ECE2024 Eposter Presentations Thyroid (198 abstracts)
1Farhat Hached Hospital, ENT Department, Sousse, Tunisia; 2Department of Radiology, Sousse, Tunisia; 3Department of Anaesthesia, Sousse, Tunisia; 4Departement of Endocrinology, Sousse, Tunisia
Introduction: In the follow-up of differentiated thyroid cancer (DTC), essential tools include iodine-131 scintigraphic imaging, coupled with cervical ultrasound and thyroglobulin measurement. An additional valuable tool is single-photon emission computed tomography combined with computed tomography (SPECT-CT), which precisely localizes fixation anomalies observed during whole-body scans. The aim of our study is to demonstrate, through a case study, the diagnostic contribution of SPECT-CT in identifying mediastinal lymphadenopathy during the follow-up of papillary carcinoma.
Observation: A 29-year-old woman underwent a comprehensive treatment regimen for papillary thyroid carcinoma, including total thyroidectomy, bilateral mediastino-recurrent lymph node dissection, and adjuvant radioiodine therapy. The tumor was classified as pt1b N1b M0. Following two courses of 100 mCi radioactive iodine, a post-therapeutic scan revealed a moderately intense mid-cervical focus of uptake, along with a less intense superior mediastinal focus. The thyroglobulin Tg T4 off assay showed elevated levels (>500 ng/ml). Further investigation using hybrid imaging SPECT-CT focused on the cervicothoracic region provided a more detailed response to the elevated thyroglobulin. The mediastinal focus was identified as a roughly oval-shaped tissue mass measuring 45*32*20 mm lateral to the trachea, causing a mass effect on the pulmonary apex. Surgical exploration uncovered a 5 cm right mediastinal mass adjacent to the right brachiocephalic trunk. Additional functional right lymph node dissection with excision of the mediastinal mass was performed. The final histopathological examination confirmed the metastatic nodal nature of the mediastinal lymphadenopathy.
Conclusion: SPECT-CT plays a crucial role in studying iodine-131 fixation anomalies in the context of DTC. It enables precise anatomical localization of lesions, enhances the detection of metastases overlooked by whole-body scans, and aids in assessing questionable fixation anomalies.