) with surgery for papillary thyroid microcarcinoma (PTMC). We agree that propensity score matching analysis is a fine choice, but we elected to do a case-control study, matching gender and age and following cases up in chronological order. There were no significant differences in age, sex, or followup time between the two groups. We have to admit our studies were retrospective in nature. The ‘inconsistent’ results are because of different treatment intervals and followup lengths between the two studies. Compared to study A [1], we expanded the time between treatment and followup in study B [2], including when we initiated MWA (January 2013–February 2014) and the subsequent followup (August 2017–September 2018). As our MWA clinical research in PTMC progressed, we had many more patients available for enrollment in study B. We also found a few patients with central lymph node metastases and recurrence after MWA during 2018 (Figure 1). We admit that preoperative examination (e.g., ultrasound) could not validly exclude lymphatic micrometastases or multifocality [3,4]. We still believe that MWA is superior to surgery for ultrasonically-detected PTMC in terms of the appearance of complications and its minimal invasiveness. We are further studying how to improve the accuracy of preoperative exploration [5,6].