Objectives: To determine the appropriate frequency and interval of FUUS during the first 10 years in patients who have undergone TT for PTC.
Methods: From January 2006 to December 2007, 272 patients underwent TT for PTC. Nineteen patients were excluded because of lack of US follow-up data for the neck. Follow-up US was performed by one of two radiologists in all patients. Tumor recurrence/persistence (TRP) was confirmed by histopathology.
Results: Mean interval between surgery and the last FUUS was 79.0 ± 39.2 months and mean number of FUUS sessions was 5.9 ± 2.8 in the 253 evaluable patients. Eleven patients (4.3%) developed TRP, and mean interval between TT and the first detection of TRP on FUUS was 23.5 ± 20.2 (range 6–60) months. T and N stages were independently associated with TRP (p<0.0001). There was no significant difference in patient age or sex, size or location of primary PTC, multifocality, or interval between surgery and the final FUUS between TRP (-) and TRP (+) groups (p>0.05). The interval between surgery and first suspicion of TRP on FUUS was ≤12 months in 6 patients (mean 8.2 [range 6–11] months) and 20, 35, 41, 53, and 60 months in remaining 5 patients.
Conclusions: For detection of TRP after TT in patients with PTC, one or two sessions of follow-up US during the first 2 years, depending on T and N stages and one session of follow-up US in every second year during the following 8 years may be appropriate.