Papiller Tiroid Kanserinde İlk Tedavi Cevabı İndetermine Yanıt Olan Hastaların İzleminde Boyun Ultrasonografi Bulgularının Değerlendirilmesi

Abstract

Papillary thyroid cancer (PTC) is the most common differantiated thyroid cancer type. The incidence of PTC is increasing gradually with the more frequent use of imaging methods. Although there are recommendations by American Thyroid Association guideline and Dynamic Risk Stratification (DRS) for the surveillance of differantiated thyroid cancer patients, there is no consensus on the frequency of neck ultrasonography for follow-up. In this study, we aimed to evaluate the power of neck ultrasonography to detect locoregional reccurrence in active surveillance in PTC patients with an indeterminate response to treatment according to DRS. With the data obtained, we also aimed to contribute to the determination of ultrasonographic scanning frequency for indeterminate response patients. Our study included a total of 477 patients from all ATA risk classes who were diagnosed with PTC in our center, underwent total or near-total thyroidectomy, and had neck ultrasonography follow-up for at least three years. The results of ultrasonography performed within three years of initial assessment after first-year treatment were recorded retrospectively. Neck ultrasonography lymph node findings were classified as suspicious, indeterminate, or benign according to the presence of microcalcification, roundness index, type of vascularity, presence of hilum, and level of echogenicity based on European Thyroid Association (ETA) guideline. The presence of lesions that did not meet the definition criteria of these three groups were defined as nonspecific findings. Patients who developed biochemical or structural disease after remission were considered reccurrence. In addition, sensitvity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated for ultrasonography performed within three years of evaluating treatment response. As a result, the median follow-up time of the entire cohort was 76 months (26-240). An indeterminate response was 24.5% of the entire cohort. In the detection of regional disease reccurrence by neck ultrasonography in the indeterminate reponse group; sensitivity was 100%, specificity 88.8%, PPV 8.5%, NPV 100%, accuracy 88.9%. Reccurrence was observed in three patients (2.6%) with an indeterminate response to treatment in the first year. Among these patients, reccurrence was detected in the second year in one patient and in the third year in two patients. When these findings are evaluated, it might be recommended to evaluate the patients in the indeterminate response group with serum thyroglobulin, serum anti-thyroglobulin antibody and neck ultrasonography once a year during the first three years, and to continue to follow-up with only serum thyroglobulin measurement in those who have no signs of disease at the end of third year. There is a need for studies to support our data in order to determinate the follow-up times by ultrasonography of the patients in the indeterminate response group.