The incidence of thyroid carcinoma has gradually increased in recent years due to the fact that imaging studies have contributed to the detection of subclinical stages, in our community the seventh neoplasm in order of frequency according to data reported in SOLCA-Guayaquil with a standardized rate of 7.27% affecting more females than men with incidence peaks between the third, fourth, sixth and seventh decade of life.1 , 2 Histopathologically, papillary carcinoma is the most common histological subtype, constituting approximately 70 - 80% of all thyroid...

117 patients diagnosed with DTC. 26 male patients (22%) and 91 female patients (78%), with ages ranging from 20 to 90 years, the average age was 53 years, evaluated in the Department of Radiology and Nuclear Medicine of Solca – Guayaquil between 2012 to 2017. All the selected patients were thyroidectomized, had estimulated thyroglobulin levels > 10 ng / ml and single wholebody scan with negative radioiodine. Subsequently, they were examined with18F-FDG PET/CT. Acquisition protocol18F-FDG PET/CT of total body: Fasting for 6 hours, average dose...

The PET/CT showed a sensitivity of 80.2% and specificity of 98.97%. Of the 117 patients, 108 had locoregional metastasis (88 adenopathies and 28 of recurrent tissue), 57 pulmonary metastases (25 unilateral and 32 bilateral) and 15 bone metastases (10 in the cervical region and 5 in the femur), all diagnosed by PET/CT. The pathological types were 108 (92%) of classic variant and 9 (8%) follicular types.

From the present study, PET/CT proved to be effective in challenging diagnoses such as recurrence and / or locoregional metastasis. The diagnostic efficiency of18F-FDG PET/CT in postoperative follow-up depends on patient selection, tumor size and thyroglobulin levels. The sensitivity and specificity ranges for recurrence and / or metastasis are from 62 to 80% and 62 to 98% respectively. Therefore, we can conclude that PET/CT is indicated in the diagnosis of TENIS Syndrome, which has been demonstrated in recent years11

Dra. Catherine Ulloa Resident in training. Department of Radiology, Instituto Oncologico Nacional SOLCA. Av. Pedro Menendez 090505 Guayaquil, Ecuador. Email:[email protected]. Dr. Luis Mora Resident in training. Department of Radiology, Instituto Oncologico Nacional SOLCA. Av. Pedro Menendez 090505 Guayaquil, Ecuador. Email:[email protected] Dr. Carlos Regalado Department of Nuclear Medicine, Instituto Oncologico Nacional SOLCA. Av. Pedro Menendez 090505 Guayaquil, Ecuador. Email:[email protected]. We don't have conflict of interest. Department of Radiology, SOLCA: Diagnostic radiology section: Dra.V. Gordillo Resident in training: Dr. C. Ulloa Dr. L. Mora Nuclear Medicine Department....

1. Web del registro de Tumores SOLCA Matriz. [on-line] 2010 URL: http://www.estadisticas.med.ec/webpages/reportes/grafico1-1.jsp 2. Web del registro de Tumores SOLCA Matriz. [on-line] 2010 URL:"http://www.estadisticas.med.ec/webpages/reportes/grafico1-2.jsp"2 HYPERLINK "http://www.estadisticas.med.ec/webpages/reportes/grafico1-2.jsp".jsp 3. Nguyen, Q. T., Lee, E. J., Huang, M. G., Park, Y. I., Khullar, A., & Plodkowski, R. A. (2015). Diagnosis and treatment of patients with thyroid cancer.American health & drug benefits,8(1), 30. 4- Shaaban, A. M., Rezvani, M., & Blodgett, T. M. (2010).Specialty Imaging:Oncology. Amirsys. 5- Haugen, B. R., Alexander, E. K., Bible, K. C., Doherty, G. M., Mandel,...