Annual Neck Ultrasonography Surveillance between 3 to 12 Years after Thyroid Lobectomy for Papillary Thyroid Microcarcinoma

ABSTRACT

Background and Objectives@#In South Korea, neck ultrasonography (US) has been used widely at 1- or 2-year intervals to detect recurrence after thyroidectomy. The aim of this study is to assess the prevalence and pattern of recurrence and to establish a proper frequency of follow-up neck US after thyroid lobectomy for papillary thyroid microcarcinoma (PTMC). @*Materials and Methods@#We retrospectively reviewed 262 consecutive patients who had undergone thyroid lobectomy for PTMC from January 2005 to October 2009. They were divided into two groups based on the presence of recurrence (240 patients in group 1 and 22 patients in group 2). The comparison between the two groups involved clinical and pathological characteristics. @*Results@#Recurrences were found in 22 (8.4%) of 262 patients with 132.5 months follow-up (range, 120-180 months). There was a significant difference in the mean number of follow-up neck US after 5 years postoperatively, shortened interval, total number of follow-up neck US (p=0.002, p＜0.001, p＜0.001). All recurrences were found between 2-3 to 11-12 years. Recurrences after 5 years were found in 16 (72.7%) of 22 patients. @*Conclusion@#Recurrence after thyroid lobectomy for PTMC occurred with various times during follow up. The minimum frequency of follow-up neck US was not enough for detecting tumor recurrence, especially after 5 years postoperatively. Our results suggest that annual neck US may be appropriate between 3 to 12 years after thyroid lobectomy for PTMC.