Reoperations for structurally persistent or recurrent disease after thyroidectomy: analysis via preoperative CT.

The incidence rates of structural persistent disease (PD) and recurrent disease (RD) after thyroidectomy, and their clinicoradiological (CT) characteristics, remain poorly understood. Therefore, we characterized differentiated thyroid cancer (DTC) patients who underwent re-operations, with a focus on preoperative CT scans. We examined neck CT scans obtained prior to initial surgery and reoperation, and classified the disease into four categories according to the persistence/recurrence and neck dissection/non-dissection status. In total, 121 of 9,173 DTC patients underwent reoperations to treat PD or RD; the mean time to reoperation was 25.5 and 54.1 months, respectively. Of all reoperations, 19% (23/121) were performed to treat RD; 81% (98/121) were performed to treat PD. Compared to RD, PD was commonly detected in the non-dissected neck. Tumor multiplicity and the number of pathologically positive lymph nodes were greater in the non-dissected than dissected neck. A review of the CT data revealed more false-negative findings on the 60-s- versus 30-40-s-delay scans of PD patients with non-dissected necks. In conclusion, most of the reoperations performed on DTC patients were for management of PD. Improved preoperative CT assessments and initial surgery, based on the information of clinico-radiological characteristics, are required in the care of DTC patients.